LDH Levels May Help to Determine Bronchiolitis Severity

Major Finding: A nasal wash lactate dehydrogenase level reaching 365 U/mL or higher in children with bronchiolitis was associated with a significant 81% reduction in the need for hospital admission.

Data Source: A retrospective analysis of prospectively collected nasal wash samples from 98 children with bronchiolitis.

Disclosures: The study was funded by a grant from the National Institutes of Health Baylor Research Training Program for Pediatricians and a Viral Respiratory Pathogen Research Unit Contract. Dr. Laham and his associates said they had no relevant financial conflicts to disclose.

The concentration of lactate dehydrogenase in nasal wash may be a useful clinical biochemical marker of the severity of bronchiolitis in children and help to determine their need for hospitalization, the results of a retrospective analysis suggest.

Dr. Federico R. Laham and his colleagues at Baylor College of Medicine, Houston, found that bronchiolitic children with lower lactate dehydrogenase (LDH) levels in their nasal wash were significantly more likely to leave the emergency department without being hospitalized and to have a shorter duration of oxygen supplementation or no need for it than were children who had higher LDH levels.

“Currently the presence of hypoxia, significant respiratory distress, and clinical judgment are the main consideration[s] for determining the need to hospitalize a child with bronchiolitis. Having a validated biochemical marker predictive for hospitalization can provide another objective parameter to the physician, and would be valuable in difficult-to-assess cases,” Dr. Laham and his associates wrote (Pediatrics 2010;125:e225–33).

The study represents the first known analysis of lactate dehydrogenase levels in nasal wash, according to the investigators. They identified viruses, tested for cytokines and chemokines, and measured levels of apoptosis and LDH in nasal wash specimens from 98 children who had participated in an earlier study of bronchiolitis. They also measured serum LDH levels. These 98 patients had a median age of 5.6 months and a median duration of illness of 4 days at the time of their presentation to the ED.

Respiratory syncytial virus (RSV) was identified in 65 (66%) patients, including 15 coinfected with RSV and another virus. Although detection of a virus alone was associated with a higher concentration of LDH in nasal wash, children with RSV infection in particular had a significantly greater LDH level in nasal wash than did children not infected with RSV.

A higher nasal wash to serum LDH ratio in children sent home from the ED, compared with those admitted to the hospital, supports the hypothesis that “LDH originates from widespread airway epithelial cell injury and apoptosis or from leukocytes (largely polymorphonuclear cells) present in the [nasal wash] fluid.”

Dr. Laham and his colleagues noted that previous studies investigating the risk of hospitalization and the severity of disease in children with RSV infection largely corroborate these results and “support the concept of a protective effect derived from a robust innate immune response during an episode of RSV bronchiolitis, where inflammatory markers inversely correlated with disease severity.”

In a multivariate analysis, an age of 3 months or younger, the need for intravenous fluids, and the presence of hypoxia were significant predictors of hospitalization among children with bronchiolitis who presented to the ED.

However, a nasal wash LDH level reaching 365 U/mL or higher was associated with a significant 81% reduction in the need for admission.

In the same prediction model, the investigators calculated an area under the receiver operating characteristic curve of 0.87. Based on that area and a cutoff value of 0.5 for the predicted probability of hospitalization, the model predicted hospitalization with 81% sensitivity and 77% specificity.

“These values are comparable to many of the point-of-care tests used in diagnosing a viral infection. The LDH assay is easy to perform, inexpensive, and available in most clinical laboratories. At our institution, the expected turnaround time for serum LDH is 1 hour, and [nasal wash] samples should not be treated differently,” Dr. Laham and his associates wrote.

Major Finding: A nasal wash lactate dehydrogenase level reaching 365 U/mL or higher in children with bronchiolitis was associated with a significant 81% reduction in the need for hospital admission.

Data Source: A retrospective analysis of prospectively collected nasal wash samples from 98 children with bronchiolitis.

Disclosures: The study was funded by a grant from the National Institutes of Health Baylor Research Training Program for Pediatricians and a Viral Respiratory Pathogen Research Unit Contract. Dr. Laham and his associates said they had no relevant financial conflicts to disclose.

The concentration of lactate dehydrogenase in nasal wash may be a useful clinical biochemical marker of the severity of bronchiolitis in children and help to determine their need for hospitalization, the results of a retrospective analysis suggest.

Dr. Federico R. Laham and his colleagues at Baylor College of Medicine, Houston, found that bronchiolitic children with lower lactate dehydrogenase (LDH) levels in their nasal wash were significantly more likely to leave the emergency department without being hospitalized and to have a shorter duration of oxygen supplementation or no need for it than were children who had higher LDH levels.

“Currently the presence of hypoxia, significant respiratory distress, and clinical judgment are the main consideration[s] for determining the need to hospitalize a child with bronchiolitis. Having a validated biochemical marker predictive for hospitalization can provide another objective parameter to the physician, and would be valuable in difficult-to-assess cases,” Dr. Laham and his associates wrote (Pediatrics 2010;125:e225–33).

The study represents the first known analysis of lactate dehydrogenase levels in nasal wash, according to the investigators. They identified viruses, tested for cytokines and chemokines, and measured levels of apoptosis and LDH in nasal wash specimens from 98 children who had participated in an earlier study of bronchiolitis. They also measured serum LDH levels. These 98 patients had a median age of 5.6 months and a median duration of illness of 4 days at the time of their presentation to the ED.

