CXCL8 and cystic fibrosis: Furthermore, clinical studies showed that treatment with azithromycin induced a decrease in IL-8 production and the release of neutrophil elastase (NE) in CF patients infected with P. aeruginosa, while in P. aeruginosa-negative patients, a reduction of serum amyloid A, calprotectin, C-reactive protein, and absolute neutrophil count was observed [37,38].