Donor Lymphocyte Infusion May Reduce the Incidence of Bronchiolitis Obliterans after Allogeneic Stem Cell Transplantation

Bronchiolitis obliterans (BO)is a serious pulmonary complication after allogeneic hematopoietic stem cell transplantation (HSCT). The aim of this study was to evaluate the diagnostic methods used, the incidence of BO, risk factors, and outcome in patients with BO at our center. The study included 527 HSCT patients transplanted between 1995 and 2003. Lung function tests (n = 1177) and risk factor analyses were performed in all patients. Chest X-rays and high-resolution tomographies were investigated in patients with BO. The incidence of BO was 4.8%, as the diagnosis was established in 25 patients (4 children). Median time between HSCT and diagnosis of BO was 356 (84-1823) days. Eight patients (32%) had radiologic changes consistent with BO. Forced expiratory volume for 1 second (FEV1) and forced expiratory flow at 50% (FEF50) and 75% (FEF75) of forced vital capacity (FVC) produced median values that were 49%, 25%, and 18% of the reference values at the time of BO diagnosis. FEF75 was reduced before BO diagnosis in 7 patients (28%). In a multivariate risk factor analysis, chronic graft-versus-host disease (cGVHD) was found to be associated with BO (P < .001), whereas donor lymphocyte infusion (DLI) diminished the risk (P = .02). For 10 patients with late BO (> 1 year after HSCT), 80% survived 5 years after diagnosis, compared to 38% survival in 15 patients with early-onset BO (P = .06). We conclude that lung function tests with a persistent decrease in FEV1 were more important than radiographic methods to recognize and monitor BO, that FEF75 may serve as an early warning of BO, and that late-onset BO appears to be associated with better outcome. Chronic GVHD was confirmed as a risk factor, and administration of DLI may diminish the risk. Biol Blood Marrow Transplant 17: 1214-1221 (2011) (C) 2011 American Society for Blood and Marrow Transplantation