A 31-year-old woman is referred by her Ob-Gyn for elevated prolactin. She initially presented with a three-month history of amenorrhea, a negative home pregnancy test, and 100% compliance with condom use. She denies hirsutism and acne but admits to thin milky nipple discharge upon squeezing (but not spontaneous).

Two weeks ago, her Ob-Gyn ordered labs; results were negative for serum beta human chorionic gonadotropin and within normal ranges for thyroid-stimulating hormone (TSH), luteinizing hormone, follicle-stimulating hormone, estradiol, free and total testosterone, dehydroepiandrosterone sulfate (DHEAs), complete chemistry panel, and complete blood count. Her serum prolactin level was 110 ng/mL (normal, 3 to 27 ng/mL).

Q: How is prolactin physiologically regulated?

The primary role of prolactin, which is produced by lactotroph cells in the anterior pituitary gland, is to stimulate lactation and breast development. Prolactin is regulated by dopamine (also known as prolactin inhibitory hormone), which is secreted from the hypothalamus via an inhibitory pathway unique to the hypothalamus-pituitary hormone system. Dopamine essentially suppresses prolactin.

Other hormones can have a stimulatory effect on the anterior pituitary gland and thus increase prolactin levels. Estrogen can induce lactotroph hyperplasia and elevated prolactin; however, this is only clinically relevant in the context of estrogen surge during pregnancy. (Estrogen therapy, such as oral contraception or hormone replacement therapy, on the other hand, is targeted to “normal” estrogen levels.) Thyrotropin-releasing hormone (TRH) from the hypothalamus also stimulates the anterior pituitary gland, so patients with inadequately treated or untreated primary hypothyroidism will have mildly elevated prolactin.

Neurogenic stimuli of the chest wall, through nipple suckling or varicella zoster infection (shingles), can also increase prolactin secretion. And since prolactin is eliminated by the liver (75%) and the kidney (25%), significant liver disease and/or renal insufficiency can raise prolactin levels, due to decreased clearance.

What are the possible etiologies for elevated prolactin? See answer on the next page... 

Q: What are the possible etiologies for elevated prolactin?

The causes of hyperprolactinemia fall into three categories: physiologic, pharmacologic, and pathologic.²  The table provides examples from each category.

A nonsecretory pituitary adenoma or any lesion in the brain that would disrupt the hypophyseal stalk may interfere with dopamine’s inhibitory control and thereby increase prolactin. This is called the stalk effect. It is ­important to note that not all MRI-proven pituitary adenomas are prolactin secreting, even in the presence of hyperprolactinemia. According to an autopsy series, about 12% of the general population had pituitary microadenoma.³

There is rough correlation between prolactinoma size and level of prolactin. Large nonsecretory pituitary adenomas have prolactin levels less than 150 ng/mL. Microprolactinomas (< 1 cm) are usually in the range of 100 to 250 ng/mL, while macroprolactinomas (> 1 cm) are generally
≥ 250 ng/mL. If the tumor is very large and invades the cavernous sinus, prolactin can measure in the 1,000s.³

Polycystic ovarian syndrome (PCOS) is a common disorder affecting women of reproductive age and the most common cause of underlying ovulatory problems. Patients with PCOS can have mildly elevated prolactin; the exact mechanism of hyperprolactinemia in PCOS is unknown. One theory is that constant high levels of estrogen experienced in PCOS would stimulate prolactin production. It is important to rule out other causes of hyperprolactinemia before making the diagnosis of PCOS.

What is the clinical significance of elevated prolactin? Why do we have to work up and treat it? See answer on the next page... 

Q: What is the clinical significance of elevated prolactin? Why do we have to work up and treat it?

By physiologic mechanisms not completely understood, hyperprolactinemia can interrupt the gonadal axis, leading to hypogonadism. In women, it can cause irregular menstrual cycles, oligomenorrhea, amenorrhea, and infertility. In men, it can lower testosterone levels. Long-term effects include declining bone mineral density due to insufficient estrogen in women or testosterone in men.

With macroadenoma, the size of the tumor can have a mass effect such as headache and visual defect by compressing the optic chiasm (bitemporal hemianopsia), which may lead to permanent vision loss if left untreated. Referral to an ophthalmologist may be necessary for formal visual field examination.

How is hyperprolactinemia treated? See answer on the next page... 

Q: How is hyperprolactinemia treated?

There are three options for treatment: medication, surgery, and radiation.

Dopamine agonists (bromo­criptine, cabergoline) are effective in normalizing prolactin and reducing the size of the tumor in the majority of cases. However, some patients may require long-term treatment. Bromocriptine has been used since the late 1970s, but, due to better tolerance and less frequent dosing, cabergoline is the preferred agent.³

Transsphenoidal surgery is indicated for patients who are intolerant to medication, who have a medication-resistant tumor or significant mass effect, or who prefer definitive treatment. Women of childbearing age with a macroadenoma might consider surgery due to the risk for tumor expansion during pregnancy (estrogen effect) and risk for pituitary apoplexy (hemorrhage or infarct of the pituitary gland). Surgical risk is usually low with a neurosurgeon who has extensive experience. 

Radiation can be considered for large tumors that are resistant to medication. It can be used as adjunctive therapy to surgery, since reducing the size of the tumor can make the surgical field smaller. In some medication-resistant tumors, radiation can raise sensitivity to medication.

What does follow-up entail? See next page for answer... 

Q: What does follow-up entail?

Once medication is initiated or dosage is adjusted, have the patient follow up in one month and recheck the prolactin level to assess responsiveness to medication (as well as medication adherence). When a therapeutic prolactin level is achieved, recheck the prolactin and have the patient follow up at three and six months and then every six months thereafter.³

MRI of the pituitary gland should be performed at baseline, then in six months to assess tumor response to medication, and then at 12 and 24 months.³ If tumor regression has stabilized or if the tumor has shrunk to a nondetectable size, consider discontinuing the dopamine agonist. If medication is discontinued, recheck prolactin every three months for the first year; if it remains in normal reference range, simply check serum prolactin annually.³

See next page for summary. 

See next page for references. 

REFERENCES

1. Jameson JL.  Harrison’s Endocrinology. 18th ed. China: McGraw-Hill; 2010.

2. Gardner D, Shoback D. Greenspan’s Basic & Clinical Endocrinology. 9th ed. China: McGraw-Hill; 2011.

3. Melmed S, Casanueva FF, Hoffman AR, et al. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2011;96(2):273-288.

A 31-year-old woman is referred by her Ob-Gyn for elevated prolactin. She initially presented with a three-month history of amenorrhea, a negative home pregnancy test, and 100% compliance with condom use. She denies hirsutism and acne but admits to thin milky nipple discharge upon squeezing (but not spontaneous).

Two weeks ago, her Ob-Gyn ordered labs; results were negative for serum beta human chorionic gonadotropin and within normal ranges for thyroid-stimulating hormone (TSH), luteinizing hormone, follicle-stimulating hormone, estradiol, free and total testosterone, dehydroepiandrosterone sulfate (DHEAs), complete chemistry panel, and complete blood count. Her serum prolactin level was 110 ng/mL (normal, 3 to 27 ng/mL).

Q: How is prolactin physiologically regulated?

The primary role of prolactin, which is produced by lactotroph cells in the anterior pituitary gland, is to stimulate lactation and breast development. Prolactin is regulated by dopamine (also known as prolactin inhibitory hormone), which is secreted from the hypothalamus via an inhibitory pathway unique to the hypothalamus-pituitary hormone system. Dopamine essentially suppresses prolactin.

Other hormones can have a stimulatory effect on the anterior pituitary gland and thus increase prolactin levels. Estrogen can induce lactotroph hyperplasia and elevated prolactin; however, this is only clinically relevant in the context of estrogen surge during pregnancy. (Estrogen therapy, such as oral contraception or hormone replacement therapy, on the other hand, is targeted to “normal” estrogen levels.) Thyrotropin-releasing hormone (TRH) from the hypothalamus also stimulates the anterior pituitary gland, so patients with inadequately treated or untreated primary hypothyroidism will have mildly elevated prolactin.

Neurogenic stimuli of the chest wall, through nipple suckling or varicella zoster infection (shingles), can also increase prolactin secretion. And since prolactin is eliminated by the liver (75%) and the kidney (25%), significant liver disease and/or renal insufficiency can raise prolactin levels, due to decreased clearance.

What are the possible etiologies for elevated prolactin? See answer on the next page... 

Q: What are the possible etiologies for elevated prolactin?

The causes of hyperprolactinemia fall into three categories: physiologic, pharmacologic, and pathologic.²  The table provides examples from each category.

A nonsecretory pituitary adenoma or any lesion in the brain that would disrupt the hypophyseal stalk may interfere with dopamine’s inhibitory control and thereby increase prolactin. This is called the stalk effect. It is ­important to note that not all MRI-proven pituitary adenomas are prolactin secreting, even in the presence of hyperprolactinemia. According to an autopsy series, about 12% of the general population had pituitary microadenoma.³

There is rough correlation between prolactinoma size and level of prolactin. Large nonsecretory pituitary adenomas have prolactin levels less than 150 ng/mL. Microprolactinomas (< 1 cm) are usually in the range of 100 to 250 ng/mL, while macroprolactinomas (> 1 cm) are generally
≥ 250 ng/mL. If the tumor is very large and invades the cavernous sinus, prolactin can measure in the 1,000s.³

Polycystic ovarian syndrome (PCOS) is a common disorder affecting women of reproductive age and the most common cause of underlying ovulatory problems. Patients with PCOS can have mildly elevated prolactin; the exact mechanism of hyperprolactinemia in PCOS is unknown. One theory is that constant high levels of estrogen experienced in PCOS would stimulate prolactin production. It is important to rule out other causes of hyperprolactinemia before making the diagnosis of PCOS.

What is the clinical significance of elevated prolactin? Why do we have to work up and treat it? See answer on the next page... 

Q: What is the clinical significance of elevated prolactin? Why do we have to work up and treat it?

By physiologic mechanisms not completely understood, hyperprolactinemia can interrupt the gonadal axis, leading to hypogonadism. In women, it can cause irregular menstrual cycles, oligomenorrhea, amenorrhea, and infertility. In men, it can lower testosterone levels. Long-term effects include declining bone mineral density due to insufficient estrogen in women or testosterone in men.

With macroadenoma, the size of the tumor can have a mass effect such as headache and visual defect by compressing the optic chiasm (bitemporal hemianopsia), which may lead to permanent vision loss if left untreated. Referral to an ophthalmologist may be necessary for formal visual field examination.

How is hyperprolactinemia treated? See answer on the next page... 

Q: How is hyperprolactinemia treated?

There are three options for treatment: medication, surgery, and radiation.

Dopamine agonists (bromo­criptine, cabergoline) are effective in normalizing prolactin and reducing the size of the tumor in the majority of cases. However, some patients may require long-term treatment. Bromocriptine has been used since the late 1970s, but, due to better tolerance and less frequent dosing, cabergoline is the preferred agent.³

Transsphenoidal surgery is indicated for patients who are intolerant to medication, who have a medication-resistant tumor or significant mass effect, or who prefer definitive treatment. Women of childbearing age with a macroadenoma might consider surgery due to the risk for tumor expansion during pregnancy (estrogen effect) and risk for pituitary apoplexy (hemorrhage or infarct of the pituitary gland). Surgical risk is usually low with a neurosurgeon who has extensive experience. 

Radiation can be considered for large tumors that are resistant to medication. It can be used as adjunctive therapy to surgery, since reducing the size of the tumor can make the surgical field smaller. In some medication-resistant tumors, radiation can raise sensitivity to medication.

What does follow-up entail? See next page for answer... 

Q: What does follow-up entail?

Once medication is initiated or dosage is adjusted, have the patient follow up in one month and recheck the prolactin level to assess responsiveness to medication (as well as medication adherence). When a therapeutic prolactin level is achieved, recheck the prolactin and have the patient follow up at three and six months and then every six months thereafter.³

MRI of the pituitary gland should be performed at baseline, then in six months to assess tumor response to medication, and then at 12 and 24 months.³ If tumor regression has stabilized or if the tumor has shrunk to a nondetectable size, consider discontinuing the dopamine agonist. If medication is discontinued, recheck prolactin every three months for the first year; if it remains in normal reference range, simply check serum prolactin annually.³

See next page for summary. 

See next page for references. 

REFERENCES

1. Jameson JL.  Harrison’s Endocrinology. 18th ed. China: McGraw-Hill; 2010.

2. Gardner D, Shoback D. Greenspan’s Basic & Clinical Endocrinology. 9th ed. China: McGraw-Hill; 2011.

3. Melmed S, Casanueva FF, Hoffman AR, et al. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2011;96(2):273-288.

A 31-year-old woman is referred by her Ob-Gyn for elevated prolactin. She initially presented with a three-month history of amenorrhea, a negative home pregnancy test, and 100% compliance with condom use. She denies hirsutism and acne but admits to thin milky nipple discharge upon squeezing (but not spontaneous).

Two weeks ago, her Ob-Gyn ordered labs; results were negative for serum beta human chorionic gonadotropin and within normal ranges for thyroid-stimulating hormone (TSH), luteinizing hormone, follicle-stimulating hormone, estradiol, free and total testosterone, dehydroepiandrosterone sulfate (DHEAs), complete chemistry panel, and complete blood count. Her serum prolactin level was 110 ng/mL (normal, 3 to 27 ng/mL).

Q: How is prolactin physiologically regulated?

The primary role of prolactin, which is produced by lactotroph cells in the anterior pituitary gland, is to stimulate lactation and breast development. Prolactin is regulated by dopamine (also known as prolactin inhibitory hormone), which is secreted from the hypothalamus via an inhibitory pathway unique to the hypothalamus-pituitary hormone system. Dopamine essentially suppresses prolactin.

Other hormones can have a stimulatory effect on the anterior pituitary gland and thus increase prolactin levels. Estrogen can induce lactotroph hyperplasia and elevated prolactin; however, this is only clinically relevant in the context of estrogen surge during pregnancy. (Estrogen therapy, such as oral contraception or hormone replacement therapy, on the other hand, is targeted to “normal” estrogen levels.) Thyrotropin-releasing hormone (TRH) from the hypothalamus also stimulates the anterior pituitary gland, so patients with inadequately treated or untreated primary hypothyroidism will have mildly elevated prolactin.

