Evaluating alloimmunization risk in patients with sickle cell disease and in prenatal care patients with RHCE variants

Abstract Background and Objectives Clinically significant alloantibodies complicate transfusion and prenatal care, especially in individuals with genetic variants affecting high‐frequency antigens. Many patients from African descent carry RHCE*ceVS alleles, which alter the expression of c (RH4), e (RH5) and hr B (RH31). However, the risk and clinical impact of alloimmunization remain uncertain. We evaluated the alloimmunization in a cohort of patients with a RHCE*ceVS genotype. Materials and Methods We conducted a retrospective study on 48 patients with a RHCE*ceVS genotype divided into three categories: prenatal care, patients with sickle cell disease (SCD) and other or unspecified diagnosis. Results No anti‐c, anti‐e or anti‐hr B were found in prenatal care patients or in patients with other or unspecified diagnosis. Among transfused patients with SCD, 50% developed an anti‐e. Anti‐hr B was identified in two patients, both with SCD. Warm autoantibodies were found in 58% of transfused patients with SCD, many of whom had an anti‐e. Conclusion The risk of developing anti‐e or anti‐hr B antibodies was low in patients with an RHCE*ceVS genotype, except in those with SCD. In patients with SCD, the presence of autoantibodies, recent transfusions and technical caveats complicate the assessment of clinical impact; therefore, an individualized evaluation of alloimmunization risk is recommended.