Increase in interleukin-8 production from circulating neutrophils upon antibiotic therapy in cystic fibrosis patients

BACKGROUND: It is not known whether antibiotic therapy for lung disease in cystic fibrosis (CF) has an influence on circulating polymorphonuclear neutrophil (PMN) function and apoptosis. PATIENTS AND METHODS: Blood PMNs were obtained from 14 CF patients before and after antibiotic treatment for an acute exacerbation, and from 10 healthy controls. PMNs were evaluated for production of reactive oxygen species (ROS) by spectrophotometry, of cytokines in the conditioned medium by ELISA, and apoptotic response by cytofluorimetry. RESULTS: ROS and interleukin (IL)-8 were produced at higher levels by CF PMNs pre-therapy than control PMNs under basal conditions. IL-8 levels further increased after therapy. Early apoptotic response was higher in CF PMNs pre-therapy than in control PMNs, and this pattern did not change after antibiotic treatment. CONCLUSIONS: Circulating PMNs are primed in CF acute patients. Further studies are needed to consider PMN-produced IL-8 as a biomarker to evaluate response to antibiotic therapy in CF patients.