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Could stem cells have a role in treating mental illnesses?
While laboratory studies move forward at full speed, the clinical use of stem cells—undifferentiated cells that can develop into many different types of specialized cells—remains controversial. Presently, only unadulterated stem cells are allowed to be used in patients, and only on an experimental and investigational basis. Stem cells that have been expanded, modified, or enhanced outside of the body are not allowed to be used for clinical application in the United States at this time. In June 2021, the FDA strengthened the language of stem cell regulation, further limiting their clinical application (see https://www.fda.gov/vaccines-blood-biologics/consumers-biologics/important-patient-and-consumer-information-about-regenerative-medicine-therapies). Yet some applications, such as treatment of lymphoma or restorative knee injections, are covered by some health insurance plans, and the acceptance of stem cell treatment is growing.
In this article, I describe the basics of stem cells, and explore the potential therapeutic use of stem cells for treating various mental illnesses.
Stem cells: A primer
Human embryonic stem cells were initially investigated for their healing properties. However, the need to harvest these cells from embryos drew much criticism, and many found the process to be ethically and religiously unacceptable. This was resolved by the Nobel prize–winning discovery that adult somatic cells can be reprogrammed into cells with embryonic stem cell properties by introducing specific transcription factors. These cells have been termed “induced pluripotent stem cells” (iPSCs).1 The use of adult stem cells and stem cells from the umbilical cords of healthy newborns has allowed for wider acceptance of stem cell research and treatment.
Stem cells may be collected from the patient himself or herself; these are autologous stem cells. They may also be harvested from healthy newborn waste, such as the umbilical cord blood and wall; these are allogenic stem cells. Autologous stem cells are present in almost any tissue but are usually collected from the patient’s adipose tissue or from bone marrow. Understandably, younger stem cells possess higher healing properties. Stem cells may be mesenchymal, producing primarily connective and nervous tissue, or hematopoietic, influencing the immune system and blood cell production, though there is a considerable overlap in the function of these types of cells.
Adult somatic stem cells may be turned into stem cells (iPSCs) and then become any tissue, including neurons. This ability of stem cells to physically regenerate the CNS is directly relevant to psychiatry.
In addition to neurogenesis, stem cell transplants can assist in immune and vascular restoration as well as in suppressing inflammation. The ability of stem cells to replace mutated genes may be useful for addressing inheritable neuropsychiatric conditions.
Both autoimmune and inflammatory mechanisms play an important role in most psychiatric illnesses. The more we learn, the more it is clear that brain function is profoundly dependent on more than just its structure, and that structure depends on more than blood supply. Stem cells influence the vascular, nutritional, functional, inflammatory, and immune environment of the brain, potentially assisting in cognitive and emotional rehabilitation.
Stem cells operate in 2 fundamental ways: via direct cell-to-cell interaction, and via the production and release of growth, immune-regulating, and anti-inflammatory factors. Such factors are produced within the cells and then released in the extracellular environment as a content of exosomes. The route of administration is important in the delivery of the stem cells to the target tissue. Unlike their direct introduction into a joint, muscle, or intervertebral disk, injection of stem cells into the brain is more complicated and not routinely feasible. Intrathecal injections may bring stem cells into the CNS, but cerebrospinal fluid does not easily carry stem cells into the brain, and certainly cannot deliver them to an identified target within the brain. Existing technology can allow stem cells to be packaged in such a way that they can penetrate the blood-brain barrier, but this requires stem cell modification, which presently is not permitted in clinical practice in the United States. Alternatively, there is a way to weaken the blood-brain barrier to allow stem cells to travel through the “opened doors,” so to speak, but this allows everything to have access to the CNS, which may be unsafe. IV administration is technologically easy, and it grants stem cells the environment to multiply and produce extracellular factors that can cross the blood-brain barrier, while large cells cannot.
Continue to: Stem cells as a treatment for mental illness...
Stem cells as a treatment for mental illness
Based on our understanding of the function of stem cells, many neurodegenerative-, vascular-, immune-, and inflammation-based psychiatric conditions can be influenced by stem cell treatment. Here I review the potential therapeutic role of stem cells in the treatment of several psychiatric disorders.
Alzheimer’s dementia
Alzheimer’s dementia (AD) is a progressive neurodegenerative pathology based on neuronal and synaptic loss. Repopulation and regeneration of depleted neuronal circuitry by exogenous stem cells may be a rational therapeutic strategy.2 The regeneration of lost neurons has the potential to restore cognitive function. Multiple growth factors that regulate neurogenesis are abundant during child development but dramatically decline with age. The introduction of stem cells—especially those derived from newborn waste—seem to promote recovery from neurodegenerative disease or injury.3
There currently is no cure for AD. Cellular therapy promises new advances in treatment.4 Neurogenesis occurs not only during fetal development but in the adult brain. Neural stem cells reside in the adult CNS of all mammals.5 They are intimately involved in continuous restoration, but age just like the rest of the animal tissue, providing ever-decreasing restorative potential.
The number of studies of stem cells in AD has increased since the early 2000 s,6,7 and research continues to demonstrate robust CNS neurogenesis. In a 2020 study, Zappa Villar et al8 evaluated stem cells as a treatment for rats in which an AD model was induced by the intracerebroventricular injection of streptozotocin (STZ). The STZ-treated rats displayed poor performance in all behavioral tests. Stem cell therapy increased exploratory behavior, decreased anxiety, and improved spatial memory and marble-burying behavior; the latter was representative of daily life activities. Importantly, stem cell therapy ameliorated and restored hippocampal atrophy and some presynaptic protein levels in the rats with AD.8 Animal models cannot be automatically applied to humans, but they shine a light on the areas that need further exploration.
In humans, elevated cortisol levels during aging predict hippocampal atrophy and memory deficits,9 and this deficiency may be positively influenced by stem cell treatment.
Schizophrenia
Recent research indicates that schizophrenia may begin with abnormal neurogenesis from neural stem cells inside the embryo, and that this process may be particularly vulnerable to numerous genetic and/or environmental disturbances of early brain development.10 Because neurogenesis is not confined to the womb but is a protracted process that continues into postnatal life, adolescence and beyond, influencing this process may be a way to add to the schizophrenia treatment armamentarium.10 Sacco et al11 described links between the alteration of intrauterine and adult neurogenesis and the causes of neuropsychiatric disorders, including schizophrenia. Immune and inflammatory mechanisms are important in the etiology of schizophrenia. By their core function, stem cells address both mechanisms, and may directly modulate this devastating disease.
In addition to clinical hopes, advances in research tools hold the promise of new discoveries. With the advent of iPSC technology, it is possible to generate live neurons in vitro from somatic tissue of patients with schizophrenia. Despite its many limitations, this revolutionary technology has already helped to advance our understanding of schizophrenia.11
Bipolar disorder
Many of the fundamental neurobiological mechanisms of schizophrenia are mirrored in bipolar disorder.12 Though we are not ready to bring stem cells into the day-to-day treatment of this condition, several groups are starting to apply iPSC technology to the study of bipolar disorder.13
Neurodevelopmental factors—particularly pathways related to nervous system development, cell migration, extracellular matrix, methylation, and calcium signaling—have been identified in large gene expression studies as altered in bipolar disorder.14 Stem cell technology opens doorways to reverse engineering of human neurodegenerative disease.15
Continue to: Autism spectrum disorders...
Autism spectrum disorders
Autism spectrum disorders (ASDs) are multiple heterogeneous neurodevelopmental disorders.16 Neuroinflammation and immune dysregulation influence the origin of ASDs. Due to the neurobiologic changes underlying ASD development, cell-based therapies, including the use of mesenchymal stem cells (MSCs), have been applied to ASDs.16 Stem cells show specific immunologic properties that make them promising candidates for treating ASDs.17
The exact mechanisms of action of MSCs to restore function in patients with ASDs are largely unknown, but proposed mechanisms include:
- synthesizing and releasing anti-inflammatory cytokines and survival-promoting growth factors
- integrating into the existing neural and synaptic network
- restoring plasticity.18
In a study of transplantation of human cord blood cells and umbilical cord–derived MSCs for patients with ASDs, Bradstreet et al19 found a statistically significant difference on scores for domains of speech, sociability, sensory, and overall health, as well as reductions in the total scores, in those who received transplants compared to their pretreatment values.
In another study of stem cell therapy for ASDs, Lv et al20 demonstrated the safety and efficacy of combined transplantation of human cord blood cells and umbilical cord–derived MSCs in treating children with ASDs. The transplantations included 4 stem cell IV infusions and intrathecal injections once a week. Statistically significant differences were shown at 24 weeks post-treatment. Although this nonrandomized, open-label, single-center Phase I/II trial cannot be relied on for any definitive conclusions, it suggests an important area of investigation.20
The vascular aspects of ASDs’ pathogenesis should not be overlooked. For example, specific temporal lobe areas associated with facial recognition, social interaction, and language comprehension have been demonstrated to be hypoperfused in children with ASDs, but not in controls. The degree of hypoperfusion and resulting hypoxia correlates with the severity of ASD symptoms. The damage causing hypoperfusion of temporal areas was associated with the onset of autism-like disorders. Damage of the amygdala, hippocampus, or other temporal structures induces permanent or transient autistic-like characteristics, such as unexpressive faces, little eye contact, and motor stereotypes. Clinically, temporal lobe damage by viral and other means has been implicated in the development of ASD in children and adults. Hypoperfusion may contribute to defects, not only by inducing hypoxia, but also by allowing for abnormal metabolite or neurotransmitter accumulation. This is one of the reasons glutamate toxicity has been implicated in ASD. The augmentation of perfusion through stimulation of angiogenesis by stem cells should allow for metabolite clearance and restoration of functionality. Vargas et al21 compared brain autopsy samples from 11 children with ASDs to those of 7 age-matched controls. They demonstrated an active neuroinflammatory process in the cerebral cortex, white matter, and cerebellum of patients with ASDs, both by immunohistochemistry and morphology.21
Multiple studies have confirmed that the systemic administration of cord blood cells is sufficient to induce neuroregeneration.22,23 Angiogenesis has been experimentally demonstrated in peripheral artery disease, myocardial ischemia, and stroke, and has direct implications on brain repair.24 Immune dysregulation25,26 and immune modulation27 also are addressed by stem cell treatment, which provides a promising avenue for battling ASDs.
Like attention-deficit/hyperactivity disorder and obsessive-compulsive disorder, ASDs are neurodevelopmental conditions. Advances based on the use of stem cells hold great promise for understanding, diagnosing and, possibly, treating these psychiatric disorders.28,29
Depression
Neuropsychiatric disorders arise from deviations from the regular differentiation process of the CNS, leading to altered neuronal connectivity. Relatively subtle abnormalities in the size and number of cells in the prefrontal cortex and basal ganglia have been observed in patients with depressive disorder and Tourette syndrome.30 Fibroblast-derived iPSCs generate serotonergic neurons through the exposure of the cells to growth factors and modulators of signaling pathways. If these serotonergic neurons are made from the patients’ own cells, they can be used to screen for new therapeutics and elucidate the unknown mechanisms through which current medications may function.31 This development could lead to the discovery of new medication targets and new insights into the molecular biology of depression.32
Deficiencies of brain-derived neurotrophic factor (BDNF) have a role in depression, anxiety, and other neuropsychiatric illnesses. The acute behavioral effects of selective serotonin reuptake inhibitors and tricyclic antidepressants seem to require BDNF signaling, which suggests that BDNF holds great potential as a therapeutic agent. Cell therapies focused on correcting BDNF deficiencies in mice have had some success.33
Dysregulation of GABAergic neurons has also been implicated in depression and anxiety. Patients with major depressive disorder have reduced gamma aminobutyric acid (GABA) receptors in the parahippocampal and lateral temporal lobes.34
Ultimately, the development of differentiation protocols for serotonergic and GABAergic neuronal populations will pave the way for examining the role of these populations in the pathogenesis of depression and anxiety, and may eventually open the door for cell-based therapies in humans.35
Studies have demonstrated a reduction in the density of pyramidal and nonpyramidal neurons in the anterior cingulate cortex of patients with schizophrenia and bipolar disorder,36 glial reduction in the subgenual prefrontal cortex in mood disorders,37 and morphometric evidence for neuronal and glial prefrontal cell pathology in major depressive disorder.38 The potential for stem cells to repair such pathology may be of clinical benefit to many patients.
Aside from their other suggested clinical uses, iPSCs may be utilized in new pathways for research on the biology and pharmacology of major depressive disorder.39
Continue to: Obsessive-compulsive disorder...
Obsessive-compulsive disorder
Obsessive-compulsive disorder (OCD) is often characterized by excessive behaviors related to cleanliness, including grooming, which is represented across most animal species. In mice, behaviors such as compulsive grooming and hair removal—similar to behaviors in humans with OCD or trichotillomania—are associated with a specific mutation. Chen et al40 reported that the transplantation of bone marrow stem cells into mice with this mutation (bone marrow–derived microglia specifically home to the brain) rescues their pathological phenotype by repairing native neurons.
The autoimmune, inflammatory, and neurodegenerative changes that are prevalent in OCD may be remedied by stem cell treatment in a fashion described throughout this article.
Other conditions
The Box41-50 describes a possible role for stem cells in the treatment or prevention of several types of substance use disorders.
Box
Researchers have begun to explore stem cells as a potential treatment for several substance use disorders, including those involving alcohol, cocaine, and opioids, as well as their interactions with cannabinoids.
Alcohol use disorder. In a 2017 study, Israel et al41 gave intra-cerebral injections of mesenchymal stem cells (MSCs) to rats that were bred to have a high alcohol intake. The MSC injections resulted in drastic reductions in the rats’ alcohol consumption. A single intracerebroventricular MSC administration inhibited relapse-like drinking by up to 85% for 40 days.
It is beyond unlikely that direct brain injections would be used to treat alcohol use disorder in humans. To address this problem, researchers aggregated MSCs into smaller spheroid shapes, which reduced their size up to 75% and allowed them to be injected intravenously to reach the brain in a study conducted in rats.42 Within 48 hours of a single treatment, the rats had reduced their intake of alcohol by 90%. The IV administration of antiinflammatory MSCs in human trials will be the next step to verify these results.
Alcohol research using human stem cells is also being conducted as a model system to understand the neural mechanisms of alcohol use disorder.43
Cocaine use disorder. In a grant proposal, Yadid and Popovtzer44 suggested that cocaine addiction affects neurogenesis, especially in the dentate gyrus, ventral tegmental area, nucleus accumbens, and prefrontal cortex; it damages mitochondrial RNA, brain-derived neurotrophic factor (BDNF), glutamate transporter (excitatory amino acid transporter; EAAT), and interleukin-10. MSCs have a predilection to these areas and influence neurogenesis. Currently, there are no FDAapproved medications for the safe and effective treatment of cocaine addiction. MSCs can home to pathological areas in the brain, release growth factors, and serve as cellular delivery tools in various brain disorders. Moreover, restoration of basal glutamate levels via the EAAT has been proposed as a promising target for treating cocaine dependence. Therefore, MSCs differentiated to express EAATs may have a combined long-term effect that can attenuate cocaine craving and relapse.44
Neural stem cells undergo a series of developmental processes before giving rise to newborn neurons, astrocytes, and oligodendrocytes in adult neurogenesis. During the past decade, studies of adult neurogenesis modulated by addictive drugs have highlighted the role of stem cells. These drugs have been shown to regulate the proliferation, differentiation, and survival of adult cells in different manners, which results in the varying consequences of adult neurogenesis.45 Reversal of these influences by healthy stem cells can be a worthy goal to pursue.
Opioid use disorder. Opiate medications cause a loss of newly born neural progenitors in the subgranular zone of the dentate gyrus by either modulating proliferation or interfering with differentiation and maturation.46 Opiates were the first medications shown to negatively impact neurogenesis in the adult mammalian hippocampus.47,48 The restoration of hippocampal function may positively affect the prognosis of a patient who is addicted.
Cannabinoids. Cannabinoids’ influence on the brain and on stem cells is controversial. On one hand, deteriorated neurogenesis results in reduced long-term potentiation in hippocampal formation. These cellular and physiological alterations lead to decreased short-term spatial memory and increased depressionlike behaviors.49 On the other hand, there is emerging evidence that cannabinoids improve neurogenesis and CNS plasticity, at least in the adult mouse.50 Through normalization of immune function, and restoration of the brain and the body, stem cells may assist in better health and in treatment of cannabis use disorder.
Chronic pain is a neuropsychiatric condition that involves the immune system, inflammation, vascularization, trophic changes, and other aspects of the CNS function in addition to peripheral factors and somatic pain generators. Treatment of painful conditions with the aid of stem cells represents a large and ever-developing field that lies outside of the scope of this article.51
Experimental, but promising
It is not easy to accept revolutionary new approaches in medicine. Endless research and due diligence are needed to prove a concept and then to work out specific applications, safeguards, and limitations for any novel treatments. The stem cell terrain is poorly explored, and one needs to be careful when venturing there. Presently, the FDA appropriately sees treatment with stem cells as experimental and investigational, particularly in the mental health arena. Stem cells are not approved for treatment of any specific condition. At the same time, research and clinical practice suggest stem cell treatment may someday play a more prominent role in health care. Undoubtedly, psychiatry will eventually benefit from the knowledge and application of stem cell research and practice.
Related Resources
- De Los Angeles A, Fernando MB, Hall NAL, et al. Induced pluripotent stem cells in psychiatry: an overview and critical perspective. Biol Psychiatry. 2021;90(6):362-372.
- Heider J, Vogel S, Volkmer H, et al. Human iPSC-derived glia as a tool for neuropsychiatric research and drug development. Int J Mol Sci. 2021;22(19):10254.
Drug Brand Name
Streptozotocin • Zanosar
Bottom Line
Treatment with stem cell transplantation is experimental and not approved for any medical or psychiatric illness. However, based on our growing understanding of the function of stem cells, and preliminary research conducted mainly in animals, many neurodegenerative-, vascular-, immune-, and inflammation-based psychiatric conditions might be beneficially influenced by stem cell treatment.
- Takahashi K, Tanabe K, Ohnuki M, et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007;131(5):861-872.
- Duncan T, Valenzuela M. Alzheimer’s disease, dementia, and stem cell therapy. Stem Cell Res Ther. 2017;8(1):111.
- Brinton RD, Wang JM. Therapeutic potential of neurogenesis for prevention and recovery from Alzheimer’s disease: allopregnanolone as a proof of concept neurogenic agent. Curr Alzheimer Res. 2006;3(3):185-190.
- Taupin P. Adult neurogenesis, neural stem cells, and Alzheimer’s disease: developments, limitations, problems, and promises. Curr Alzheimer Res. 2009;6(6):461-470.
- Taupin P. Neurogenesis, NSCs, pathogenesis, and therapies for Alzheimer’s disease. Front Biosci (Schol Ed). 2011;3:178-90.
- Kang JM, Yeon BK, Cho SJ, et al. Stem cell therapy for Alzheimer’s disease: a review of recent clinical trials. J Alzheimers Dis. 2016;54(3):879-889.
- Li M, Guo K, Ikehara S. Stem cell treatment for Alzheimer’s disease. Int J Mol Sci. 2014;15(10):19226-19238.
- Zappa Villar MF, López Hanotte J, Pardo J, et al. Mesenchymal stem cells therapy improved the streptozotocin-induced behavioral and hippocampal impairment in rats. Mol Neurobiol. 2020;57(2):600-615.
- Lupien SJ, de Leon M, de Santi S, et al. Cortisol levels during human aging predict hippocampal atrophy and memory deficits. Nat Neurosci. 1998;1(1):69-73.
- Iannitelli A, Quartini A, Tirassa P, et al. Schizophrenia and neurogenesis: a stem cell approach. Neurosci Biobehav Rev. 2017;80:414-442.
- Sacco R, Cacci E, Novarino G. Neural stem cells in neuropsychiatric disorders. Curr Opin Neurobiol. 2018; 48:131-138.
- Miller ND, Kelsoe JR. Unraveling the biology of bipolar disorder using induced pluripotent stem-derived neurons. Bipolar Disord. 2017;19(7):544-551.
- O’Shea KS, McInnis MG. Neurodevelopmental origins of bipolar disorder: iPSC models. Mol Cell Neurosci. 2016;73:63-83.
- Jacobs BM. A dangerous method? The use of induced pluripotent stem cells as a model for schizophrenia. Schizophr Res. 2015;168(1-2):563-568.
- Liu Y, Deng W. Reverse engineering human neurodegenerative disease using pluripotent stem cell technology. Brain Res. 2016;1638(Pt A):30-41.
- Siniscalco D, Kannan S, Semprún-Hernández N, et al. Stem cell therapy in autism: recent insights. Stem Cells Cloning. 2018;11:55-67.
- Siniscalco D, Bradstreet JJ, Sych N, et al. Mesenchymal stem cells in treating autism: novel insights. World J Stem Cells. 2014;6(2):173-178.
- Siniscalco D, Sapone A, Cirillo A, et al. Autism spectrum disorders: is mesenchymal stem cell personalized therapy the future? J Biomed Biotechnol. 2012; 2012:480289.
- Bradstreet JJ, Sych N, Antonucci N, et al. Efficacy of fetal stem cell transplantation in autism spectrum disorders: an open-labeled pilot study. Cell Transplant. 2014;23(Suppl 1):S105-S112.
- Lv YT, Zhang Y, Liu M, et al. Transplantation of human cord blood mononuclear cells and umbilical cordderived mesenchymal stem cells in autism. J Transl Med. 2013;11:196.
