The effects of erythromycin on human peripheral neutrophil apoptosis

Erythromycin is reported to have an anti-inflammatory action, which may acc ount for ifs clinical effectiveness in creating chronic inflammatory diseas es of the respiratory tract such as diffuse panbronchiolitis (DPB) and chro nic sinusitis. To evaluate the anti-inflammatory action of erythromycin, we examined apopt osis of isolated neutrophils incubated with and without erythromycin. As a result, erythromycin augmented neutrophil apoptosis in a dose-dependent man ner, with a maximal effect at 10 mug/ml and above The percentage of neutrop hil apoptosis at 12 h was 79.2+/-2.3% in medium with 10 mug/ml of erythromy cin compared with 51.2+/-4.1% in control medium (p<0.005). In a manner simi lar to that of erythromycin, another macrolide antibiotic, roxithromycin, a lso increased neutrophil apoptosis. However, there was no effect on apoptos is induced by treatment with josamycin (macrolide antibiotic), ampicillin ( <beta>-lactam.) and cefazolin (cephalosporin antibiotic), or gentamycin (am inoglycoside). These findings suggest that erythromycin shortens neutrophil survival by accelerating neutrophil apoptosis.