Effect of race on outcomes after allogeneic hematopoietic cell transplantation for severe aplastic anemia

We compared outcomes after hematopoietic cell transplantation in patients of African American (n=84) and Caucasian (n=215) descent with severe aplastic anemia. African Americans and Caucasians were matched for age, donor-recipient human leukocyte antigen match, graft type, and transplantation year. The median follow-up of surviving patients was 5 years. In multivariate analysis, overall mortality risks were higher for African Americans compared to Caucasians (relative risk 1.73, P=0.01). The 5-year probabilities of overall survival adjusted for interval from diagnosis to transplantation, and performance score was 58% for African Americans and 73% for Caucasians. The day-100 cumulative incidence of grade III-IV, but not grade II-IV acute graft-versus-host disease (GVHD), was higher in African Americans compared to Caucasians (29% vs. 13%, P=0.006). Although the 5-year cumulative incidence of chronic GVHD was not significantly different between the racial groups, African Americans were more likely to have extensive chronic GVHD compared to Caucasians (72% vs. 49%, P=0.06). Survival differences between Caucasians and African Americans can be attributed to multiple factors. Our data suggest that some of the observed survival differences between Caucasians and African Americans may be explained by higher rates of acute GVHD and severity of chronic GVHD.