- Vargas DL, Nascimbene C, Krishnan C, et al. Neuroglial activation and neuroinflammation in the brain of patients with autism. Ann Neurol. 2005;57(1):67-81.
- Wei L, Keogh CL, Whitaker VR, et al. Angiogenesis and stem cell transplantation as potential treatments of cerebral ischemic stroke. Pathophysiology. 2005;12(1): 47-62.
- Newman MB, Willing AE, Manresa JJ, et al. Cytokines produced by cultured human umbilical cord blood (HUCB) cells: implications for brain repair. Exp Neurol. 2006;199(1):201-218.
- Peterson DA. Umbilical cord blood cells and brain stroke injury: bringing in fresh blood to address an old problem. J Clin Invest. 2004;114(3):312-314.
- Cohly HH, Panja A. Immunological findings in autism. Int Rev Neurobiol. 2005;71:317-341.
- Ashwood P, Van de Water J. Is autism an autoimmune disease? Autoimmun Rev. 2004;3(7-8):557-562.
- Yagi H, Soto-Gutierrez A, Parekkadan B, et al. Mesenchymal stem cells: mechanisms of immunomodulation and homing. Cell Transplant. 2010;19(6):667-679.
- Vaccarino FM, Urban AE, Stevens HE, et al. Annual Research Review: The promise of stem cell research for neuropsychiatric disorders. J Child Psychol Psychiatry. 2011;52(4):504-516.
- Liu EY, Scott CT. Great expectations: autism spectrum disorder and induced pluripotent stem cell technologies. Stem Cell Rev Rep. 2014;10(2):145-150.
- Richardson-Jones JW, Craige CP, Guiard BP, et al. 5-HT1A autoreceptor levels determine vulnerability to stress and response to antidepressants. Neuron. 2010;65(1):40-52.
- Saarelainen T, Hendolin P, Lucas G, et al. Activation of the TrkB neurotrophin receptor is induced by antidepressant drugs and is required for antidepressant-induced behavioral effects. J Neurosci. 2003;23(1):349-357.
- Klumpers UM, Veltman DJ, Drent ML, et al. Reduced parahippocampal and lateral temporal GABAA-[11C] flumazenil binding in major depression: preliminary results. Eur J Nucl Med Mol Imaging. 2010;37(3): 565-574.
- Bremner JD, Narayan M, Anderson ER, et al. Hippocampal volume reduction in major depression. Am J Psychiatry. 2000;157(1):115-118.
- Bremner JD, Randall P, Scott TM, et al. MRI-based measurement of hippocampal volume in patients with combat-related posttraumatic stress disorder. Am J Psychiatry. 1995;152(7):973-981.
- Vincent SL, Todtenkopf MS, Benes FM. A comparison of the density of pyramidal and non-pyramidal neurons in the anterior cingulate cortex of schizophrenics and manic depressives. Soc Neurosci Abstr. 1997;23:2199.
- Benes FM, Kwok EW, Vincent SL, et al. A reduction of nonpyramidal cells in sector CA2 of schizophrenics and manic depressives. Biol Psychiatry. 1998;44(2): 88-97.
- Ongür D, Drevets WC, Price JL. Glial reduction in the subgenual prefrontal cortex in mood disorders. Proc Natl Acad Sci U S A. 1998;95(22):13290-13295.
- Rajkowska G, Miguel-Hidalgo JJ, Wei J, et al. Morphometric evidence for neuronal and glial prefrontal cell pathology in major depression. Biol Psychiatry. 1999;45(9): 1085-1098.
- Licinio J, Wong ML. Serotonergic neurons derived from induced pluripotent stem cells (iPSCs): a new pathway for research on the biology and pharmacology of major depression. Mol Psychiatry. 2016;21(1):1-2.
- Chen SK, Tvrdik P, Peden E, et al. Hematopoietic origin of pathological grooming in Hoxb8 mutant mice. Cell. 2010;141(5):775-785.
- Israel Y, Ezquer F, Quintanilla ME, et al. Intracerebral stem cell administration inhibits relapse-like alcohol drinking in rats. Alcohol Alcohol. 2017;52(1):1-4.
- Ezquer F, Morales P, Quintanilla ME, et al. Intravenous administration of anti-inflammatory mesenchymal stem cell spheroids reduces chronic alcohol intake and abolishes binge-drinking. Sci Rep. 2018;8(1):4325.
- Scarnati MS, Halikere A, Pang ZP. Using human stem cells as a model system to understand the neural mechanisms of alcohol use disorders: current status and outlook. Alcohol. 2019;74:83-93.
- Yadid GM, Popovtzer R. Nanoparticle-mesenchymal stem cell conjugates for cell therapy in drug addiction. NIH grant application. 2017.
- Xu C, Loh HH, Law PY. Effects of addictive drugs on adult neural stem/progenitor cells. Cell Mol Life Sci. 2016;73(2):327-348.
- Dholakiya SL, Aliberti A, Barile FA. Morphine sulfate concomitantly decreases neuronal differentiation and opioid receptor expression in mouse embryonic stem cells. Toxicol Lett. 2016;247:45-55.
- Zhang Y, Loh HH, Law PY. Effect of opioid on adult hippocampal neurogenesis. Scientific World Journal. 2016;2016:2601264.
- Bortolotto V, Grilli M. Opiate analgesics as negative modulators of adult hippocampal neurogenesis: potential implications in clinical practice. Front Pharmacol. 2017; 8:254.
- Galve-Roperh I, Chiurchiù V, Díaz-Alonso J, et al. Cannabinoid receptor signaling in progenitor/stem cell proliferation and differentiation. Prog Lipid Res. 2013; 52(4):633-650.
- Zimmermann T, Maroso M, Beer A, et al. Neural stem cell lineage-specific cannabinoid type-1 receptor regulates neurogenesis and plasticity in the adult mouse hippocampus. Cereb Cortex. 2018;28(12):4454-4471.
- Ren J, Liu N, Sun N, et al. Mesenchymal stem cells and their exosomes: promising therapies for chronic pain. Curr Stem Cell Res Ther. 2019;14(8):644-653.
While laboratory studies move forward at full speed, the clinical use of stem cells—undifferentiated cells that can develop into many different types of specialized cells—remains controversial. Presently, only unadulterated stem cells are allowed to be used in patients, and only on an experimental and investigational basis. Stem cells that have been expanded, modified, or enhanced outside of the body are not allowed to be used for clinical application in the United States at this time. In June 2021, the FDA strengthened the language of stem cell regulation, further limiting their clinical application (see https://www.fda.gov/vaccines-blood-biologics/consumers-biologics/important-patient-and-consumer-information-about-regenerative-medicine-therapies). Yet some applications, such as treatment of lymphoma or restorative knee injections, are covered by some health insurance plans, and the acceptance of stem cell treatment is growing.
In this article, I describe the basics of stem cells, and explore the potential therapeutic use of stem cells for treating various mental illnesses.
Stem cells: A primer
Human embryonic stem cells were initially investigated for their healing properties. However, the need to harvest these cells from embryos drew much criticism, and many found the process to be ethically and religiously unacceptable. This was resolved by the Nobel prize–winning discovery that adult somatic cells can be reprogrammed into cells with embryonic stem cell properties by introducing specific transcription factors. These cells have been termed “induced pluripotent stem cells” (iPSCs).1 The use of adult stem cells and stem cells from the umbilical cords of healthy newborns has allowed for wider acceptance of stem cell research and treatment.
Stem cells may be collected from the patient himself or herself; these are autologous stem cells. They may also be harvested from healthy newborn waste, such as the umbilical cord blood and wall; these are allogenic stem cells. Autologous stem cells are present in almost any tissue but are usually collected from the patient’s adipose tissue or from bone marrow. Understandably, younger stem cells possess higher healing properties. Stem cells may be mesenchymal, producing primarily connective and nervous tissue, or hematopoietic, influencing the immune system and blood cell production, though there is a considerable overlap in the function of these types of cells.
Adult somatic stem cells may be turned into stem cells (iPSCs) and then become any tissue, including neurons. This ability of stem cells to physically regenerate the CNS is directly relevant to psychiatry.
In addition to neurogenesis, stem cell transplants can assist in immune and vascular restoration as well as in suppressing inflammation. The ability of stem cells to replace mutated genes may be useful for addressing inheritable neuropsychiatric conditions.
Both autoimmune and inflammatory mechanisms play an important role in most psychiatric illnesses. The more we learn, the more it is clear that brain function is profoundly dependent on more than just its structure, and that structure depends on more than blood supply. Stem cells influence the vascular, nutritional, functional, inflammatory, and immune environment of the brain, potentially assisting in cognitive and emotional rehabilitation.
Stem cells operate in 2 fundamental ways: via direct cell-to-cell interaction, and via the production and release of growth, immune-regulating, and anti-inflammatory factors. Such factors are produced within the cells and then released in the extracellular environment as a content of exosomes. The route of administration is important in the delivery of the stem cells to the target tissue. Unlike their direct introduction into a joint, muscle, or intervertebral disk, injection of stem cells into the brain is more complicated and not routinely feasible. Intrathecal injections may bring stem cells into the CNS, but cerebrospinal fluid does not easily carry stem cells into the brain, and certainly cannot deliver them to an identified target within the brain. Existing technology can allow stem cells to be packaged in such a way that they can penetrate the blood-brain barrier, but this requires stem cell modification, which presently is not permitted in clinical practice in the United States. Alternatively, there is a way to weaken the blood-brain barrier to allow stem cells to travel through the “opened doors,” so to speak, but this allows everything to have access to the CNS, which may be unsafe. IV administration is technologically easy, and it grants stem cells the environment to multiply and produce extracellular factors that can cross the blood-brain barrier, while large cells cannot.
Continue to: Stem cells as a treatment for mental illness...
Stem cells as a treatment for mental illness
Based on our understanding of the function of stem cells, many neurodegenerative-, vascular-, immune-, and inflammation-based psychiatric conditions can be influenced by stem cell treatment. Here I review the potential therapeutic role of stem cells in the treatment of several psychiatric disorders.
Alzheimer’s dementia
Alzheimer’s dementia (AD) is a progressive neurodegenerative pathology based on neuronal and synaptic loss. Repopulation and regeneration of depleted neuronal circuitry by exogenous stem cells may be a rational therapeutic strategy.2 The regeneration of lost neurons has the potential to restore cognitive function. Multiple growth factors that regulate neurogenesis are abundant during child development but dramatically decline with age. The introduction of stem cells—especially those derived from newborn waste—seem to promote recovery from neurodegenerative disease or injury.3
There currently is no cure for AD. Cellular therapy promises new advances in treatment.4 Neurogenesis occurs not only during fetal development but in the adult brain. Neural stem cells reside in the adult CNS of all mammals.5 They are intimately involved in continuous restoration, but age just like the rest of the animal tissue, providing ever-decreasing restorative potential.
The number of studies of stem cells in AD has increased since the early 2000 s,6,7 and research continues to demonstrate robust CNS neurogenesis. In a 2020 study, Zappa Villar et al8 evaluated stem cells as a treatment for rats in which an AD model was induced by the intracerebroventricular injection of streptozotocin (STZ). The STZ-treated rats displayed poor performance in all behavioral tests. Stem cell therapy increased exploratory behavior, decreased anxiety, and improved spatial memory and marble-burying behavior; the latter was representative of daily life activities. Importantly, stem cell therapy ameliorated and restored hippocampal atrophy and some presynaptic protein levels in the rats with AD.8 Animal models cannot be automatically applied to humans, but they shine a light on the areas that need further exploration.
In humans, elevated cortisol levels during aging predict hippocampal atrophy and memory deficits,9 and this deficiency may be positively influenced by stem cell treatment.
Schizophrenia
Recent research indicates that schizophrenia may begin with abnormal neurogenesis from neural stem cells inside the embryo, and that this process may be particularly vulnerable to numerous genetic and/or environmental disturbances of early brain development.10 Because neurogenesis is not confined to the womb but is a protracted process that continues into postnatal life, adolescence and beyond, influencing this process may be a way to add to the schizophrenia treatment armamentarium.10 Sacco et al11 described links between the alteration of intrauterine and adult neurogenesis and the causes of neuropsychiatric disorders, including schizophrenia. Immune and inflammatory mechanisms are important in the etiology of schizophrenia. By their core function, stem cells address both mechanisms, and may directly modulate this devastating disease.
In addition to clinical hopes, advances in research tools hold the promise of new discoveries. With the advent of iPSC technology, it is possible to generate live neurons in vitro from somatic tissue of patients with schizophrenia. Despite its many limitations, this revolutionary technology has already helped to advance our understanding of schizophrenia.11
Bipolar disorder
Many of the fundamental neurobiological mechanisms of schizophrenia are mirrored in bipolar disorder.12 Though we are not ready to bring stem cells into the day-to-day treatment of this condition, several groups are starting to apply iPSC technology to the study of bipolar disorder.13
Neurodevelopmental factors—particularly pathways related to nervous system development, cell migration, extracellular matrix, methylation, and calcium signaling—have been identified in large gene expression studies as altered in bipolar disorder.14 Stem cell technology opens doorways to reverse engineering of human neurodegenerative disease.15
Continue to: Autism spectrum disorders...
Autism spectrum disorders
Autism spectrum disorders (ASDs) are multiple heterogeneous neurodevelopmental disorders.16 Neuroinflammation and immune dysregulation influence the origin of ASDs. Due to the neurobiologic changes underlying ASD development, cell-based therapies, including the use of mesenchymal stem cells (MSCs), have been applied to ASDs.16 Stem cells show specific immunologic properties that make them promising candidates for treating ASDs.17
The exact mechanisms of action of MSCs to restore function in patients with ASDs are largely unknown, but proposed mechanisms include:
- synthesizing and releasing anti-inflammatory cytokines and survival-promoting growth factors
- integrating into the existing neural and synaptic network
- restoring plasticity.18
In a study of transplantation of human cord blood cells and umbilical cord–derived MSCs for patients with ASDs, Bradstreet et al19 found a statistically significant difference on scores for domains of speech, sociability, sensory, and overall health, as well as reductions in the total scores, in those who received transplants compared to their pretreatment values.
In another study of stem cell therapy for ASDs, Lv et al20 demonstrated the safety and efficacy of combined transplantation of human cord blood cells and umbilical cord–derived MSCs in treating children with ASDs. The transplantations included 4 stem cell IV infusions and intrathecal injections once a week. Statistically significant differences were shown at 24 weeks post-treatment. Although this nonrandomized, open-label, single-center Phase I/II trial cannot be relied on for any definitive conclusions, it suggests an important area of investigation.20
The vascular aspects of ASDs’ pathogenesis should not be overlooked. For example, specific temporal lobe areas associated with facial recognition, social interaction, and language comprehension have been demonstrated to be hypoperfused in children with ASDs, but not in controls. The degree of hypoperfusion and resulting hypoxia correlates with the severity of ASD symptoms. The damage causing hypoperfusion of temporal areas was associated with the onset of autism-like disorders. Damage of the amygdala, hippocampus, or other temporal structures induces permanent or transient autistic-like characteristics, such as unexpressive faces, little eye contact, and motor stereotypes. Clinically, temporal lobe damage by viral and other means has been implicated in the development of ASD in children and adults. Hypoperfusion may contribute to defects, not only by inducing hypoxia, but also by allowing for abnormal metabolite or neurotransmitter accumulation. This is one of the reasons glutamate toxicity has been implicated in ASD. The augmentation of perfusion through stimulation of angiogenesis by stem cells should allow for metabolite clearance and restoration of functionality. Vargas et al21 compared brain autopsy samples from 11 children with ASDs to those of 7 age-matched controls. They demonstrated an active neuroinflammatory process in the cerebral cortex, white matter, and cerebellum of patients with ASDs, both by immunohistochemistry and morphology.21
Multiple studies have confirmed that the systemic administration of cord blood cells is sufficient to induce neuroregeneration.22,23 Angiogenesis has been experimentally demonstrated in peripheral artery disease, myocardial ischemia, and stroke, and has direct implications on brain repair.24 Immune dysregulation25,26 and immune modulation27 also are addressed by stem cell treatment, which provides a promising avenue for battling ASDs.
Like attention-deficit/hyperactivity disorder and obsessive-compulsive disorder, ASDs are neurodevelopmental conditions. Advances based on the use of stem cells hold great promise for understanding, diagnosing and, possibly, treating these psychiatric disorders.28,29
Depression
Neuropsychiatric disorders arise from deviations from the regular differentiation process of the CNS, leading to altered neuronal connectivity. Relatively subtle abnormalities in the size and number of cells in the prefrontal cortex and basal ganglia have been observed in patients with depressive disorder and Tourette syndrome.30 Fibroblast-derived iPSCs generate serotonergic neurons through the exposure of the cells to growth factors and modulators of signaling pathways. If these serotonergic neurons are made from the patients’ own cells, they can be used to screen for new therapeutics and elucidate the unknown mechanisms through which current medications may function.31 This development could lead to the discovery of new medication targets and new insights into the molecular biology of depression.32
Deficiencies of brain-derived neurotrophic factor (BDNF) have a role in depression, anxiety, and other neuropsychiatric illnesses. The acute behavioral effects of selective serotonin reuptake inhibitors and tricyclic antidepressants seem to require BDNF signaling, which suggests that BDNF holds great potential as a therapeutic agent. Cell therapies focused on correcting BDNF deficiencies in mice have had some success.33
Dysregulation of GABAergic neurons has also been implicated in depression and anxiety. Patients with major depressive disorder have reduced gamma aminobutyric acid (GABA) receptors in the parahippocampal and lateral temporal lobes.34
Ultimately, the development of differentiation protocols for serotonergic and GABAergic neuronal populations will pave the way for examining the role of these populations in the pathogenesis of depression and anxiety, and may eventually open the door for cell-based therapies in humans.35
Studies have demonstrated a reduction in the density of pyramidal and nonpyramidal neurons in the anterior cingulate cortex of patients with schizophrenia and bipolar disorder,36 glial reduction in the subgenual prefrontal cortex in mood disorders,37 and morphometric evidence for neuronal and glial prefrontal cell pathology in major depressive disorder.38 The potential for stem cells to repair such pathology may be of clinical benefit to many patients.
Aside from their other suggested clinical uses, iPSCs may be utilized in new pathways for research on the biology and pharmacology of major depressive disorder.39
Continue to: Obsessive-compulsive disorder...
Obsessive-compulsive disorder
Obsessive-compulsive disorder (OCD) is often characterized by excessive behaviors related to cleanliness, including grooming, which is represented across most animal species. In mice, behaviors such as compulsive grooming and hair removal—similar to behaviors in humans with OCD or trichotillomania—are associated with a specific mutation. Chen et al40 reported that the transplantation of bone marrow stem cells into mice with this mutation (bone marrow–derived microglia specifically home to the brain) rescues their pathological phenotype by repairing native neurons.
The autoimmune, inflammatory, and neurodegenerative changes that are prevalent in OCD may be remedied by stem cell treatment in a fashion described throughout this article.
Other conditions
The Box41-50 describes a possible role for stem cells in the treatment or prevention of several types of substance use disorders.
Box
Researchers have begun to explore stem cells as a potential treatment for several substance use disorders, including those involving alcohol, cocaine, and opioids, as well as their interactions with cannabinoids.
Alcohol use disorder. In a 2017 study, Israel et al41 gave intra-cerebral injections of mesenchymal stem cells (MSCs) to rats that were bred to have a high alcohol intake. The MSC injections resulted in drastic reductions in the rats’ alcohol consumption. A single intracerebroventricular MSC administration inhibited relapse-like drinking by up to 85% for 40 days.
It is beyond unlikely that direct brain injections would be used to treat alcohol use disorder in humans. To address this problem, researchers aggregated MSCs into smaller spheroid shapes, which reduced their size up to 75% and allowed them to be injected intravenously to reach the brain in a study conducted in rats.42 Within 48 hours of a single treatment, the rats had reduced their intake of alcohol by 90%. The IV administration of antiinflammatory MSCs in human trials will be the next step to verify these results.
Alcohol research using human stem cells is also being conducted as a model system to understand the neural mechanisms of alcohol use disorder.43
Cocaine use disorder. In a grant proposal, Yadid and Popovtzer44 suggested that cocaine addiction affects neurogenesis, especially in the dentate gyrus, ventral tegmental area, nucleus accumbens, and prefrontal cortex; it damages mitochondrial RNA, brain-derived neurotrophic factor (BDNF), glutamate transporter (excitatory amino acid transporter; EAAT), and interleukin-10. MSCs have a predilection to these areas and influence neurogenesis. Currently, there are no FDAapproved medications for the safe and effective treatment of cocaine addiction. MSCs can home to pathological areas in the brain, release growth factors, and serve as cellular delivery tools in various brain disorders. Moreover, restoration of basal glutamate levels via the EAAT has been proposed as a promising target for treating cocaine dependence. Therefore, MSCs differentiated to express EAATs may have a combined long-term effect that can attenuate cocaine craving and relapse.44
Neural stem cells undergo a series of developmental processes before giving rise to newborn neurons, astrocytes, and oligodendrocytes in adult neurogenesis. During the past decade, studies of adult neurogenesis modulated by addictive drugs have highlighted the role of stem cells. These drugs have been shown to regulate the proliferation, differentiation, and survival of adult cells in different manners, which results in the varying consequences of adult neurogenesis.45 Reversal of these influences by healthy stem cells can be a worthy goal to pursue.
