Red blood cell minor antigen mismatches during chronic transfusion therapy for sickle cell anemia

BACKGROUND Red blood cell (RBC) alloimmunization occurs at a high frequency in sickle cell anemia (SCA) despite serologic matching for Rh (C/c, E/e) and K antigens. RBC minor antigen genotyping allows for prediction of antigens and RH variants that may lead to alloimmunization.