Positive bronchoalveolar lavage pepsin assay associated with viral and fungal respiratory infections in children with chronic cough.

Objective: To assess the association between commonly obtained endoscopic and serologic data and bronchoalveolar lavage pepsin assay (BAL) results in children with chronic cough.

Study Design: We performed a retrospective chart review of 72 children with a BAL pepsin obtained through our Aerodigestive Center over an 18-month period. BAL outcomes include evidence of viral, bacterial, or fungal infection, presence of lipid-laden macrophages, and cytology (eosinophils, neutrophils, and lymphocytes). Gastrointestinal outcomes include esophagogastroduodenoscopy (EGD) and pH impedance probe findings. Other characteristics include serum eosinophils, neutrophils, and lymphocytes; spirometry; FeNO; and IgE.

Results: Seventy-two patients underwent BAL pepsin testing. Median age was 4.9 years, 30.6% had severe persistent asthma, and 59.2% were on reflux medication. There was an association between positive BAL pepsin assay and positive viral panel (p = .002) or fungal culture (p = .027). No significant association found between positive BAL bacterial culture; BAL cytology; the presence of BAL lipid-laden macrophages; IgE; spirometry; FeNO; CBC neutrophil, eosinophil, or lymphocytes; pH impedance testing parameters; or EGD pathology.

Conclusions: BAL pepsin is associated with a positive BAL viral PCR or fungal culture. Lack of correlation between pepsin-positivity and pH-impedance parameters or EGD pathology suggests microaspiration may be due to an acute event (such as a respiratory infection) rather than chronic gastroesophageal reflux disease. This may be especially true in the presence of a positive viral panel or fungal culture when a BAL pepsin is obtained.