Pulmonary Function After Non-Myeloablative Hematopoietic Cell Transplant for Sickle Cell Disease.

Sickle cell disease (SCD) is a monogenetic condition with recurring vaso-occlusive events causing lifelong pulmonary morbidity and mortality. There is increasing access to curative therapies, such as hematopoietic cell transplant (HCT), for people living with SCD. However, more information on pulmonary function in adults with SCD after HCT is needed in order to best guide decisions for HCT and post-HCT care. To test the hypothesis that forced expiratory volume in one second (FEV1), and other pulmonary function testing (PFT) parameters, remain stable three years post-HCT. People living with SCD undergoing non-myeloablative HCT in a prospective cohort at the NIH Clinical Center from 2004 - 2019 were evaluated for enrollment. Global Lung Function Initiative reference equations and descriptive statistics were calculated prior to HCT and annually for three years. Six-minute walk distance (6MWD) testing was performed. Generalized estimating equations (GEE) were employed to evaluate inter-individual changes in PFT parameters and 6MWD. Of 97 SCD patients undergoing HCT, 41 (42%) were female with median (25th, 75th percentile) age 31.8 (24.8, 38.0) years. Each year of measurement included the following numbers of subjects available for analysis with PFTs: baseline (97), year 1 (91), year 2 (72), year 3 (55); and the following numbers of subjects available for analysis with 6MWD: baseline (79), year 1 (73), year 2 (57), year 3 (41). Pre-HCT FEV1 was median (25 Overall, PFTs remained stable and there was an improvement in DL