Lactate dehydrogenase and caspase activity in nasopharyngeal secretions are predictors of bronchiolitis severity

Mehta, Reena; Scheffler, Margaret; Tapia, Lorena; Aideyan, Letisha; Patel, Kirtida D; Jewell, Alan M; Avadhanula, Vasanthi; Mei, Minghua; Garofalo, Roberto P; Piedra, Pedro A

Recently, we observed that nasal wash lactate dehydrogenase (NW-LDH) was a good predictor of bronchiolitis severity. 13 NW-LDH was inversely correlated with disease severity in infants and young children presenting to the emergency department with bronchiolitis. 13 It also significantly correlated with NW-caspase 3/7 activity, which is a marker of apoptosis, and was shown not to correlate with serum LDH. 13 Our observation was validated in a multicenter study conducted by Mansbach and colleagues, who also observed an inverse relationship between NW-LDH levels and bronchiolitis severity in young children presenting to the emergency department. 14 In a bronchiolitis study conducted in the emergency department, Bennett and colleagues observed that an early robust proinflammatory immune response in the upper respiratory tract inversely correlated with duration of supplemental-oxygen therapy and did not contribute to severity of disease. 15 In synthesizing the findings of these studies, we hypothesize that a major source of the lactate dehydrogenase in the nasal washes of children with bronchiolitis is likely derived from epithelial cells and/or neutrophils undergoing apoptosis as part of an innate immune response for controlling viral infection rather than from cellular necrosis of the epithelial cells and or inflammatory cells.