Macrolide Antibiotics Directly Reduce Active Oxygen Generation by Neutrophils in Human Peripheral Blood

Since a “low-dose and long-term” administration of erythromycin (EM) was reported to be effective in patients with chronic respiratory diseases, including diffuse panbronchiolitis (DPB), the modulation of host defense responses by EM has attracted much attention. Despite considerable controversy, it was recently demonstrated that macrolides reduced neutrophil function. In this study, we investigated the effects of EM, a 14-membered ring macrolide, azithromycin (AZM), a 15-membered ring macrolide, and rokitamycin (RKM), a 16-membered ring macrolide, on neutrophil function in terms of active oxygen generation of neutrophils in the absence and presence of mononuclear cells in vitro. EM and AZM significantly suppressed active oxygen generation by neutrophils in the absence of mononuclear cells at low concentration (0.5 μg/ml. p