A retrospective study published in the journal Blood suggests that red cell alloimmunization is common among chronically transfused patients with sickle cell disease (SCD), despite the use of Rh-matched blood from minority donors. Researchers identified 146 antibodies among 182 SCD patients receiving blood matched for D, C, E, and K from African American donors. 91 who had unexplained Rh antibodies. Among patients receiving chronic transfusion therapy, 58% were alloimmunized and 45% were Rh immunized. One-third of the Rh antibodies were associated with delayed transfusion reactions. Further high-resolution RH genotyping showed that 87% of individuals experiencing Rh alloimmunization had variant alleles, suggesting that altered RH alleles led to the high prevalence of Rh alloimmunization among these patients.
1. Chou ST, Jackson T, Vege S, Smith-Whitley K, Friedman DF, Westhoff CM. High prevalence of red blood cell alloimmunization in sickle cell disease despite transfusion from Rh-matched minority donors. Blood 2013;122: 1062-71.