The double-edged sword of AlloHCT for SCD

Abstract

In this issue of Blood, Ghannam and colleagues report on the development of myeloid malignancy in 3 individuals with homozygous sickle cell disease (SCD).1 This represented a total of 4% (3 of 76) of their cohort transplanted for SCD from 2004 to 2018. Participants with severe SCD had 4 common features: (1) before transplant, clonal hematopoiesis of indeterminate potential (CHIP)- related mutations were detected in the blood of both individuals assessed; (2) all received nonmyeloablative, allogeneic hematopoietic cell transplant (AlloHCT) using total body irradiation (TBI) (300 to 400 cGy) and alemtuzumabbased conditioning; (3) participants received mobilized peripheral blood stem cells; (4) the myeloid malignancy occurred 2 to 5 years after a failed allograft. 2020 by The American Society of Hematology