Risk factor and clinical outcome of bronchiolitis obliterans syndrome after allogeneic hematopoietic stem cell transplantation

Purpose: The development of bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic stem cell transplantation (HSCT) deteriorates patients' quality of life. This study aimed to analyze the prevalence, clinical features, risk factors and prognostic factors of BOS. Materials and Methods: This retrospective study included patients who underwent allogeneic HSCT from January 2002 to December 2008 and survived for ≥100 days after transplantation. Results: Of 860 patients who survived for ≥100 days, 36 (4.2%) met the diagnostic criteria. The duration of BOS development after transplantation was 466.00 (284.00–642.75) [median (interquartile range)] days. The risk factor for the development of BOS was peripheral blood as the stem cell source with a hazard ratio (HR) of 2.550 [95% confidence interval (CI): 1.274–5.104, p=0.008]. In multivariate analysis, pretransplant FEV₁/FVC (HR: 0.956, 95% CI: 0.921–0.993, p=0.020) and time from HSCT to diagnosis of BOS (HR: 0.997, 95% CI: 0.994–0.999, p=0.009) were independent prognostic factors associated with mortality. Conclusion: Peripheral blood as a stem cell source is a risk factor for the development of BOS. A decreased pretransplant FEV₁/FVC and shorter duration of time from transplantation to diagnosis of BOS are poor prognostic factors for BOS.