Airway, but not serum or urinary, levels of YKL-40 reflect inflammation in early cystic fibrosis lung disease

Cystic fibrosis (CF) lung disease begins in early life and is progressive with the major risk factor being an exaggerated inflammatory response. Currently, assessment of neutrophilic inflammation in early cystic fibrosis (CF) lung disease relies on bronchoalveolar lavage (BAL).