Pediatric Chronic Pulmonary Aspiration Is Associated With Low Molecular Weight Hyaluronic Acid in the Bronchoalveolar Lavage

ABSTRACT Objectives Low molecular‐weight hyaluronic acid (LMW‐HA) is produced by the degradation of high‐molecular‐weight hyaluronic acid at the pulmonary interstitium and alveolar epithelium by reactive intermediates following lung injury. We aimed to investigate the role of bronchoalveolar lavage (BAL) LMW‐HA as a biomarker of pediatric chronic pulmonary aspiration (CPA). Methods Single‐center prospective comparison of LMW‐HA presence in BAL in pediatric Aerodigestive patients with and without CPA undergoing clinically indicated bronchoscopy. Pediatric pulmonologists diagnosed CPA based on video‐fluoroscopic swallowing evaluation. Results Fifteen children (mean age 6.1 years, male predominance at 73%, and 53% with CPA) were enrolled. Children with CPA have comparable baseline characteristics (age, sex, and race), but their BAL had higher white blood cell count, higher neutrophil percentages, higher bacterial culture positivity rates, and lower macrophage percentages than those without CPA. The two groups were comparable in sex, BAL lymphocyte percentages, eosinophil percentages, red blood cell counts, and lipid‐laden macrophage positivity. Detection of BAL LMW‐HA in the BAL had a 100% specificity and 88% sensitivity for CPA diagnosis. BAL protein levels were higher in the CPA group and in participants with positive LMW‐HA. Conclusions We suggest BAL LMW‐HA as a potential novel biomarker of pediatric CPA with high specificity and sensitivity. BAL LMW‐HA is not detectable in subjects without CPA and is associated with increased BAL protein levels.