[Transfusion and alloimmunization in sickle cell anemia patients].

Transfusion therapy for sickle cell anemia is limited by the development of antibodies to red cell antigens. The aim of this study was to evaluate whether transfusion of blood matched for antigens Rh and Kell would reduce the incidence of alloimmunization. We determined the transfusion history, red cell phenotype and development of alloantibodies in 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 patient developed 2 antibodies. In a control group of 124 patients who received standard red blood cells, the rate of alloimmunization was significantly increased to 30.6% (p < 0.05); antibodies against C, E, K, Fya were the most frequently developed and 19 patients (16%) developed antibodies reacting with different antigens. In the 2 groups, alloimmunization occurred after receiving a significantly different number of transfusions: 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 patients with that of a panel of unselected blood bank donors was performed: the patients had a significant decrease in the frequency of red cell antigens corresponding to most of the detected alloantibodies JkB, C, S. Fyb, Fya and Kell.(ABSTRACT TRUNCATED AT 250 WORDS)