Pre-Hematopoietic Stem Cell Transplantation Lung Function and Pulmonary Complications in Children

Rationale: Pulmonary complications are a significant cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation.

Objectives: The relationship between pre-transplant pulmonary function tests (PFT) and development of post-transplant pulmonary complications in children was studied.

Methods: This is a retrospective single institution cohort study of 410 patients who underwent pre-transplant PFT and were followed up to 10 years post-transplant.

Results: Pulmonary complications were observed in 174 (42%) patients. Children with pulmonary complications had significantly lower FEF_25-75% (P = 0.02) derived using conventional predicted equations for age, and the Global Lung Initiative-2012 predicted equations (P = 0.01). T-cell depletion (P = 0.001), acute grade 3-4 graft-versus-host disease (GVHD; P = 0.008), and chronic GVHD (P = 0.01) increased risk for pulmonary complications. Patients who had pulmonary complications had a 2.8-fold increased risk of mortality (P < 0.0001). The cumulative incidence of death due to pulmonary complications was significantly higher in children who had low lung volumes, functional residual capacity (FRC) < 50% (P = 0.005), total lung capacity (TLC) < 50% (P = 0.0002), residual volume (RV) < 50% (P = 0.007), and T-cell depletion (P = 0.01). Lower forced expiratory volume in one second (FEV₁; P = 0.0005), forced vital capacity (FVC; P = 0.0005), TLC (P < 0.0001), RV < 50% (P = 0.01), and restrictive lung disease (RLD; P= 0.01) predicted worse overall survival.

Conclusions: Abnormal pre-transplant PFT significantly increased risk post-transplant. These patients may benefit from modified transplant strategies to reduce morbidity and mortality.