Neurogenic stimuli of the chest wall, through nipple suckling or varicella zoster infection (shingles), can also increase prolactin secretion. And since prolactin is eliminated by the liver (75%) and the kidney (25%), significant liver disease and/or renal insufficiency can raise prolactin levels, due to decreased clearance.

What are the possible etiologies for elevated prolactin? See answer on the next page... 

Q: What are the possible etiologies for elevated prolactin?

The causes of hyperprolactinemia fall into three categories: physiologic, pharmacologic, and pathologic.²  The table provides examples from each category.

A nonsecretory pituitary adenoma or any lesion in the brain that would disrupt the hypophyseal stalk may interfere with dopamine’s inhibitory control and thereby increase prolactin. This is called the stalk effect. It is ­important to note that not all MRI-proven pituitary adenomas are prolactin secreting, even in the presence of hyperprolactinemia. According to an autopsy series, about 12% of the general population had pituitary microadenoma.³

There is rough correlation between prolactinoma size and level of prolactin. Large nonsecretory pituitary adenomas have prolactin levels less than 150 ng/mL. Microprolactinomas (< 1 cm) are usually in the range of 100 to 250 ng/mL, while macroprolactinomas (> 1 cm) are generally
≥ 250 ng/mL. If the tumor is very large and invades the cavernous sinus, prolactin can measure in the 1,000s.³

Polycystic ovarian syndrome (PCOS) is a common disorder affecting women of reproductive age and the most common cause of underlying ovulatory problems. Patients with PCOS can have mildly elevated prolactin; the exact mechanism of hyperprolactinemia in PCOS is unknown. One theory is that constant high levels of estrogen experienced in PCOS would stimulate prolactin production. It is important to rule out other causes of hyperprolactinemia before making the diagnosis of PCOS.

What is the clinical significance of elevated prolactin? Why do we have to work up and treat it? See answer on the next page... 

Q: What is the clinical significance of elevated prolactin? Why do we have to work up and treat it?

By physiologic mechanisms not completely understood, hyperprolactinemia can interrupt the gonadal axis, leading to hypogonadism. In women, it can cause irregular menstrual cycles, oligomenorrhea, amenorrhea, and infertility. In men, it can lower testosterone levels. Long-term effects include declining bone mineral density due to insufficient estrogen in women or testosterone in men.

With macroadenoma, the size of the tumor can have a mass effect such as headache and visual defect by compressing the optic chiasm (bitemporal hemianopsia), which may lead to permanent vision loss if left untreated. Referral to an ophthalmologist may be necessary for formal visual field examination.

How is hyperprolactinemia treated? See answer on the next page... 

Q: How is hyperprolactinemia treated?

There are three options for treatment: medication, surgery, and radiation.

Dopamine agonists (bromo­criptine, cabergoline) are effective in normalizing prolactin and reducing the size of the tumor in the majority of cases. However, some patients may require long-term treatment. Bromocriptine has been used since the late 1970s, but, due to better tolerance and less frequent dosing, cabergoline is the preferred agent.³

Transsphenoidal surgery is indicated for patients who are intolerant to medication, who have a medication-resistant tumor or significant mass effect, or who prefer definitive treatment. Women of childbearing age with a macroadenoma might consider surgery due to the risk for tumor expansion during pregnancy (estrogen effect) and risk for pituitary apoplexy (hemorrhage or infarct of the pituitary gland). Surgical risk is usually low with a neurosurgeon who has extensive experience. 

Radiation can be considered for large tumors that are resistant to medication. It can be used as adjunctive therapy to surgery, since reducing the size of the tumor can make the surgical field smaller. In some medication-resistant tumors, radiation can raise sensitivity to medication.

What does follow-up entail? See next page for answer... 

Q: What does follow-up entail?

Once medication is initiated or dosage is adjusted, have the patient follow up in one month and recheck the prolactin level to assess responsiveness to medication (as well as medication adherence). When a therapeutic prolactin level is achieved, recheck the prolactin and have the patient follow up at three and six months and then every six months thereafter.³

MRI of the pituitary gland should be performed at baseline, then in six months to assess tumor response to medication, and then at 12 and 24 months.³ If tumor regression has stabilized or if the tumor has shrunk to a nondetectable size, consider discontinuing the dopamine agonist. If medication is discontinued, recheck prolactin every three months for the first year; if it remains in normal reference range, simply check serum prolactin annually.³

See next page for summary. 

See next page for references. 

REFERENCES

1. Jameson JL.  Harrison’s Endocrinology. 18th ed. China: McGraw-Hill; 2010.

2. Gardner D, Shoback D. Greenspan’s Basic & Clinical Endocrinology. 9th ed. China: McGraw-Hill; 2011.

3. Melmed S, Casanueva FF, Hoffman AR, et al. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2011;96(2):273-288.

ANSWER

This ECG shows atrial flutter with 2:1 atrioventricular conduction. Additionally, ST depressions are seen in the anterior leads.

Typical sinus node P waves are absent, and atrial conduction at a rate of 310 beats/min is indicated by the sawtooth pattern in leads II and aVF. The ventricular rate is half that of the atrial rate (hence the 2:1 ratio). The ST depressions seen in the anterior leads, thought to be rate related, resolved upon cardioversion to terminate the atrial flutter.

Atrial flutter is uncommon in patients with structurally normal hearts and occurs far less frequently than atrial fibrillation. The etiology of this man’s arrhythmia may be due to pericarditis, based on his history and physical examination. 

ANSWER

This ECG shows atrial flutter with 2:1 atrioventricular conduction. Additionally, ST depressions are seen in the anterior leads.

Typical sinus node P waves are absent, and atrial conduction at a rate of 310 beats/min is indicated by the sawtooth pattern in leads II and aVF. The ventricular rate is half that of the atrial rate (hence the 2:1 ratio). The ST depressions seen in the anterior leads, thought to be rate related, resolved upon cardioversion to terminate the atrial flutter.

Atrial flutter is uncommon in patients with structurally normal hearts and occurs far less frequently than atrial fibrillation. The etiology of this man’s arrhythmia may be due to pericarditis, based on his history and physical examination. 

ANSWER

This ECG shows atrial flutter with 2:1 atrioventricular conduction. Additionally, ST depressions are seen in the anterior leads.

Typical sinus node P waves are absent, and atrial conduction at a rate of 310 beats/min is indicated by the sawtooth pattern in leads II and aVF. The ventricular rate is half that of the atrial rate (hence the 2:1 ratio). The ST depressions seen in the anterior leads, thought to be rate related, resolved upon cardioversion to terminate the atrial flutter.

Atrial flutter is uncommon in patients with structurally normal hearts and occurs far less frequently than atrial fibrillation. The etiology of this man’s arrhythmia may be due to pericarditis, based on his history and physical examination. 

The correct answer is benign familial pemphigus (choice “b”). Also known as Hailey-Hailey disease, this is an unusual autosomally inherited blistering disease.

Benign familial pemphigus (BFP) is often mistaken for bacterial infection, such as pyoderma (choice “a”) or impetigo (choice “c”). Although it can become secondarily infected, its origins are entirely different.

Contact dermatitis (choice “d”) in its more severe forms can present in a similar manner. However, it would have shown entirely different changes (acute inflammation and spongiosis) on biopsy.

See next page for the discussion... 

DISCUSSION

In 1939, two dermatologist-brothers in Georgia saw a patient with this previously unreported condition. They uncovered the family history and worked out the histologic basis, which they then described in the literature. They named the condition benign familial pemphigus, but it is now more commonly known as Hailey-Hailey disease in their honor.

Pemphigus vulgaris (PV), a serious blistering disease, was more common and far more feared at the time of the Hailey brothers’ discovery. Nearly 100% of PV patients died from the condition in that pre-steroid, pre-antibiotic era (most from secondary bacterial infection).

Fortunately, BFP is more benign, though it shares some features with PV. Both are said to be Nikolsky-positive, meaning the initial blisters can be extended with digital pressure. But BFP, unlike PV, does not involve deposition of immunoglobulins (IgA in the case of PV), nor is it accompanied by circulating auto-antibodies. BFP patients typically have no systemic symptoms, whereas in those with PV, the oral mucosae are often affected.

Herpes simplex virus, which was the primary care provider’s initial suspected diagnosis, can cause somewhat similar outbreaks, even in this area. However, it was effectively ruled out by the lack of response to treatment and by the biopsy results.

Although BFP is an inherited condition, it demonstrates variable penetrance, as in our case. It is rare enough that diagnosis is almost invariably delayed while other diagnoses are considered and treated. The actual “lesion” of BFP is still debated, but appears to involve the quality and quantity of desmosomes (microscopic structures that act as connecting fibers between layers of tissue) breaking down, often because of heat and friction, eventuating in blistering. This theory is bolstered by considerable research and by the fact that most cases present in intertriginous areas, such as the neck, axillae, and groin. Appearing episodically, it typically ­begins in the third to fourth decade of life, tending to diminish with age.

Biopsy is often necessary to confirm the diagnosis of BFP, with the sample best taken from perilesional skin to avoid separation of friable sample fragments. Additional specimens can be taken for special handling (Michel’s media) to detect immunoglobulins that might be seen in other blistering diseases.

See next page for treatment... 

TREATMENT

BFP can be treated empirically with application of a soothing solution of aluminum acetate, or more specifically with topical corticosteroids (class III to IV) and topical antibiotics (eg, clindamycin 2% solution), plus/minus oral minocycline, which has potent anti-inflammatory as well as antimicrobial effects.

Difficult cases should be referred to dermatology, which has a number of treatments at its disposal. This includes diaminodiphenyl sulfone (dapsone), systemic glucocorticoids, methotrexate, systemic retinoids, and even local injection of botulinum toxin to decrease local hidrosis.

This patient is responding well to a regimen of oral minocycline 100 mg bid, topical clindamycin 2% bid application, and topical tacrolimus. 

The correct answer is benign familial pemphigus (choice “b”). Also known as Hailey-Hailey disease, this is an unusual autosomally inherited blistering disease.

Benign familial pemphigus (BFP) is often mistaken for bacterial infection, such as pyoderma (choice “a”) or impetigo (choice “c”). Although it can become secondarily infected, its origins are entirely different.

Contact dermatitis (choice “d”) in its more severe forms can present in a similar manner. However, it would have shown entirely different changes (acute inflammation and spongiosis) on biopsy.

See next page for the discussion... 

DISCUSSION

In 1939, two dermatologist-brothers in Georgia saw a patient with this previously unreported condition. They uncovered the family history and worked out the histologic basis, which they then described in the literature. They named the condition benign familial pemphigus, but it is now more commonly known as Hailey-Hailey disease in their honor.

Pemphigus vulgaris (PV), a serious blistering disease, was more common and far more feared at the time of the Hailey brothers’ discovery. Nearly 100% of PV patients died from the condition in that pre-steroid, pre-antibiotic era (most from secondary bacterial infection).

Fortunately, BFP is more benign, though it shares some features with PV. Both are said to be Nikolsky-positive, meaning the initial blisters can be extended with digital pressure. But BFP, unlike PV, does not involve deposition of immunoglobulins (IgA in the case of PV), nor is it accompanied by circulating auto-antibodies. BFP patients typically have no systemic symptoms, whereas in those with PV, the oral mucosae are often affected.

Herpes simplex virus, which was the primary care provider’s initial suspected diagnosis, can cause somewhat similar outbreaks, even in this area. However, it was effectively ruled out by the lack of response to treatment and by the biopsy results.

Although BFP is an inherited condition, it demonstrates variable penetrance, as in our case. It is rare enough that diagnosis is almost invariably delayed while other diagnoses are considered and treated. The actual “lesion” of BFP is still debated, but appears to involve the quality and quantity of desmosomes (microscopic structures that act as connecting fibers between layers of tissue) breaking down, often because of heat and friction, eventuating in blistering. This theory is bolstered by considerable research and by the fact that most cases present in intertriginous areas, such as the neck, axillae, and groin. Appearing episodically, it typically ­begins in the third to fourth decade of life, tending to diminish with age.

Biopsy is often necessary to confirm the diagnosis of BFP, with the sample best taken from perilesional skin to avoid separation of friable sample fragments. Additional specimens can be taken for special handling (Michel’s media) to detect immunoglobulins that might be seen in other blistering diseases.

See next page for treatment... 

TREATMENT

BFP can be treated empirically with application of a soothing solution of aluminum acetate, or more specifically with topical corticosteroids (class III to IV) and topical antibiotics (eg, clindamycin 2% solution), plus/minus oral minocycline, which has potent anti-inflammatory as well as antimicrobial effects.

Difficult cases should be referred to dermatology, which has a number of treatments at its disposal. This includes diaminodiphenyl sulfone (dapsone), systemic glucocorticoids, methotrexate, systemic retinoids, and even local injection of botulinum toxin to decrease local hidrosis.

This patient is responding well to a regimen of oral minocycline 100 mg bid, topical clindamycin 2% bid application, and topical tacrolimus. 

The correct answer is benign familial pemphigus (choice “b”). Also known as Hailey-Hailey disease, this is an unusual autosomally inherited blistering disease.

Benign familial pemphigus (BFP) is often mistaken for bacterial infection, such as pyoderma (choice “a”) or impetigo (choice “c”). Although it can become secondarily infected, its origins are entirely different.

Contact dermatitis (choice “d”) in its more severe forms can present in a similar manner. However, it would have shown entirely different changes (acute inflammation and spongiosis) on biopsy.

See next page for the discussion... 

DISCUSSION

In 1939, two dermatologist-brothers in Georgia saw a patient with this previously unreported condition. They uncovered the family history and worked out the histologic basis, which they then described in the literature. They named the condition benign familial pemphigus, but it is now more commonly known as Hailey-Hailey disease in their honor.

Pemphigus vulgaris (PV), a serious blistering disease, was more common and far more feared at the time of the Hailey brothers’ discovery. Nearly 100% of PV patients died from the condition in that pre-steroid, pre-antibiotic era (most from secondary bacterial infection).

Fortunately, BFP is more benign, though it shares some features with PV. Both are said to be Nikolsky-positive, meaning the initial blisters can be extended with digital pressure. But BFP, unlike PV, does not involve deposition of immunoglobulins (IgA in the case of PV), nor is it accompanied by circulating auto-antibodies. BFP patients typically have no systemic symptoms, whereas in those with PV, the oral mucosae are often affected.

