Azithromycin Attenuates Effects of Lipopolysaccharide on Lung Allograft Bronchial Epithelial Cells

Background: The bronchial epithelium is a Source of mediators that may play a role in the airway inflammation and remodeling of post-transplant obliterative bronchiolitis (OB). Traditional strategies have failed to have an impact on OB. Recent studies have suggested a role for azithromycin in managing the condition. In this study we aimed to determine the effect of azithromycin on LPS-mediated epithelial release of factors relevant to airway neutrophilia and remodeling in a unique population of primary bronchial epithelial cells (PBECs) derived from stable lung allografts. Methods: PBECs were established from bronchial brushings of stable lung transplant recipients and treated with lipopolysaccharide (LPS, 0.1, 1 and 10 mu g/ml) for 48 hours. Interleukin-8 (IL-8), granulocyte macrophage colony-stimulating factor (GM-CSF) and vascular endothelial growth factor (VEGF) protein levels were measured by Luminex analyzer. PBECs were then incubated with LPS and azithromycin, and protein levels were again determined. Results: LPS caused a significant increase in IL-8 and GM-CSF at concentrations of I and 10 mu g/ml, with no effect on VEGF release. Azithromycin caused a significant decrease in the LPS-stimulated IL-8 and GM-CSF release. Conclusions: LPS upregulates release of IL-8 and GM-CSF from PBECs derived from stable lung allografts. Sub-microbicidal concentrations of azithromycin attenuate this and may, therefore, alleviate infection-driven neutrophilic airway inflammation and remodeling in the allograft airway. J Heart Lung Transplant 2008;27:1210- 6. Copyright (C) 2008 by the International Society for Heart and Lung Transplantation.