Pulmonary function in children and adolescents with sickle cell disease after nonmyeloablative hematopoietic cell transplantation.

ABSTRACT

BACKGROUND: Pulmonary complications are common in sickle cell disease (SCD). The use of standard myeloablative conditioning regimens may increase the risk of lung injury. We report serial pulmonary function testing (PFT) outcomes in children with SCD who underwent a matched-sibling donor hematopoietic cell transplantation (HCT) using nonmyeloablative (NMA) protocol. METHODS: This is a retrospective chart review describing pulmonary outcomes in pediatric patients post HCT. The conditioning regimen consisted of alemtuzumab and a single fraction of 300 cGy of total body irradiation (TBI), and sirolimus for graft-versus-host disease (GVHD) prophylaxis. Serial PFT testing was performed pre and post HCT. The evaluated pulmonary measures included forced vital capacity (FVC), forced expiratory volume in the first second (FEV1 ), FEV1 /FVC, and forced expiratory flow (FEF25-75 ). RESULTS: Twelve subjects were included in the analysis. All had HbSS genotype, and five of the 12 patients had one or more episodes of acute chest syndrome prior to HCT. Serial PFT measures were completed per patient. No patient was diagnosed with chronic GVHD of any organ post HCT. The baseline median FVC, FEV1 , FEV1 /FVC, and FEF25-75 were within the normal range and remained relatively unchanged post HCT. A linear mixed effects model, adjusting for gender and time from HCT, suggested no significant relationship between HCT and PFT parameters, including FVC, FEV1 , and FEV1 /FVC. Interestingly, the FEF25-75 results exhibited a shift in the means post HCT (pre-HCT 86.2% predicted and post-HCT 93.05% predicted, p-value = .018). CONCLUSION: Our study suggests that HCT in children with SCD may prevent the anticipated decline in pulmonary function over time.