Herpes simplex virus, which was the primary care provider’s initial suspected diagnosis, can cause somewhat similar outbreaks, even in this area. However, it was effectively ruled out by the lack of response to treatment and by the biopsy results.

Although BFP is an inherited condition, it demonstrates variable penetrance, as in our case. It is rare enough that diagnosis is almost invariably delayed while other diagnoses are considered and treated. The actual “lesion” of BFP is still debated, but appears to involve the quality and quantity of desmosomes (microscopic structures that act as connecting fibers between layers of tissue) breaking down, often because of heat and friction, eventuating in blistering. This theory is bolstered by considerable research and by the fact that most cases present in intertriginous areas, such as the neck, axillae, and groin. Appearing episodically, it typically ­begins in the third to fourth decade of life, tending to diminish with age.

Biopsy is often necessary to confirm the diagnosis of BFP, with the sample best taken from perilesional skin to avoid separation of friable sample fragments. Additional specimens can be taken for special handling (Michel’s media) to detect immunoglobulins that might be seen in other blistering diseases.

See next page for treatment... 

TREATMENT

BFP can be treated empirically with application of a soothing solution of aluminum acetate, or more specifically with topical corticosteroids (class III to IV) and topical antibiotics (eg, clindamycin 2% solution), plus/minus oral minocycline, which has potent anti-inflammatory as well as antimicrobial effects.

Difficult cases should be referred to dermatology, which has a number of treatments at its disposal. This includes diaminodiphenyl sulfone (dapsone), systemic glucocorticoids, methotrexate, systemic retinoids, and even local injection of botulinum toxin to decrease local hidrosis.

This patient is responding well to a regimen of oral minocycline 100 mg bid, topical clindamycin 2% bid application, and topical tacrolimus. 

CASE › A young patient has been struggling in school. His worried mother, having had several conferences with the child’s teachers, brings him to the family physician (FP), where he is given a diagnosis of attention deficit hyperactivity disorder (ADHD). The FP considers prescribing a stimulant medication, but first plans on conducting a more thorough family history and exam. She also debates the merits of ordering an electrocardiogram (EKG) to screen for conditions that could lead to sudden cardiac death.

If you were caring for this patient, how would you proceed?

That’s a good question, given the debate that has surrounded this subject since the US Food and Drug Administration (FDA) first learned of 25 cases of sudden death that were linked to stimulant medications.¹ The majority of the cases, which were reported to the FDA’s Adverse Event Reporting System between 1999 and 2003, involved amphetamines or methylphenidate in patients under the age of 19.¹ In 2008, the American Heart Association (AHA) issued a scientific statement advocating that physicians perform a proper family history and physical exam that includes blood pressure (BP) and an EKG before prescribing a stimulant for children and adolescents.² The inclusion of EKG screening was intended to increase the likelihood of identifying patients with potentially life-threatening conditions that could lead to sudden cardiac death (SCD).²

Not everyone, however, agreed.

Later that year, the American Academy of Pediatrics (AAP) challenged the routine use of EKGs in this screening process, citing a lack of evidence between stimulant use and the induction of potentially lethal arrhythmias.³ And in 2011, the European Guideline Group also concluded that there was no evidence to suggest an incremental benefit for routine EKG assessment of ADHD patients before initiation of medication.⁴

Underscoring the uncertainty surrounding the subject are the findings of a 2012 survey of 525 randomly selected US pediatricians.⁵ Nearly a quarter of the respondents expressed concerns over the risk for SCD in children receiving stimulants for ADHD, and a slightly higher number—30%—worried that the risks for legal liability were high enough to warrant cardiac assessment.⁵

More than 70% of the families reported that the patient had at least one cardiovascular symptom before sudden cardiac death.So how should the prudent FP proceed? In this review, we will describe how to thoroughly screen children and adolescents for their risk of SCD before prescribing stimulants for ADHD. We’ll also summarize what the evidence tells us about whether—and when—you should order an EKG. But first, a word about the pharmacology of stimulants.

How stimulants might increase SCD risk

Stimulants have been used to treat ADHD for more than 40 years⁶ and are a first-line of therapy for children with ADHD. Stimulants increase attention span by releasing dopamine and norepinephrine at synapses in the frontal cortex, brain stem, and midbrain.

The effect on heart rate and BP. In clinical trials with small samples sizes, children and adolescents receiving stimulants to treat ADHD experienced a minimal rise in heart rate and BP. As measured by 24-hour ambulatory BP monitoring, 13 subjects in a double-blind, randomized, placebo/stimulant crossover trial had slightly elevated total diastolic BP (69.7 vs 65.8 mm Hg; P=.02), waking diastolic BP (75.5 vs 72.3 mm Hg; P=.03), and total heart rate (85.5 vs 79.9 beats per minutes [bpm]; P=.004) while receiving stimulants.⁷ Other investigators noted similar findings among 17 boys ages 7 to 11 years.⁸

Whether prolonged childhood exposure to stimulants increases the risk for developing hypertension or tachycardia is unknown. A 10-year follow-up study of 579 children between the ages of 7 to 9 years found stimulants had no effect on systolic or diastolic BP.9 Stimulants use did, however, lead to a higher heart rate (84.2±12.4 vs 79.1±12.0 bpm) during treatment.⁹ No stimulant-related QT interval changes—which some have proposed might explain SCD in ADHD patients—have been reported in pediatric patients.¹⁰ Researchers have noted small increases in mean QTc intervals in adults treated with stimulants for ADHD, but none were >480 msec.¹¹

Steps you should always take before prescribing a stimulant

Before prescribing stimulants to children or adolescents with ADHD, complete an in-depth cardiac history and physical examination, as recommended by the AHA and AAP (TABLE),^2,3 to identify conditions that increase the likelihood of SCD, such as hypertrophic cardiomyopathy (HCM), long QT interval syndrome (LQTS), and preexcitation syndromes such as Wolff-Parkinson-White syndrome (WPW).

Confirm, for instance, that your patient has a normal heart rate, rhythm, and BP, and no pathological murmurs. In a survey of families with a child or young adult who had sudden cardiac arrest, 72% reported the patient had at least one cardiovascular symptom within 19 to 71 months of SCD, and 27% reported having a family member with a history of SCD before age 50.¹² For patients with no such complaints or family history, the news is good. Two large studies found that in the absence of any suspected or overt cardiac disease, children with ADHD who were receiving stimulant therapy had no increased risk of SCD.^13,14

What about patients with this common heart problem? Physicians face a dilemma when a stimulant is needed and the patient has a common acyanotic congenital heart lesion, such as a small atrial or ventricular septal defect, which is considered nonlethal. Based on limited data, there is no evidence that the risk of SCD is higher when these patients take stimulants.¹⁵

Should you order that EKG—or not?

Currently, the AHA still favors an EKG, though in a correction to its original statement, it adjusted the language to say that EKG could be “useful,” in addition to an in-depth cardiac history and physical examination.¹⁶

Opposition to routine EKG screening in these patients stems from the procedure’s extremely low yield and relatively high false positive findings, which may result in higher financial and psychological burdens for patients and families. Thomas et al¹⁷ reported that at a single center, the number of EKGs ordered with an indication of “stimulant medication screening” quadrupled during 2009, the year after the AHA published its recommendations. Of 372 patients referred for EKG, 24 (6.4%) had abnormal findings and 18 were referred for further evaluation, but none were found to have cardiac disease. ADHD therapy was delayed in 6 patients because of the EKG.

In a similar evaluation of 1470 ADHD patients ages 21 years and younger, Mahle et al18 noted that 119 patients (8.1%) had an abnormal EKG, 78 of whom (65%) were already receiving stimulants. Five patients had cardiac disease, including 2 who had a preexcitation syndrome. Overall, the positive predictive value was low (4.2%).¹⁸ Other research, including a study lead by one of this article’s authors (SKM), has found similar increases in the number of EKGs ordered for patients with ADHD.¹⁹

Cost vs benefit. In the Mahle et al¹⁸ study described above, the mean cost of EKG screening, including further testing for patients with abnormal initial results, was $58 per child. The mean cost to identify a true-positive result was $17,162.¹⁸

Two large studies found no evidence to support an increased risk of SCD in children with ADHD who are receiving stimulant therapy in the absence of any suspected or overt cardiac disease.In 2012, Leslie et al²⁰ used simulation models to estimate the societal cost of routine EKG screening to prevent SCD in children with ADHD. Their findings: The cost would be high relative to its health benefits—approximately $91,000 to $204,000 per life year saved. Furthermore, these researchers found that ordering an EKG to screen for 3 common cardiac conditions linked to SCD (HCM, WPW, and LQTS) would add <2 days to a patient’s projected life expectancy.²⁰

Our recommendations

We believe stimulants can safely be used in the treatment of children and adolescents with ADHD, given the evidence that suggests a low risk of SCD. That said, it is prudent to avoid prescribing stimulants for children who have an underlying condition that may deteriorate secondary to increased blood pressure or heart rate.

We agree with the current AHA and AAP recommendations that physicians should obtain an in-depth cardiac history and physical examination, with emphasis on screening for cardiac disorders that may put a child at risk for SCD, such as HCM, LQTS, and preexcitation syndromes. For instance, a history of a family member with palpitations should prompt an EKG, which may reveal familial preexcitation syndrome. Similarly, an EKG is in order if you suspect LQTS based on a parent’s description of a family member’s death after hearing a loud noise, such as fireworks.

A story of a patient's grandfather who died while taking a drug linked to QT prolongation prompted an EKG and the discovery that the child had LQTS.It often takes active probing to uncover a history of sudden death in the family that a parent may not consider relevant. For example, one of the authors (SKM) cared for a 6-year-old boy who presented with a history of syncope after his hand got caught in a door jam. On further probing, his mother revealed that her father had died at age 30 while he was taking astemizole, an allergy drug known to prolong the QT interval. Subsequent EKGs revealed that both the boy and his mother had LQTS.

For patients already taking stimulants, we recommend monitoring BP and heart rate and ordering an EKG only if the patient exhibits cardiac symptoms or there are concerns based on follow-up history and physical examination. Should a patient develop palpitations while taking a therapeutic dose of stimulants, a detailed history of the onset and duration of symptoms is important. For example, tachycardia that has a gradual onset and occurs with exercise is suggestive of physiological sinus tachycardia. In our judgment, most patients who experience symptoms that suggest sinus tachycardia simply require downward readjustment of their medication or a switch to a nonstimulant.

However, if the patient or family history prompts you to suspect other arrhythmias such as ectopic beats or supraventricular tachycardia, immediate assessment either in an emergency department or in the physician’s office may be required, because obtaining an EKG during symptoms is crucial for the diagnosis. Similarly, unexplained exercise intolerance or the onset of chest pain associated with exercise, dizziness, syncope, seizures, or dyspnea requires immediate cardiovascular assessment.

And finally, whether your patient has just started taking medication for his or her ADHD or has been on the medication for some time, it’s important to periodically reassess the need to continue the stimulant therapy; ADHD symptoms may decrease during mid- to late adolescence and into adulthood.²¹

CASE › The FP completed a thorough physical exam and found no evidence of any conditions that would increase the likelihood of SCD in the young patient. There was no history of SCD in the boy’s family, either. Based on these findings, the FP opted to forgo an EKG. She prescribed lisdexamfetamine, starting with 20 mg/d (the lowest dose available) and then monitored his course by telephone. Eventually, 30 mg was found to be an effective dose. At a 6-week follow-up visit, the boy’s ADHD symptoms were substantially reduced, without any adverse effects—cardiac or otherwise.

CORRESPONDENCE
Sudhir Ken Mehta, Cleveland Clinic Children’s Hospital, 9500 Euclid Avenue, Cleveland, OH 44111; [email protected]

CASE › A young patient has been struggling in school. His worried mother, having had several conferences with the child’s teachers, brings him to the family physician (FP), where he is given a diagnosis of attention deficit hyperactivity disorder (ADHD). The FP considers prescribing a stimulant medication, but first plans on conducting a more thorough family history and exam. She also debates the merits of ordering an electrocardiogram (EKG) to screen for conditions that could lead to sudden cardiac death.

If you were caring for this patient, how would you proceed?

That’s a good question, given the debate that has surrounded this subject since the US Food and Drug Administration (FDA) first learned of 25 cases of sudden death that were linked to stimulant medications.¹ The majority of the cases, which were reported to the FDA’s Adverse Event Reporting System between 1999 and 2003, involved amphetamines or methylphenidate in patients under the age of 19.¹ In 2008, the American Heart Association (AHA) issued a scientific statement advocating that physicians perform a proper family history and physical exam that includes blood pressure (BP) and an EKG before prescribing a stimulant for children and adolescents.² The inclusion of EKG screening was intended to increase the likelihood of identifying patients with potentially life-threatening conditions that could lead to sudden cardiac death (SCD).²

Not everyone, however, agreed.

Later that year, the American Academy of Pediatrics (AAP) challenged the routine use of EKGs in this screening process, citing a lack of evidence between stimulant use and the induction of potentially lethal arrhythmias.³ And in 2011, the European Guideline Group also concluded that there was no evidence to suggest an incremental benefit for routine EKG assessment of ADHD patients before initiation of medication.⁴

Underscoring the uncertainty surrounding the subject are the findings of a 2012 survey of 525 randomly selected US pediatricians.⁵ Nearly a quarter of the respondents expressed concerns over the risk for SCD in children receiving stimulants for ADHD, and a slightly higher number—30%—worried that the risks for legal liability were high enough to warrant cardiac assessment.⁵

More than 70% of the families reported that the patient had at least one cardiovascular symptom before sudden cardiac death.So how should the prudent FP proceed? In this review, we will describe how to thoroughly screen children and adolescents for their risk of SCD before prescribing stimulants for ADHD. We’ll also summarize what the evidence tells us about whether—and when—you should order an EKG. But first, a word about the pharmacology of stimulants.

How stimulants might increase SCD risk

Stimulants have been used to treat ADHD for more than 40 years⁶ and are a first-line of therapy for children with ADHD. Stimulants increase attention span by releasing dopamine and norepinephrine at synapses in the frontal cortex, brain stem, and midbrain.

