Leucocyte populations in respiratory syncytial virus-induced bronchiolitis

Objectives: To enumerate the cellular composition of the airways in infants with acute bronchiolitis. Methodology: Cells were obtained by airway lavage from the upper and lower airway and the peripheral blood of infants with respiratory syncytial virus (RSV)+ bronchiolitis. RSV-bronchiolitis and age-matched controls. Results: Neutrophils are the predominant cells present in the upper and lower airway. Neutrophils are present at a higher number/unit volume in the airway than in the peripheral blood. Conclusions: Neutrophils, being the dominant cellular infiltrate into the airway, are likely to contribute to the pathophysiology of bronchiolitis. Therapies targeted at limiting neutrophil influx or neutrophil mediated damage in the airway may have a therapeutic role.