Risk factors and outcome of pulmonary complications after autologous hematopoietic stem cell transplant

Background: Most reports addressing pulmonary complications (PCs) in hematopoietic stem cell transplant (HSCT) recipients have focused on allogeneics. This study describes the PCs, their risk factors, and the impact on mortality in autologous recipients. Methods: We reviewed the medical records of 1,243 adult autologous HSCT recipients. We collected pretransplant and posttransplant data and data on PC after transplant and long-term mortality. Results: Four hundred eighty-seven PC developed in 343 patients (27.6%): 173 infectious (13.9%), 127 noninfectious (10.2%), and 43 both infectious and noninfectious (3.5%). Bacterial, fungal, and viral pneumonias were the most common infectious complications. The main noninfectious complications were acute pulmonary edema (APE) (59 [4.7%]), diffuse alveolar hemorrhage (DAH) (26 [2.1%]), peri-engraftment respiratory distress syndrome (PERDS) (31 [2.5%]), and idiopathic pneumonia syndrome (IPS) (12 [1.0%]). Independent factors associated with PC included diffusing capacity of lung for carbon monoxide and indications for transplant. Factors associated with mortality included sex, history of pulmonary disease, disease status at the time of transplant, FVC, Karnofsky score, and underlying diagnosis. A Cox proportional hazards regression model with separate time-dependent predictors for the first 1 month, 1 to 2 months, 2 to 6 months, and 6 or more months showed an association with mortality at hazard ratios (HRs) of 32.39, 10.13, 4.29, and 0.98, respectively, compared with persons without PC. Conclusions: More than 25% of autologous HSCT recipients develop PCs within 1 year of transplant. Most of the complications are infections. The most common noninfectious complications are APE, DAH, PERDS, and IPS. PCs increase the risk of death, with HR as high as 32.