TRANSFUSION AND ALLOIMMUNIZATION IN SICKL E-CELL DISEASE

Transfusion therapy for sickle cell anemia is limited by the developme nt of antibodies to red cell antigens. The aim of this study was to ev aluate whether transfusion of blood matched for antigens Rh and Kell w ould reduce the incidence of alloimmunization. We determined the trans fusion history, red cell phenotype and development of alloantibodies i n 173 patients with sickle all anemia who received transfusions. Forty nine patients were transfused exclusively with frozen red blood cells (RBL) matched for antigens Rh and Kell; the rate of alloimmunization was 8,2%; antibodies to the Jkb, Jka, Fya and S were developed; 1 pati ent developed 2 antibodies. In a control group of 124 patients who rec eived standard red blood cells, the rate of alloimmunization was signi ficantly increased to 30,6% (p < 0,05);antibodies against C, E, K, Fya were the most frequently developed and 19 patients (16%) developed an tibodies reacting with different antigens. In the 2 groups, alloimmuni zation occurred after receiving a significantly different number of tr ansfusions: mean 9 in the patients transfused with matched RBC and 32 in the control group. The influence of the kinetics of transfusion was not demonstrated. To assess the effect that racial differences might have on alloimmunization, comparison of the red cell phenotype of pati ents with that of a panel of unselected blood bank donors was performe d : the patients had a significant decrease in the frequency of red ce ll antigens corresponding to most of the detected alloantibodies JkB, C, S, Fyb, Fya and Kell. In conclusion, transfusion of red blood cells matched for antigens Rh and Kell may reduce the incidence of alloimmu nization in patients with sickle cell disease.