The effect on heart rate and BP. In clinical trials with small samples sizes, children and adolescents receiving stimulants to treat ADHD experienced a minimal rise in heart rate and BP. As measured by 24-hour ambulatory BP monitoring, 13 subjects in a double-blind, randomized, placebo/stimulant crossover trial had slightly elevated total diastolic BP (69.7 vs 65.8 mm Hg; P=.02), waking diastolic BP (75.5 vs 72.3 mm Hg; P=.03), and total heart rate (85.5 vs 79.9 beats per minutes [bpm]; P=.004) while receiving stimulants.⁷ Other investigators noted similar findings among 17 boys ages 7 to 11 years.⁸

Whether prolonged childhood exposure to stimulants increases the risk for developing hypertension or tachycardia is unknown. A 10-year follow-up study of 579 children between the ages of 7 to 9 years found stimulants had no effect on systolic or diastolic BP.9 Stimulants use did, however, lead to a higher heart rate (84.2±12.4 vs 79.1±12.0 bpm) during treatment.⁹ No stimulant-related QT interval changes—which some have proposed might explain SCD in ADHD patients—have been reported in pediatric patients.¹⁰ Researchers have noted small increases in mean QTc intervals in adults treated with stimulants for ADHD, but none were >480 msec.¹¹

Steps you should always take before prescribing a stimulant

Before prescribing stimulants to children or adolescents with ADHD, complete an in-depth cardiac history and physical examination, as recommended by the AHA and AAP (TABLE),^2,3 to identify conditions that increase the likelihood of SCD, such as hypertrophic cardiomyopathy (HCM), long QT interval syndrome (LQTS), and preexcitation syndromes such as Wolff-Parkinson-White syndrome (WPW).

Confirm, for instance, that your patient has a normal heart rate, rhythm, and BP, and no pathological murmurs. In a survey of families with a child or young adult who had sudden cardiac arrest, 72% reported the patient had at least one cardiovascular symptom within 19 to 71 months of SCD, and 27% reported having a family member with a history of SCD before age 50.¹² For patients with no such complaints or family history, the news is good. Two large studies found that in the absence of any suspected or overt cardiac disease, children with ADHD who were receiving stimulant therapy had no increased risk of SCD.^13,14

What about patients with this common heart problem? Physicians face a dilemma when a stimulant is needed and the patient has a common acyanotic congenital heart lesion, such as a small atrial or ventricular septal defect, which is considered nonlethal. Based on limited data, there is no evidence that the risk of SCD is higher when these patients take stimulants.¹⁵

Should you order that EKG—or not?

Currently, the AHA still favors an EKG, though in a correction to its original statement, it adjusted the language to say that EKG could be “useful,” in addition to an in-depth cardiac history and physical examination.¹⁶

Opposition to routine EKG screening in these patients stems from the procedure’s extremely low yield and relatively high false positive findings, which may result in higher financial and psychological burdens for patients and families. Thomas et al¹⁷ reported that at a single center, the number of EKGs ordered with an indication of “stimulant medication screening” quadrupled during 2009, the year after the AHA published its recommendations. Of 372 patients referred for EKG, 24 (6.4%) had abnormal findings and 18 were referred for further evaluation, but none were found to have cardiac disease. ADHD therapy was delayed in 6 patients because of the EKG.

In a similar evaluation of 1470 ADHD patients ages 21 years and younger, Mahle et al18 noted that 119 patients (8.1%) had an abnormal EKG, 78 of whom (65%) were already receiving stimulants. Five patients had cardiac disease, including 2 who had a preexcitation syndrome. Overall, the positive predictive value was low (4.2%).¹⁸ Other research, including a study lead by one of this article’s authors (SKM), has found similar increases in the number of EKGs ordered for patients with ADHD.¹⁹

Cost vs benefit. In the Mahle et al¹⁸ study described above, the mean cost of EKG screening, including further testing for patients with abnormal initial results, was $58 per child. The mean cost to identify a true-positive result was $17,162.¹⁸

Two large studies found no evidence to support an increased risk of SCD in children with ADHD who are receiving stimulant therapy in the absence of any suspected or overt cardiac disease.In 2012, Leslie et al²⁰ used simulation models to estimate the societal cost of routine EKG screening to prevent SCD in children with ADHD. Their findings: The cost would be high relative to its health benefits—approximately $91,000 to $204,000 per life year saved. Furthermore, these researchers found that ordering an EKG to screen for 3 common cardiac conditions linked to SCD (HCM, WPW, and LQTS) would add <2 days to a patient’s projected life expectancy.²⁰

Our recommendations

We believe stimulants can safely be used in the treatment of children and adolescents with ADHD, given the evidence that suggests a low risk of SCD. That said, it is prudent to avoid prescribing stimulants for children who have an underlying condition that may deteriorate secondary to increased blood pressure or heart rate.

We agree with the current AHA and AAP recommendations that physicians should obtain an in-depth cardiac history and physical examination, with emphasis on screening for cardiac disorders that may put a child at risk for SCD, such as HCM, LQTS, and preexcitation syndromes. For instance, a history of a family member with palpitations should prompt an EKG, which may reveal familial preexcitation syndrome. Similarly, an EKG is in order if you suspect LQTS based on a parent’s description of a family member’s death after hearing a loud noise, such as fireworks.

A story of a patient's grandfather who died while taking a drug linked to QT prolongation prompted an EKG and the discovery that the child had LQTS.It often takes active probing to uncover a history of sudden death in the family that a parent may not consider relevant. For example, one of the authors (SKM) cared for a 6-year-old boy who presented with a history of syncope after his hand got caught in a door jam. On further probing, his mother revealed that her father had died at age 30 while he was taking astemizole, an allergy drug known to prolong the QT interval. Subsequent EKGs revealed that both the boy and his mother had LQTS.

For patients already taking stimulants, we recommend monitoring BP and heart rate and ordering an EKG only if the patient exhibits cardiac symptoms or there are concerns based on follow-up history and physical examination. Should a patient develop palpitations while taking a therapeutic dose of stimulants, a detailed history of the onset and duration of symptoms is important. For example, tachycardia that has a gradual onset and occurs with exercise is suggestive of physiological sinus tachycardia. In our judgment, most patients who experience symptoms that suggest sinus tachycardia simply require downward readjustment of their medication or a switch to a nonstimulant.

However, if the patient or family history prompts you to suspect other arrhythmias such as ectopic beats or supraventricular tachycardia, immediate assessment either in an emergency department or in the physician’s office may be required, because obtaining an EKG during symptoms is crucial for the diagnosis. Similarly, unexplained exercise intolerance or the onset of chest pain associated with exercise, dizziness, syncope, seizures, or dyspnea requires immediate cardiovascular assessment.

And finally, whether your patient has just started taking medication for his or her ADHD or has been on the medication for some time, it’s important to periodically reassess the need to continue the stimulant therapy; ADHD symptoms may decrease during mid- to late adolescence and into adulthood.²¹

CASE › The FP completed a thorough physical exam and found no evidence of any conditions that would increase the likelihood of SCD in the young patient. There was no history of SCD in the boy’s family, either. Based on these findings, the FP opted to forgo an EKG. She prescribed lisdexamfetamine, starting with 20 mg/d (the lowest dose available) and then monitored his course by telephone. Eventually, 30 mg was found to be an effective dose. At a 6-week follow-up visit, the boy’s ADHD symptoms were substantially reduced, without any adverse effects—cardiac or otherwise.

CORRESPONDENCE
Sudhir Ken Mehta, Cleveland Clinic Children’s Hospital, 9500 Euclid Avenue, Cleveland, OH 44111; [email protected]

CASE › A young patient has been struggling in school. His worried mother, having had several conferences with the child’s teachers, brings him to the family physician (FP), where he is given a diagnosis of attention deficit hyperactivity disorder (ADHD). The FP considers prescribing a stimulant medication, but first plans on conducting a more thorough family history and exam. She also debates the merits of ordering an electrocardiogram (EKG) to screen for conditions that could lead to sudden cardiac death.

If you were caring for this patient, how would you proceed?

That’s a good question, given the debate that has surrounded this subject since the US Food and Drug Administration (FDA) first learned of 25 cases of sudden death that were linked to stimulant medications.¹ The majority of the cases, which were reported to the FDA’s Adverse Event Reporting System between 1999 and 2003, involved amphetamines or methylphenidate in patients under the age of 19.¹ In 2008, the American Heart Association (AHA) issued a scientific statement advocating that physicians perform a proper family history and physical exam that includes blood pressure (BP) and an EKG before prescribing a stimulant for children and adolescents.² The inclusion of EKG screening was intended to increase the likelihood of identifying patients with potentially life-threatening conditions that could lead to sudden cardiac death (SCD).²

Not everyone, however, agreed.

Later that year, the American Academy of Pediatrics (AAP) challenged the routine use of EKGs in this screening process, citing a lack of evidence between stimulant use and the induction of potentially lethal arrhythmias.³ And in 2011, the European Guideline Group also concluded that there was no evidence to suggest an incremental benefit for routine EKG assessment of ADHD patients before initiation of medication.⁴

Underscoring the uncertainty surrounding the subject are the findings of a 2012 survey of 525 randomly selected US pediatricians.⁵ Nearly a quarter of the respondents expressed concerns over the risk for SCD in children receiving stimulants for ADHD, and a slightly higher number—30%—worried that the risks for legal liability were high enough to warrant cardiac assessment.⁵

More than 70% of the families reported that the patient had at least one cardiovascular symptom before sudden cardiac death.So how should the prudent FP proceed? In this review, we will describe how to thoroughly screen children and adolescents for their risk of SCD before prescribing stimulants for ADHD. We’ll also summarize what the evidence tells us about whether—and when—you should order an EKG. But first, a word about the pharmacology of stimulants.

How stimulants might increase SCD risk

Stimulants have been used to treat ADHD for more than 40 years⁶ and are a first-line of therapy for children with ADHD. Stimulants increase attention span by releasing dopamine and norepinephrine at synapses in the frontal cortex, brain stem, and midbrain.

The effect on heart rate and BP. In clinical trials with small samples sizes, children and adolescents receiving stimulants to treat ADHD experienced a minimal rise in heart rate and BP. As measured by 24-hour ambulatory BP monitoring, 13 subjects in a double-blind, randomized, placebo/stimulant crossover trial had slightly elevated total diastolic BP (69.7 vs 65.8 mm Hg; P=.02), waking diastolic BP (75.5 vs 72.3 mm Hg; P=.03), and total heart rate (85.5 vs 79.9 beats per minutes [bpm]; P=.004) while receiving stimulants.⁷ Other investigators noted similar findings among 17 boys ages 7 to 11 years.⁸

Whether prolonged childhood exposure to stimulants increases the risk for developing hypertension or tachycardia is unknown. A 10-year follow-up study of 579 children between the ages of 7 to 9 years found stimulants had no effect on systolic or diastolic BP.9 Stimulants use did, however, lead to a higher heart rate (84.2±12.4 vs 79.1±12.0 bpm) during treatment.⁹ No stimulant-related QT interval changes—which some have proposed might explain SCD in ADHD patients—have been reported in pediatric patients.¹⁰ Researchers have noted small increases in mean QTc intervals in adults treated with stimulants for ADHD, but none were >480 msec.¹¹

Steps you should always take before prescribing a stimulant

Before prescribing stimulants to children or adolescents with ADHD, complete an in-depth cardiac history and physical examination, as recommended by the AHA and AAP (TABLE),^2,3 to identify conditions that increase the likelihood of SCD, such as hypertrophic cardiomyopathy (HCM), long QT interval syndrome (LQTS), and preexcitation syndromes such as Wolff-Parkinson-White syndrome (WPW).

Confirm, for instance, that your patient has a normal heart rate, rhythm, and BP, and no pathological murmurs. In a survey of families with a child or young adult who had sudden cardiac arrest, 72% reported the patient had at least one cardiovascular symptom within 19 to 71 months of SCD, and 27% reported having a family member with a history of SCD before age 50.¹² For patients with no such complaints or family history, the news is good. Two large studies found that in the absence of any suspected or overt cardiac disease, children with ADHD who were receiving stimulant therapy had no increased risk of SCD.^13,14

What about patients with this common heart problem? Physicians face a dilemma when a stimulant is needed and the patient has a common acyanotic congenital heart lesion, such as a small atrial or ventricular septal defect, which is considered nonlethal. Based on limited data, there is no evidence that the risk of SCD is higher when these patients take stimulants.¹⁵

Should you order that EKG—or not?

Currently, the AHA still favors an EKG, though in a correction to its original statement, it adjusted the language to say that EKG could be “useful,” in addition to an in-depth cardiac history and physical examination.¹⁶

Opposition to routine EKG screening in these patients stems from the procedure’s extremely low yield and relatively high false positive findings, which may result in higher financial and psychological burdens for patients and families. Thomas et al¹⁷ reported that at a single center, the number of EKGs ordered with an indication of “stimulant medication screening” quadrupled during 2009, the year after the AHA published its recommendations. Of 372 patients referred for EKG, 24 (6.4%) had abnormal findings and 18 were referred for further evaluation, but none were found to have cardiac disease. ADHD therapy was delayed in 6 patients because of the EKG.

In a similar evaluation of 1470 ADHD patients ages 21 years and younger, Mahle et al18 noted that 119 patients (8.1%) had an abnormal EKG, 78 of whom (65%) were already receiving stimulants. Five patients had cardiac disease, including 2 who had a preexcitation syndrome. Overall, the positive predictive value was low (4.2%).¹⁸ Other research, including a study lead by one of this article’s authors (SKM), has found similar increases in the number of EKGs ordered for patients with ADHD.¹⁹

Cost vs benefit. In the Mahle et al¹⁸ study described above, the mean cost of EKG screening, including further testing for patients with abnormal initial results, was $58 per child. The mean cost to identify a true-positive result was $17,162.¹⁸

Two large studies found no evidence to support an increased risk of SCD in children with ADHD who are receiving stimulant therapy in the absence of any suspected or overt cardiac disease.In 2012, Leslie et al²⁰ used simulation models to estimate the societal cost of routine EKG screening to prevent SCD in children with ADHD. Their findings: The cost would be high relative to its health benefits—approximately $91,000 to $204,000 per life year saved. Furthermore, these researchers found that ordering an EKG to screen for 3 common cardiac conditions linked to SCD (HCM, WPW, and LQTS) would add <2 days to a patient’s projected life expectancy.²⁰

Our recommendations

We believe stimulants can safely be used in the treatment of children and adolescents with ADHD, given the evidence that suggests a low risk of SCD. That said, it is prudent to avoid prescribing stimulants for children who have an underlying condition that may deteriorate secondary to increased blood pressure or heart rate.

