781 CHRONIC TRANSFUSION THERAPY IN SICKLE CELL ANEMIA (SSA) USING DONORS MATCHED FOR MINOR RBC ANTIGENS

Nine patients with SSA (ages 8-32) with stroke, corpulmonale, severe vaso-occlusive crises, and serious anemia have been transfused with leukocyte-poor red blood cells every 3-4 weeks for 6-to-30 months to keep the Hgb >10.5 gm %. Because the incidence of alloimmunization in previously transfused patients with SSA was high (24% in our population), black donors were matched closely with recipients for 17 minor blood group antigens, and a limited number of donors gave regularly to each patient. Before treatment, hematologic values included Hgb of 6.1-10.3 gm %, reticulocytes 6-34%. On chronic transfusion, the mean Hgb ranged from 10.0-14.2 gm % and reticulocytes from 0.7-11.5. All but one patient maintained a Hgb S of 5%-30%. These 9 patients had previously been intermittently transfused with 342 units of blood and had developed 10 antibodies. On the current program, 404 units of closely matched blood have been given with no new alloantibodies detected and no evidence of serum hepatitis. Subcutaneous deferoxamine has been instituted in 5 for iron overload. Clinical complications and symptoms were prevented in 8. Hospitalizations, clinic visits, and school absences were significantly decreased. Marked suppression of Hgb S was achieved in 8 of 9. The use of closely matched black donors appeared to greatly reduce the risk of isoimmunization to minor RBC antigens.