Anti-inflammatory effects of macrolides: applications in chronic rhinosinusitis

The anti-inflammatory effects of macrolides are significant. The clinical impact on diffuse panbronchiolitis (DPB) has improved 10-year survival from 12% to more than 90% for these patients. The immunomodulatory activity of macrolides has been a source of mechanistic research as well as clinical research in non-DPB inflammatory airway disease. Suppression of neutrophilic inflammation of the airways has been demonstrated as the most robust immunomodulatory response from 14- and 15-membered ring macrolides. The inhibition of transcription factors, mainly nuclear factor-kB and activator protein 1, from alterations in intracellular cell signaling drives this mechanism. The suppression of interleukin-8 to a range of endogenous and exogenous challenges characterizes the alterations to cytokine production. The inflammatory mechanisms of chronic rhinosinusitis (CRS) have been a major non-DPB focus. Macrolides have been trialed in more than 14 prospective trials and are the focus of numerous research projects. Evidence for a strong clinical effect in CRS is mounting, but results may be tempered by researchers' inability to characterize the disease process. Eosinophilic dominated CRS is unlikely to respond, based on current research understanding and data from clinical trials. This article discusses the current concepts of macrolides and their application in the management of CRS.