Opioid use disorder. Opiate medications cause a loss of newly born neural progenitors in the subgranular zone of the dentate gyrus by either modulating proliferation or interfering with differentiation and maturation.46 Opiates were the first medications shown to negatively impact neurogenesis in the adult mammalian hippocampus.47,48 The restoration of hippocampal function may positively affect the prognosis of a patient who is addicted.
Cannabinoids. Cannabinoids’ influence on the brain and on stem cells is controversial. On one hand, deteriorated neurogenesis results in reduced long-term potentiation in hippocampal formation. These cellular and physiological alterations lead to decreased short-term spatial memory and increased depressionlike behaviors.49 On the other hand, there is emerging evidence that cannabinoids improve neurogenesis and CNS plasticity, at least in the adult mouse.50 Through normalization of immune function, and restoration of the brain and the body, stem cells may assist in better health and in treatment of cannabis use disorder.
Chronic pain is a neuropsychiatric condition that involves the immune system, inflammation, vascularization, trophic changes, and other aspects of the CNS function in addition to peripheral factors and somatic pain generators. Treatment of painful conditions with the aid of stem cells represents a large and ever-developing field that lies outside of the scope of this article.51
Experimental, but promising
It is not easy to accept revolutionary new approaches in medicine. Endless research and due diligence are needed to prove a concept and then to work out specific applications, safeguards, and limitations for any novel treatments. The stem cell terrain is poorly explored, and one needs to be careful when venturing there. Presently, the FDA appropriately sees treatment with stem cells as experimental and investigational, particularly in the mental health arena. Stem cells are not approved for treatment of any specific condition. At the same time, research and clinical practice suggest stem cell treatment may someday play a more prominent role in health care. Undoubtedly, psychiatry will eventually benefit from the knowledge and application of stem cell research and practice.
Related Resources
- De Los Angeles A, Fernando MB, Hall NAL, et al. Induced pluripotent stem cells in psychiatry: an overview and critical perspective. Biol Psychiatry. 2021;90(6):362-372.
- Heider J, Vogel S, Volkmer H, et al. Human iPSC-derived glia as a tool for neuropsychiatric research and drug development. Int J Mol Sci. 2021;22(19):10254.
Drug Brand Name
Streptozotocin • Zanosar
Bottom Line
Treatment with stem cell transplantation is experimental and not approved for any medical or psychiatric illness. However, based on our growing understanding of the function of stem cells, and preliminary research conducted mainly in animals, many neurodegenerative-, vascular-, immune-, and inflammation-based psychiatric conditions might be beneficially influenced by stem cell treatment.
While laboratory studies move forward at full speed, the clinical use of stem cells—undifferentiated cells that can develop into many different types of specialized cells—remains controversial. Presently, only unadulterated stem cells are allowed to be used in patients, and only on an experimental and investigational basis. Stem cells that have been expanded, modified, or enhanced outside of the body are not allowed to be used for clinical application in the United States at this time. In June 2021, the FDA strengthened the language of stem cell regulation, further limiting their clinical application (see https://www.fda.gov/vaccines-blood-biologics/consumers-biologics/important-patient-and-consumer-information-about-regenerative-medicine-therapies). Yet some applications, such as treatment of lymphoma or restorative knee injections, are covered by some health insurance plans, and the acceptance of stem cell treatment is growing.
In this article, I describe the basics of stem cells, and explore the potential therapeutic use of stem cells for treating various mental illnesses.
Stem cells: A primer
Human embryonic stem cells were initially investigated for their healing properties. However, the need to harvest these cells from embryos drew much criticism, and many found the process to be ethically and religiously unacceptable. This was resolved by the Nobel prize–winning discovery that adult somatic cells can be reprogrammed into cells with embryonic stem cell properties by introducing specific transcription factors. These cells have been termed “induced pluripotent stem cells” (iPSCs).1 The use of adult stem cells and stem cells from the umbilical cords of healthy newborns has allowed for wider acceptance of stem cell research and treatment.
Stem cells may be collected from the patient himself or herself; these are autologous stem cells. They may also be harvested from healthy newborn waste, such as the umbilical cord blood and wall; these are allogenic stem cells. Autologous stem cells are present in almost any tissue but are usually collected from the patient’s adipose tissue or from bone marrow. Understandably, younger stem cells possess higher healing properties. Stem cells may be mesenchymal, producing primarily connective and nervous tissue, or hematopoietic, influencing the immune system and blood cell production, though there is a considerable overlap in the function of these types of cells.
Adult somatic stem cells may be turned into stem cells (iPSCs) and then become any tissue, including neurons. This ability of stem cells to physically regenerate the CNS is directly relevant to psychiatry.
In addition to neurogenesis, stem cell transplants can assist in immune and vascular restoration as well as in suppressing inflammation. The ability of stem cells to replace mutated genes may be useful for addressing inheritable neuropsychiatric conditions.
Both autoimmune and inflammatory mechanisms play an important role in most psychiatric illnesses. The more we learn, the more it is clear that brain function is profoundly dependent on more than just its structure, and that structure depends on more than blood supply. Stem cells influence the vascular, nutritional, functional, inflammatory, and immune environment of the brain, potentially assisting in cognitive and emotional rehabilitation.
Stem cells operate in 2 fundamental ways: via direct cell-to-cell interaction, and via the production and release of growth, immune-regulating, and anti-inflammatory factors. Such factors are produced within the cells and then released in the extracellular environment as a content of exosomes. The route of administration is important in the delivery of the stem cells to the target tissue. Unlike their direct introduction into a joint, muscle, or intervertebral disk, injection of stem cells into the brain is more complicated and not routinely feasible. Intrathecal injections may bring stem cells into the CNS, but cerebrospinal fluid does not easily carry stem cells into the brain, and certainly cannot deliver them to an identified target within the brain. Existing technology can allow stem cells to be packaged in such a way that they can penetrate the blood-brain barrier, but this requires stem cell modification, which presently is not permitted in clinical practice in the United States. Alternatively, there is a way to weaken the blood-brain barrier to allow stem cells to travel through the “opened doors,” so to speak, but this allows everything to have access to the CNS, which may be unsafe. IV administration is technologically easy, and it grants stem cells the environment to multiply and produce extracellular factors that can cross the blood-brain barrier, while large cells cannot.
Continue to: Stem cells as a treatment for mental illness...
Stem cells as a treatment for mental illness
Based on our understanding of the function of stem cells, many neurodegenerative-, vascular-, immune-, and inflammation-based psychiatric conditions can be influenced by stem cell treatment. Here I review the potential therapeutic role of stem cells in the treatment of several psychiatric disorders.
Alzheimer’s dementia
Alzheimer’s dementia (AD) is a progressive neurodegenerative pathology based on neuronal and synaptic loss. Repopulation and regeneration of depleted neuronal circuitry by exogenous stem cells may be a rational therapeutic strategy.2 The regeneration of lost neurons has the potential to restore cognitive function. Multiple growth factors that regulate neurogenesis are abundant during child development but dramatically decline with age. The introduction of stem cells—especially those derived from newborn waste—seem to promote recovery from neurodegenerative disease or injury.3
There currently is no cure for AD. Cellular therapy promises new advances in treatment.4 Neurogenesis occurs not only during fetal development but in the adult brain. Neural stem cells reside in the adult CNS of all mammals.5 They are intimately involved in continuous restoration, but age just like the rest of the animal tissue, providing ever-decreasing restorative potential.
The number of studies of stem cells in AD has increased since the early 2000 s,6,7 and research continues to demonstrate robust CNS neurogenesis. In a 2020 study, Zappa Villar et al8 evaluated stem cells as a treatment for rats in which an AD model was induced by the intracerebroventricular injection of streptozotocin (STZ). The STZ-treated rats displayed poor performance in all behavioral tests. Stem cell therapy increased exploratory behavior, decreased anxiety, and improved spatial memory and marble-burying behavior; the latter was representative of daily life activities. Importantly, stem cell therapy ameliorated and restored hippocampal atrophy and some presynaptic protein levels in the rats with AD.8 Animal models cannot be automatically applied to humans, but they shine a light on the areas that need further exploration.
In humans, elevated cortisol levels during aging predict hippocampal atrophy and memory deficits,9 and this deficiency may be positively influenced by stem cell treatment.
Schizophrenia
Recent research indicates that schizophrenia may begin with abnormal neurogenesis from neural stem cells inside the embryo, and that this process may be particularly vulnerable to numerous genetic and/or environmental disturbances of early brain development.10 Because neurogenesis is not confined to the womb but is a protracted process that continues into postnatal life, adolescence and beyond, influencing this process may be a way to add to the schizophrenia treatment armamentarium.10 Sacco et al11 described links between the alteration of intrauterine and adult neurogenesis and the causes of neuropsychiatric disorders, including schizophrenia. Immune and inflammatory mechanisms are important in the etiology of schizophrenia. By their core function, stem cells address both mechanisms, and may directly modulate this devastating disease.
In addition to clinical hopes, advances in research tools hold the promise of new discoveries. With the advent of iPSC technology, it is possible to generate live neurons in vitro from somatic tissue of patients with schizophrenia. Despite its many limitations, this revolutionary technology has already helped to advance our understanding of schizophrenia.11
Bipolar disorder
Many of the fundamental neurobiological mechanisms of schizophrenia are mirrored in bipolar disorder.12 Though we are not ready to bring stem cells into the day-to-day treatment of this condition, several groups are starting to apply iPSC technology to the study of bipolar disorder.13
Neurodevelopmental factors—particularly pathways related to nervous system development, cell migration, extracellular matrix, methylation, and calcium signaling—have been identified in large gene expression studies as altered in bipolar disorder.14 Stem cell technology opens doorways to reverse engineering of human neurodegenerative disease.15
Continue to: Autism spectrum disorders...
Autism spectrum disorders
Autism spectrum disorders (ASDs) are multiple heterogeneous neurodevelopmental disorders.16 Neuroinflammation and immune dysregulation influence the origin of ASDs. Due to the neurobiologic changes underlying ASD development, cell-based therapies, including the use of mesenchymal stem cells (MSCs), have been applied to ASDs.16 Stem cells show specific immunologic properties that make them promising candidates for treating ASDs.17
The exact mechanisms of action of MSCs to restore function in patients with ASDs are largely unknown, but proposed mechanisms include:
- synthesizing and releasing anti-inflammatory cytokines and survival-promoting growth factors
- integrating into the existing neural and synaptic network
- restoring plasticity.18
In a study of transplantation of human cord blood cells and umbilical cord–derived MSCs for patients with ASDs, Bradstreet et al19 found a statistically significant difference on scores for domains of speech, sociability, sensory, and overall health, as well as reductions in the total scores, in those who received transplants compared to their pretreatment values.
In another study of stem cell therapy for ASDs, Lv et al20 demonstrated the safety and efficacy of combined transplantation of human cord blood cells and umbilical cord–derived MSCs in treating children with ASDs. The transplantations included 4 stem cell IV infusions and intrathecal injections once a week. Statistically significant differences were shown at 24 weeks post-treatment. Although this nonrandomized, open-label, single-center Phase I/II trial cannot be relied on for any definitive conclusions, it suggests an important area of investigation.20
The vascular aspects of ASDs’ pathogenesis should not be overlooked. For example, specific temporal lobe areas associated with facial recognition, social interaction, and language comprehension have been demonstrated to be hypoperfused in children with ASDs, but not in controls. The degree of hypoperfusion and resulting hypoxia correlates with the severity of ASD symptoms. The damage causing hypoperfusion of temporal areas was associated with the onset of autism-like disorders. Damage of the amygdala, hippocampus, or other temporal structures induces permanent or transient autistic-like characteristics, such as unexpressive faces, little eye contact, and motor stereotypes. Clinically, temporal lobe damage by viral and other means has been implicated in the development of ASD in children and adults. Hypoperfusion may contribute to defects, not only by inducing hypoxia, but also by allowing for abnormal metabolite or neurotransmitter accumulation. This is one of the reasons glutamate toxicity has been implicated in ASD. The augmentation of perfusion through stimulation of angiogenesis by stem cells should allow for metabolite clearance and restoration of functionality. Vargas et al21 compared brain autopsy samples from 11 children with ASDs to those of 7 age-matched controls. They demonstrated an active neuroinflammatory process in the cerebral cortex, white matter, and cerebellum of patients with ASDs, both by immunohistochemistry and morphology.21
Multiple studies have confirmed that the systemic administration of cord blood cells is sufficient to induce neuroregeneration.22,23 Angiogenesis has been experimentally demonstrated in peripheral artery disease, myocardial ischemia, and stroke, and has direct implications on brain repair.24 Immune dysregulation25,26 and immune modulation27 also are addressed by stem cell treatment, which provides a promising avenue for battling ASDs.
Like attention-deficit/hyperactivity disorder and obsessive-compulsive disorder, ASDs are neurodevelopmental conditions. Advances based on the use of stem cells hold great promise for understanding, diagnosing and, possibly, treating these psychiatric disorders.28,29
Depression
Neuropsychiatric disorders arise from deviations from the regular differentiation process of the CNS, leading to altered neuronal connectivity. Relatively subtle abnormalities in the size and number of cells in the prefrontal cortex and basal ganglia have been observed in patients with depressive disorder and Tourette syndrome.30 Fibroblast-derived iPSCs generate serotonergic neurons through the exposure of the cells to growth factors and modulators of signaling pathways. If these serotonergic neurons are made from the patients’ own cells, they can be used to screen for new therapeutics and elucidate the unknown mechanisms through which current medications may function.31 This development could lead to the discovery of new medication targets and new insights into the molecular biology of depression.32
Deficiencies of brain-derived neurotrophic factor (BDNF) have a role in depression, anxiety, and other neuropsychiatric illnesses. The acute behavioral effects of selective serotonin reuptake inhibitors and tricyclic antidepressants seem to require BDNF signaling, which suggests that BDNF holds great potential as a therapeutic agent. Cell therapies focused on correcting BDNF deficiencies in mice have had some success.33
Dysregulation of GABAergic neurons has also been implicated in depression and anxiety. Patients with major depressive disorder have reduced gamma aminobutyric acid (GABA) receptors in the parahippocampal and lateral temporal lobes.34
Ultimately, the development of differentiation protocols for serotonergic and GABAergic neuronal populations will pave the way for examining the role of these populations in the pathogenesis of depression and anxiety, and may eventually open the door for cell-based therapies in humans.35
Studies have demonstrated a reduction in the density of pyramidal and nonpyramidal neurons in the anterior cingulate cortex of patients with schizophrenia and bipolar disorder,36 glial reduction in the subgenual prefrontal cortex in mood disorders,37 and morphometric evidence for neuronal and glial prefrontal cell pathology in major depressive disorder.38 The potential for stem cells to repair such pathology may be of clinical benefit to many patients.
Aside from their other suggested clinical uses, iPSCs may be utilized in new pathways for research on the biology and pharmacology of major depressive disorder.39
Continue to: Obsessive-compulsive disorder...
Obsessive-compulsive disorder
Obsessive-compulsive disorder (OCD) is often characterized by excessive behaviors related to cleanliness, including grooming, which is represented across most animal species. In mice, behaviors such as compulsive grooming and hair removal—similar to behaviors in humans with OCD or trichotillomania—are associated with a specific mutation. Chen et al40 reported that the transplantation of bone marrow stem cells into mice with this mutation (bone marrow–derived microglia specifically home to the brain) rescues their pathological phenotype by repairing native neurons.
The autoimmune, inflammatory, and neurodegenerative changes that are prevalent in OCD may be remedied by stem cell treatment in a fashion described throughout this article.
Other conditions
The Box41-50 describes a possible role for stem cells in the treatment or prevention of several types of substance use disorders.
Box
Researchers have begun to explore stem cells as a potential treatment for several substance use disorders, including those involving alcohol, cocaine, and opioids, as well as their interactions with cannabinoids.
Alcohol use disorder. In a 2017 study, Israel et al41 gave intra-cerebral injections of mesenchymal stem cells (MSCs) to rats that were bred to have a high alcohol intake. The MSC injections resulted in drastic reductions in the rats’ alcohol consumption. A single intracerebroventricular MSC administration inhibited relapse-like drinking by up to 85% for 40 days.
It is beyond unlikely that direct brain injections would be used to treat alcohol use disorder in humans. To address this problem, researchers aggregated MSCs into smaller spheroid shapes, which reduced their size up to 75% and allowed them to be injected intravenously to reach the brain in a study conducted in rats.42 Within 48 hours of a single treatment, the rats had reduced their intake of alcohol by 90%. The IV administration of antiinflammatory MSCs in human trials will be the next step to verify these results.
Alcohol research using human stem cells is also being conducted as a model system to understand the neural mechanisms of alcohol use disorder.43
Cocaine use disorder. In a grant proposal, Yadid and Popovtzer44 suggested that cocaine addiction affects neurogenesis, especially in the dentate gyrus, ventral tegmental area, nucleus accumbens, and prefrontal cortex; it damages mitochondrial RNA, brain-derived neurotrophic factor (BDNF), glutamate transporter (excitatory amino acid transporter; EAAT), and interleukin-10. MSCs have a predilection to these areas and influence neurogenesis. Currently, there are no FDAapproved medications for the safe and effective treatment of cocaine addiction. MSCs can home to pathological areas in the brain, release growth factors, and serve as cellular delivery tools in various brain disorders. Moreover, restoration of basal glutamate levels via the EAAT has been proposed as a promising target for treating cocaine dependence. Therefore, MSCs differentiated to express EAATs may have a combined long-term effect that can attenuate cocaine craving and relapse.44
Neural stem cells undergo a series of developmental processes before giving rise to newborn neurons, astrocytes, and oligodendrocytes in adult neurogenesis. During the past decade, studies of adult neurogenesis modulated by addictive drugs have highlighted the role of stem cells. These drugs have been shown to regulate the proliferation, differentiation, and survival of adult cells in different manners, which results in the varying consequences of adult neurogenesis.45 Reversal of these influences by healthy stem cells can be a worthy goal to pursue.
Opioid use disorder. Opiate medications cause a loss of newly born neural progenitors in the subgranular zone of the dentate gyrus by either modulating proliferation or interfering with differentiation and maturation.46 Opiates were the first medications shown to negatively impact neurogenesis in the adult mammalian hippocampus.47,48 The restoration of hippocampal function may positively affect the prognosis of a patient who is addicted.
Cannabinoids. Cannabinoids’ influence on the brain and on stem cells is controversial. On one hand, deteriorated neurogenesis results in reduced long-term potentiation in hippocampal formation. These cellular and physiological alterations lead to decreased short-term spatial memory and increased depressionlike behaviors.49 On the other hand, there is emerging evidence that cannabinoids improve neurogenesis and CNS plasticity, at least in the adult mouse.50 Through normalization of immune function, and restoration of the brain and the body, stem cells may assist in better health and in treatment of cannabis use disorder.
Chronic pain is a neuropsychiatric condition that involves the immune system, inflammation, vascularization, trophic changes, and other aspects of the CNS function in addition to peripheral factors and somatic pain generators. Treatment of painful conditions with the aid of stem cells represents a large and ever-developing field that lies outside of the scope of this article.51
Experimental, but promising
It is not easy to accept revolutionary new approaches in medicine. Endless research and due diligence are needed to prove a concept and then to work out specific applications, safeguards, and limitations for any novel treatments. The stem cell terrain is poorly explored, and one needs to be careful when venturing there. Presently, the FDA appropriately sees treatment with stem cells as experimental and investigational, particularly in the mental health arena. Stem cells are not approved for treatment of any specific condition. At the same time, research and clinical practice suggest stem cell treatment may someday play a more prominent role in health care. Undoubtedly, psychiatry will eventually benefit from the knowledge and application of stem cell research and practice.
Related Resources
- De Los Angeles A, Fernando MB, Hall NAL, et al. Induced pluripotent stem cells in psychiatry: an overview and critical perspective. Biol Psychiatry. 2021;90(6):362-372.
- Heider J, Vogel S, Volkmer H, et al. Human iPSC-derived glia as a tool for neuropsychiatric research and drug development. Int J Mol Sci. 2021;22(19):10254.
Drug Brand Name
Streptozotocin • Zanosar
Bottom Line
Treatment with stem cell transplantation is experimental and not approved for any medical or psychiatric illness. However, based on our growing understanding of the function of stem cells, and preliminary research conducted mainly in animals, many neurodegenerative-, vascular-, immune-, and inflammation-based psychiatric conditions might be beneficially influenced by stem cell treatment.
- Takahashi K, Tanabe K, Ohnuki M, et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007;131(5):861-872.
- Duncan T, Valenzuela M. Alzheimer’s disease, dementia, and stem cell therapy. Stem Cell Res Ther. 2017;8(1):111.
- Brinton RD, Wang JM. Therapeutic potential of neurogenesis for prevention and recovery from Alzheimer’s disease: allopregnanolone as a proof of concept neurogenic agent. Curr Alzheimer Res. 2006;3(3):185-190.
- Taupin P. Adult neurogenesis, neural stem cells, and Alzheimer’s disease: developments, limitations, problems, and promises. Curr Alzheimer Res. 2009;6(6):461-470.
- Taupin P. Neurogenesis, NSCs, pathogenesis, and therapies for Alzheimer’s disease. Front Biosci (Schol Ed). 2011;3:178-90.
- Kang JM, Yeon BK, Cho SJ, et al. Stem cell therapy for Alzheimer’s disease: a review of recent clinical trials. J Alzheimers Dis. 2016;54(3):879-889.
