CHEMOTACTIC FACTORS IN BRONCHIAL-SECRETIONS OF CYSTIC-FIBROSIS PATIENTS

To understand chronic neutrophil attraction into cystic fibrosis airwa ys, both global chemotactic activity and individual chemotactic factor s were studied in bronchial secretions. Bronchial secretions of 8 cyst ic fibrosis patients, collected on the first day of admission for anti biotic treatment, showed a high chemotactic index (19.4 +/- 5.7, n = 8 ). Fractionation by gel filtration of bronchial secretions resulted in three chemotactic fractions. The first factor corresponded to interle ukin-8, and the second activated neutrophils via the FMLP receptor. Th e third factor, which was of lower molecular weight, did not activate FMLP or leukotriene B-4 receptors, and its nature is still under inves tigation. Treating patients with antibiotics reduced global chemotacti c activity, mainly by reducing the activity due to stimulation of the FMLP receptor.