Abstract
Serial serum myeloperoxidase was determined in 27 cystic fibrosis patients with chronic endobronchial Pseudomonas aeruginosa infection over the course of 1 y. The effect of repeated courses of antibiotic therapy on mean serum myeloperoxidase levels was significant (p = 0.034). Serial serum myeloperoxidase may help to guide therapy for pulmonary exacerbations.