- Li M, Guo K, Ikehara S. Stem cell treatment for Alzheimer’s disease. Int J Mol Sci. 2014;15(10):19226-19238.
- Zappa Villar MF, López Hanotte J, Pardo J, et al. Mesenchymal stem cells therapy improved the streptozotocin-induced behavioral and hippocampal impairment in rats. Mol Neurobiol. 2020;57(2):600-615.
- Lupien SJ, de Leon M, de Santi S, et al. Cortisol levels during human aging predict hippocampal atrophy and memory deficits. Nat Neurosci. 1998;1(1):69-73.
- Iannitelli A, Quartini A, Tirassa P, et al. Schizophrenia and neurogenesis: a stem cell approach. Neurosci Biobehav Rev. 2017;80:414-442.
- Sacco R, Cacci E, Novarino G. Neural stem cells in neuropsychiatric disorders. Curr Opin Neurobiol. 2018; 48:131-138.
- Miller ND, Kelsoe JR. Unraveling the biology of bipolar disorder using induced pluripotent stem-derived neurons. Bipolar Disord. 2017;19(7):544-551.
- O’Shea KS, McInnis MG. Neurodevelopmental origins of bipolar disorder: iPSC models. Mol Cell Neurosci. 2016;73:63-83.
- Jacobs BM. A dangerous method? The use of induced pluripotent stem cells as a model for schizophrenia. Schizophr Res. 2015;168(1-2):563-568.
- Liu Y, Deng W. Reverse engineering human neurodegenerative disease using pluripotent stem cell technology. Brain Res. 2016;1638(Pt A):30-41.
- Siniscalco D, Kannan S, Semprún-Hernández N, et al. Stem cell therapy in autism: recent insights. Stem Cells Cloning. 2018;11:55-67.
- Siniscalco D, Bradstreet JJ, Sych N, et al. Mesenchymal stem cells in treating autism: novel insights. World J Stem Cells. 2014;6(2):173-178.
- Siniscalco D, Sapone A, Cirillo A, et al. Autism spectrum disorders: is mesenchymal stem cell personalized therapy the future? J Biomed Biotechnol. 2012; 2012:480289.
- Bradstreet JJ, Sych N, Antonucci N, et al. Efficacy of fetal stem cell transplantation in autism spectrum disorders: an open-labeled pilot study. Cell Transplant. 2014;23(Suppl 1):S105-S112.
- Lv YT, Zhang Y, Liu M, et al. Transplantation of human cord blood mononuclear cells and umbilical cordderived mesenchymal stem cells in autism. J Transl Med. 2013;11:196.
- Vargas DL, Nascimbene C, Krishnan C, et al. Neuroglial activation and neuroinflammation in the brain of patients with autism. Ann Neurol. 2005;57(1):67-81.
- Wei L, Keogh CL, Whitaker VR, et al. Angiogenesis and stem cell transplantation as potential treatments of cerebral ischemic stroke. Pathophysiology. 2005;12(1): 47-62.
- Newman MB, Willing AE, Manresa JJ, et al. Cytokines produced by cultured human umbilical cord blood (HUCB) cells: implications for brain repair. Exp Neurol. 2006;199(1):201-218.
- Peterson DA. Umbilical cord blood cells and brain stroke injury: bringing in fresh blood to address an old problem. J Clin Invest. 2004;114(3):312-314.
- Cohly HH, Panja A. Immunological findings in autism. Int Rev Neurobiol. 2005;71:317-341.
- Ashwood P, Van de Water J. Is autism an autoimmune disease? Autoimmun Rev. 2004;3(7-8):557-562.
- Yagi H, Soto-Gutierrez A, Parekkadan B, et al. Mesenchymal stem cells: mechanisms of immunomodulation and homing. Cell Transplant. 2010;19(6):667-679.
- Vaccarino FM, Urban AE, Stevens HE, et al. Annual Research Review: The promise of stem cell research for neuropsychiatric disorders. J Child Psychol Psychiatry. 2011;52(4):504-516.
- Liu EY, Scott CT. Great expectations: autism spectrum disorder and induced pluripotent stem cell technologies. Stem Cell Rev Rep. 2014;10(2):145-150.
- Richardson-Jones JW, Craige CP, Guiard BP, et al. 5-HT1A autoreceptor levels determine vulnerability to stress and response to antidepressants. Neuron. 2010;65(1):40-52.
- Saarelainen T, Hendolin P, Lucas G, et al. Activation of the TrkB neurotrophin receptor is induced by antidepressant drugs and is required for antidepressant-induced behavioral effects. J Neurosci. 2003;23(1):349-357.
- Klumpers UM, Veltman DJ, Drent ML, et al. Reduced parahippocampal and lateral temporal GABAA-[11C] flumazenil binding in major depression: preliminary results. Eur J Nucl Med Mol Imaging. 2010;37(3): 565-574.
- Bremner JD, Narayan M, Anderson ER, et al. Hippocampal volume reduction in major depression. Am J Psychiatry. 2000;157(1):115-118.
- Bremner JD, Randall P, Scott TM, et al. MRI-based measurement of hippocampal volume in patients with combat-related posttraumatic stress disorder. Am J Psychiatry. 1995;152(7):973-981.
- Vincent SL, Todtenkopf MS, Benes FM. A comparison of the density of pyramidal and non-pyramidal neurons in the anterior cingulate cortex of schizophrenics and manic depressives. Soc Neurosci Abstr. 1997;23:2199.
- Benes FM, Kwok EW, Vincent SL, et al. A reduction of nonpyramidal cells in sector CA2 of schizophrenics and manic depressives. Biol Psychiatry. 1998;44(2): 88-97.
- Ongür D, Drevets WC, Price JL. Glial reduction in the subgenual prefrontal cortex in mood disorders. Proc Natl Acad Sci U S A. 1998;95(22):13290-13295.
- Rajkowska G, Miguel-Hidalgo JJ, Wei J, et al. Morphometric evidence for neuronal and glial prefrontal cell pathology in major depression. Biol Psychiatry. 1999;45(9): 1085-1098.
- Licinio J, Wong ML. Serotonergic neurons derived from induced pluripotent stem cells (iPSCs): a new pathway for research on the biology and pharmacology of major depression. Mol Psychiatry. 2016;21(1):1-2.
- Chen SK, Tvrdik P, Peden E, et al. Hematopoietic origin of pathological grooming in Hoxb8 mutant mice. Cell. 2010;141(5):775-785.
- Israel Y, Ezquer F, Quintanilla ME, et al. Intracerebral stem cell administration inhibits relapse-like alcohol drinking in rats. Alcohol Alcohol. 2017;52(1):1-4.
- Ezquer F, Morales P, Quintanilla ME, et al. Intravenous administration of anti-inflammatory mesenchymal stem cell spheroids reduces chronic alcohol intake and abolishes binge-drinking. Sci Rep. 2018;8(1):4325.
- Scarnati MS, Halikere A, Pang ZP. Using human stem cells as a model system to understand the neural mechanisms of alcohol use disorders: current status and outlook. Alcohol. 2019;74:83-93.
- Yadid GM, Popovtzer R. Nanoparticle-mesenchymal stem cell conjugates for cell therapy in drug addiction. NIH grant application. 2017.
- Xu C, Loh HH, Law PY. Effects of addictive drugs on adult neural stem/progenitor cells. Cell Mol Life Sci. 2016;73(2):327-348.
- Dholakiya SL, Aliberti A, Barile FA. Morphine sulfate concomitantly decreases neuronal differentiation and opioid receptor expression in mouse embryonic stem cells. Toxicol Lett. 2016;247:45-55.
- Zhang Y, Loh HH, Law PY. Effect of opioid on adult hippocampal neurogenesis. Scientific World Journal. 2016;2016:2601264.
- Bortolotto V, Grilli M. Opiate analgesics as negative modulators of adult hippocampal neurogenesis: potential implications in clinical practice. Front Pharmacol. 2017; 8:254.
- Galve-Roperh I, Chiurchiù V, Díaz-Alonso J, et al. Cannabinoid receptor signaling in progenitor/stem cell proliferation and differentiation. Prog Lipid Res. 2013; 52(4):633-650.
- Zimmermann T, Maroso M, Beer A, et al. Neural stem cell lineage-specific cannabinoid type-1 receptor regulates neurogenesis and plasticity in the adult mouse hippocampus. Cereb Cortex. 2018;28(12):4454-4471.
- Ren J, Liu N, Sun N, et al. Mesenchymal stem cells and their exosomes: promising therapies for chronic pain. Curr Stem Cell Res Ther. 2019;14(8):644-653.
- Takahashi K, Tanabe K, Ohnuki M, et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007;131(5):861-872.
- Duncan T, Valenzuela M. Alzheimer’s disease, dementia, and stem cell therapy. Stem Cell Res Ther. 2017;8(1):111.
- Brinton RD, Wang JM. Therapeutic potential of neurogenesis for prevention and recovery from Alzheimer’s disease: allopregnanolone as a proof of concept neurogenic agent. Curr Alzheimer Res. 2006;3(3):185-190.
- Taupin P. Adult neurogenesis, neural stem cells, and Alzheimer’s disease: developments, limitations, problems, and promises. Curr Alzheimer Res. 2009;6(6):461-470.
- Taupin P. Neurogenesis, NSCs, pathogenesis, and therapies for Alzheimer’s disease. Front Biosci (Schol Ed). 2011;3:178-90.
- Kang JM, Yeon BK, Cho SJ, et al. Stem cell therapy for Alzheimer’s disease: a review of recent clinical trials. J Alzheimers Dis. 2016;54(3):879-889.
- Li M, Guo K, Ikehara S. Stem cell treatment for Alzheimer’s disease. Int J Mol Sci. 2014;15(10):19226-19238.
- Zappa Villar MF, López Hanotte J, Pardo J, et al. Mesenchymal stem cells therapy improved the streptozotocin-induced behavioral and hippocampal impairment in rats. Mol Neurobiol. 2020;57(2):600-615.
- Lupien SJ, de Leon M, de Santi S, et al. Cortisol levels during human aging predict hippocampal atrophy and memory deficits. Nat Neurosci. 1998;1(1):69-73.
- Iannitelli A, Quartini A, Tirassa P, et al. Schizophrenia and neurogenesis: a stem cell approach. Neurosci Biobehav Rev. 2017;80:414-442.
- Sacco R, Cacci E, Novarino G. Neural stem cells in neuropsychiatric disorders. Curr Opin Neurobiol. 2018; 48:131-138.
- Miller ND, Kelsoe JR. Unraveling the biology of bipolar disorder using induced pluripotent stem-derived neurons. Bipolar Disord. 2017;19(7):544-551.
- O’Shea KS, McInnis MG. Neurodevelopmental origins of bipolar disorder: iPSC models. Mol Cell Neurosci. 2016;73:63-83.
- Jacobs BM. A dangerous method? The use of induced pluripotent stem cells as a model for schizophrenia. Schizophr Res. 2015;168(1-2):563-568.
- Liu Y, Deng W. Reverse engineering human neurodegenerative disease using pluripotent stem cell technology. Brain Res. 2016;1638(Pt A):30-41.
- Siniscalco D, Kannan S, Semprún-Hernández N, et al. Stem cell therapy in autism: recent insights. Stem Cells Cloning. 2018;11:55-67.
- Siniscalco D, Bradstreet JJ, Sych N, et al. Mesenchymal stem cells in treating autism: novel insights. World J Stem Cells. 2014;6(2):173-178.
- Siniscalco D, Sapone A, Cirillo A, et al. Autism spectrum disorders: is mesenchymal stem cell personalized therapy the future? J Biomed Biotechnol. 2012; 2012:480289.
- Bradstreet JJ, Sych N, Antonucci N, et al. Efficacy of fetal stem cell transplantation in autism spectrum disorders: an open-labeled pilot study. Cell Transplant. 2014;23(Suppl 1):S105-S112.
- Lv YT, Zhang Y, Liu M, et al. Transplantation of human cord blood mononuclear cells and umbilical cordderived mesenchymal stem cells in autism. J Transl Med. 2013;11:196.
- Vargas DL, Nascimbene C, Krishnan C, et al. Neuroglial activation and neuroinflammation in the brain of patients with autism. Ann Neurol. 2005;57(1):67-81.
- Wei L, Keogh CL, Whitaker VR, et al. Angiogenesis and stem cell transplantation as potential treatments of cerebral ischemic stroke. Pathophysiology. 2005;12(1): 47-62.
- Newman MB, Willing AE, Manresa JJ, et al. Cytokines produced by cultured human umbilical cord blood (HUCB) cells: implications for brain repair. Exp Neurol. 2006;199(1):201-218.
- Peterson DA. Umbilical cord blood cells and brain stroke injury: bringing in fresh blood to address an old problem. J Clin Invest. 2004;114(3):312-314.
- Cohly HH, Panja A. Immunological findings in autism. Int Rev Neurobiol. 2005;71:317-341.
- Ashwood P, Van de Water J. Is autism an autoimmune disease? Autoimmun Rev. 2004;3(7-8):557-562.
- Yagi H, Soto-Gutierrez A, Parekkadan B, et al. Mesenchymal stem cells: mechanisms of immunomodulation and homing. Cell Transplant. 2010;19(6):667-679.
- Vaccarino FM, Urban AE, Stevens HE, et al. Annual Research Review: The promise of stem cell research for neuropsychiatric disorders. J Child Psychol Psychiatry. 2011;52(4):504-516.
- Liu EY, Scott CT. Great expectations: autism spectrum disorder and induced pluripotent stem cell technologies. Stem Cell Rev Rep. 2014;10(2):145-150.
- Richardson-Jones JW, Craige CP, Guiard BP, et al. 5-HT1A autoreceptor levels determine vulnerability to stress and response to antidepressants. Neuron. 2010;65(1):40-52.
- Saarelainen T, Hendolin P, Lucas G, et al. Activation of the TrkB neurotrophin receptor is induced by antidepressant drugs and is required for antidepressant-induced behavioral effects. J Neurosci. 2003;23(1):349-357.
- Klumpers UM, Veltman DJ, Drent ML, et al. Reduced parahippocampal and lateral temporal GABAA-[11C] flumazenil binding in major depression: preliminary results. Eur J Nucl Med Mol Imaging. 2010;37(3): 565-574.
- Bremner JD, Narayan M, Anderson ER, et al. Hippocampal volume reduction in major depression. Am J Psychiatry. 2000;157(1):115-118.
- Bremner JD, Randall P, Scott TM, et al. MRI-based measurement of hippocampal volume in patients with combat-related posttraumatic stress disorder. Am J Psychiatry. 1995;152(7):973-981.
- Vincent SL, Todtenkopf MS, Benes FM. A comparison of the density of pyramidal and non-pyramidal neurons in the anterior cingulate cortex of schizophrenics and manic depressives. Soc Neurosci Abstr. 1997;23:2199.
- Benes FM, Kwok EW, Vincent SL, et al. A reduction of nonpyramidal cells in sector CA2 of schizophrenics and manic depressives. Biol Psychiatry. 1998;44(2): 88-97.
- Ongür D, Drevets WC, Price JL. Glial reduction in the subgenual prefrontal cortex in mood disorders. Proc Natl Acad Sci U S A. 1998;95(22):13290-13295.
- Rajkowska G, Miguel-Hidalgo JJ, Wei J, et al. Morphometric evidence for neuronal and glial prefrontal cell pathology in major depression. Biol Psychiatry. 1999;45(9): 1085-1098.
- Licinio J, Wong ML. Serotonergic neurons derived from induced pluripotent stem cells (iPSCs): a new pathway for research on the biology and pharmacology of major depression. Mol Psychiatry. 2016;21(1):1-2.
- Chen SK, Tvrdik P, Peden E, et al. Hematopoietic origin of pathological grooming in Hoxb8 mutant mice. Cell. 2010;141(5):775-785.
- Israel Y, Ezquer F, Quintanilla ME, et al. Intracerebral stem cell administration inhibits relapse-like alcohol drinking in rats. Alcohol Alcohol. 2017;52(1):1-4.
- Ezquer F, Morales P, Quintanilla ME, et al. Intravenous administration of anti-inflammatory mesenchymal stem cell spheroids reduces chronic alcohol intake and abolishes binge-drinking. Sci Rep. 2018;8(1):4325.
- Scarnati MS, Halikere A, Pang ZP. Using human stem cells as a model system to understand the neural mechanisms of alcohol use disorders: current status and outlook. Alcohol. 2019;74:83-93.
- Yadid GM, Popovtzer R. Nanoparticle-mesenchymal stem cell conjugates for cell therapy in drug addiction. NIH grant application. 2017.
- Xu C, Loh HH, Law PY. Effects of addictive drugs on adult neural stem/progenitor cells. Cell Mol Life Sci. 2016;73(2):327-348.
- Dholakiya SL, Aliberti A, Barile FA. Morphine sulfate concomitantly decreases neuronal differentiation and opioid receptor expression in mouse embryonic stem cells. Toxicol Lett. 2016;247:45-55.
- Zhang Y, Loh HH, Law PY. Effect of opioid on adult hippocampal neurogenesis. Scientific World Journal. 2016;2016:2601264.
- Bortolotto V, Grilli M. Opiate analgesics as negative modulators of adult hippocampal neurogenesis: potential implications in clinical practice. Front Pharmacol. 2017; 8:254.
- Galve-Roperh I, Chiurchiù V, Díaz-Alonso J, et al. Cannabinoid receptor signaling in progenitor/stem cell proliferation and differentiation. Prog Lipid Res. 2013; 52(4):633-650.
- Zimmermann T, Maroso M, Beer A, et al. Neural stem cell lineage-specific cannabinoid type-1 receptor regulates neurogenesis and plasticity in the adult mouse hippocampus. Cereb Cortex. 2018;28(12):4454-4471.
- Ren J, Liu N, Sun N, et al. Mesenchymal stem cells and their exosomes: promising therapies for chronic pain. Curr Stem Cell Res Ther. 2019;14(8):644-653.
Could an oral PCSK9 inhibitor be on the horizon?
The investigational PCSK9 inhibitor that Merck showcased recently would be more than a “me-too” drug if it ultimately wins approval, despite competition from several approved agents that slash elevated cholesterol levels by targeting the same protein.
In fact, it would be something of a breakthrough. The new agent under study – now called MK-0616 – comes in pill form, in contrast to the three currently available PCSK9-lowering drugs that must be given in injections separated by weeks to months.
The drug faces an uncertain road to regulatory review and any approval, but MK-0616 at least seems to be starting out in the right direction.
In two phase 1 studies with a total of 100 participants, plasma PCSK9 levels plunged more than 90% after a single dose of the drug; and low-density-lipoprotein cholesterol (LDL-C) levels dropped about 65% when MK-0616 was given daily for 2 weeks on a background of statin therapy.
Moreover, “MK-0616 was generally well tolerated at up to and including single doses of 300 milligrams,” the maximum tested in the studies, Douglas G. Johns, PhD, reported at the virtual American Heart Association scientific sessions.
The collective results from the oral agent’s earliest human experience are “definitely encouraging” and support MK-0616 as a potential LDL-lowering agent that would be more convenient and arguably more accessible to patients compared to current injectable PCSK9 inhibitors, proposed Dr. Johns, clinical director of translational medicine for Merck in Kenilworth, N.J.
Available PCSK9-targeting agents include alirocumab (Praluent, Sanofi/Regeneron), Food and Drug Administration–approved in July 2015, and evolocumab (Repatha, Amgen), approved by the agency the following month. Both are monoclonal antibodies with neutralizing specificity for the PCSK9 protein; whereas the third such agent, inclisiran (Leqvio, Novartis) is a small-molecule interfering-RNA that suppresses PCSK9 synthesis. Inclisiran is approved in the European Union but its case to the FDA was turned down in 2020.
Dr. Johns said MK-0616 is a cyclic peptide that is “about one-hundredth the size of a monoclonal antibody, but we’re able to achieve monoclonal antibody-like potency and selectivity with this much smaller footprint.”
Added to statin therapy, the current PCSK9-targeting agents reduce LDL-C by an additional one-half or more, and the two antibody-based agents “also decrease atherosclerotic cardiovascular events. They are, however, expensive and not always available, requiring insurance or other approval,” observed Anne C. Goldberg, MD, as invited discussant after Dr. Johns’ presentation.
“They require every 2- to 4-week injections. They’re generally reserved for secondary prevention, and sometimes primary prevention as in familial hypercholesterolemia,” said Dr. Goldberg, of Washington University, St. Louis. Inclisiran, she noted, requires injections every 6 months and has yet to show its mettle in cardiovascular outcomes trials.
“Certainly, an oral form would be easier to use,” she said. “This would be particularly helpful in patients averse to injections,” especially, perhaps, in children. “Children with familial hypercholesterolemia could benefit with greater cholesterol lowering and might be better off with a pill than an injection.” That would be good reason to emphasize the enrollment of children in the drug’s upcoming clinical trials, Dr. Goldberg said.
But cost could potentially become restrictive for MK-0616 as well, should it ever be approved. “If it’s priced too high, then are you really going to see the increased use?” she posed. “Certainly, there’s a high bar for therapies that are add-on to statins in terms of cost effectiveness.”
In the first of the two trials, 60 predominantly White male participants aged 50 or younger were randomly assigned to receive a single dose of MK-0616, at different levels ranging from 10 mg to 300 mg, or placebo. They subsequently crossed over to a different group for a second round of dosing. Both times, three participants took the drug for every one who received placebo.
