Barriers to using molecularly typed minority red blood cell donors in support of chronically transfused adult patients with sickle cell disease.

BACKGROUND: Much effort and resources have been devoted to programs that provide transfusion support for patients with sickle cell disease (SCD). The focus of many donor programs is to prevent alloimmunization by recruiting racially matched African American donors to limit the red blood cell (RBC) antigenic differences that exist between Caucasian donors and patients with SCD. STUDY DESIGN AND METHODS: In this study, we evaluated the RBC antigen characteristics of both the recipient population with SCD and the African American donor population from 2010 to 2013. We evaluated the genotype-derived predicted antigen frequencies of the donors and compared these frequencies with those of the population supported by these units. Specific attention was given to the alloimmunization rate over the 3 years and the number of D- units provided to D+ patients. RESULTS: We recruited 6066 African American donors during the 3-year study period with 77.3% of these donors donating no more than twice. The observed genotype-derived predicted antigen frequencies were similar to the expected frequencies, and the antigen frequencies of a cohort of 54 adult patients with SCD (p > 0.05). Twelve patients (22.2%) with SCD had alloantibodies and five of these patients developed these antibodies while receiving Rh and K antigen-matched blood during the study interval. Finally, we found that 607 (37.1%) D- units were diverted to D+ patients. CONCLUSIONS: New recruitment and prevention strategies are needed to increase the pool of available antigen-matched RBCs and decrease alloimmunization risk for this patient population.