Directed neutrophil migration to IL-8 is increased in cystic fibrosis: a study of the effect of erythromycin

Background-The aim of this study was to compare neutrophil migration in cys tic fibrosis (CF) and non-CF populations and to investigate the effect of e rythromycin on directed migration of neutrophils (PMNs) in CF. Methods-PMNs were isolated and their migratory capacity in response to inte rleukin-8 (IL-8) or f-Met-Leu-Phe (fMLP) in the presence or absence of eryt hromycin (1-100 mug/ml) was assessed. Results-CF derived PMNs showed significantly increased migration to IL-8 bu t not to fMLP compared with non-CF PMNs. Erythromycin had no significant ef fect on migration responses to IL-8 and in vitro exposure of PMNs to erythr omycin had no effect. Conclusions-CF derived PMNs show higher migratory responsiveness to IL-8 bu t not to fMLP, suggesting that CF PMNs may be "primed" to IL-8 which is sig nificantly increased in CF serum compared with non-CF serum. Treatment with erythromycin had no significant effect on PMN migration in vitro.