The Leuven experience with a dichotomy in Bronchiolitis Obliterans Syndrome (BOS) after lung transplantation revealed by azithromycin

Abstract

BOS is the most important cause of late mortality after LTx. Until 5 years ago, the prevalence was around 30% and 50%, 3 and 5 years after LTx. Introduction of azithromycin (AZI) improved the FEV1 in 40% of BOS patients. AZI treatment may explain why in our center, the BOS prevalence at 3 years has decreased from 30% to 15% compared to the ISHLT registry. Opposed to the current belief about BOS, we hypothesize a dichotomy within BOS: Neutrophilic Reversible Allograft Dysfunction (NRAD) and fibropoliferative BOS (fBOS; table 1). This dichotomy is based on the discrepancy in AZI response and observations within our center consisting of clinical, biochemical and cellular (BAL) analysis.