Variability of markers of inflammation and infection in induced sputum in children with cystic fibrosis.

To determine reproducibility of inflammatory marker concentrations in induced sputum from subjects with cystic fibrosis (CF), 15 nonexpectorating children, 6 to 13 years of age with mild CF lung disease, underwent 3 weekly sputum inductions with 3% saline. Neutrophil elastase concentration and bacterial cultures were reproducible. This study provides useful information for investigators designing trials of anti-inflammatory therapies in CF involving sputum induction.