The Immunomodulatory effects of erythromycin and its semisynthetic derivatives were verified both in vitro and in artificial chronic inflammation in animal testing. Mechanisms leading to the anti-inflammatory effects were also studied.
Only then, patients with chronic respiratory diseases were treated with subtherapeutic concentrations of some macrolide antibiotics for months or even years. The studies were mainly performed in patients with diffuse panbronchiolitis, cystic fibrosis, refractory asthma or chronic pansinusitis.
After at least 2 months of therapy, the treated patients had fewer inflammatory exacerbations, significantly improved quality of life, decreased levels of inflammatory parameters including lower sputum neutrophil count and decreased production of IL-8.