Low-dose azithromycin improves phagocytosis of bacteria by both alveolar and monocyte-derived macrophagesin chronic obstructive pulmonary disease subjects
Article first published online: 25 JUN 2012
© 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology
Volume 17, Issue 5, pages 802–807, July 2012
How to Cite
HODGE, S. and REYNOLDS, P. N. (2012), Low-dose azithromycin improves phagocytosis of bacteria by both alveolar and monocyte-derived macrophagesin chronic obstructive pulmonary disease subjects. Respirology, 17: 802–807. doi: 10.1111/j.1440-1843.2012.02135.x
- Issue published online: 25 JUN 2012
- Article first published online: 25 JUN 2012
- Accepted manuscript online: 31 JAN 2012 03:35AM EST
- Received 28 October 2011; invited to revise 8 December 2011; revised 15 December 2011; accepted 28 December 2011 (Associate Editor: Marcos Restrepo).
- alveolar macrophage;
- chronic obstructive pulmonary disease;
- monocyte-derived macrophage;
Background and objective: Chronic inflammation and reduced airways integrity in chronic obstructive pulmonary disease (COPD) potentially results from secondary necrosis as a result of impaired phagocytosis of apoptotic material by airway macrophages, and increased bacterial colonization. We have previously shown that administration of low-dose azithromycin to subjects with COPD improved macrophage phagocytosis of apoptotic airway epithelial cells, reduced inflammation and increased expression of macrophage mannose receptor.
Methods: We firstly investigated whether there were defects in the ability of both alveolar (AM) and monocyte-derived macrophages (MDM) to phagocytose bacteria in COPD, as we have previously reported for phagocytosis of apoptotic cells. We then assessed the effects of administration of low-dose azithromycin to COPD patients on the ability of AM and MDM to phagocytose bacteria. Azithromycin (250 mg orally daily for 5 days then 2× weekly (total 12 weeks)) was administered to 11 COPD subjects and phagocytosis of fluorescein isothiocyanate-labelled Escherichia coli assessed by flow cytometry.
Results: COPD subjects had a significant defect in the ability of both AM and MDM to phagocytose bacteria that was significantly improved by administration of low-dose azithromycin
Conclusions: The data provide further support for the long-term use of low dose azithromycin as an attractive adjunct treatment option for COPD. Improved clearance of both apoptotic cells and bacteria in the airway may have a dual effect; reducing the risk of secondary necrosis and release of toxic cell contents that perpetuate inflammation as well as contributing to a reduction in the rate of exacerbations in COPD.