This study consists of two parts which will be conducted in parallel. In the first part of the study, 14 subjects will be recruited for the Clinically Stable Cohort. Subjects will be asked to provide 1 gm of expectorated sputum and 40-ml of blood. A cell count and differential will be performed on the sputum followed by analysis for IL-17 PMNs by fluorescence-activated cell sorter (FACS). IL-17 PMNs also will be isolated by running the remainder of the cell pellet through a column of magnetic beads designed for this purpose. These neutrophils will be lysed and intracellular cytokines determined. Sputum supernatants will be stored frozen until analyzed for the presence of IL-1β, IL-6, IL-8, IL-17A, TGF-β, TNF-α, and neutrophil elastase. Clinical data will be captured from the subject's clinical outpatient visit including lung function measures and clinical culture results. IL-17 PMNs will be correlated with lung function measures and inflammatory mediators at baseline.