Red cell alloimmunization in multi-transfused patients with sickle cell anemia in Benin City, Nigeria

Sickle cell anemia (SCA) is an inherited hemoglobin disorder characterized by chronic anemia and occasional crises. Clinical features are variable. While some individuals are relatively stable and rarely require blood transfusion, others often require blood transfusion. Multiple blood transfusion is associated with complications including alloimmunization, infections, and iron overload.

The study aimed at determining the prevalence of red cell alloimmunization among multi-transfused patients with SCA.

A cross-sectional study of adult SCA patients who have received multiple blood transfusion and those who have never received blood was done. Antibody screening and identification were carried out using gel technology with commercially made panel of cells.

A total of 145 SCA subjects were studied. They were made up of 86 test group (those that had received two or more units of blood) and 59 control group (those that had never received blood transfusion). Prevalence of red cell alloantibody among multi-transfused patients with SCA was found to be 9.3%. Alloantibodies identified were mainly against Rhesus antigens contributing 87.5% (anti-E 37.5%, anti-C 25%, anti-D 12.5%, anti-e 12.5%). A combination of Kell and Lutheran blood group antigens contributed 12.5%. No antibody was detected among the control group.

Blood transfusion is associated with the development of alloantibodies. Routine blood grouping for multi-transfused patients with SCA should be extended to include other blood group antigens in addition to Rhesus D and ABO antigens.