Erythrocyte alloimmunization in children with sickle cell anemia living in Kilifi, Kenya

Abstract

Sickle cell anemia (SCA) management in sub-Saharan Africa relies on transfusion, whose safety is compromised by a lack of extended blood group matching beyond ABO and Rhesus D antigens, and the absence of routine alloantibody screening. To determine the incidence of erythrocyte alloimmunization in children with SCA who received multiple transfusions in Kilifi, Kenya, we retrospectively studied 98 children with SCA admitted to Kilifi County Referral Hospital from 2003 to 2023. Plasma samples collected over this period through a routine ward surveillance study were screened for alloantibodies. Alloantibodies were detected in 14 of 98 (14.3%) participants, and an autoantibody was detected in 1 participant (1.0%). Anti-e was found in 2 children, whereas anti-E, anti-M, anti-S, anti-s, anti-Lua, and anti-Leb were each found in single individuals. Five children had pan-reactive alloantibodies, and 3 had antibodies of unidentified specificity. Older age was significantly associated with the development of alloantibodies (P = .027). Our alloimmunization rate of 14.3% is higher than previously reported from East Africa (2.9%-8%). Given that most alloantibodies were specific to Rhesus and MNS blood groups, and age was significantly associated with alloimmunization, these findings underscore the importance of routine alloantibody screening in children who received multiple transfusions and suggest the need for extended antigen matching in patients with SCA to improve transfusion safety.