Respiratory syncytial virus (RSV) was identified in 65 (66%) patients, including 15 coinfected with RSV and another virus. Although detection of a virus alone was associated with a higher concentration of LDH in nasal wash, children with RSV infection in particular had a significantly greater LDH level in nasal wash than did children not infected with RSV.

A higher nasal wash to serum LDH ratio in children sent home from the ED, compared with those admitted to the hospital, supports the hypothesis that “LDH originates from widespread airway epithelial cell injury and apoptosis or from leukocytes (largely polymorphonuclear cells) present in the [nasal wash] fluid.”

Dr. Laham and his colleagues noted that previous studies investigating the risk of hospitalization and the severity of disease in children with RSV infection largely corroborate these results and “support the concept of a protective effect derived from a robust innate immune response during an episode of RSV bronchiolitis, where inflammatory markers inversely correlated with disease severity.”

In a multivariate analysis, an age of 3 months or younger, the need for intravenous fluids, and the presence of hypoxia were significant predictors of hospitalization among children with bronchiolitis who presented to the ED.

However, a nasal wash LDH level reaching 365 U/mL or higher was associated with a significant 81% reduction in the need for admission.

In the same prediction model, the investigators calculated an area under the receiver operating characteristic curve of 0.87. Based on that area and a cutoff value of 0.5 for the predicted probability of hospitalization, the model predicted hospitalization with 81% sensitivity and 77% specificity.

“These values are comparable to many of the point-of-care tests used in diagnosing a viral infection. The LDH assay is easy to perform, inexpensive, and available in most clinical laboratories. At our institution, the expected turnaround time for serum LDH is 1 hour, and [nasal wash] samples should not be treated differently,” Dr. Laham and his associates wrote.

Major Finding: A nasal wash lactate dehydrogenase level reaching 365 U/mL or higher in children with bronchiolitis was associated with a significant 81% reduction in the need for hospital admission.

Data Source: A retrospective analysis of prospectively collected nasal wash samples from 98 children with bronchiolitis.

Disclosures: The study was funded by a grant from the National Institutes of Health Baylor Research Training Program for Pediatricians and a Viral Respiratory Pathogen Research Unit Contract. Dr. Laham and his associates said they had no relevant financial conflicts to disclose.

The concentration of lactate dehydrogenase in nasal wash may be a useful clinical biochemical marker of the severity of bronchiolitis in children and help to determine their need for hospitalization, the results of a retrospective analysis suggest.

Dr. Federico R. Laham and his colleagues at Baylor College of Medicine, Houston, found that bronchiolitic children with lower lactate dehydrogenase (LDH) levels in their nasal wash were significantly more likely to leave the emergency department without being hospitalized and to have a shorter duration of oxygen supplementation or no need for it than were children who had higher LDH levels.

“Currently the presence of hypoxia, significant respiratory distress, and clinical judgment are the main consideration[s] for determining the need to hospitalize a child with bronchiolitis. Having a validated biochemical marker predictive for hospitalization can provide another objective parameter to the physician, and would be valuable in difficult-to-assess cases,” Dr. Laham and his associates wrote (Pediatrics 2010;125:e225–33).

The study represents the first known analysis of lactate dehydrogenase levels in nasal wash, according to the investigators. They identified viruses, tested for cytokines and chemokines, and measured levels of apoptosis and LDH in nasal wash specimens from 98 children who had participated in an earlier study of bronchiolitis. They also measured serum LDH levels. These 98 patients had a median age of 5.6 months and a median duration of illness of 4 days at the time of their presentation to the ED.

Respiratory syncytial virus (RSV) was identified in 65 (66%) patients, including 15 coinfected with RSV and another virus. Although detection of a virus alone was associated with a higher concentration of LDH in nasal wash, children with RSV infection in particular had a significantly greater LDH level in nasal wash than did children not infected with RSV.

A higher nasal wash to serum LDH ratio in children sent home from the ED, compared with those admitted to the hospital, supports the hypothesis that “LDH originates from widespread airway epithelial cell injury and apoptosis or from leukocytes (largely polymorphonuclear cells) present in the [nasal wash] fluid.”

Dr. Laham and his colleagues noted that previous studies investigating the risk of hospitalization and the severity of disease in children with RSV infection largely corroborate these results and “support the concept of a protective effect derived from a robust innate immune response during an episode of RSV bronchiolitis, where inflammatory markers inversely correlated with disease severity.”

In a multivariate analysis, an age of 3 months or younger, the need for intravenous fluids, and the presence of hypoxia were significant predictors of hospitalization among children with bronchiolitis who presented to the ED.

However, a nasal wash LDH level reaching 365 U/mL or higher was associated with a significant 81% reduction in the need for admission.

In the same prediction model, the investigators calculated an area under the receiver operating characteristic curve of 0.87. Based on that area and a cutoff value of 0.5 for the predicted probability of hospitalization, the model predicted hospitalization with 81% sensitivity and 77% specificity.

“These values are comparable to many of the point-of-care tests used in diagnosing a viral infection. The LDH assay is easy to perform, inexpensive, and available in most clinical laboratories. At our institution, the expected turnaround time for serum LDH is 1 hour, and [nasal wash] samples should not be treated differently,” Dr. Laham and his associates wrote.