Interpreting pulmonary function tests in allogeneic hematopoietic cell transplant recipients

Pulmonary complications are a significant cause of non-relapse mortality in allogeneic hematopoietic cell transplant (HCT) recipients. Pulmonary function tests (PFTs) are recommended to screen for asymptomatic lung function decline that precedes overt disease. HCT clinicians must understand the critical importance of PFTs in the post-HCT context and be able to identify abnormalities for timely intervention. This article provides a concise summary of contemporary PFT interpretation practices, tailored to clinicians caring for this complex patient population. Key principles, including comparison of pre-transplant and routine post-transplant studies, the importance of longitudinal assessments, and consideration of the clinical context of the HCT survivor, are illustrated through case vignettes. We review remaining fundamental questions about the application of PFTs post-transplant and suggest a path towards improved implementation and utilization of PFT data to guide clinical decision-making.