A SIMPLE, PRACTICAL MODEL FOR REDUCING ALLOIMMUNIZATION IN PATIENTS WITH SICKLE-CELL DISEASE

Patients with sickle cell disease (SCD) form immune alloantibodies mor e frequently than other transfused populations because red cells (RBCs ) from white donors (with a higher incidence of certain Rh, Duffy, Kel l, and Kidd blood group antigens) are transfused to black patients oft en lacking these antigens. We propose a model to reduce alloimmunizati on in patients with SCD by providing them with blood from only black r andom donors. Rationale is shown by examining calculations based on th e phenotype E- , C-, Fy(a-), K-, and Jk(b-). There is a 7% probability that this phenotype belongs to a white donor, while there is a 93% pr obability that this phenotype belongs to a black donor. The probabilit y of selecting blood from a black donor identical with the above pheno type for black recipients from an all black population and from a typi cal urban blood inventory population (90% white, 10% black) is 1/4 and 1/33, respectively. Therefore, an 8-fold greater chance of selecting antigen non-identical blood occurs if blood is obtained from a typical urban donor population as compared to a black population. Based on th ese calculations, alloimmunization can be reduced prospectively in pat ients with SCD by meeting their transfusion requirements with blood se lected from random black blood donors.