Participants who took the active drug, regardless of dosage, showed greater than 90% reductions in circulating PCSK9 levels compared to baseline. Six participants discontinued the study before its completion.
In the second trial, 40 White adults aged 65 or younger (mean, 58), including 13 women, with LDL-C of 60 mg/dL to 160 mg/dL (mean, 87 mg/dL) on statin therapy for at least 3 months were randomly assigned 3-to-1 to add-on MK-0616, either 10 mg or 20 mg daily, or placebo for 14 days.
LDL-C levels fell an average of about 65% over the 2 weeks among those taking the active drug; they declined less than 5% for those who took placebo.
There were no deaths or serious adverse events in either trial, Dr. Johns reported. On the other hand, pharmacokinetics studies showed that exposure to the drug fell by “about 50%-60%” when dosing was preceded by food intake within the previous 30 minutes. “However, if a meal is consumed 30 minutes after the dose, this food effect is much, much less prominent, almost negligible.”
These preliminary results show the drug is “orally bioavailable and exerts a clinically meaningful effect,” Dr. Johns said. “However, there’s definitely more to be done. And we are planning the next phase of clinical development, a phase 2 trial, sometime next year.”
The research was funded by Merck. Dr. Johns disclosed employment with and equity ownership in Merck, as did all the study’s coauthors. Dr. Goldberg disclosed holding research contracts through her institution with Regeneron/Sanofi-Aventis, Amarin, Amgen, Pfizer, IONIS/Akcea, Regeneron, Novartis, Arrowroot Pharmaceuticals, and the FH Foundation; and consulting for Novartis, Akcea, Regeneron, and Esperion.
A version of this article first appeared on Medscape.com.
The investigational PCSK9 inhibitor that Merck showcased recently would be more than a “me-too” drug if it ultimately wins approval, despite competition from several approved agents that slash elevated cholesterol levels by targeting the same protein.
In fact, it would be something of a breakthrough. The new agent under study – now called MK-0616 – comes in pill form, in contrast to the three currently available PCSK9-lowering drugs that must be given in injections separated by weeks to months.
The drug faces an uncertain road to regulatory review and any approval, but MK-0616 at least seems to be starting out in the right direction.
In two phase 1 studies with a total of 100 participants, plasma PCSK9 levels plunged more than 90% after a single dose of the drug; and low-density-lipoprotein cholesterol (LDL-C) levels dropped about 65% when MK-0616 was given daily for 2 weeks on a background of statin therapy.
Moreover, “MK-0616 was generally well tolerated at up to and including single doses of 300 milligrams,” the maximum tested in the studies, Douglas G. Johns, PhD, reported at the virtual American Heart Association scientific sessions.
The collective results from the oral agent’s earliest human experience are “definitely encouraging” and support MK-0616 as a potential LDL-lowering agent that would be more convenient and arguably more accessible to patients compared to current injectable PCSK9 inhibitors, proposed Dr. Johns, clinical director of translational medicine for Merck in Kenilworth, N.J.
Available PCSK9-targeting agents include alirocumab (Praluent, Sanofi/Regeneron), Food and Drug Administration–approved in July 2015, and evolocumab (Repatha, Amgen), approved by the agency the following month. Both are monoclonal antibodies with neutralizing specificity for the PCSK9 protein; whereas the third such agent, inclisiran (Leqvio, Novartis) is a small-molecule interfering-RNA that suppresses PCSK9 synthesis. Inclisiran is approved in the European Union but its case to the FDA was turned down in 2020.
Dr. Johns said MK-0616 is a cyclic peptide that is “about one-hundredth the size of a monoclonal antibody, but we’re able to achieve monoclonal antibody-like potency and selectivity with this much smaller footprint.”
Added to statin therapy, the current PCSK9-targeting agents reduce LDL-C by an additional one-half or more, and the two antibody-based agents “also decrease atherosclerotic cardiovascular events. They are, however, expensive and not always available, requiring insurance or other approval,” observed Anne C. Goldberg, MD, as invited discussant after Dr. Johns’ presentation.
“They require every 2- to 4-week injections. They’re generally reserved for secondary prevention, and sometimes primary prevention as in familial hypercholesterolemia,” said Dr. Goldberg, of Washington University, St. Louis. Inclisiran, she noted, requires injections every 6 months and has yet to show its mettle in cardiovascular outcomes trials.
“Certainly, an oral form would be easier to use,” she said. “This would be particularly helpful in patients averse to injections,” especially, perhaps, in children. “Children with familial hypercholesterolemia could benefit with greater cholesterol lowering and might be better off with a pill than an injection.” That would be good reason to emphasize the enrollment of children in the drug’s upcoming clinical trials, Dr. Goldberg said.
But cost could potentially become restrictive for MK-0616 as well, should it ever be approved. “If it’s priced too high, then are you really going to see the increased use?” she posed. “Certainly, there’s a high bar for therapies that are add-on to statins in terms of cost effectiveness.”
In the first of the two trials, 60 predominantly White male participants aged 50 or younger were randomly assigned to receive a single dose of MK-0616, at different levels ranging from 10 mg to 300 mg, or placebo. They subsequently crossed over to a different group for a second round of dosing. Both times, three participants took the drug for every one who received placebo.
Participants who took the active drug, regardless of dosage, showed greater than 90% reductions in circulating PCSK9 levels compared to baseline. Six participants discontinued the study before its completion.
In the second trial, 40 White adults aged 65 or younger (mean, 58), including 13 women, with LDL-C of 60 mg/dL to 160 mg/dL (mean, 87 mg/dL) on statin therapy for at least 3 months were randomly assigned 3-to-1 to add-on MK-0616, either 10 mg or 20 mg daily, or placebo for 14 days.
LDL-C levels fell an average of about 65% over the 2 weeks among those taking the active drug; they declined less than 5% for those who took placebo.
There were no deaths or serious adverse events in either trial, Dr. Johns reported. On the other hand, pharmacokinetics studies showed that exposure to the drug fell by “about 50%-60%” when dosing was preceded by food intake within the previous 30 minutes. “However, if a meal is consumed 30 minutes after the dose, this food effect is much, much less prominent, almost negligible.”
These preliminary results show the drug is “orally bioavailable and exerts a clinically meaningful effect,” Dr. Johns said. “However, there’s definitely more to be done. And we are planning the next phase of clinical development, a phase 2 trial, sometime next year.”
The research was funded by Merck. Dr. Johns disclosed employment with and equity ownership in Merck, as did all the study’s coauthors. Dr. Goldberg disclosed holding research contracts through her institution with Regeneron/Sanofi-Aventis, Amarin, Amgen, Pfizer, IONIS/Akcea, Regeneron, Novartis, Arrowroot Pharmaceuticals, and the FH Foundation; and consulting for Novartis, Akcea, Regeneron, and Esperion.
A version of this article first appeared on Medscape.com.
The investigational PCSK9 inhibitor that Merck showcased recently would be more than a “me-too” drug if it ultimately wins approval, despite competition from several approved agents that slash elevated cholesterol levels by targeting the same protein.
In fact, it would be something of a breakthrough. The new agent under study – now called MK-0616 – comes in pill form, in contrast to the three currently available PCSK9-lowering drugs that must be given in injections separated by weeks to months.
The drug faces an uncertain road to regulatory review and any approval, but MK-0616 at least seems to be starting out in the right direction.
In two phase 1 studies with a total of 100 participants, plasma PCSK9 levels plunged more than 90% after a single dose of the drug; and low-density-lipoprotein cholesterol (LDL-C) levels dropped about 65% when MK-0616 was given daily for 2 weeks on a background of statin therapy.
Moreover, “MK-0616 was generally well tolerated at up to and including single doses of 300 milligrams,” the maximum tested in the studies, Douglas G. Johns, PhD, reported at the virtual American Heart Association scientific sessions.
The collective results from the oral agent’s earliest human experience are “definitely encouraging” and support MK-0616 as a potential LDL-lowering agent that would be more convenient and arguably more accessible to patients compared to current injectable PCSK9 inhibitors, proposed Dr. Johns, clinical director of translational medicine for Merck in Kenilworth, N.J.
Available PCSK9-targeting agents include alirocumab (Praluent, Sanofi/Regeneron), Food and Drug Administration–approved in July 2015, and evolocumab (Repatha, Amgen), approved by the agency the following month. Both are monoclonal antibodies with neutralizing specificity for the PCSK9 protein; whereas the third such agent, inclisiran (Leqvio, Novartis) is a small-molecule interfering-RNA that suppresses PCSK9 synthesis. Inclisiran is approved in the European Union but its case to the FDA was turned down in 2020.
Dr. Johns said MK-0616 is a cyclic peptide that is “about one-hundredth the size of a monoclonal antibody, but we’re able to achieve monoclonal antibody-like potency and selectivity with this much smaller footprint.”
Added to statin therapy, the current PCSK9-targeting agents reduce LDL-C by an additional one-half or more, and the two antibody-based agents “also decrease atherosclerotic cardiovascular events. They are, however, expensive and not always available, requiring insurance or other approval,” observed Anne C. Goldberg, MD, as invited discussant after Dr. Johns’ presentation.
“They require every 2- to 4-week injections. They’re generally reserved for secondary prevention, and sometimes primary prevention as in familial hypercholesterolemia,” said Dr. Goldberg, of Washington University, St. Louis. Inclisiran, she noted, requires injections every 6 months and has yet to show its mettle in cardiovascular outcomes trials.
“Certainly, an oral form would be easier to use,” she said. “This would be particularly helpful in patients averse to injections,” especially, perhaps, in children. “Children with familial hypercholesterolemia could benefit with greater cholesterol lowering and might be better off with a pill than an injection.” That would be good reason to emphasize the enrollment of children in the drug’s upcoming clinical trials, Dr. Goldberg said.
But cost could potentially become restrictive for MK-0616 as well, should it ever be approved. “If it’s priced too high, then are you really going to see the increased use?” she posed. “Certainly, there’s a high bar for therapies that are add-on to statins in terms of cost effectiveness.”
In the first of the two trials, 60 predominantly White male participants aged 50 or younger were randomly assigned to receive a single dose of MK-0616, at different levels ranging from 10 mg to 300 mg, or placebo. They subsequently crossed over to a different group for a second round of dosing. Both times, three participants took the drug for every one who received placebo.
Participants who took the active drug, regardless of dosage, showed greater than 90% reductions in circulating PCSK9 levels compared to baseline. Six participants discontinued the study before its completion.
In the second trial, 40 White adults aged 65 or younger (mean, 58), including 13 women, with LDL-C of 60 mg/dL to 160 mg/dL (mean, 87 mg/dL) on statin therapy for at least 3 months were randomly assigned 3-to-1 to add-on MK-0616, either 10 mg or 20 mg daily, or placebo for 14 days.
LDL-C levels fell an average of about 65% over the 2 weeks among those taking the active drug; they declined less than 5% for those who took placebo.
There were no deaths or serious adverse events in either trial, Dr. Johns reported. On the other hand, pharmacokinetics studies showed that exposure to the drug fell by “about 50%-60%” when dosing was preceded by food intake within the previous 30 minutes. “However, if a meal is consumed 30 minutes after the dose, this food effect is much, much less prominent, almost negligible.”
These preliminary results show the drug is “orally bioavailable and exerts a clinically meaningful effect,” Dr. Johns said. “However, there’s definitely more to be done. And we are planning the next phase of clinical development, a phase 2 trial, sometime next year.”
The research was funded by Merck. Dr. Johns disclosed employment with and equity ownership in Merck, as did all the study’s coauthors. Dr. Goldberg disclosed holding research contracts through her institution with Regeneron/Sanofi-Aventis, Amarin, Amgen, Pfizer, IONIS/Akcea, Regeneron, Novartis, Arrowroot Pharmaceuticals, and the FH Foundation; and consulting for Novartis, Akcea, Regeneron, and Esperion.
A version of this article first appeared on Medscape.com.
FROM AHA 2021
Virtual center boosts liver transplant listings in rural area
A “virtual” liver transplant center servicing Vermont and New Hampshire has improved access to liver transplant listing among patients in rural areas of the region, according to a new analysis.
The virtual center was established in 2016 at Dartmouth Hitchcock Medical Center, and it allows patients to receive pre–liver transplant evaluations, testing, and care and posttransplant follow-up there rather than at the liver transplant center that conducts the surgery. The center includes two hepatologists, two associate care providers, and a nurse liver transplant coordinator at DHMC, and led to increased transplant listing in the vicinity, according to Margaret Liu, MD, who presented the study at the virtual annual meeting of the American Association for the Study of Liver Diseases.
“The initiation of this Virtual Liver Transplant Center has been able to provide patients with the ability to get a full liver transplant workup and evaluation at a center near their home rather than the often time-consuming and costly process of potentially multiple trips to a liver transplant center up to 250 miles away for a full transplant evaluation,” said Dr. Liu in an interview. Dr. Liu is an internal medicine resident at Dartmouth Hitchcock Medical Center.
“Our results did show that the initiation of a virtual liver transplant center correlated with an increased and sustained liver transplant listing rate within 60 miles of Dartmouth over that particular study period. Conversely there was no significant change in the listing rate of New Hampshire zip codes that were within 60 miles of the nearest transplant center during the same study period,” said Dr. Liu.
The center receives referrals of patients who are potential candidates for liver transplant listing from practices throughout New Hampshire and Vermont, or from their own center. Their specialists conduct full testing, including a full liver transplant workup that includes evaluation of the patient’s general health and social factors, prior to sending the patient to the actual liver transplant center for their evaluation and transplant surgery. “We essentially do all of the pre–liver transplant workup, a formal liver transplant evaluation, and then the whole packet gets sent to an actual liver transplant center to expedite the process of getting listed for liver transplant. We’re able to streamline the process, so they get everything done here at a hospital near their home. If that requires multiple trips, it’s a lot more doable for the patients,” said Dr. Liu.
The researchers defined urban areas as having more than 50,000 people per square mile and within 30 miles of the nearest hospital, and rural as fewer than 10,000 and more than 60 miles from the nearest hospital. They used the Scientific Registry of Transplant Recipients to determine the number of liver transplant listings per zip code.
Between 2015 and 2019, the frequency of liver transplant listings per 10,000 people remained nearly unchanged in the metropolitan area of southern New Hampshire, ranging from around 0.36 to 0.75. In the rural area within 60 miles of DHMC, the frequency increased from about 0.7 per 10,000 in 2015 to about 1.4 in 2016 and 0.9 in 2017. There was an increase to nearly 3 in 10,000 in 2018, and the frequency was just over 2 in 2019.
The model has the potential to be used in other areas, according to Dr. Liu. “This could potentially be implemented in other rural areas that do not have a transplant center or don’t have a formal liver transplant evaluation process,” said Dr. Liu.
While other centers may have taken on some aspects of liver transplant evaluation and posttransplant care, the Virtual Liver Transplant Center is unique in that a great deal of effort has gone into covering all of a patient’s needs for the liver transplant evaluation. “It’s really the formalization that, from what I have researched, has not been done before,” said Dr. Liu.
The model addresses transplant-listing disparity, as well as improves patient quality of life through reduction in travel, according to Mayur Brahmania, MD, of Western University, London, Ont., who moderated the session. “They’ve proven that they can get more of their patients listed over the study period, which I think is amazing. The next step, I think, would be about whether getting them onto the transplant list actually made a difference in terms of outcome – looking at their wait list mortality, looking at how many of these patients actually got a liver transplantation. That’s the ultimate outcome,” said Dr. Brahmania.
He also noted the challenge of setting up a virtual center. “You have to have allied health staff – addiction counselors, physical therapists, dietitians, social workers. You need to have the appropriate ancillary services like cardiac testing, pulmonary function testing. It’s quite an endeavor, and if the program isn’t too enthusiastic or doesn’t have a local champion, it’s really hard to get something like this started off. So kudos to them for taking on this challenge and getting this up and running over the last 5 years,” said Dr. Brahmania.
Dr. Liu and Dr. Brahmania have no relevant financial disclosures.
AGA applauds researchers who are working to raise our awareness of health disparities in digestive diseases. AGA is committed to addressing this important societal issue head on. Learn more about AGA’s commitment through the AGA Equity Project.
A “virtual” liver transplant center servicing Vermont and New Hampshire has improved access to liver transplant listing among patients in rural areas of the region, according to a new analysis.
The virtual center was established in 2016 at Dartmouth Hitchcock Medical Center, and it allows patients to receive pre–liver transplant evaluations, testing, and care and posttransplant follow-up there rather than at the liver transplant center that conducts the surgery. The center includes two hepatologists, two associate care providers, and a nurse liver transplant coordinator at DHMC, and led to increased transplant listing in the vicinity, according to Margaret Liu, MD, who presented the study at the virtual annual meeting of the American Association for the Study of Liver Diseases.
“The initiation of this Virtual Liver Transplant Center has been able to provide patients with the ability to get a full liver transplant workup and evaluation at a center near their home rather than the often time-consuming and costly process of potentially multiple trips to a liver transplant center up to 250 miles away for a full transplant evaluation,” said Dr. Liu in an interview. Dr. Liu is an internal medicine resident at Dartmouth Hitchcock Medical Center.
“Our results did show that the initiation of a virtual liver transplant center correlated with an increased and sustained liver transplant listing rate within 60 miles of Dartmouth over that particular study period. Conversely there was no significant change in the listing rate of New Hampshire zip codes that were within 60 miles of the nearest transplant center during the same study period,” said Dr. Liu.
The center receives referrals of patients who are potential candidates for liver transplant listing from practices throughout New Hampshire and Vermont, or from their own center. Their specialists conduct full testing, including a full liver transplant workup that includes evaluation of the patient’s general health and social factors, prior to sending the patient to the actual liver transplant center for their evaluation and transplant surgery. “We essentially do all of the pre–liver transplant workup, a formal liver transplant evaluation, and then the whole packet gets sent to an actual liver transplant center to expedite the process of getting listed for liver transplant. We’re able to streamline the process, so they get everything done here at a hospital near their home. If that requires multiple trips, it’s a lot more doable for the patients,” said Dr. Liu.
The researchers defined urban areas as having more than 50,000 people per square mile and within 30 miles of the nearest hospital, and rural as fewer than 10,000 and more than 60 miles from the nearest hospital. They used the Scientific Registry of Transplant Recipients to determine the number of liver transplant listings per zip code.
Between 2015 and 2019, the frequency of liver transplant listings per 10,000 people remained nearly unchanged in the metropolitan area of southern New Hampshire, ranging from around 0.36 to 0.75. In the rural area within 60 miles of DHMC, the frequency increased from about 0.7 per 10,000 in 2015 to about 1.4 in 2016 and 0.9 in 2017. There was an increase to nearly 3 in 10,000 in 2018, and the frequency was just over 2 in 2019.
The model has the potential to be used in other areas, according to Dr. Liu. “This could potentially be implemented in other rural areas that do not have a transplant center or don’t have a formal liver transplant evaluation process,” said Dr. Liu.
While other centers may have taken on some aspects of liver transplant evaluation and posttransplant care, the Virtual Liver Transplant Center is unique in that a great deal of effort has gone into covering all of a patient’s needs for the liver transplant evaluation. “It’s really the formalization that, from what I have researched, has not been done before,” said Dr. Liu.
The model addresses transplant-listing disparity, as well as improves patient quality of life through reduction in travel, according to Mayur Brahmania, MD, of Western University, London, Ont., who moderated the session. “They’ve proven that they can get more of their patients listed over the study period, which I think is amazing. The next step, I think, would be about whether getting them onto the transplant list actually made a difference in terms of outcome – looking at their wait list mortality, looking at how many of these patients actually got a liver transplantation. That’s the ultimate outcome,” said Dr. Brahmania.
He also noted the challenge of setting up a virtual center. “You have to have allied health staff – addiction counselors, physical therapists, dietitians, social workers. You need to have the appropriate ancillary services like cardiac testing, pulmonary function testing. It’s quite an endeavor, and if the program isn’t too enthusiastic or doesn’t have a local champion, it’s really hard to get something like this started off. So kudos to them for taking on this challenge and getting this up and running over the last 5 years,” said Dr. Brahmania.
Dr. Liu and Dr. Brahmania have no relevant financial disclosures.
AGA applauds researchers who are working to raise our awareness of health disparities in digestive diseases. AGA is committed to addressing this important societal issue head on. Learn more about AGA’s commitment through the AGA Equity Project.
A “virtual” liver transplant center servicing Vermont and New Hampshire has improved access to liver transplant listing among patients in rural areas of the region, according to a new analysis.
The virtual center was established in 2016 at Dartmouth Hitchcock Medical Center, and it allows patients to receive pre–liver transplant evaluations, testing, and care and posttransplant follow-up there rather than at the liver transplant center that conducts the surgery. The center includes two hepatologists, two associate care providers, and a nurse liver transplant coordinator at DHMC, and led to increased transplant listing in the vicinity, according to Margaret Liu, MD, who presented the study at the virtual annual meeting of the American Association for the Study of Liver Diseases.
“The initiation of this Virtual Liver Transplant Center has been able to provide patients with the ability to get a full liver transplant workup and evaluation at a center near their home rather than the often time-consuming and costly process of potentially multiple trips to a liver transplant center up to 250 miles away for a full transplant evaluation,” said Dr. Liu in an interview. Dr. Liu is an internal medicine resident at Dartmouth Hitchcock Medical Center.
