Incidence and risk factors for bronchiolitis obliterans syndrome stage 0p after lung transplantation

Introduction: Lung transplantation is a therapy for end-stage pulmonary diseases. However, long term survival remains limited because of the development of bronchiolitis obliterans syndrome (BOS), and BOS stage 0p (BOS 0p) have been considered as the prodromal phase before BOS development. Objectives: We are to investigate the incidence of BOS 0p and analyze the risk factors for development of BOS 0p. Methods: We reviewed the medical records of 112 lung transplant patients at one tertiary care hospital in South Korea, between January 2010 and August 2015. Definition of BOS 0p was from that of International Society for Heart and Lung Transplantation. The patients who survived for more than one year and performed pulmonary function test more than three times were enrolled for this study. Results: Total 56 patients were enrolled, and BOS 0p developed in 27 patients (48.2%). Median age was lower in BOS 0p group compared to BOS-free group (45 vs. 54; P-value, 0.035) and there was no difference in gender, underlying disease, pre-transplantation status, baseline cardiac function, frequency of acute rejection or CMV reactivation. And the proportion of high men fluorescence intensity(MFI) in anti-HLA antibody was higher in BOS 0p group (44.4% vs. 20.0%; P-value, 0.06) although the difference was not statistical important. In donor perspective, ratio of PaO2 on FiO2 (PF ratio) before transplantation was lower in BOS 0p group (419 vs. 488; P-value, 0.045). Conclusions: High MFI in anti-HLA antibody and lower PF ratio in donor lung may risk factors for development of BOS 0p.