Long-term azithromycin therapy for bronchiolitis obliterans syndrome: divide and conquer?

Area of Science:

• Pulmonology
• Transplant Surgery
• Pharmacology

Background:

• Bronchiolitis obliterans syndrome (BOS) is a major cause of lung transplant failure.
• Azithromycin is being investigated for its potential to reverse or halt pulmonary function decline in BOS.
• This study focuses on the long-term effects of azithromycin in lung transplant recipients with BOS.

Purpose of the Study:

• To investigate the efficacy of long-term azithromycin treatment in lung transplant recipients diagnosed with BOS.
• To assess the impact of azithromycin on pulmonary function (FEV(1)), bronchoalveolar lavage neutrophilia, and overall survival.

Main Methods:

• A retrospective, observational cohort study involving 107 BOS patients (Stages 0p/1/2/3).
• Patients received azithromycin for an average of 3.1 years.
• Evaluations included FEV(1) changes, bronchoalveolar lavage neutrophilia, and survival analysis using log-rank and Cox regression.

Main Results:

• 40% of patients experienced a ≥10% increase in FEV(1) within 3-6 months; 33% of these later redeveloped BOS.
• Non-responders showed continued FEV(1) decline (78%) or stabilization (22%).
• Higher pre-treatment neutrophilia was observed in responders (29.3% vs 11.5%, p=0.025) and significantly decreased post-treatment.
• Responders had significantly better survival rates (p=0.050) and lower mortality (p=0.027).
• Initial azithromycin response and earlier post-transplant initiation were protective against BOS progression/relapse and death/retransplantation.

Conclusions:

• Long-term azithromycin administration demonstrates significant benefits for pulmonary function and survival in lung transplant recipients with BOS.
• Patients with higher pre-treatment lavage neutrophilia appear to benefit most from azithromycin therapy.
• Early response to azithromycin and timely initiation post-transplant are crucial for improved patient outcomes.