“Our results did show that the initiation of a virtual liver transplant center correlated with an increased and sustained liver transplant listing rate within 60 miles of Dartmouth over that particular study period. Conversely there was no significant change in the listing rate of New Hampshire zip codes that were within 60 miles of the nearest transplant center during the same study period,” said Dr. Liu.
The center receives referrals of patients who are potential candidates for liver transplant listing from practices throughout New Hampshire and Vermont, or from their own center. Their specialists conduct full testing, including a full liver transplant workup that includes evaluation of the patient’s general health and social factors, prior to sending the patient to the actual liver transplant center for their evaluation and transplant surgery. “We essentially do all of the pre–liver transplant workup, a formal liver transplant evaluation, and then the whole packet gets sent to an actual liver transplant center to expedite the process of getting listed for liver transplant. We’re able to streamline the process, so they get everything done here at a hospital near their home. If that requires multiple trips, it’s a lot more doable for the patients,” said Dr. Liu.
The researchers defined urban areas as having more than 50,000 people per square mile and within 30 miles of the nearest hospital, and rural as fewer than 10,000 and more than 60 miles from the nearest hospital. They used the Scientific Registry of Transplant Recipients to determine the number of liver transplant listings per zip code.
Between 2015 and 2019, the frequency of liver transplant listings per 10,000 people remained nearly unchanged in the metropolitan area of southern New Hampshire, ranging from around 0.36 to 0.75. In the rural area within 60 miles of DHMC, the frequency increased from about 0.7 per 10,000 in 2015 to about 1.4 in 2016 and 0.9 in 2017. There was an increase to nearly 3 in 10,000 in 2018, and the frequency was just over 2 in 2019.
The model has the potential to be used in other areas, according to Dr. Liu. “This could potentially be implemented in other rural areas that do not have a transplant center or don’t have a formal liver transplant evaluation process,” said Dr. Liu.
While other centers may have taken on some aspects of liver transplant evaluation and posttransplant care, the Virtual Liver Transplant Center is unique in that a great deal of effort has gone into covering all of a patient’s needs for the liver transplant evaluation. “It’s really the formalization that, from what I have researched, has not been done before,” said Dr. Liu.
The model addresses transplant-listing disparity, as well as improves patient quality of life through reduction in travel, according to Mayur Brahmania, MD, of Western University, London, Ont., who moderated the session. “They’ve proven that they can get more of their patients listed over the study period, which I think is amazing. The next step, I think, would be about whether getting them onto the transplant list actually made a difference in terms of outcome – looking at their wait list mortality, looking at how many of these patients actually got a liver transplantation. That’s the ultimate outcome,” said Dr. Brahmania.
He also noted the challenge of setting up a virtual center. “You have to have allied health staff – addiction counselors, physical therapists, dietitians, social workers. You need to have the appropriate ancillary services like cardiac testing, pulmonary function testing. It’s quite an endeavor, and if the program isn’t too enthusiastic or doesn’t have a local champion, it’s really hard to get something like this started off. So kudos to them for taking on this challenge and getting this up and running over the last 5 years,” said Dr. Brahmania.
Dr. Liu and Dr. Brahmania have no relevant financial disclosures.
AGA applauds researchers who are working to raise our awareness of health disparities in digestive diseases. AGA is committed to addressing this important societal issue head on. Learn more about AGA’s commitment through the AGA Equity Project.
FROM THE LIVER MEETING
Infectious disease pop quiz: Clinical challenge #4 for the ObGyn
What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?
Continue to the answer...
Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.
- Duff P. Maternal and perinatal infections: bacterial. In: Landon MB, Galan HL, Jauniaux ERM, et al. Gabbe’s Obstetrics: Normal and Problem Pregnancies. 8th ed. Elsevier; 2021:1124-1146.
- Duff P. Maternal and fetal infections. In: Resnik R, Lockwood CJ, Moore TJ, et al. Creasy & Resnik’s Maternal-Fetal Medicine: Principles and Practice. 8th ed. Elsevier; 2019:862-919.
What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?
Continue to the answer...
Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.
What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?
Continue to the answer...
Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.
- Duff P. Maternal and perinatal infections: bacterial. In: Landon MB, Galan HL, Jauniaux ERM, et al. Gabbe’s Obstetrics: Normal and Problem Pregnancies. 8th ed. Elsevier; 2021:1124-1146.
- Duff P. Maternal and fetal infections. In: Resnik R, Lockwood CJ, Moore TJ, et al. Creasy & Resnik’s Maternal-Fetal Medicine: Principles and Practice. 8th ed. Elsevier; 2019:862-919.
- Duff P. Maternal and perinatal infections: bacterial. In: Landon MB, Galan HL, Jauniaux ERM, et al. Gabbe’s Obstetrics: Normal and Problem Pregnancies. 8th ed. Elsevier; 2021:1124-1146.
- Duff P. Maternal and fetal infections. In: Resnik R, Lockwood CJ, Moore TJ, et al. Creasy & Resnik’s Maternal-Fetal Medicine: Principles and Practice. 8th ed. Elsevier; 2019:862-919.
Infectious disease pop quiz: Clinical challenge #3 for the ObGyn
What are the major complications of pyelonephritis in pregnancy?
Continue to the answer...
Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.
- Duff P. Maternal and perinatal infections: bacterial. In: Landon MB, Galan HL, Jauniaux ERM, et al. Gabbe’s Obstetrics: Normal and Problem Pregnancies. 8th ed. Elsevier; 2021:1124-1146.
- Duff P. Maternal and fetal infections. In: Resnik R, Lockwood CJ, Moore TJ, et al. Creasy & Resnik’s Maternal-Fetal Medicine: Principles and Practice. 8th ed. Elsevier; 2019:862-919.
What are the major complications of pyelonephritis in pregnancy?
Continue to the answer...
Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.
What are the major complications of pyelonephritis in pregnancy?
Continue to the answer...
Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.
- Duff P. Maternal and perinatal infections: bacterial. In: Landon MB, Galan HL, Jauniaux ERM, et al. Gabbe’s Obstetrics: Normal and Problem Pregnancies. 8th ed. Elsevier; 2021:1124-1146.
- Duff P. Maternal and fetal infections. In: Resnik R, Lockwood CJ, Moore TJ, et al. Creasy & Resnik’s Maternal-Fetal Medicine: Principles and Practice. 8th ed. Elsevier; 2019:862-919.
- Duff P. Maternal and perinatal infections: bacterial. In: Landon MB, Galan HL, Jauniaux ERM, et al. Gabbe’s Obstetrics: Normal and Problem Pregnancies. 8th ed. Elsevier; 2021:1124-1146.
- Duff P. Maternal and fetal infections. In: Resnik R, Lockwood CJ, Moore TJ, et al. Creasy & Resnik’s Maternal-Fetal Medicine: Principles and Practice. 8th ed. Elsevier; 2019:862-919.
FDA approves imaging drug for detecting ovarian cancer lesions
The new drug “is designed to improve the ability to locate additional ovarian cancerous tissue that is normally difficult to detect during surgery,” according to the agency.
Pafolacianine, administered via intravenous injection prior to surgery, is the first FDA-approved tumor-targeted fluorescent agent for ovarian cancer.
In a press statement, drug inventor Philip Low, PhD, of Purdue University in West Lafayette, Ind., said the agent causes ovarian cancer lesions to “light up like stars against a night sky.”
Improving detection of ovarian cancer lesions is critical given that ovarian cancer is one of the “deadliest of all female reproductive system cancers,” according to the American Cancer Society. The organization estimates that there will be more than 21,000 new cases and more than 13,000 deaths in 2021.
Currently, surgeons use preoperative imaging as well as visual inspection of tumors under normal light and examination by touch to identify ovarian cancer lesions.
Pafolacianine offers a new tool to enhance surgeons’ ability “to identify deadly ovarian tumors that may otherwise go undetected,” Alex Gorovets, MD, deputy director of the office of specialty medicine in the FDA’s Center for Drug Evaluation and Research, said in a press statement.
Ovarian cancer often causes the body to overproduce the folate receptor protein in cell membranes. Pafolacianine, employed with a near-infrared fluorescence imaging system cleared by the FDA for use alongside the drug, binds to and illuminates these proteins under fluorescent light, “boosting surgeons’ ability to identify the cancerous tissue,” the agency in a statement.
The safety and effectiveness of pafolacianine was evaluated in a randomized, multi-center, open-label study of women diagnosed with ovarian cancer or with high clinical suspicion of ovarian cancer. Of the 134 women undergoing surgery who received a dose of pafolacianine and were evaluated under both normal and fluorescent light, 26.9% had at least one cancerous lesion detected that was not observed by standard visual or tactile inspection.
The most common side effects of pafolacianine were infusion-related reactions, including nausea, vomiting, abdominal pain, flushing, dyspepsia, chest discomfort, itching, and hypersensitivity.
Pafolacianine may cause fetal harm when administered to a pregnant woman. The use of folate, folic acid, or folate-containing supplements should be avoided within 48 hours before administration of pafolacianine.
The FDA also cautioned about the possible risk of image interpretation errors, including false negatives and false positives, with the use of the new drug and near-infrared fluorescence imaging system.
The FDA previously granted pafolacianine orphan-drug, priority, and fast track designations.
A version of this article first appeared on Medscape.com.
The new drug “is designed to improve the ability to locate additional ovarian cancerous tissue that is normally difficult to detect during surgery,” according to the agency.
Pafolacianine, administered via intravenous injection prior to surgery, is the first FDA-approved tumor-targeted fluorescent agent for ovarian cancer.
In a press statement, drug inventor Philip Low, PhD, of Purdue University in West Lafayette, Ind., said the agent causes ovarian cancer lesions to “light up like stars against a night sky.”
Improving detection of ovarian cancer lesions is critical given that ovarian cancer is one of the “deadliest of all female reproductive system cancers,” according to the American Cancer Society. The organization estimates that there will be more than 21,000 new cases and more than 13,000 deaths in 2021.
Currently, surgeons use preoperative imaging as well as visual inspection of tumors under normal light and examination by touch to identify ovarian cancer lesions.
Pafolacianine offers a new tool to enhance surgeons’ ability “to identify deadly ovarian tumors that may otherwise go undetected,” Alex Gorovets, MD, deputy director of the office of specialty medicine in the FDA’s Center for Drug Evaluation and Research, said in a press statement.
Ovarian cancer often causes the body to overproduce the folate receptor protein in cell membranes. Pafolacianine, employed with a near-infrared fluorescence imaging system cleared by the FDA for use alongside the drug, binds to and illuminates these proteins under fluorescent light, “boosting surgeons’ ability to identify the cancerous tissue,” the agency in a statement.
The safety and effectiveness of pafolacianine was evaluated in a randomized, multi-center, open-label study of women diagnosed with ovarian cancer or with high clinical suspicion of ovarian cancer. Of the 134 women undergoing surgery who received a dose of pafolacianine and were evaluated under both normal and fluorescent light, 26.9% had at least one cancerous lesion detected that was not observed by standard visual or tactile inspection.
The most common side effects of pafolacianine were infusion-related reactions, including nausea, vomiting, abdominal pain, flushing, dyspepsia, chest discomfort, itching, and hypersensitivity.
Pafolacianine may cause fetal harm when administered to a pregnant woman. The use of folate, folic acid, or folate-containing supplements should be avoided within 48 hours before administration of pafolacianine.
The FDA also cautioned about the possible risk of image interpretation errors, including false negatives and false positives, with the use of the new drug and near-infrared fluorescence imaging system.
The FDA previously granted pafolacianine orphan-drug, priority, and fast track designations.
A version of this article first appeared on Medscape.com.
The new drug “is designed to improve the ability to locate additional ovarian cancerous tissue that is normally difficult to detect during surgery,” according to the agency.
Pafolacianine, administered via intravenous injection prior to surgery, is the first FDA-approved tumor-targeted fluorescent agent for ovarian cancer.
In a press statement, drug inventor Philip Low, PhD, of Purdue University in West Lafayette, Ind., said the agent causes ovarian cancer lesions to “light up like stars against a night sky.”
Improving detection of ovarian cancer lesions is critical given that ovarian cancer is one of the “deadliest of all female reproductive system cancers,” according to the American Cancer Society. The organization estimates that there will be more than 21,000 new cases and more than 13,000 deaths in 2021.
Currently, surgeons use preoperative imaging as well as visual inspection of tumors under normal light and examination by touch to identify ovarian cancer lesions.
Pafolacianine offers a new tool to enhance surgeons’ ability “to identify deadly ovarian tumors that may otherwise go undetected,” Alex Gorovets, MD, deputy director of the office of specialty medicine in the FDA’s Center for Drug Evaluation and Research, said in a press statement.
Ovarian cancer often causes the body to overproduce the folate receptor protein in cell membranes. Pafolacianine, employed with a near-infrared fluorescence imaging system cleared by the FDA for use alongside the drug, binds to and illuminates these proteins under fluorescent light, “boosting surgeons’ ability to identify the cancerous tissue,” the agency in a statement.
The safety and effectiveness of pafolacianine was evaluated in a randomized, multi-center, open-label study of women diagnosed with ovarian cancer or with high clinical suspicion of ovarian cancer. Of the 134 women undergoing surgery who received a dose of pafolacianine and were evaluated under both normal and fluorescent light, 26.9% had at least one cancerous lesion detected that was not observed by standard visual or tactile inspection.
The most common side effects of pafolacianine were infusion-related reactions, including nausea, vomiting, abdominal pain, flushing, dyspepsia, chest discomfort, itching, and hypersensitivity.
Pafolacianine may cause fetal harm when administered to a pregnant woman. The use of folate, folic acid, or folate-containing supplements should be avoided within 48 hours before administration of pafolacianine.
The FDA also cautioned about the possible risk of image interpretation errors, including false negatives and false positives, with the use of the new drug and near-infrared fluorescence imaging system.
The FDA previously granted pafolacianine orphan-drug, priority, and fast track designations.
A version of this article first appeared on Medscape.com.
Microbleeds, age contribute to ARIA risk with aducanumab
Though primary efficacy results have yet to be published,
Amyloid-related imaging abnormalities, or ARIA, have been seen linked to a variety of experimental amyloid-lowering treatments for Alzheimer’s disease. The abnormalities include brain bleeding (ARIA-H) and brain edema (ARIA-E), detected on magnetic resonance imaging.
Safety findings
In a study published Nov. 22 in JAMA Neurology, Stephen Salloway, MD, director of neurology and the memory and aging program at Butler Hospital and the Martin M. Zucker Professor of Psychiatry and Human Behavior and Professor of Neurology at the Warren Alpert Medical School of Brown University in Providence, R.I., and his colleagues, reported that 41% of 1,029 patients in the high-dose (10 mg/kg) treatment groups of aducanumab (Aduhelm, Biogen) developed ARIA.
Thirty-five percent of the high-dose patients (n = 362) developed ARIA-E, and 94 had symptoms, with headache the most commonly reported, followed by confusion. ARIA-E occurred only sporadically in the placebo groups, while ARIA-H was more common. Microbleeds were seen in 19% of the high-dose patients compared with 6.6% in the placebo group, while superficial siderosis occurred in about 15%, versus 2.2% on placebo. Most of the ARIA-E events occurred during the first eight doses of the infusion treatment. People with one or more copies of the APOE4 genetic variant saw higher risk of ARIA-E associated with treatment compared with noncarriers (hazard ratio [HR] 2.5; 95% confidence interval [CI], 1.90-3.20). Evidence of brain micro-hemorrhages at baseline was associated with higher risk of ARIA-E (HR 1.7; 95% CI, 1.31-2.27) compared with patients without MRI evidence of brain bleeds in the year before treatment began.
Older age independently increased risk of ARIA-H, with a risk that was seen increasing 6% with each additional year of age.
The identically designed EMERGE and ENGAGE trials of aducanumab enrolled nearly 3,300 patients worldwide (mean age 70.4, 52% female). Participants were screened to include only those with amyloid-positive mild cognitive impairment (81% of the cohort) or mild Alzheimer’s dementia. Both trials were halted early after a futility analysis concluded that treatment was unlikely to result in benefit.
A post hoc analysis later determined that patients in one trial, EMERGE, showed slight clinical benefit on follow-up in the high-dose group only. The Food and Drug Administration approved the drug in July 2021 on the basis of that finding, overriding the consensus of its independent advisory committee, which was not persuaded. Since then the drug has become synonymous with controversy, not aided by its high list price of more than $50,000 per year, with many insurers and large health care systems refusing to deliver it. The recent reported death of a woman participating in an open-label extension trial of aducanumab, who was admitted to the hospital with brain swelling, has added to safety concerns.
Brain bleeds and age affect risk
In an interview with MDedge Neurology, neurologist Madhav Thambisetty, MD, PhD, a senior investigator with the National Institute on Aging in Baltimore, and a member of the FDA advisory committee that recommended against approval for aducanumab, said that while physicians are aware that APOE4 carriers face higher risks of treatment-related complications, the new safety findings offer additional guidance on patient selection.
“The older you are the greater your risk of ARIA, and the more micro-hemorrhages you have at baseline the greater your risk. Those are important findings that were not previously well publicized before,” Dr. Thambisetty said.
In the EMERGE and ENGAGE trials, Dr. Thambisetty pointed out, patients with four or more micro-hemorrhages at baseline were excluded. The new findings reveal that even a small number of bleeds at baseline can contribute to ARIA risk.
“Patients in real-world clinical practice are going to be very different from the tightly controlled, well-screened participants who were enrolled in these trials. Microbleeds are very common in Alzheimer’s patients, occurring in 18-32%. Now that these findings are available, it’s important for a practicing physician to obtain a baseline MRI scan and really pay attention to microbleeds, because that will affect treatment decisions.”
Additional concerns
Dr. Thambisetty cautioned that the new results made no mention of another important safety outcome: loss of brain volume associated with treatment.
Changes in brain volume have been seen associated with other amyloid-lowering treatments, though the reasons for this are poorly understood. Participants in EMERGE and ENGAGE “received numerous MRI scans,” Dr. Thambisetty said. “This was one of the strengths of the trials. Thanks to an open-label extension we now have more than 2 years of MRI data from meticulously monitored patients, and there has been no mention of brain volume changes despite this being a prespecified outcome. This, for me, is one of the glaring omissions of this paper, and the fact that it’s not even mentioned is really worrisome.”
The sponsor of the aducanumab trials, Biogen, has yet to publish efficacy findings in a peer-reviewed journal, instead presenting them piecemeal at conferences.
“The current paper was a secondary analysis,” Dr. Thambisetty said. “The authors say the primary analysis will be published elsewhere. I think it’s important to reflect upon the fact that these clinical trials enrolled more than 3,000 participants at more than 300 trial centers in 20 countries. We now have an approved drug that’s commercially available. And yet we don’t have a single peer-reviewed publication discussing the efficacy data. None of this is in the interest of our patients, or in advancing the science.”
The EMERGE and ENGAGE trials were funded by Biogen. Eight of the current paper’s 14 authors are Biogen employees. Dr. Salloway, the lead author, disclosed financial support from Biogen and other manufacturers, as did two of his coauthors. Dr. Thambisetty disclosed no financial conflicts of interest.
Though primary efficacy results have yet to be published,
Amyloid-related imaging abnormalities, or ARIA, have been seen linked to a variety of experimental amyloid-lowering treatments for Alzheimer’s disease. The abnormalities include brain bleeding (ARIA-H) and brain edema (ARIA-E), detected on magnetic resonance imaging.
Safety findings
In a study published Nov. 22 in JAMA Neurology, Stephen Salloway, MD, director of neurology and the memory and aging program at Butler Hospital and the Martin M. Zucker Professor of Psychiatry and Human Behavior and Professor of Neurology at the Warren Alpert Medical School of Brown University in Providence, R.I., and his colleagues, reported that 41% of 1,029 patients in the high-dose (10 mg/kg) treatment groups of aducanumab (Aduhelm, Biogen) developed ARIA.
Thirty-five percent of the high-dose patients (n = 362) developed ARIA-E, and 94 had symptoms, with headache the most commonly reported, followed by confusion. ARIA-E occurred only sporadically in the placebo groups, while ARIA-H was more common. Microbleeds were seen in 19% of the high-dose patients compared with 6.6% in the placebo group, while superficial siderosis occurred in about 15%, versus 2.2% on placebo. Most of the ARIA-E events occurred during the first eight doses of the infusion treatment. People with one or more copies of the APOE4 genetic variant saw higher risk of ARIA-E associated with treatment compared with noncarriers (hazard ratio [HR] 2.5; 95% confidence interval [CI], 1.90-3.20). Evidence of brain micro-hemorrhages at baseline was associated with higher risk of ARIA-E (HR 1.7; 95% CI, 1.31-2.27) compared with patients without MRI evidence of brain bleeds in the year before treatment began.
Older age independently increased risk of ARIA-H, with a risk that was seen increasing 6% with each additional year of age.
The identically designed EMERGE and ENGAGE trials of aducanumab enrolled nearly 3,300 patients worldwide (mean age 70.4, 52% female). Participants were screened to include only those with amyloid-positive mild cognitive impairment (81% of the cohort) or mild Alzheimer’s dementia. Both trials were halted early after a futility analysis concluded that treatment was unlikely to result in benefit.
A post hoc analysis later determined that patients in one trial, EMERGE, showed slight clinical benefit on follow-up in the high-dose group only. The Food and Drug Administration approved the drug in July 2021 on the basis of that finding, overriding the consensus of its independent advisory committee, which was not persuaded. Since then the drug has become synonymous with controversy, not aided by its high list price of more than $50,000 per year, with many insurers and large health care systems refusing to deliver it. The recent reported death of a woman participating in an open-label extension trial of aducanumab, who was admitted to the hospital with brain swelling, has added to safety concerns.