We agree with the current AHA and AAP recommendations that physicians should obtain an in-depth cardiac history and physical examination, with emphasis on screening for cardiac disorders that may put a child at risk for SCD, such as HCM, LQTS, and preexcitation syndromes. For instance, a history of a family member with palpitations should prompt an EKG, which may reveal familial preexcitation syndrome. Similarly, an EKG is in order if you suspect LQTS based on a parent’s description of a family member’s death after hearing a loud noise, such as fireworks.

A story of a patient's grandfather who died while taking a drug linked to QT prolongation prompted an EKG and the discovery that the child had LQTS.It often takes active probing to uncover a history of sudden death in the family that a parent may not consider relevant. For example, one of the authors (SKM) cared for a 6-year-old boy who presented with a history of syncope after his hand got caught in a door jam. On further probing, his mother revealed that her father had died at age 30 while he was taking astemizole, an allergy drug known to prolong the QT interval. Subsequent EKGs revealed that both the boy and his mother had LQTS.

For patients already taking stimulants, we recommend monitoring BP and heart rate and ordering an EKG only if the patient exhibits cardiac symptoms or there are concerns based on follow-up history and physical examination. Should a patient develop palpitations while taking a therapeutic dose of stimulants, a detailed history of the onset and duration of symptoms is important. For example, tachycardia that has a gradual onset and occurs with exercise is suggestive of physiological sinus tachycardia. In our judgment, most patients who experience symptoms that suggest sinus tachycardia simply require downward readjustment of their medication or a switch to a nonstimulant.

However, if the patient or family history prompts you to suspect other arrhythmias such as ectopic beats or supraventricular tachycardia, immediate assessment either in an emergency department or in the physician’s office may be required, because obtaining an EKG during symptoms is crucial for the diagnosis. Similarly, unexplained exercise intolerance or the onset of chest pain associated with exercise, dizziness, syncope, seizures, or dyspnea requires immediate cardiovascular assessment.

And finally, whether your patient has just started taking medication for his or her ADHD or has been on the medication for some time, it’s important to periodically reassess the need to continue the stimulant therapy; ADHD symptoms may decrease during mid- to late adolescence and into adulthood.²¹

CASE › The FP completed a thorough physical exam and found no evidence of any conditions that would increase the likelihood of SCD in the young patient. There was no history of SCD in the boy’s family, either. Based on these findings, the FP opted to forgo an EKG. She prescribed lisdexamfetamine, starting with 20 mg/d (the lowest dose available) and then monitored his course by telephone. Eventually, 30 mg was found to be an effective dose. At a 6-week follow-up visit, the boy’s ADHD symptoms were substantially reduced, without any adverse effects—cardiac or otherwise.

CORRESPONDENCE
Sudhir Ken Mehta, Cleveland Clinic Children’s Hospital, 9500 Euclid Avenue, Cleveland, OH 44111; [email protected]

More than 300 attendees heard Dr. Mickey Karram address urodynamics and cystoscopy at the annual Pelvic Anatomy and Gynecologic Surgery Symposium (PAGS) in Las Vegas, December 12-14, 2013. Here, a key topic from his presentation.

Dr. Karram is  Professor of OB/GYN and Urology, University of Cincinnati School of Medicine, and Director, Urogynecology, The Christ Hospital, Cincinnati, Ohio. He also is Course Director of the Pelvic Anatomy and Gynecologic Surgery Symposium (PAGS) and the Female Urology and Urogynecology Symposium (FUUS), both co-sponsored by OBG Management.

FUUS 2014: June 14-16, Aria, Las Vegas
Click here for more info.

More than 300 attendees heard Dr. Mickey Karram address urodynamics and cystoscopy at the annual Pelvic Anatomy and Gynecologic Surgery Symposium (PAGS) in Las Vegas, December 12-14, 2013. Here, a key topic from his presentation.

Dr. Karram is  Professor of OB/GYN and Urology, University of Cincinnati School of Medicine, and Director, Urogynecology, The Christ Hospital, Cincinnati, Ohio. He also is Course Director of the Pelvic Anatomy and Gynecologic Surgery Symposium (PAGS) and the Female Urology and Urogynecology Symposium (FUUS), both co-sponsored by OBG Management.

FUUS 2014: June 14-16, Aria, Las Vegas
Click here for more info.

More than 300 attendees heard Dr. Mickey Karram address urodynamics and cystoscopy at the annual Pelvic Anatomy and Gynecologic Surgery Symposium (PAGS) in Las Vegas, December 12-14, 2013. Here, a key topic from his presentation.

Dr. Karram is  Professor of OB/GYN and Urology, University of Cincinnati School of Medicine, and Director, Urogynecology, The Christ Hospital, Cincinnati, Ohio. He also is Course Director of the Pelvic Anatomy and Gynecologic Surgery Symposium (PAGS) and the Female Urology and Urogynecology Symposium (FUUS), both co-sponsored by OBG Management.

FUUS 2014: June 14-16, Aria, Las Vegas
Click here for more info.

Plasmodium parasite in a red

blood cell; Credit: St Jude

Children’s Research Hospital

A school-based, intermittent screening and treatment program for malaria did not confer any benefits for children living in an area of low-to-moderate malaria transmission.

The program, which was implemented at schools in Kenya, did not significantly reduce the incidence of malaria infection or the prevalence of anemia.

Katherine Halliday, of the London School of Hygiene & Tropical Medicine in the UK, and her colleagues reported these results in PLOS Medicine.

The study included 5233 children, ages 5 to 20, studying at 101 government schools located on the south coast of Kenya. Fifty-one of the schools were randomized to the intermittent screening and treatment program.

Over 24 months, children in these schools underwent screening for malaria parasites once each term (a total of 5 times). And those who tested positive for malaria parasitemia (whether symptomatic or asymptomatic) received 6 cycles of treatment with the anti-malarial drug artemether-lumefantrine.

Eighty-four percent of the children were screened at 4 or more rounds, and 66.8% were screened at all 5 rounds. By the fifth round, 20% of children had been lost due to death, withdrawal, or migration.

The percentage of children who were positive for malaria at each screening ranged from 14.8% to 19.2%, and there was no distinct trend over time. Overall, 99.1% of the positive results led to treatment, and 92.6% of these were recorded as receiving the fully supervised, 6-dose treatment regimen.

The investigators followed a majority of the children in each group for an additional 24 months after the intervention ended. And the team found that the intervention had no significant impact on the prevalence of Plasmodium falciparum infection at 12 months or 24 months.

At 12 months, the prevalence of P falciparum (adjusted for age, sex, and stratification effects) was 10.7% in the intervention group and 14.3% in the control group (P=0.131). At 24 months, the prevalence of P falciparum was 11.8% in the intervention group and 8.5% in the control group (P=0.124).

Similarly, there was no significant difference between the 2 groups with regard to anemia.

At 12 months, the prevalence of anemia was 38.5% among controls and 40.1% in the intervention group (P=0.621). At 24 months, the prevalence was 39.5% among controls and 41.5% in the intervention group (P=0.953).

The investigators also evaluated education-related outcomes at 9 months and 24 months of follow-up. They found no significant difference between the study groups with regard to classroom attention.

However, younger children in the intervention group did not score as well as controls in spelling or arithmetic tests.

The team said this may be a chance finding, or it may indicate that apprehension about the finger prick needed for the diagnostic test had a negative effect on the children’s performance during educational tests.

In closing, the investigators said there are a number of possible reasons why this screening and treatment intervention proved unsuccesful.

These include geographical heterogeneity in transmission, a rapid rate of reinfection following treatment, the variable reliability of the diagnostic tests used, and the relative contribution of malaria to the etiology of anemia in this setting.

In a related perspective article, Lorenz von Seidlein, MD, PhD, of the Menzies School of Health Research in Casuarina, Australia, discusses these possibilities in more detail, as well as the wider issues involved in failure of screening and treating as a malaria elimination strategy.

Plasmodium parasite in a red

blood cell; Credit: St Jude

Children’s Research Hospital

A school-based, intermittent screening and treatment program for malaria did not confer any benefits for children living in an area of low-to-moderate malaria transmission.

The program, which was implemented at schools in Kenya, did not significantly reduce the incidence of malaria infection or the prevalence of anemia.

Katherine Halliday, of the London School of Hygiene & Tropical Medicine in the UK, and her colleagues reported these results in PLOS Medicine.

The study included 5233 children, ages 5 to 20, studying at 101 government schools located on the south coast of Kenya. Fifty-one of the schools were randomized to the intermittent screening and treatment program.

Over 24 months, children in these schools underwent screening for malaria parasites once each term (a total of 5 times). And those who tested positive for malaria parasitemia (whether symptomatic or asymptomatic) received 6 cycles of treatment with the anti-malarial drug artemether-lumefantrine.

Eighty-four percent of the children were screened at 4 or more rounds, and 66.8% were screened at all 5 rounds. By the fifth round, 20% of children had been lost due to death, withdrawal, or migration.

The percentage of children who were positive for malaria at each screening ranged from 14.8% to 19.2%, and there was no distinct trend over time. Overall, 99.1% of the positive results led to treatment, and 92.6% of these were recorded as receiving the fully supervised, 6-dose treatment regimen.

The investigators followed a majority of the children in each group for an additional 24 months after the intervention ended. And the team found that the intervention had no significant impact on the prevalence of Plasmodium falciparum infection at 12 months or 24 months.

At 12 months, the prevalence of P falciparum (adjusted for age, sex, and stratification effects) was 10.7% in the intervention group and 14.3% in the control group (P=0.131). At 24 months, the prevalence of P falciparum was 11.8% in the intervention group and 8.5% in the control group (P=0.124).

Similarly, there was no significant difference between the 2 groups with regard to anemia.

At 12 months, the prevalence of anemia was 38.5% among controls and 40.1% in the intervention group (P=0.621). At 24 months, the prevalence was 39.5% among controls and 41.5% in the intervention group (P=0.953).

The investigators also evaluated education-related outcomes at 9 months and 24 months of follow-up. They found no significant difference between the study groups with regard to classroom attention.

However, younger children in the intervention group did not score as well as controls in spelling or arithmetic tests.

The team said this may be a chance finding, or it may indicate that apprehension about the finger prick needed for the diagnostic test had a negative effect on the children’s performance during educational tests.

In closing, the investigators said there are a number of possible reasons why this screening and treatment intervention proved unsuccesful.

These include geographical heterogeneity in transmission, a rapid rate of reinfection following treatment, the variable reliability of the diagnostic tests used, and the relative contribution of malaria to the etiology of anemia in this setting.

In a related perspective article, Lorenz von Seidlein, MD, PhD, of the Menzies School of Health Research in Casuarina, Australia, discusses these possibilities in more detail, as well as the wider issues involved in failure of screening and treating as a malaria elimination strategy.

Plasmodium parasite in a red

blood cell; Credit: St Jude

Children’s Research Hospital

A school-based, intermittent screening and treatment program for malaria did not confer any benefits for children living in an area of low-to-moderate malaria transmission.

The program, which was implemented at schools in Kenya, did not significantly reduce the incidence of malaria infection or the prevalence of anemia.

Katherine Halliday, of the London School of Hygiene & Tropical Medicine in the UK, and her colleagues reported these results in PLOS Medicine.

The study included 5233 children, ages 5 to 20, studying at 101 government schools located on the south coast of Kenya. Fifty-one of the schools were randomized to the intermittent screening and treatment program.

Over 24 months, children in these schools underwent screening for malaria parasites once each term (a total of 5 times). And those who tested positive for malaria parasitemia (whether symptomatic or asymptomatic) received 6 cycles of treatment with the anti-malarial drug artemether-lumefantrine.

Eighty-four percent of the children were screened at 4 or more rounds, and 66.8% were screened at all 5 rounds. By the fifth round, 20% of children had been lost due to death, withdrawal, or migration.

The percentage of children who were positive for malaria at each screening ranged from 14.8% to 19.2%, and there was no distinct trend over time. Overall, 99.1% of the positive results led to treatment, and 92.6% of these were recorded as receiving the fully supervised, 6-dose treatment regimen.

The investigators followed a majority of the children in each group for an additional 24 months after the intervention ended. And the team found that the intervention had no significant impact on the prevalence of Plasmodium falciparum infection at 12 months or 24 months.

At 12 months, the prevalence of P falciparum (adjusted for age, sex, and stratification effects) was 10.7% in the intervention group and 14.3% in the control group (P=0.131). At 24 months, the prevalence of P falciparum was 11.8% in the intervention group and 8.5% in the control group (P=0.124).

Similarly, there was no significant difference between the 2 groups with regard to anemia.

At 12 months, the prevalence of anemia was 38.5% among controls and 40.1% in the intervention group (P=0.621). At 24 months, the prevalence was 39.5% among controls and 41.5% in the intervention group (P=0.953).

The investigators also evaluated education-related outcomes at 9 months and 24 months of follow-up. They found no significant difference between the study groups with regard to classroom attention.

However, younger children in the intervention group did not score as well as controls in spelling or arithmetic tests.

The team said this may be a chance finding, or it may indicate that apprehension about the finger prick needed for the diagnostic test had a negative effect on the children’s performance during educational tests.

In closing, the investigators said there are a number of possible reasons why this screening and treatment intervention proved unsuccesful.

These include geographical heterogeneity in transmission, a rapid rate of reinfection following treatment, the variable reliability of the diagnostic tests used, and the relative contribution of malaria to the etiology of anemia in this setting.

In a related perspective article, Lorenz von Seidlein, MD, PhD, of the Menzies School of Health Research in Casuarina, Australia, discusses these possibilities in more detail, as well as the wider issues involved in failure of screening and treating as a malaria elimination strategy.

AML in the bone marrow

Studies have suggested that mutations in isocitrate dehydrogenase-1 and 2 (IDH1 and IDH2) are present in approximately 20% of all acute myeloid leukemias (AMLs), and this implies that mutant IDH proteins are attractive drug targets.

With this in mind, a group of scientists generated a transgenic mouse model of the most common IDH2 mutation in human AML.

Experiments conducted with this model revealed that mutant IDH2 contributes to leukemia initiation and is required for the maintenance of leukemic cells in a living organism.

