Novel neutrophil-derived proteins in bronchoalveolar lavage fluid indicate an exaggerated inflammatory response in pediatric cystic fibrosis patients

Background: Airway inflammation in cystic fibrosis (CF) is exaggerated and characterized by neutrophilmediated tissue destruction, but its genesis and mechanisms remain poorly understood. To further define the pulmonary inflammatory response, we conducted a proteome-based screen of bronchoalveolar lavage fluid (BALF) collected from young children with and without CF experiencing endobronchial infection. Methods: We collected BALF samples from 45 children younger than 5 years and grouped them according to the presence of respiratory pathogens: >= 1 X 10(5) colony forming units (CFU)/mL BALF (18 and 12 samples with and without CF, respectively) an