Brain bleeds and age affect risk
In an interview with MDedge Neurology, neurologist Madhav Thambisetty, MD, PhD, a senior investigator with the National Institute on Aging in Baltimore, and a member of the FDA advisory committee that recommended against approval for aducanumab, said that while physicians are aware that APOE4 carriers face higher risks of treatment-related complications, the new safety findings offer additional guidance on patient selection.
“The older you are the greater your risk of ARIA, and the more micro-hemorrhages you have at baseline the greater your risk. Those are important findings that were not previously well publicized before,” Dr. Thambisetty said.
In the EMERGE and ENGAGE trials, Dr. Thambisetty pointed out, patients with four or more micro-hemorrhages at baseline were excluded. The new findings reveal that even a small number of bleeds at baseline can contribute to ARIA risk.
“Patients in real-world clinical practice are going to be very different from the tightly controlled, well-screened participants who were enrolled in these trials. Microbleeds are very common in Alzheimer’s patients, occurring in 18-32%. Now that these findings are available, it’s important for a practicing physician to obtain a baseline MRI scan and really pay attention to microbleeds, because that will affect treatment decisions.”
Additional concerns
Dr. Thambisetty cautioned that the new results made no mention of another important safety outcome: loss of brain volume associated with treatment.
Changes in brain volume have been seen associated with other amyloid-lowering treatments, though the reasons for this are poorly understood. Participants in EMERGE and ENGAGE “received numerous MRI scans,” Dr. Thambisetty said. “This was one of the strengths of the trials. Thanks to an open-label extension we now have more than 2 years of MRI data from meticulously monitored patients, and there has been no mention of brain volume changes despite this being a prespecified outcome. This, for me, is one of the glaring omissions of this paper, and the fact that it’s not even mentioned is really worrisome.”
The sponsor of the aducanumab trials, Biogen, has yet to publish efficacy findings in a peer-reviewed journal, instead presenting them piecemeal at conferences.
“The current paper was a secondary analysis,” Dr. Thambisetty said. “The authors say the primary analysis will be published elsewhere. I think it’s important to reflect upon the fact that these clinical trials enrolled more than 3,000 participants at more than 300 trial centers in 20 countries. We now have an approved drug that’s commercially available. And yet we don’t have a single peer-reviewed publication discussing the efficacy data. None of this is in the interest of our patients, or in advancing the science.”
The EMERGE and ENGAGE trials were funded by Biogen. Eight of the current paper’s 14 authors are Biogen employees. Dr. Salloway, the lead author, disclosed financial support from Biogen and other manufacturers, as did two of his coauthors. Dr. Thambisetty disclosed no financial conflicts of interest.
Though primary efficacy results have yet to be published,
Amyloid-related imaging abnormalities, or ARIA, have been seen linked to a variety of experimental amyloid-lowering treatments for Alzheimer’s disease. The abnormalities include brain bleeding (ARIA-H) and brain edema (ARIA-E), detected on magnetic resonance imaging.
Safety findings
In a study published Nov. 22 in JAMA Neurology, Stephen Salloway, MD, director of neurology and the memory and aging program at Butler Hospital and the Martin M. Zucker Professor of Psychiatry and Human Behavior and Professor of Neurology at the Warren Alpert Medical School of Brown University in Providence, R.I., and his colleagues, reported that 41% of 1,029 patients in the high-dose (10 mg/kg) treatment groups of aducanumab (Aduhelm, Biogen) developed ARIA.
Thirty-five percent of the high-dose patients (n = 362) developed ARIA-E, and 94 had symptoms, with headache the most commonly reported, followed by confusion. ARIA-E occurred only sporadically in the placebo groups, while ARIA-H was more common. Microbleeds were seen in 19% of the high-dose patients compared with 6.6% in the placebo group, while superficial siderosis occurred in about 15%, versus 2.2% on placebo. Most of the ARIA-E events occurred during the first eight doses of the infusion treatment. People with one or more copies of the APOE4 genetic variant saw higher risk of ARIA-E associated with treatment compared with noncarriers (hazard ratio [HR] 2.5; 95% confidence interval [CI], 1.90-3.20). Evidence of brain micro-hemorrhages at baseline was associated with higher risk of ARIA-E (HR 1.7; 95% CI, 1.31-2.27) compared with patients without MRI evidence of brain bleeds in the year before treatment began.
Older age independently increased risk of ARIA-H, with a risk that was seen increasing 6% with each additional year of age.
The identically designed EMERGE and ENGAGE trials of aducanumab enrolled nearly 3,300 patients worldwide (mean age 70.4, 52% female). Participants were screened to include only those with amyloid-positive mild cognitive impairment (81% of the cohort) or mild Alzheimer’s dementia. Both trials were halted early after a futility analysis concluded that treatment was unlikely to result in benefit.
A post hoc analysis later determined that patients in one trial, EMERGE, showed slight clinical benefit on follow-up in the high-dose group only. The Food and Drug Administration approved the drug in July 2021 on the basis of that finding, overriding the consensus of its independent advisory committee, which was not persuaded. Since then the drug has become synonymous with controversy, not aided by its high list price of more than $50,000 per year, with many insurers and large health care systems refusing to deliver it. The recent reported death of a woman participating in an open-label extension trial of aducanumab, who was admitted to the hospital with brain swelling, has added to safety concerns.
Brain bleeds and age affect risk
In an interview with MDedge Neurology, neurologist Madhav Thambisetty, MD, PhD, a senior investigator with the National Institute on Aging in Baltimore, and a member of the FDA advisory committee that recommended against approval for aducanumab, said that while physicians are aware that APOE4 carriers face higher risks of treatment-related complications, the new safety findings offer additional guidance on patient selection.
“The older you are the greater your risk of ARIA, and the more micro-hemorrhages you have at baseline the greater your risk. Those are important findings that were not previously well publicized before,” Dr. Thambisetty said.
In the EMERGE and ENGAGE trials, Dr. Thambisetty pointed out, patients with four or more micro-hemorrhages at baseline were excluded. The new findings reveal that even a small number of bleeds at baseline can contribute to ARIA risk.
“Patients in real-world clinical practice are going to be very different from the tightly controlled, well-screened participants who were enrolled in these trials. Microbleeds are very common in Alzheimer’s patients, occurring in 18-32%. Now that these findings are available, it’s important for a practicing physician to obtain a baseline MRI scan and really pay attention to microbleeds, because that will affect treatment decisions.”
Additional concerns
Dr. Thambisetty cautioned that the new results made no mention of another important safety outcome: loss of brain volume associated with treatment.
Changes in brain volume have been seen associated with other amyloid-lowering treatments, though the reasons for this are poorly understood. Participants in EMERGE and ENGAGE “received numerous MRI scans,” Dr. Thambisetty said. “This was one of the strengths of the trials. Thanks to an open-label extension we now have more than 2 years of MRI data from meticulously monitored patients, and there has been no mention of brain volume changes despite this being a prespecified outcome. This, for me, is one of the glaring omissions of this paper, and the fact that it’s not even mentioned is really worrisome.”
The sponsor of the aducanumab trials, Biogen, has yet to publish efficacy findings in a peer-reviewed journal, instead presenting them piecemeal at conferences.
“The current paper was a secondary analysis,” Dr. Thambisetty said. “The authors say the primary analysis will be published elsewhere. I think it’s important to reflect upon the fact that these clinical trials enrolled more than 3,000 participants at more than 300 trial centers in 20 countries. We now have an approved drug that’s commercially available. And yet we don’t have a single peer-reviewed publication discussing the efficacy data. None of this is in the interest of our patients, or in advancing the science.”
The EMERGE and ENGAGE trials were funded by Biogen. Eight of the current paper’s 14 authors are Biogen employees. Dr. Salloway, the lead author, disclosed financial support from Biogen and other manufacturers, as did two of his coauthors. Dr. Thambisetty disclosed no financial conflicts of interest.
FROM JAMA NEUROLOGY
Ulcerative colitis: Donor-derived strains predict response in FMT
The Odoribacter splanchnicus strain of human donor-derived bacteria correlated with clinical response to ulcerative colitis in study in which mouse models were colonized with patient-derived strains.
Although some recent trials have shown the effectiveness of fecal microbiota transplantation (FMT) for patients with ulcerative colitis (UC), the current process is limited by the used of crude donor fecal material, which increases the risk of infection and decreases potential effectiveness, Svetlana Lima, MD, of Weill Cornell Medicine, New York, and colleagues wrote.
“Rational selection and production of specific microbial strains or communities could improve efficacy, minimize the risk of adverse reactions as well as increase the acceptance of microbiome-based therapies,” the researchers wrote.
In a study published in Gastroenterology, the researchers used metagenomic analysis and IgA sequencing (for sorting and sequencing IgA-coated microbiota) to identify a core of transferable and IgA-coated microbiota. They conducted metagenomic sequencing on 60 stool samples, including 20 recipient-participants with active UC who were treated with FMT, and another 20 FMT recipients with data from 4 weeks after FMT from a previously reported trial.
The core transferable microbiota (CTM) included 22 species of bacteria at 4 weeks after FMT. To determine a relationship between CTM and clinical response to FMT, the researchers defined clinical response as a decrease in Mayo score of 3 or greater with a rectal bleeding score of 1 or less by 4 weeks after FMT; 35% of study participants met this endpoint.* A total of 20 species were unique to the responders. “Of the donor-derived genera, only the relative abundance of Odoribacter at [week 4] post FMT and its increase post FMT was found to significantly correlate with decrease in Mayo score,” the researchers noted.
The researchers then colonized germ-free or genetically engineered mice with patient-derived bacterial strains.
O. splanchnicus also increased induction of interleukin-10, and increased the production of short-chain fatty acids. Taken together, these factors allowed for O. splanchnicus to limit colitis in the mice.
The study findings represent the first strain-level analysis of FMT in UC participants, and define a transferable microbiota associated with clinical response that could serve as a prognostic biomarker, the researchers noted in their discussion section. Although analysis revealed 12 donor-derived bacterial species that predicted clinical response, further IgA analysis identified O. splanchnicus as “the only microbe within the responders core that correlates with clinical response and highlights the potential impact of this taxa seen in independent cohorts, as well as mouse models of colitis and colorectal cancer,” the researchers emphasized.
The study findings were limited by the small sample size and the lack of prospective data. However, “collectively, this work provides the first evidence of transferable, donor-derived strains that correlate with clinical response to FMT in UC and reveals O. splanchnicus as a key component, which mechanistically promotes protection through both cellular and metabolic function,” the researchers said. “These mechanistic features will help enable desperately needed strategies to enhance therapeutic efficacy of microbial therapy for UC.”
Study strains improve effectiveness
“There is an accumulating body of evidence that suggests that gut dysbiosis, or the imbalance between good and bad microbes, plays an important role in the pathogenesis and progression of ulcerative colitis,” Jeffrey Berinstein, MD, of the University of Michigan, Ann Arbor, said in an interview. “It is for this reason that therapeutic manipulation of gut microbiota with fecal microbiota transplant is being explored as a potential treatment option for UC. FMT has demonstrated promise for ulcerative colitis, however little is known about the specific microbiota strains contributing to this observed improvement. In this study, the authors aimed to better understand the mechanisms and the specific strains in FMT contributing to this observed improvement, which is an important step toward improving efficacy and minimizing the risk of adverse events related to FMT in the future.”
Dr. Berinstein was surprised that O. splanchnicus was the only microbe identified that correlated with clinical response. “Previous studies have suggested that microbial diversity is a key factor in successful response to FMT,” he noted. “FMT remains an important potential nonpharmacologic treatment strategy for ulcerative colitis, however more research is needed to understand the mechanism and to develop safer and more efficacious methods for delivering FMT.” Specifically, prospective studies are needed to explore the efficacy and safety of FMT enriched in strains of O. splanchnicus to confirm the current study findings.
The current study is important at this time because, although microbial transferability has emerged as a potential to treat IBD, “the mechanistic understanding of microbial transferability and engraftment has been lacking,” Atsushi Sakuraba, MD, PhD of the University of Chicago, said in an interview. “I was surprised that the effectiveness of FMT in UC could be narrowed down to O. splanchnicus.” The current take-home message for clinicians is that, although FMT currently uses crude donor fecal material, it may soon use more selected microbial strains. However, “whether transfer of O. splanchnicus alone or enriched fecal material provide improved efficacy and safety need to be analyzed,” he added.
The study was supported by Boehringer Ingelheim, the National Institutes of Health, the Kenneth Rainin Foundation, and the Charina Foundation. One coauthor disclosed grant support from Boehringer Ingelheim for this study, and several coauthors are employees of Boehringer Ingelheim. Neither Dr. Berinstein nor Dr. Sakuraba had no financial conflicts to disclose.
This article was updated Dec. 1, 2021.
*Correction, 4/11/22: An earlier version of this article misstated the definition of clinical response.
The Odoribacter splanchnicus strain of human donor-derived bacteria correlated with clinical response to ulcerative colitis in study in which mouse models were colonized with patient-derived strains.
Although some recent trials have shown the effectiveness of fecal microbiota transplantation (FMT) for patients with ulcerative colitis (UC), the current process is limited by the used of crude donor fecal material, which increases the risk of infection and decreases potential effectiveness, Svetlana Lima, MD, of Weill Cornell Medicine, New York, and colleagues wrote.
“Rational selection and production of specific microbial strains or communities could improve efficacy, minimize the risk of adverse reactions as well as increase the acceptance of microbiome-based therapies,” the researchers wrote.
In a study published in Gastroenterology, the researchers used metagenomic analysis and IgA sequencing (for sorting and sequencing IgA-coated microbiota) to identify a core of transferable and IgA-coated microbiota. They conducted metagenomic sequencing on 60 stool samples, including 20 recipient-participants with active UC who were treated with FMT, and another 20 FMT recipients with data from 4 weeks after FMT from a previously reported trial.
The core transferable microbiota (CTM) included 22 species of bacteria at 4 weeks after FMT. To determine a relationship between CTM and clinical response to FMT, the researchers defined clinical response as a decrease in Mayo score of 3 or greater with a rectal bleeding score of 1 or less by 4 weeks after FMT; 35% of study participants met this endpoint.* A total of 20 species were unique to the responders. “Of the donor-derived genera, only the relative abundance of Odoribacter at [week 4] post FMT and its increase post FMT was found to significantly correlate with decrease in Mayo score,” the researchers noted.
The researchers then colonized germ-free or genetically engineered mice with patient-derived bacterial strains.
O. splanchnicus also increased induction of interleukin-10, and increased the production of short-chain fatty acids. Taken together, these factors allowed for O. splanchnicus to limit colitis in the mice.
The study findings represent the first strain-level analysis of FMT in UC participants, and define a transferable microbiota associated with clinical response that could serve as a prognostic biomarker, the researchers noted in their discussion section. Although analysis revealed 12 donor-derived bacterial species that predicted clinical response, further IgA analysis identified O. splanchnicus as “the only microbe within the responders core that correlates with clinical response and highlights the potential impact of this taxa seen in independent cohorts, as well as mouse models of colitis and colorectal cancer,” the researchers emphasized.
The study findings were limited by the small sample size and the lack of prospective data. However, “collectively, this work provides the first evidence of transferable, donor-derived strains that correlate with clinical response to FMT in UC and reveals O. splanchnicus as a key component, which mechanistically promotes protection through both cellular and metabolic function,” the researchers said. “These mechanistic features will help enable desperately needed strategies to enhance therapeutic efficacy of microbial therapy for UC.”
Study strains improve effectiveness
“There is an accumulating body of evidence that suggests that gut dysbiosis, or the imbalance between good and bad microbes, plays an important role in the pathogenesis and progression of ulcerative colitis,” Jeffrey Berinstein, MD, of the University of Michigan, Ann Arbor, said in an interview. “It is for this reason that therapeutic manipulation of gut microbiota with fecal microbiota transplant is being explored as a potential treatment option for UC. FMT has demonstrated promise for ulcerative colitis, however little is known about the specific microbiota strains contributing to this observed improvement. In this study, the authors aimed to better understand the mechanisms and the specific strains in FMT contributing to this observed improvement, which is an important step toward improving efficacy and minimizing the risk of adverse events related to FMT in the future.”
Dr. Berinstein was surprised that O. splanchnicus was the only microbe identified that correlated with clinical response. “Previous studies have suggested that microbial diversity is a key factor in successful response to FMT,” he noted. “FMT remains an important potential nonpharmacologic treatment strategy for ulcerative colitis, however more research is needed to understand the mechanism and to develop safer and more efficacious methods for delivering FMT.” Specifically, prospective studies are needed to explore the efficacy and safety of FMT enriched in strains of O. splanchnicus to confirm the current study findings.
The current study is important at this time because, although microbial transferability has emerged as a potential to treat IBD, “the mechanistic understanding of microbial transferability and engraftment has been lacking,” Atsushi Sakuraba, MD, PhD of the University of Chicago, said in an interview. “I was surprised that the effectiveness of FMT in UC could be narrowed down to O. splanchnicus.” The current take-home message for clinicians is that, although FMT currently uses crude donor fecal material, it may soon use more selected microbial strains. However, “whether transfer of O. splanchnicus alone or enriched fecal material provide improved efficacy and safety need to be analyzed,” he added.
The study was supported by Boehringer Ingelheim, the National Institutes of Health, the Kenneth Rainin Foundation, and the Charina Foundation. One coauthor disclosed grant support from Boehringer Ingelheim for this study, and several coauthors are employees of Boehringer Ingelheim. Neither Dr. Berinstein nor Dr. Sakuraba had no financial conflicts to disclose.
This article was updated Dec. 1, 2021.
*Correction, 4/11/22: An earlier version of this article misstated the definition of clinical response.
The Odoribacter splanchnicus strain of human donor-derived bacteria correlated with clinical response to ulcerative colitis in study in which mouse models were colonized with patient-derived strains.
Although some recent trials have shown the effectiveness of fecal microbiota transplantation (FMT) for patients with ulcerative colitis (UC), the current process is limited by the used of crude donor fecal material, which increases the risk of infection and decreases potential effectiveness, Svetlana Lima, MD, of Weill Cornell Medicine, New York, and colleagues wrote.
“Rational selection and production of specific microbial strains or communities could improve efficacy, minimize the risk of adverse reactions as well as increase the acceptance of microbiome-based therapies,” the researchers wrote.
In a study published in Gastroenterology, the researchers used metagenomic analysis and IgA sequencing (for sorting and sequencing IgA-coated microbiota) to identify a core of transferable and IgA-coated microbiota. They conducted metagenomic sequencing on 60 stool samples, including 20 recipient-participants with active UC who were treated with FMT, and another 20 FMT recipients with data from 4 weeks after FMT from a previously reported trial.
The core transferable microbiota (CTM) included 22 species of bacteria at 4 weeks after FMT. To determine a relationship between CTM and clinical response to FMT, the researchers defined clinical response as a decrease in Mayo score of 3 or greater with a rectal bleeding score of 1 or less by 4 weeks after FMT; 35% of study participants met this endpoint.* A total of 20 species were unique to the responders. “Of the donor-derived genera, only the relative abundance of Odoribacter at [week 4] post FMT and its increase post FMT was found to significantly correlate with decrease in Mayo score,” the researchers noted.
The researchers then colonized germ-free or genetically engineered mice with patient-derived bacterial strains.
O. splanchnicus also increased induction of interleukin-10, and increased the production of short-chain fatty acids. Taken together, these factors allowed for O. splanchnicus to limit colitis in the mice.
The study findings represent the first strain-level analysis of FMT in UC participants, and define a transferable microbiota associated with clinical response that could serve as a prognostic biomarker, the researchers noted in their discussion section. Although analysis revealed 12 donor-derived bacterial species that predicted clinical response, further IgA analysis identified O. splanchnicus as “the only microbe within the responders core that correlates with clinical response and highlights the potential impact of this taxa seen in independent cohorts, as well as mouse models of colitis and colorectal cancer,” the researchers emphasized.
The study findings were limited by the small sample size and the lack of prospective data. However, “collectively, this work provides the first evidence of transferable, donor-derived strains that correlate with clinical response to FMT in UC and reveals O. splanchnicus as a key component, which mechanistically promotes protection through both cellular and metabolic function,” the researchers said. “These mechanistic features will help enable desperately needed strategies to enhance therapeutic efficacy of microbial therapy for UC.”
Study strains improve effectiveness
“There is an accumulating body of evidence that suggests that gut dysbiosis, or the imbalance between good and bad microbes, plays an important role in the pathogenesis and progression of ulcerative colitis,” Jeffrey Berinstein, MD, of the University of Michigan, Ann Arbor, said in an interview. “It is for this reason that therapeutic manipulation of gut microbiota with fecal microbiota transplant is being explored as a potential treatment option for UC. FMT has demonstrated promise for ulcerative colitis, however little is known about the specific microbiota strains contributing to this observed improvement. In this study, the authors aimed to better understand the mechanisms and the specific strains in FMT contributing to this observed improvement, which is an important step toward improving efficacy and minimizing the risk of adverse events related to FMT in the future.”
Dr. Berinstein was surprised that O. splanchnicus was the only microbe identified that correlated with clinical response. “Previous studies have suggested that microbial diversity is a key factor in successful response to FMT,” he noted. “FMT remains an important potential nonpharmacologic treatment strategy for ulcerative colitis, however more research is needed to understand the mechanism and to develop safer and more efficacious methods for delivering FMT.” Specifically, prospective studies are needed to explore the efficacy and safety of FMT enriched in strains of O. splanchnicus to confirm the current study findings.