The researchers said these findings, published in Cell Stem Cell, confirm a potent oncogenic role for IDH2 and support its relevance as a therapeutic target for AML.

Furthermore, the model can be used to evaluate the pharmacological efficacy of IDH2 inhibitors, either alone or in combination with other compounds.

“The real hope is that we would one day be able to treat IDH2-mutant leukemia patients with a drug that targets this genetic abnormality,” said senior study author Pier Paolo Pandolfi, MD, PhD, of Beth Israel Deaconess Medical Center (BIDMC) in Boston.

He and his colleagues knew that IDH1 and IDH2 proteins are critical enzymes in the TCA cycle, which is centrally important to many biochemical pathways. Mutated forms of these proteins gain a novel ability to produce 2-hydroxyglutarate (2HG), a metabolite that has been shown to accumulate at high levels in cancer patients.

“Our goal was to generate an animal model of mutant IDH that was both inducible and reversible,” said Markus Reschke, PhD, also of BIDMC.

“This enabled us to address an important unanswered question: Does inhibition of mutant IDH proteins in active disease have an effect on tumor maintenance or progression in a living organism?”

The researchers studied 2 different models: a retroviral transduction model and a genetically engineered model in which IDH mice were crossed with mice harboring other leukemia-relevant mutations.

In the first model, the IDH mutation was combined with the oncogenes HoxA9 and Meis1a, 2 downstream targets of numerous pathways that are deregulated in AML.

The results showed evidence of differentiation within 2 weeks of genetic deinduction of mutant IDH. And 2 weeks later, 6 of 8 animals showed complete remission with elimination of any detectable leukemic cells.

The researchers said these results were both surprising and encouraging, demonstrating a situation in which IDH mutation occurs as an early event, and leukemic transformation occurs as a result of subsequent genetic hits.

“The retroviral model enabled us to observe that mutant IDH2 is essential for the maintenance of HoxA9/Meis1a-induced AML,” said Lev Kats, PhD, of BIDMC. “But this was still a surrogate model. This isn’t what happens in human patients, per se.”

The researchers therefore went on to develop a transgenic model that more closely recapitulates the genetics of human AML.

“By crossing the mutant IDH2 animals with other leukemia-relevant mutations, including mutations in the FMS-like tyrosine kinase 3 [FLT3], we observed that compound-mutant animals developed acute leukemias,” Dr Reschke said. “This exciting finding told us that mutant IDH2 contributes to leukemia initiation in vivo.”

As with the retroviral transduction model, genetic deinduction of mutant IDH2 in the context of a cooperating FLT3 mutation resulted in reduced proliferation and/or differentiation of leukemic cells, further demonstrating that mutant IDH2 expression is required for leukemia maintenance.

“This model has validated mutant IDH proteins as very strong candidates for continued development of targeted anticancer therapeutics,” Dr Pandolfi said. “The model will also be of paramount importance to study mechanisms of resistance to treatment that may occur.”

AML in the bone marrow

Studies have suggested that mutations in isocitrate dehydrogenase-1 and 2 (IDH1 and IDH2) are present in approximately 20% of all acute myeloid leukemias (AMLs), and this implies that mutant IDH proteins are attractive drug targets.

With this in mind, a group of scientists generated a transgenic mouse model of the most common IDH2 mutation in human AML.

Experiments conducted with this model revealed that mutant IDH2 contributes to leukemia initiation and is required for the maintenance of leukemic cells in a living organism.

The researchers said these findings, published in Cell Stem Cell, confirm a potent oncogenic role for IDH2 and support its relevance as a therapeutic target for AML.

Furthermore, the model can be used to evaluate the pharmacological efficacy of IDH2 inhibitors, either alone or in combination with other compounds.

“The real hope is that we would one day be able to treat IDH2-mutant leukemia patients with a drug that targets this genetic abnormality,” said senior study author Pier Paolo Pandolfi, MD, PhD, of Beth Israel Deaconess Medical Center (BIDMC) in Boston.

He and his colleagues knew that IDH1 and IDH2 proteins are critical enzymes in the TCA cycle, which is centrally important to many biochemical pathways. Mutated forms of these proteins gain a novel ability to produce 2-hydroxyglutarate (2HG), a metabolite that has been shown to accumulate at high levels in cancer patients.

“Our goal was to generate an animal model of mutant IDH that was both inducible and reversible,” said Markus Reschke, PhD, also of BIDMC.

“This enabled us to address an important unanswered question: Does inhibition of mutant IDH proteins in active disease have an effect on tumor maintenance or progression in a living organism?”

The researchers studied 2 different models: a retroviral transduction model and a genetically engineered model in which IDH mice were crossed with mice harboring other leukemia-relevant mutations.

In the first model, the IDH mutation was combined with the oncogenes HoxA9 and Meis1a, 2 downstream targets of numerous pathways that are deregulated in AML.

The results showed evidence of differentiation within 2 weeks of genetic deinduction of mutant IDH. And 2 weeks later, 6 of 8 animals showed complete remission with elimination of any detectable leukemic cells.

The researchers said these results were both surprising and encouraging, demonstrating a situation in which IDH mutation occurs as an early event, and leukemic transformation occurs as a result of subsequent genetic hits.

“The retroviral model enabled us to observe that mutant IDH2 is essential for the maintenance of HoxA9/Meis1a-induced AML,” said Lev Kats, PhD, of BIDMC. “But this was still a surrogate model. This isn’t what happens in human patients, per se.”

The researchers therefore went on to develop a transgenic model that more closely recapitulates the genetics of human AML.

“By crossing the mutant IDH2 animals with other leukemia-relevant mutations, including mutations in the FMS-like tyrosine kinase 3 [FLT3], we observed that compound-mutant animals developed acute leukemias,” Dr Reschke said. “This exciting finding told us that mutant IDH2 contributes to leukemia initiation in vivo.”

As with the retroviral transduction model, genetic deinduction of mutant IDH2 in the context of a cooperating FLT3 mutation resulted in reduced proliferation and/or differentiation of leukemic cells, further demonstrating that mutant IDH2 expression is required for leukemia maintenance.

“This model has validated mutant IDH proteins as very strong candidates for continued development of targeted anticancer therapeutics,” Dr Pandolfi said. “The model will also be of paramount importance to study mechanisms of resistance to treatment that may occur.”

AML in the bone marrow

Studies have suggested that mutations in isocitrate dehydrogenase-1 and 2 (IDH1 and IDH2) are present in approximately 20% of all acute myeloid leukemias (AMLs), and this implies that mutant IDH proteins are attractive drug targets.

With this in mind, a group of scientists generated a transgenic mouse model of the most common IDH2 mutation in human AML.

Experiments conducted with this model revealed that mutant IDH2 contributes to leukemia initiation and is required for the maintenance of leukemic cells in a living organism.

The researchers said these findings, published in Cell Stem Cell, confirm a potent oncogenic role for IDH2 and support its relevance as a therapeutic target for AML.

Furthermore, the model can be used to evaluate the pharmacological efficacy of IDH2 inhibitors, either alone or in combination with other compounds.

“The real hope is that we would one day be able to treat IDH2-mutant leukemia patients with a drug that targets this genetic abnormality,” said senior study author Pier Paolo Pandolfi, MD, PhD, of Beth Israel Deaconess Medical Center (BIDMC) in Boston.

He and his colleagues knew that IDH1 and IDH2 proteins are critical enzymes in the TCA cycle, which is centrally important to many biochemical pathways. Mutated forms of these proteins gain a novel ability to produce 2-hydroxyglutarate (2HG), a metabolite that has been shown to accumulate at high levels in cancer patients.

“Our goal was to generate an animal model of mutant IDH that was both inducible and reversible,” said Markus Reschke, PhD, also of BIDMC.

“This enabled us to address an important unanswered question: Does inhibition of mutant IDH proteins in active disease have an effect on tumor maintenance or progression in a living organism?”

The researchers studied 2 different models: a retroviral transduction model and a genetically engineered model in which IDH mice were crossed with mice harboring other leukemia-relevant mutations.

In the first model, the IDH mutation was combined with the oncogenes HoxA9 and Meis1a, 2 downstream targets of numerous pathways that are deregulated in AML.

The results showed evidence of differentiation within 2 weeks of genetic deinduction of mutant IDH. And 2 weeks later, 6 of 8 animals showed complete remission with elimination of any detectable leukemic cells.

The researchers said these results were both surprising and encouraging, demonstrating a situation in which IDH mutation occurs as an early event, and leukemic transformation occurs as a result of subsequent genetic hits.

“The retroviral model enabled us to observe that mutant IDH2 is essential for the maintenance of HoxA9/Meis1a-induced AML,” said Lev Kats, PhD, of BIDMC. “But this was still a surrogate model. This isn’t what happens in human patients, per se.”

The researchers therefore went on to develop a transgenic model that more closely recapitulates the genetics of human AML.

“By crossing the mutant IDH2 animals with other leukemia-relevant mutations, including mutations in the FMS-like tyrosine kinase 3 [FLT3], we observed that compound-mutant animals developed acute leukemias,” Dr Reschke said. “This exciting finding told us that mutant IDH2 contributes to leukemia initiation in vivo.”

As with the retroviral transduction model, genetic deinduction of mutant IDH2 in the context of a cooperating FLT3 mutation resulted in reduced proliferation and/or differentiation of leukemic cells, further demonstrating that mutant IDH2 expression is required for leukemia maintenance.

“This model has validated mutant IDH proteins as very strong candidates for continued development of targeted anticancer therapeutics,” Dr Pandolfi said. “The model will also be of paramount importance to study mechanisms of resistance to treatment that may occur.”

Lab mouse

A new analysis indicates that animal studies not funded by industry produce favorable results more often than animal studies that are industry-funded.

In other words, published reports of non-industry-sponsored studies were more likely to contain data suggesting a drug was effective.

However, reports of industry-funded studies were more likely to contain favorable conclusions, even though data were less favorable.

Investigators recounted these findings in PLOS Biology.

They analyzed 63 studies in which statins were tested in animal models. Forty-two of the studies had quantitative results and disclosed sponsorship.

Among these studies, industry-sponsored research was less likely to measure a benefit for the statins in slowing or preventing arterial disease. Favorable results were reported in 47% (9/19) of the industry-sponsored studies and 72% (18/25) of the studies not sponsored by industry.

“The interests of the pharmaceutical industry might be best served by underestimating efficacy prior to clinical trials and overestimating efficacy in clinical trials,” said study author Lisa Bero, PhD, of the University of California, San Francisco.

“By underestimating efficacy in preclinical studies, the pharmaceutical industry could reduce the money spent on clinical trials that did not lead to marketable products. Because demonstrating drug efficacy in human studies is linked to drug company profits, drug companies may have more incentive to publish favorable efficacy findings of human drug studies than animal studies.”

However, Dr Bero and her colleagues also found that favorable conclusions were more likely in industry-sponsored studies, even when data were less favorable. Study authors drew favorable conclusions in 94.7% (18/19) of industry-sponsored studies and 75% (21/28) of studies not funded by industry.

Other key findings of this analysis were that methodological problems were common in both types of studies, and harmful side effects were not investigated.

“Not a single animal study we looked at assessed adverse events following the statin intervention,” Dr Bero said. “As toxicity data from animal studies must be submitted to drug regulatory authorities before a compound can proceed to testing in humans, it is surprising that so little data on harm appear in the published scientific literature.”

The investigators also noted that about half of the studies analyzed were randomized, and about half were blinded. Inclusion and exclusion criteria were often not included in the published reports, and many studies failed to account properly for changes in the assigned treatment arm that occurred during the course of treatment.

Most of the studies in this analysis were conducted in rabbits and mice. To gauge atherosclerosis, targeted by statins, investigators quantified qualities such as the number of damaged blood vessels, blood-vessel diameter, plaque severity, blockage to coronary and other arteries, and plaque rupture.

Lab mouse

A new analysis indicates that animal studies not funded by industry produce favorable results more often than animal studies that are industry-funded.

In other words, published reports of non-industry-sponsored studies were more likely to contain data suggesting a drug was effective.

However, reports of industry-funded studies were more likely to contain favorable conclusions, even though data were less favorable.

Investigators recounted these findings in PLOS Biology.

They analyzed 63 studies in which statins were tested in animal models. Forty-two of the studies had quantitative results and disclosed sponsorship.

Among these studies, industry-sponsored research was less likely to measure a benefit for the statins in slowing or preventing arterial disease. Favorable results were reported in 47% (9/19) of the industry-sponsored studies and 72% (18/25) of the studies not sponsored by industry.

“The interests of the pharmaceutical industry might be best served by underestimating efficacy prior to clinical trials and overestimating efficacy in clinical trials,” said study author Lisa Bero, PhD, of the University of California, San Francisco.

“By underestimating efficacy in preclinical studies, the pharmaceutical industry could reduce the money spent on clinical trials that did not lead to marketable products. Because demonstrating drug efficacy in human studies is linked to drug company profits, drug companies may have more incentive to publish favorable efficacy findings of human drug studies than animal studies.”

However, Dr Bero and her colleagues also found that favorable conclusions were more likely in industry-sponsored studies, even when data were less favorable. Study authors drew favorable conclusions in 94.7% (18/19) of industry-sponsored studies and 75% (21/28) of studies not funded by industry.

Other key findings of this analysis were that methodological problems were common in both types of studies, and harmful side effects were not investigated.

“Not a single animal study we looked at assessed adverse events following the statin intervention,” Dr Bero said. “As toxicity data from animal studies must be submitted to drug regulatory authorities before a compound can proceed to testing in humans, it is surprising that so little data on harm appear in the published scientific literature.”

The investigators also noted that about half of the studies analyzed were randomized, and about half were blinded. Inclusion and exclusion criteria were often not included in the published reports, and many studies failed to account properly for changes in the assigned treatment arm that occurred during the course of treatment.

Most of the studies in this analysis were conducted in rabbits and mice. To gauge atherosclerosis, targeted by statins, investigators quantified qualities such as the number of damaged blood vessels, blood-vessel diameter, plaque severity, blockage to coronary and other arteries, and plaque rupture.

Lab mouse

A new analysis indicates that animal studies not funded by industry produce favorable results more often than animal studies that are industry-funded.

In other words, published reports of non-industry-sponsored studies were more likely to contain data suggesting a drug was effective.

However, reports of industry-funded studies were more likely to contain favorable conclusions, even though data were less favorable.

