Pulmonary Complications Following Hematopoietic Cell Transplantation in Patients with Myelofibrosis: A Single-Center...

Myelofibrosis (MF) is a clonal hematopoietic stem cell disorder that frequently results in extramedullary hematopoiesis. Hematopoietic cell transplantation (HCT) is the only cure. While a 2-fold increase in pneumonia and respiratory-related mortality was recently reported in MF patients compared to the general population, the incidence and etiology of HCT-related pulmonary complications have not been well studied. We performed a retrospective chart review of consecutive MF patients who underwent HCT between 2002 and 2022. Patients with evidence of pulmonary impairment on pulmonary function tests, defined as a ≥10-point decline in forced expiratory volume in 1 second (FEV1) compared to pre-HCT and/or a decline in the FEV1/forced vital capacity (FVC) ratio to <0.7, received further chart review to determine the etiology of this decline. Of 228 patients evaluated, 126 (55%) met either the FEV1 or FEV1/FVC criteria for pulmonary impairment. After further chart review, 35 patients (15.4%) were diagnosed with broncholitis obliterans (BOS) by a pulmonologist or graft-versus-host disease specialist. Other common causes of impairment included respiratory infections (n =10), cryptogenic organizing pneumonia (n = 8), and deconditioning (n = 8). MF patients have a >50% likelihood of developing pulmonary impairment following HCT and a higher-than-expected incidence of BOS. This study supports increased pulmonary monitoring post-HCT in patients with MF.