Azithromycin in Lung Transplantation

Rates of chronic rejection following lung transplantation approach 45% at 5 years and reduce the 5-year survival to about 50%. The most common clinical surrogate of chronic rejection is bronchiolitis obliterans syndrome (BOS), which is defined as an irreversible loss in the FEV₁ of 20% or greater.

Currently, there are no satisfactory treatments for BOS. Following the success of erythromycin in diffuse panbronchiolitis, several groups have investigated the role of the neomacrolide azithromycin in treatment of BOS. Several retrospective and prospective studies have shown an improvement in the FEV₁, which is significant both clinically and statistically. In these reports, high BAL neutrophilia, typically greater than 15%, has been predictive of a response to azithromycin.

Two recent studies by the Belgian transplant group have looked at this in greater detail. The first study published in the Journal of Heart and Lung Transplantation in December 2010 (Vos et al. J Heart Lung Transplant. 2010; 29[12]:1358) was a retrospective look at long-term azithromycin therapy for BOS in 103 patients and showed an improvement in pulmonary function and survival in patients with BOS.

The second study by the same group that was published in the European Respiratory Journal (Vos et al. Eur Respir J. 2011;37[1]:164) was a randomized, prospective, placebo-controlled trial looking at the role of azithromycin in preventing BOS and showed a much lower incidence of BOS in patients treated with the drug.

The addition of azithromycin is the first intervention that has been shown to reverse the loss of lung function in patients with BOS and is a standard therapy for BOS, but with recent data, it should be considered upfront for the prevention of BOS.

Dr. Rajat Walia, FCCP
Steering Committee Member