Investigators recounted these findings in PLOS Biology.

They analyzed 63 studies in which statins were tested in animal models. Forty-two of the studies had quantitative results and disclosed sponsorship.

Among these studies, industry-sponsored research was less likely to measure a benefit for the statins in slowing or preventing arterial disease. Favorable results were reported in 47% (9/19) of the industry-sponsored studies and 72% (18/25) of the studies not sponsored by industry.

“The interests of the pharmaceutical industry might be best served by underestimating efficacy prior to clinical trials and overestimating efficacy in clinical trials,” said study author Lisa Bero, PhD, of the University of California, San Francisco.

“By underestimating efficacy in preclinical studies, the pharmaceutical industry could reduce the money spent on clinical trials that did not lead to marketable products. Because demonstrating drug efficacy in human studies is linked to drug company profits, drug companies may have more incentive to publish favorable efficacy findings of human drug studies than animal studies.”

However, Dr Bero and her colleagues also found that favorable conclusions were more likely in industry-sponsored studies, even when data were less favorable. Study authors drew favorable conclusions in 94.7% (18/19) of industry-sponsored studies and 75% (21/28) of studies not funded by industry.

Other key findings of this analysis were that methodological problems were common in both types of studies, and harmful side effects were not investigated.

“Not a single animal study we looked at assessed adverse events following the statin intervention,” Dr Bero said. “As toxicity data from animal studies must be submitted to drug regulatory authorities before a compound can proceed to testing in humans, it is surprising that so little data on harm appear in the published scientific literature.”

The investigators also noted that about half of the studies analyzed were randomized, and about half were blinded. Inclusion and exclusion criteria were often not included in the published reports, and many studies failed to account properly for changes in the assigned treatment arm that occurred during the course of treatment.

Most of the studies in this analysis were conducted in rabbits and mice. To gauge atherosclerosis, targeted by statins, investigators quantified qualities such as the number of damaged blood vessels, blood-vessel diameter, plaque severity, blockage to coronary and other arteries, and plaque rupture.

SAN FRANCISCO—Researchers have found evidence to suggest that tumor necrosis factor receptor II (TNFRII) may be an important driver of cutaneous T-cell lymphomas (CTCLs).

The team discovered that a mutation in this receptor—TNFRII T377I—is present in patients with mycosis fungoides (MF) and those with Sézary syndrome (SS).

And previous research showed that the region encoding TNFRII on chromosome 1 is sometimes amplified in MF and SS patients.

So if, as these factors suggest, TNFRII does play a key role in CTCL, a number of currently available drugs—including proteasome inhibitors and MEK inhibitors—may be effective treatment options.

Alexander Ungewickell, MD, PhD, of Stanford University in California, discussed this possibility and the research supporting it at the 6th Annual T-cell Lymphoma Forum.

A novel mutation

Dr Ungewickell and his colleagues began this research by conducting transcriptome sequencing on samples from 3 patients with SS (Lee et al, Blood 2012). This revealed about 500 genes that were upregulated and about 500 that were downregulated in SS cells.

And pathway enrichment analysis showed that molecular mechanisms of cancer were the most significantly altered pathways. But the researchers also observed PI3 kinase signaling, T-cell receptor signaling, regulation of IL-2, and CD8 signaling.

To better understand the basis for these transcriptional changes, the team performed whole-exome sequencing in 11 CTCL-normal pairs. They uncovered an average of 46 mutations per exome, as well as pathways similar to those observed in the transcriptional analysis.

The researchers then used this information to generate a 245-gene capture reagent. And they used that to perform ultra-deep targeted resequencing on 83 samples from CTCL patients.

“Two things that stood out right away were that TNFRSF1B and KRAS had recurrent point mutations that suggested an activating phenotype,” Dr Ungewickell said. “It’s already known that KRAS is mutated in many human cancers, including CTCL. TNFRSF1B encodes TNFRII and was not previously associated with any malignancies.”

“We also found a smattering of other genes that were mutated, [but] we were most interested in the TNFRII mutation because of the novelty of the finding and also the potential for therapeutic intervention.”

Driving disease

Dr Ungewickell noted that TNFRII is expressed in CD4 and CD8 T lymphocytes but relatively few other cell types. TNFRII is activated by membrane-bound TNFα, which mediates the signal through TRAF proteins and CIAP proteins to activate the NF-κB-inducing kinase (NIK).

This activates the I kappa B kinase (IKK) complex to phosphorylate p100. When phosphorylated, it is processed in the proteasome and translocates to the nucleus. There, it interacts with RelB to mediate transcription that tends to cause T-cell activation and proliferation.

TNFRII also binds to TRAF2 and induces its degradation. The recurrent mutation the researchers identified in TNFRII (T377I) is in the TRAF2 regulatory domain in an evolutionarily conserved residue.

The ultra-deep targeted resequencing of 83 CTCL samples showed 4 mutations at that locus, all of which were acquired in the lymphoma.

This suggests TNFRII is important in CTCL. And the researchers hypothesized that, if that’s the case, TNFRII might be overexpressed in SS cells. So they looked at their transcriptome data and found TNFRII to be overexpressed in all 3 patients.

“Interestingly, the region that encodes TNFRII on chromosome 1 is also amplified in 1 of the 4 commonly used CTCL cell lines, suggesting that amplification may be another way of activating this pathway,” Dr Ungewickell said.

“And we were very interested by a study published by van Doorn et al a few years ago [Blood 2009], which showed that that region of chromosome 1 p36 is, in fact, amplified in 45% of cases of MF and 15% of cases of Sézary syndrome.”

“So we are currently doing FISH studies to confirm that this receptor is actually amplified in as many as half of cases of MF, suggesting that maybe, between mutation and amplification, this is an important driver of CTCL.”

Therapeutic possibilities

The researchers also thought that, if TNFRII is an important driver of CTCL, there would be some kind of transcriptional mark on the lymphoma cells. So they performed gene set enrichment analyses on 24 CTCL samples that had undergone 3-seq.

By comparing tumors expressing high levels of TNFRII and those expressing low levels of TNFRII, the team identified an expression signature that corresponds to the receptor’s known effects on RNA levels in T cells.

When they searched publicly available datasets, the researchers found this signature in 63 cases of MF (Shin et al, Blood 2007). And results of control experiments suggested the signature is specific to CTCL.

“If TNFRII is more active [in CTCL] and the mutation that we found is a hyperactivating mutation, we would expect this pathway to show increased activity downstream; namely, you would expect more processing of p100 to p52,” Dr Ungewickell said.

To investigate this possibility, the researchers generated Jurkat cells expressing empty vector, wild-type TNFRII, or mutant TNFRII and looked at NF-κB processing. They did see an increase in processing with the mutant receptor, compared to the wild-type receptor or empty vector.

“We also found, somewhat surprisingly, increases in phospho-ERK with the mutant receptor, as well as phospho-MEK,” Dr Ungewickell said.

“And to our knowledge, the RAS/MAP kinase pathway has not previously been linked to TNFRII signaling, suggesting that there is some kind of direct or indirect cross-talk between these pathways. We think it’s very interesting, since there are KRAS mutations that activate the RAS/MAP kinase pathway in a subset of these cases, suggesting some kind of synergy.”

Introducing the mutant receptor into primary CD4+ T cells had an effect similar to that observed in the Jurkat cells. The researchers did western blotting for NF-kB processing, and they saw an increase in p100 to p52 processing.

“This is a preliminary experiment, but we’re actually quite excited about this, since Jurkat cells have many abnormalities, due to the fact that they’re a leukemia line, and primary T cells will have the rest of the genome intact,” Dr Ungewickell said.

Now, he and his colleagues are conducting several studies to identify the changes that occur in primary T cells when mutant TNFRII is expressed. They also want to see if they can recapitulate CTCL and identify the transcriptional signature they previously found in patient biopsies and cells.

Lastly, the researchers are performing functional assays to evaluate proliferation, apoptosis, and pharmacological information, with the goal of identifying therapies that might be effective in patients with TNFRII mutation or amplification.

“Patients who have increased TNFRII signaling might respond to proteasome inhibitors, since p100 and p52 processing requires the proteasome,” Dr Ungewickell said. “And given that cross-talk with the RAS/MAP kinase signaling, as well as the KRAS mutations, we also think . . . that MEK inhibitors might be effective in the treatment of CTCL.”

SAN FRANCISCO—Researchers have found evidence to suggest that tumor necrosis factor receptor II (TNFRII) may be an important driver of cutaneous T-cell lymphomas (CTCLs).

The team discovered that a mutation in this receptor—TNFRII T377I—is present in patients with mycosis fungoides (MF) and those with Sézary syndrome (SS).

And previous research showed that the region encoding TNFRII on chromosome 1 is sometimes amplified in MF and SS patients.

So if, as these factors suggest, TNFRII does play a key role in CTCL, a number of currently available drugs—including proteasome inhibitors and MEK inhibitors—may be effective treatment options.

Alexander Ungewickell, MD, PhD, of Stanford University in California, discussed this possibility and the research supporting it at the 6th Annual T-cell Lymphoma Forum.

A novel mutation

Dr Ungewickell and his colleagues began this research by conducting transcriptome sequencing on samples from 3 patients with SS (Lee et al, Blood 2012). This revealed about 500 genes that were upregulated and about 500 that were downregulated in SS cells.

And pathway enrichment analysis showed that molecular mechanisms of cancer were the most significantly altered pathways. But the researchers also observed PI3 kinase signaling, T-cell receptor signaling, regulation of IL-2, and CD8 signaling.

To better understand the basis for these transcriptional changes, the team performed whole-exome sequencing in 11 CTCL-normal pairs. They uncovered an average of 46 mutations per exome, as well as pathways similar to those observed in the transcriptional analysis.

The researchers then used this information to generate a 245-gene capture reagent. And they used that to perform ultra-deep targeted resequencing on 83 samples from CTCL patients.

“Two things that stood out right away were that TNFRSF1B and KRAS had recurrent point mutations that suggested an activating phenotype,” Dr Ungewickell said. “It’s already known that KRAS is mutated in many human cancers, including CTCL. TNFRSF1B encodes TNFRII and was not previously associated with any malignancies.”

“We also found a smattering of other genes that were mutated, [but] we were most interested in the TNFRII mutation because of the novelty of the finding and also the potential for therapeutic intervention.”

Driving disease

Dr Ungewickell noted that TNFRII is expressed in CD4 and CD8 T lymphocytes but relatively few other cell types. TNFRII is activated by membrane-bound TNFα, which mediates the signal through TRAF proteins and CIAP proteins to activate the NF-κB-inducing kinase (NIK).

This activates the I kappa B kinase (IKK) complex to phosphorylate p100. When phosphorylated, it is processed in the proteasome and translocates to the nucleus. There, it interacts with RelB to mediate transcription that tends to cause T-cell activation and proliferation.

TNFRII also binds to TRAF2 and induces its degradation. The recurrent mutation the researchers identified in TNFRII (T377I) is in the TRAF2 regulatory domain in an evolutionarily conserved residue.

The ultra-deep targeted resequencing of 83 CTCL samples showed 4 mutations at that locus, all of which were acquired in the lymphoma.

This suggests TNFRII is important in CTCL. And the researchers hypothesized that, if that’s the case, TNFRII might be overexpressed in SS cells. So they looked at their transcriptome data and found TNFRII to be overexpressed in all 3 patients.

“Interestingly, the region that encodes TNFRII on chromosome 1 is also amplified in 1 of the 4 commonly used CTCL cell lines, suggesting that amplification may be another way of activating this pathway,” Dr Ungewickell said.

“And we were very interested by a study published by van Doorn et al a few years ago [Blood 2009], which showed that that region of chromosome 1 p36 is, in fact, amplified in 45% of cases of MF and 15% of cases of Sézary syndrome.”

“So we are currently doing FISH studies to confirm that this receptor is actually amplified in as many as half of cases of MF, suggesting that maybe, between mutation and amplification, this is an important driver of CTCL.”

Therapeutic possibilities

The researchers also thought that, if TNFRII is an important driver of CTCL, there would be some kind of transcriptional mark on the lymphoma cells. So they performed gene set enrichment analyses on 24 CTCL samples that had undergone 3-seq.

By comparing tumors expressing high levels of TNFRII and those expressing low levels of TNFRII, the team identified an expression signature that corresponds to the receptor’s known effects on RNA levels in T cells.

When they searched publicly available datasets, the researchers found this signature in 63 cases of MF (Shin et al, Blood 2007). And results of control experiments suggested the signature is specific to CTCL.

“If TNFRII is more active [in CTCL] and the mutation that we found is a hyperactivating mutation, we would expect this pathway to show increased activity downstream; namely, you would expect more processing of p100 to p52,” Dr Ungewickell said.

To investigate this possibility, the researchers generated Jurkat cells expressing empty vector, wild-type TNFRII, or mutant TNFRII and looked at NF-κB processing. They did see an increase in processing with the mutant receptor, compared to the wild-type receptor or empty vector.

“We also found, somewhat surprisingly, increases in phospho-ERK with the mutant receptor, as well as phospho-MEK,” Dr Ungewickell said.

“And to our knowledge, the RAS/MAP kinase pathway has not previously been linked to TNFRII signaling, suggesting that there is some kind of direct or indirect cross-talk between these pathways. We think it’s very interesting, since there are KRAS mutations that activate the RAS/MAP kinase pathway in a subset of these cases, suggesting some kind of synergy.”

Introducing the mutant receptor into primary CD4+ T cells had an effect similar to that observed in the Jurkat cells. The researchers did western blotting for NF-kB processing, and they saw an increase in p100 to p52 processing.

“This is a preliminary experiment, but we’re actually quite excited about this, since Jurkat cells have many abnormalities, due to the fact that they’re a leukemia line, and primary T cells will have the rest of the genome intact,” Dr Ungewickell said.

Now, he and his colleagues are conducting several studies to identify the changes that occur in primary T cells when mutant TNFRII is expressed. They also want to see if they can recapitulate CTCL and identify the transcriptional signature they previously found in patient biopsies and cells.

Lastly, the researchers are performing functional assays to evaluate proliferation, apoptosis, and pharmacological information, with the goal of identifying therapies that might be effective in patients with TNFRII mutation or amplification.