The current study is important at this time because, although microbial transferability has emerged as a potential to treat IBD, “the mechanistic understanding of microbial transferability and engraftment has been lacking,” Atsushi Sakuraba, MD, PhD of the University of Chicago, said in an interview. “I was surprised that the effectiveness of FMT in UC could be narrowed down to O. splanchnicus.” The current take-home message for clinicians is that, although FMT currently uses crude donor fecal material, it may soon use more selected microbial strains. However, “whether transfer of O. splanchnicus alone or enriched fecal material provide improved efficacy and safety need to be analyzed,” he added.
The study was supported by Boehringer Ingelheim, the National Institutes of Health, the Kenneth Rainin Foundation, and the Charina Foundation. One coauthor disclosed grant support from Boehringer Ingelheim for this study, and several coauthors are employees of Boehringer Ingelheim. Neither Dr. Berinstein nor Dr. Sakuraba had no financial conflicts to disclose.
This article was updated Dec. 1, 2021.
*Correction, 4/11/22: An earlier version of this article misstated the definition of clinical response.
FROM GASTROENTEROLOGY
We physicians must pull together as a knowledge community
The COVID-19 pandemic is a biosocial phenomenon. Patients and doctors alike find themselves assigned to groups designated as responsible and wise, or selfish and irrational, based strictly upon their personal assessments of medical risk. This trend in our culture is represented by threats of disciplinary action issued by medical regulators against physicians who are perceived to be undermining the public health message by spreading “misinformation.”
Our review of the literature reveals many references to “misinformation” but no definition narrow and precise enough to be interpreted consistently in a disciplinary environment. More pressing, this ambiguous word’s use is correlated with negative meaning and innuendo, often discrediting valuable information a priori without actual data points.
The most basic definition available is Merriam Webster’s: “incorrect or misleading information.” This definition includes no point of reference against which competing scientific claims can be measured.
Claudia E. Haupt, PhD, a political scientist and law professor, articulates a useful framework for understanding the relationship between medicine and state regulators. In the Yale Law Journal, Dr. Haupt wrote: “Knowledge communities have specialized expertise and are closest to those affected; they must have the freedom to work things out for themselves. The professions as knowledge communities have a fundamental interest in not having the state (or anyone else, for that matter) corrupt or distort what amounts to the state of the art in their respective fields.”
Injecting the artificial term “misinformation” into the science information ecosystem obfuscates and impedes the very ability of this vital knowledge community to perform its raison d’être. , rather than attending to healing or promoting progress.
Time has certainly shown us that science is anything but settled on all things COVID. If the scientific community accepts disrespect as the response of choice to difference of opinion and practice, we lose the trust in one another as colleagues; we need to keep scientific inquiry and exploration alive. Curiosity, equanimity, and tolerance are key components of the professional attitude as we deftly maneuver against the virus together.
In the face of deadly disease, it is especially imperative that intelligent, thoughtful, highly respected scientists, researchers, and physicians have room to safely share their knowledge and clinical experience. The Association of American Physicians and Surgeons has published a statement on scientific integrity that can be used as a measuring stick for claims about misinformation in medicine. We call on physicians to pull together as a knowledge community. Kindness and respect for patients starts with kindness and respect for one another as colleagues.
Dr. Kohanski is in private practice in Somerset, N.J., and is a diplomate of the American Board of Psychiatry & Neurology. She disclosed no relevant financial relationships. Dr. Emmons is part-time clinical associate professor in the department of psychiatry at the University of Vermont, Burlington, and is a past chair of the Ethics Committee for the Vermont District Branch of the American Psychiatric Association. He is in private practice in Moretown, Vt., and disclosed no relevant financial relationships.
The COVID-19 pandemic is a biosocial phenomenon. Patients and doctors alike find themselves assigned to groups designated as responsible and wise, or selfish and irrational, based strictly upon their personal assessments of medical risk. This trend in our culture is represented by threats of disciplinary action issued by medical regulators against physicians who are perceived to be undermining the public health message by spreading “misinformation.”
Our review of the literature reveals many references to “misinformation” but no definition narrow and precise enough to be interpreted consistently in a disciplinary environment. More pressing, this ambiguous word’s use is correlated with negative meaning and innuendo, often discrediting valuable information a priori without actual data points.
The most basic definition available is Merriam Webster’s: “incorrect or misleading information.” This definition includes no point of reference against which competing scientific claims can be measured.
Claudia E. Haupt, PhD, a political scientist and law professor, articulates a useful framework for understanding the relationship between medicine and state regulators. In the Yale Law Journal, Dr. Haupt wrote: “Knowledge communities have specialized expertise and are closest to those affected; they must have the freedom to work things out for themselves. The professions as knowledge communities have a fundamental interest in not having the state (or anyone else, for that matter) corrupt or distort what amounts to the state of the art in their respective fields.”
Injecting the artificial term “misinformation” into the science information ecosystem obfuscates and impedes the very ability of this vital knowledge community to perform its raison d’être. , rather than attending to healing or promoting progress.
Time has certainly shown us that science is anything but settled on all things COVID. If the scientific community accepts disrespect as the response of choice to difference of opinion and practice, we lose the trust in one another as colleagues; we need to keep scientific inquiry and exploration alive. Curiosity, equanimity, and tolerance are key components of the professional attitude as we deftly maneuver against the virus together.
In the face of deadly disease, it is especially imperative that intelligent, thoughtful, highly respected scientists, researchers, and physicians have room to safely share their knowledge and clinical experience. The Association of American Physicians and Surgeons has published a statement on scientific integrity that can be used as a measuring stick for claims about misinformation in medicine. We call on physicians to pull together as a knowledge community. Kindness and respect for patients starts with kindness and respect for one another as colleagues.
Dr. Kohanski is in private practice in Somerset, N.J., and is a diplomate of the American Board of Psychiatry & Neurology. She disclosed no relevant financial relationships. Dr. Emmons is part-time clinical associate professor in the department of psychiatry at the University of Vermont, Burlington, and is a past chair of the Ethics Committee for the Vermont District Branch of the American Psychiatric Association. He is in private practice in Moretown, Vt., and disclosed no relevant financial relationships.
The COVID-19 pandemic is a biosocial phenomenon. Patients and doctors alike find themselves assigned to groups designated as responsible and wise, or selfish and irrational, based strictly upon their personal assessments of medical risk. This trend in our culture is represented by threats of disciplinary action issued by medical regulators against physicians who are perceived to be undermining the public health message by spreading “misinformation.”
Our review of the literature reveals many references to “misinformation” but no definition narrow and precise enough to be interpreted consistently in a disciplinary environment. More pressing, this ambiguous word’s use is correlated with negative meaning and innuendo, often discrediting valuable information a priori without actual data points.
The most basic definition available is Merriam Webster’s: “incorrect or misleading information.” This definition includes no point of reference against which competing scientific claims can be measured.
Claudia E. Haupt, PhD, a political scientist and law professor, articulates a useful framework for understanding the relationship between medicine and state regulators. In the Yale Law Journal, Dr. Haupt wrote: “Knowledge communities have specialized expertise and are closest to those affected; they must have the freedom to work things out for themselves. The professions as knowledge communities have a fundamental interest in not having the state (or anyone else, for that matter) corrupt or distort what amounts to the state of the art in their respective fields.”
Injecting the artificial term “misinformation” into the science information ecosystem obfuscates and impedes the very ability of this vital knowledge community to perform its raison d’être. , rather than attending to healing or promoting progress.
Time has certainly shown us that science is anything but settled on all things COVID. If the scientific community accepts disrespect as the response of choice to difference of opinion and practice, we lose the trust in one another as colleagues; we need to keep scientific inquiry and exploration alive. Curiosity, equanimity, and tolerance are key components of the professional attitude as we deftly maneuver against the virus together.
In the face of deadly disease, it is especially imperative that intelligent, thoughtful, highly respected scientists, researchers, and physicians have room to safely share their knowledge and clinical experience. The Association of American Physicians and Surgeons has published a statement on scientific integrity that can be used as a measuring stick for claims about misinformation in medicine. We call on physicians to pull together as a knowledge community. Kindness and respect for patients starts with kindness and respect for one another as colleagues.
Dr. Kohanski is in private practice in Somerset, N.J., and is a diplomate of the American Board of Psychiatry & Neurology. She disclosed no relevant financial relationships. Dr. Emmons is part-time clinical associate professor in the department of psychiatry at the University of Vermont, Burlington, and is a past chair of the Ethics Committee for the Vermont District Branch of the American Psychiatric Association. He is in private practice in Moretown, Vt., and disclosed no relevant financial relationships.
NAFLD, ALD prevalent among teens, young adults
Two-fifths of adolescents and young adults in the United States may have nonalcoholic fatty liver disease (NAFLD), many with significant or advanced fibrosis, results of a nationwide surveillance study suggest.
In addition, among those who drink alcohol in excess, slightly more than half may have alcohol-associated fatty liver disease (ALD) that may lead to moderate to severe fibrosis in a substantial proportion, said Naim Alkhouri, MD, from Arizona Liver Health, Peoria, during a presentation of the findings at The Liver Meeting 2021: American Association for the Study of Liver Diseases (AASLD), held online.
“Efforts should focus on increasing awareness of the burden of ALD and NAFLD in this population and [mitigating] modifiable risk factors to prevent disease development and disease progression to potentially advanced fibrosis and cirrhosis,” he said.
Liver stiffness measured
Unlike previous studies that relied on liver enzyme levels or ultrasonography to estimate the prevalence of fatty liver disease among adolescents and young adults in the United States, Dr. Alkhouri and colleagues used valid liver ultrasonographic elastography (FibroScan) measurements, recorded during 2017-2018, from the National Health and Nutrition Examination Survey (NHANES) database.
The sample included participants aged 15 to 39 years. Those with viral hepatitis, alanine aminotransferase (ALT) levels greater than 500 U/L, or pregnancy were excluded.
The investigators divided the participants into those with excessive alcohol consumption, defined using the NHANES Alcohol Use Questionnaire as having more than two drinks per day for males or more than one drink per day for females, and those with no excessive alcohol consumption.
The authors used controlled attenuation parameters to identify participants with suspected ALD or NAFLD.
They then used liver stiffness measurement cutoffs of greater than or equal to 7.5 kPa to identify moderate fibrosis and greater than or equal to 9.5 kPa to identify severe fibrosis in those with evidence of ALD and cutoffs of greater than or equal to 6.1 kPa and greater than or equal to 7.1 kPa, respectively, in those with suspected NAFLD.
The cutoffs were chosen to maximize sensitivity, as determined from published literature, Dr. Alkhouri said.
Uncovering a high prevalence of ALD and NAFLD
The final sample comprised 1,319 participants, including 100 with excessive alcohol use and 1,219 without.
The heavy drinkers were significantly more likely to be older, male, White, current smokers, have lower platelet counts, higher aspartate aminotransferase (AST) and ALT levels, and higher mean corpuscular volumes.
Among the excessive drinkers, 52% had ALD. Of this group, 87.7% had either no or mild fibrosis, and 12.3% had moderate to severe fibrosis.
Among patients with excessive alcohol consumption, significant predictors of ALD included male sex, higher body mass index, ALT greater than the upper limit of normal, and higher A1c percentage.
Among those who were moderate drinkers or abstemious, 40% had NAFLD. Of this subgroup, 68.9% had no or mild fibrosis, and 31.1% had moderate to severe fibrosis.
Predictors of NAFLD in this group included older age, male sex, higher body mass index, and elevated ALT, AST, albumin, platelet counts, and A1c.
Is drinking underreported?
In a question-and-answer session following the presentation, co-moderator Miriam B. Vos, MD, a pediatric hepatologist at Children’s Healthcare of Atlanta, asked Dr. Alkhouri about his confidence in the accuracy of the measurements of alcohol consumption and whether there could be significant overlap between the ALD and NAFLD populations.
Dr. Alkhouri noted that he and his colleagues relied on items 121 and 130 of the NHANES Alcohol Use Questionnaire, which are self-reported by participants.
“Obviously, we’re not going to get honest answers all the time,” he said. “We’ve seen even in NASH [nonalcoholic steatohepatitis] clinical trials that when patients say they do not drink any alcohol, if you actually look for alcohol metabolites, up to 20% may have some evidence of alcohol consumption.
“I’m sure there’s a lot of overlap, but there’s no formal assessment,” he added.
Dr. Alkhouri noted that among the cohort with ALD, obesity and increased A1c were prevalent, “so it goes both ways. I think NAFLD can also contribute to progression of ALD, and that’s why we need to study another entity called ‘both alcoholic and nonalcoholic fatty liver disease.’”
Dr. Vos suggested that biomarkers may be useful for detecting alcohol use among patients with NAFLD and for further study of the progression of NAFLD to ALD.
No source of funding for the study has been disclosed. Dr. Alkhouri and Dr. Vos reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.
Two-fifths of adolescents and young adults in the United States may have nonalcoholic fatty liver disease (NAFLD), many with significant or advanced fibrosis, results of a nationwide surveillance study suggest.
In addition, among those who drink alcohol in excess, slightly more than half may have alcohol-associated fatty liver disease (ALD) that may lead to moderate to severe fibrosis in a substantial proportion, said Naim Alkhouri, MD, from Arizona Liver Health, Peoria, during a presentation of the findings at The Liver Meeting 2021: American Association for the Study of Liver Diseases (AASLD), held online.
“Efforts should focus on increasing awareness of the burden of ALD and NAFLD in this population and [mitigating] modifiable risk factors to prevent disease development and disease progression to potentially advanced fibrosis and cirrhosis,” he said.
Liver stiffness measured
Unlike previous studies that relied on liver enzyme levels or ultrasonography to estimate the prevalence of fatty liver disease among adolescents and young adults in the United States, Dr. Alkhouri and colleagues used valid liver ultrasonographic elastography (FibroScan) measurements, recorded during 2017-2018, from the National Health and Nutrition Examination Survey (NHANES) database.
The sample included participants aged 15 to 39 years. Those with viral hepatitis, alanine aminotransferase (ALT) levels greater than 500 U/L, or pregnancy were excluded.
The investigators divided the participants into those with excessive alcohol consumption, defined using the NHANES Alcohol Use Questionnaire as having more than two drinks per day for males or more than one drink per day for females, and those with no excessive alcohol consumption.
The authors used controlled attenuation parameters to identify participants with suspected ALD or NAFLD.
They then used liver stiffness measurement cutoffs of greater than or equal to 7.5 kPa to identify moderate fibrosis and greater than or equal to 9.5 kPa to identify severe fibrosis in those with evidence of ALD and cutoffs of greater than or equal to 6.1 kPa and greater than or equal to 7.1 kPa, respectively, in those with suspected NAFLD.
The cutoffs were chosen to maximize sensitivity, as determined from published literature, Dr. Alkhouri said.
Uncovering a high prevalence of ALD and NAFLD
The final sample comprised 1,319 participants, including 100 with excessive alcohol use and 1,219 without.
The heavy drinkers were significantly more likely to be older, male, White, current smokers, have lower platelet counts, higher aspartate aminotransferase (AST) and ALT levels, and higher mean corpuscular volumes.
Among the excessive drinkers, 52% had ALD. Of this group, 87.7% had either no or mild fibrosis, and 12.3% had moderate to severe fibrosis.
Among patients with excessive alcohol consumption, significant predictors of ALD included male sex, higher body mass index, ALT greater than the upper limit of normal, and higher A1c percentage.
Among those who were moderate drinkers or abstemious, 40% had NAFLD. Of this subgroup, 68.9% had no or mild fibrosis, and 31.1% had moderate to severe fibrosis.
Predictors of NAFLD in this group included older age, male sex, higher body mass index, and elevated ALT, AST, albumin, platelet counts, and A1c.
Is drinking underreported?
In a question-and-answer session following the presentation, co-moderator Miriam B. Vos, MD, a pediatric hepatologist at Children’s Healthcare of Atlanta, asked Dr. Alkhouri about his confidence in the accuracy of the measurements of alcohol consumption and whether there could be significant overlap between the ALD and NAFLD populations.
Dr. Alkhouri noted that he and his colleagues relied on items 121 and 130 of the NHANES Alcohol Use Questionnaire, which are self-reported by participants.
“Obviously, we’re not going to get honest answers all the time,” he said. “We’ve seen even in NASH [nonalcoholic steatohepatitis] clinical trials that when patients say they do not drink any alcohol, if you actually look for alcohol metabolites, up to 20% may have some evidence of alcohol consumption.
“I’m sure there’s a lot of overlap, but there’s no formal assessment,” he added.
Dr. Alkhouri noted that among the cohort with ALD, obesity and increased A1c were prevalent, “so it goes both ways. I think NAFLD can also contribute to progression of ALD, and that’s why we need to study another entity called ‘both alcoholic and nonalcoholic fatty liver disease.’”
Dr. Vos suggested that biomarkers may be useful for detecting alcohol use among patients with NAFLD and for further study of the progression of NAFLD to ALD.
No source of funding for the study has been disclosed. Dr. Alkhouri and Dr. Vos reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.
Two-fifths of adolescents and young adults in the United States may have nonalcoholic fatty liver disease (NAFLD), many with significant or advanced fibrosis, results of a nationwide surveillance study suggest.
In addition, among those who drink alcohol in excess, slightly more than half may have alcohol-associated fatty liver disease (ALD) that may lead to moderate to severe fibrosis in a substantial proportion, said Naim Alkhouri, MD, from Arizona Liver Health, Peoria, during a presentation of the findings at The Liver Meeting 2021: American Association for the Study of Liver Diseases (AASLD), held online.
“Efforts should focus on increasing awareness of the burden of ALD and NAFLD in this population and [mitigating] modifiable risk factors to prevent disease development and disease progression to potentially advanced fibrosis and cirrhosis,” he said.
Liver stiffness measured
Unlike previous studies that relied on liver enzyme levels or ultrasonography to estimate the prevalence of fatty liver disease among adolescents and young adults in the United States, Dr. Alkhouri and colleagues used valid liver ultrasonographic elastography (FibroScan) measurements, recorded during 2017-2018, from the National Health and Nutrition Examination Survey (NHANES) database.
The sample included participants aged 15 to 39 years. Those with viral hepatitis, alanine aminotransferase (ALT) levels greater than 500 U/L, or pregnancy were excluded.
The investigators divided the participants into those with excessive alcohol consumption, defined using the NHANES Alcohol Use Questionnaire as having more than two drinks per day for males or more than one drink per day for females, and those with no excessive alcohol consumption.
The authors used controlled attenuation parameters to identify participants with suspected ALD or NAFLD.
They then used liver stiffness measurement cutoffs of greater than or equal to 7.5 kPa to identify moderate fibrosis and greater than or equal to 9.5 kPa to identify severe fibrosis in those with evidence of ALD and cutoffs of greater than or equal to 6.1 kPa and greater than or equal to 7.1 kPa, respectively, in those with suspected NAFLD.
The cutoffs were chosen to maximize sensitivity, as determined from published literature, Dr. Alkhouri said.
Uncovering a high prevalence of ALD and NAFLD
The final sample comprised 1,319 participants, including 100 with excessive alcohol use and 1,219 without.
The heavy drinkers were significantly more likely to be older, male, White, current smokers, have lower platelet counts, higher aspartate aminotransferase (AST) and ALT levels, and higher mean corpuscular volumes.
Among the excessive drinkers, 52% had ALD. Of this group, 87.7% had either no or mild fibrosis, and 12.3% had moderate to severe fibrosis.
Among patients with excessive alcohol consumption, significant predictors of ALD included male sex, higher body mass index, ALT greater than the upper limit of normal, and higher A1c percentage.
Among those who were moderate drinkers or abstemious, 40% had NAFLD. Of this subgroup, 68.9% had no or mild fibrosis, and 31.1% had moderate to severe fibrosis.
Predictors of NAFLD in this group included older age, male sex, higher body mass index, and elevated ALT, AST, albumin, platelet counts, and A1c.
Is drinking underreported?
In a question-and-answer session following the presentation, co-moderator Miriam B. Vos, MD, a pediatric hepatologist at Children’s Healthcare of Atlanta, asked Dr. Alkhouri about his confidence in the accuracy of the measurements of alcohol consumption and whether there could be significant overlap between the ALD and NAFLD populations.
Dr. Alkhouri noted that he and his colleagues relied on items 121 and 130 of the NHANES Alcohol Use Questionnaire, which are self-reported by participants.
“Obviously, we’re not going to get honest answers all the time,” he said. “We’ve seen even in NASH [nonalcoholic steatohepatitis] clinical trials that when patients say they do not drink any alcohol, if you actually look for alcohol metabolites, up to 20% may have some evidence of alcohol consumption.
“I’m sure there’s a lot of overlap, but there’s no formal assessment,” he added.
Dr. Alkhouri noted that among the cohort with ALD, obesity and increased A1c were prevalent, “so it goes both ways. I think NAFLD can also contribute to progression of ALD, and that’s why we need to study another entity called ‘both alcoholic and nonalcoholic fatty liver disease.’”
Dr. Vos suggested that biomarkers may be useful for detecting alcohol use among patients with NAFLD and for further study of the progression of NAFLD to ALD.
No source of funding for the study has been disclosed. Dr. Alkhouri and Dr. Vos reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.