Irradiation of Red Blood Cells and Alloimmunization.

Abstract

Animal models suggest that red blood cell (RBC) damage incurred during storage can increase immunogenicity to some RBC antigens. We hypothesized that RBC irradiation, a source of oxidative damage, may result in higher RBC alloimmunization rates among transfusion recipients. Individuals receiving 1 or more gamma-irradiated RBC units, with follow-up antibody screening, were studied. We recorded diagnosis at the time of first irradiated RBC-unit transfusion, total irradiated RBCs received, and alloantibodies detected before and after irradiated RBC transfusion. The alloimmunization rate for patients receiving irradiated RBCs was 1.9% (3/154); this rate was not significantly different from the rate of 2.5% (5/200) derived from a control group that had undergone transfusion with nonirradiated RBCs ( P > .99). Most of the study subjects (83/154 [53.9%]) did not harbor an immunosuppressive disorder at the time of transfusion of irradiated RBCs, with postoperative bleeding (36/83 [43.4%]) being the most common diagnosis. This analysis provides reassurance that irradiated RBCs are not more immunogenic in patients with immunosuppression than in patients with immunocompetence.