“Patients who have increased TNFRII signaling might respond to proteasome inhibitors, since p100 and p52 processing requires the proteasome,” Dr Ungewickell said. “And given that cross-talk with the RAS/MAP kinase signaling, as well as the KRAS mutations, we also think . . . that MEK inhibitors might be effective in the treatment of CTCL.”

SAN FRANCISCO—Researchers have found evidence to suggest that tumor necrosis factor receptor II (TNFRII) may be an important driver of cutaneous T-cell lymphomas (CTCLs).

The team discovered that a mutation in this receptor—TNFRII T377I—is present in patients with mycosis fungoides (MF) and those with Sézary syndrome (SS).

And previous research showed that the region encoding TNFRII on chromosome 1 is sometimes amplified in MF and SS patients.

So if, as these factors suggest, TNFRII does play a key role in CTCL, a number of currently available drugs—including proteasome inhibitors and MEK inhibitors—may be effective treatment options.

Alexander Ungewickell, MD, PhD, of Stanford University in California, discussed this possibility and the research supporting it at the 6th Annual T-cell Lymphoma Forum.

A novel mutation

Dr Ungewickell and his colleagues began this research by conducting transcriptome sequencing on samples from 3 patients with SS (Lee et al, Blood 2012). This revealed about 500 genes that were upregulated and about 500 that were downregulated in SS cells.

And pathway enrichment analysis showed that molecular mechanisms of cancer were the most significantly altered pathways. But the researchers also observed PI3 kinase signaling, T-cell receptor signaling, regulation of IL-2, and CD8 signaling.

To better understand the basis for these transcriptional changes, the team performed whole-exome sequencing in 11 CTCL-normal pairs. They uncovered an average of 46 mutations per exome, as well as pathways similar to those observed in the transcriptional analysis.

The researchers then used this information to generate a 245-gene capture reagent. And they used that to perform ultra-deep targeted resequencing on 83 samples from CTCL patients.

“Two things that stood out right away were that TNFRSF1B and KRAS had recurrent point mutations that suggested an activating phenotype,” Dr Ungewickell said. “It’s already known that KRAS is mutated in many human cancers, including CTCL. TNFRSF1B encodes TNFRII and was not previously associated with any malignancies.”

“We also found a smattering of other genes that were mutated, [but] we were most interested in the TNFRII mutation because of the novelty of the finding and also the potential for therapeutic intervention.”

Driving disease

Dr Ungewickell noted that TNFRII is expressed in CD4 and CD8 T lymphocytes but relatively few other cell types. TNFRII is activated by membrane-bound TNFα, which mediates the signal through TRAF proteins and CIAP proteins to activate the NF-κB-inducing kinase (NIK).

This activates the I kappa B kinase (IKK) complex to phosphorylate p100. When phosphorylated, it is processed in the proteasome and translocates to the nucleus. There, it interacts with RelB to mediate transcription that tends to cause T-cell activation and proliferation.

TNFRII also binds to TRAF2 and induces its degradation. The recurrent mutation the researchers identified in TNFRII (T377I) is in the TRAF2 regulatory domain in an evolutionarily conserved residue.

The ultra-deep targeted resequencing of 83 CTCL samples showed 4 mutations at that locus, all of which were acquired in the lymphoma.

This suggests TNFRII is important in CTCL. And the researchers hypothesized that, if that’s the case, TNFRII might be overexpressed in SS cells. So they looked at their transcriptome data and found TNFRII to be overexpressed in all 3 patients.

“Interestingly, the region that encodes TNFRII on chromosome 1 is also amplified in 1 of the 4 commonly used CTCL cell lines, suggesting that amplification may be another way of activating this pathway,” Dr Ungewickell said.

“And we were very interested by a study published by van Doorn et al a few years ago [Blood 2009], which showed that that region of chromosome 1 p36 is, in fact, amplified in 45% of cases of MF and 15% of cases of Sézary syndrome.”

“So we are currently doing FISH studies to confirm that this receptor is actually amplified in as many as half of cases of MF, suggesting that maybe, between mutation and amplification, this is an important driver of CTCL.”

Therapeutic possibilities

The researchers also thought that, if TNFRII is an important driver of CTCL, there would be some kind of transcriptional mark on the lymphoma cells. So they performed gene set enrichment analyses on 24 CTCL samples that had undergone 3-seq.

By comparing tumors expressing high levels of TNFRII and those expressing low levels of TNFRII, the team identified an expression signature that corresponds to the receptor’s known effects on RNA levels in T cells.

When they searched publicly available datasets, the researchers found this signature in 63 cases of MF (Shin et al, Blood 2007). And results of control experiments suggested the signature is specific to CTCL.

“If TNFRII is more active [in CTCL] and the mutation that we found is a hyperactivating mutation, we would expect this pathway to show increased activity downstream; namely, you would expect more processing of p100 to p52,” Dr Ungewickell said.

To investigate this possibility, the researchers generated Jurkat cells expressing empty vector, wild-type TNFRII, or mutant TNFRII and looked at NF-κB processing. They did see an increase in processing with the mutant receptor, compared to the wild-type receptor or empty vector.

“We also found, somewhat surprisingly, increases in phospho-ERK with the mutant receptor, as well as phospho-MEK,” Dr Ungewickell said.

“And to our knowledge, the RAS/MAP kinase pathway has not previously been linked to TNFRII signaling, suggesting that there is some kind of direct or indirect cross-talk between these pathways. We think it’s very interesting, since there are KRAS mutations that activate the RAS/MAP kinase pathway in a subset of these cases, suggesting some kind of synergy.”

Introducing the mutant receptor into primary CD4+ T cells had an effect similar to that observed in the Jurkat cells. The researchers did western blotting for NF-kB processing, and they saw an increase in p100 to p52 processing.

“This is a preliminary experiment, but we’re actually quite excited about this, since Jurkat cells have many abnormalities, due to the fact that they’re a leukemia line, and primary T cells will have the rest of the genome intact,” Dr Ungewickell said.

Now, he and his colleagues are conducting several studies to identify the changes that occur in primary T cells when mutant TNFRII is expressed. They also want to see if they can recapitulate CTCL and identify the transcriptional signature they previously found in patient biopsies and cells.

Lastly, the researchers are performing functional assays to evaluate proliferation, apoptosis, and pharmacological information, with the goal of identifying therapies that might be effective in patients with TNFRII mutation or amplification.

“Patients who have increased TNFRII signaling might respond to proteasome inhibitors, since p100 and p52 processing requires the proteasome,” Dr Ungewickell said. “And given that cross-talk with the RAS/MAP kinase signaling, as well as the KRAS mutations, we also think . . . that MEK inhibitors might be effective in the treatment of CTCL.”

Platelets, 3rd Edition

Edited by Alan Michelson, MD

The textbook marketplace is crowded with many titles pertinent to the topic of hemostasis and thrombosis, and the field is becoming increasingly complex, with the addition of new antiplatelet medications and novel, target-specific therapeutic agents.

It has become incumbent for hematologists and oncologist-hematologists who care for or consult on patients with any disease process involving platelets to understand the pathophysiology and rationale of treatment of these disorders.

This third edition of Platelets is again an aggregation of the most prominent physicians, physician-scientists, and basic researchers in platelet biology and clinical hemostasis.

Very much an encyclopedia of platelet biology, Platelets is an informative tome that will serve as a comprehensive resource for the busy clinician, the academic hematologist preparing for lectures on platelet physiology and hemostasis, the basic scientist preparing a research grant, the house officer trying to understand treatment algorithms, the blood banker who runs a busy transfusion service, and the clinical pathologist who supervises a coagulation laboratory.

The foreword chapter by Dr Barry Coller sets the tone for the book, with a thoughtful, interesting, and easily readable overview of the platelet in health and disease.

Over the next 63 chapters and more than 1300 pages, the platelet is examined as an active organ that expresses mRNAs from one-quarter to one-third of the human genome; contains a highly adaptive proteome responsive to external signals of both healthy and pathological processes; and can then participate directly and indirectly as modulators of hemostasis, inflammation, immunology, atherogenesis, angiogenesis, carcinogenesis, etc.

The chapters on laboratory measurements of platelet function and interpretation thereof are very useful and provide practical information for the clinician and clinical laboratorian. The review of the new antiplatelet aggregating agents succinctly and comprehensively describes their pharmacology and their appropriate placement in therapeutic algorithms of many disease processes.

Similarly, the chapters on thrombopoietin and autoimmune thrombocytopenia provide critical insight on the appropriate use of and the potential complications associated with use of the new thrombopoietic agonists.

Finally, the chapters that concentrate on the blood banking aspects of platelet therapy and platelet disorders are particularly well-written and understandable. The chapters on the pathogenesis, diagnosis, and treatment of neonatal alloimmune thrombocytopenia and post-transfusion purpura are very helpful, and I found myself consulting them in my clinical practice, even as I was preparing this review on Platelets.

In summary, Platelets fills an important niche on the bookshelf of any academic hematologist. The user- friendly online access to the figures contained in the textbook will be especially useful for teaching purposes. Notwithstanding its considerable size and weight, this encyclopedia of the platelet contains critical information for physicians, educators, students, and research scientists.

Craig M. Kessler, MD, MACP

Lombardi Comprehensive Cancer Center

Georgetown University School of Medicine, Washington, DC

Platelets, 3rd Edition

Edited by Alan Michelson, MD

The textbook marketplace is crowded with many titles pertinent to the topic of hemostasis and thrombosis, and the field is becoming increasingly complex, with the addition of new antiplatelet medications and novel, target-specific therapeutic agents.

It has become incumbent for hematologists and oncologist-hematologists who care for or consult on patients with any disease process involving platelets to understand the pathophysiology and rationale of treatment of these disorders.

This third edition of Platelets is again an aggregation of the most prominent physicians, physician-scientists, and basic researchers in platelet biology and clinical hemostasis.

Very much an encyclopedia of platelet biology, Platelets is an informative tome that will serve as a comprehensive resource for the busy clinician, the academic hematologist preparing for lectures on platelet physiology and hemostasis, the basic scientist preparing a research grant, the house officer trying to understand treatment algorithms, the blood banker who runs a busy transfusion service, and the clinical pathologist who supervises a coagulation laboratory.

The foreword chapter by Dr Barry Coller sets the tone for the book, with a thoughtful, interesting, and easily readable overview of the platelet in health and disease.

Over the next 63 chapters and more than 1300 pages, the platelet is examined as an active organ that expresses mRNAs from one-quarter to one-third of the human genome; contains a highly adaptive proteome responsive to external signals of both healthy and pathological processes; and can then participate directly and indirectly as modulators of hemostasis, inflammation, immunology, atherogenesis, angiogenesis, carcinogenesis, etc.

The chapters on laboratory measurements of platelet function and interpretation thereof are very useful and provide practical information for the clinician and clinical laboratorian. The review of the new antiplatelet aggregating agents succinctly and comprehensively describes their pharmacology and their appropriate placement in therapeutic algorithms of many disease processes.

Similarly, the chapters on thrombopoietin and autoimmune thrombocytopenia provide critical insight on the appropriate use of and the potential complications associated with use of the new thrombopoietic agonists.

Finally, the chapters that concentrate on the blood banking aspects of platelet therapy and platelet disorders are particularly well-written and understandable. The chapters on the pathogenesis, diagnosis, and treatment of neonatal alloimmune thrombocytopenia and post-transfusion purpura are very helpful, and I found myself consulting them in my clinical practice, even as I was preparing this review on Platelets.

In summary, Platelets fills an important niche on the bookshelf of any academic hematologist. The user- friendly online access to the figures contained in the textbook will be especially useful for teaching purposes. Notwithstanding its considerable size and weight, this encyclopedia of the platelet contains critical information for physicians, educators, students, and research scientists.

Craig M. Kessler, MD, MACP

Lombardi Comprehensive Cancer Center

Georgetown University School of Medicine, Washington, DC

Platelets, 3rd Edition

Edited by Alan Michelson, MD

The textbook marketplace is crowded with many titles pertinent to the topic of hemostasis and thrombosis, and the field is becoming increasingly complex, with the addition of new antiplatelet medications and novel, target-specific therapeutic agents.

It has become incumbent for hematologists and oncologist-hematologists who care for or consult on patients with any disease process involving platelets to understand the pathophysiology and rationale of treatment of these disorders.

This third edition of Platelets is again an aggregation of the most prominent physicians, physician-scientists, and basic researchers in platelet biology and clinical hemostasis.

Very much an encyclopedia of platelet biology, Platelets is an informative tome that will serve as a comprehensive resource for the busy clinician, the academic hematologist preparing for lectures on platelet physiology and hemostasis, the basic scientist preparing a research grant, the house officer trying to understand treatment algorithms, the blood banker who runs a busy transfusion service, and the clinical pathologist who supervises a coagulation laboratory.

The foreword chapter by Dr Barry Coller sets the tone for the book, with a thoughtful, interesting, and easily readable overview of the platelet in health and disease.

Over the next 63 chapters and more than 1300 pages, the platelet is examined as an active organ that expresses mRNAs from one-quarter to one-third of the human genome; contains a highly adaptive proteome responsive to external signals of both healthy and pathological processes; and can then participate directly and indirectly as modulators of hemostasis, inflammation, immunology, atherogenesis, angiogenesis, carcinogenesis, etc.

The chapters on laboratory measurements of platelet function and interpretation thereof are very useful and provide practical information for the clinician and clinical laboratorian. The review of the new antiplatelet aggregating agents succinctly and comprehensively describes their pharmacology and their appropriate placement in therapeutic algorithms of many disease processes.

Similarly, the chapters on thrombopoietin and autoimmune thrombocytopenia provide critical insight on the appropriate use of and the potential complications associated with use of the new thrombopoietic agonists.

Finally, the chapters that concentrate on the blood banking aspects of platelet therapy and platelet disorders are particularly well-written and understandable. The chapters on the pathogenesis, diagnosis, and treatment of neonatal alloimmune thrombocytopenia and post-transfusion purpura are very helpful, and I found myself consulting them in my clinical practice, even as I was preparing this review on Platelets.

In summary, Platelets fills an important niche on the bookshelf of any academic hematologist. The user- friendly online access to the figures contained in the textbook will be especially useful for teaching purposes. Notwithstanding its considerable size and weight, this encyclopedia of the platelet contains critical information for physicians, educators, students, and research scientists.

Craig M. Kessler, MD, MACP

Lombardi Comprehensive Cancer Center

Georgetown University School of Medicine, Washington, DC