P-035: RED BLOOD CELL ALLOIMMUNIZATION IN SICKLE CELL DISEASE PATIENTS IN THE DEMOCRATIC REPUBLIC OF THE CONGO

Abstract

Purpose: Data regarding red blood cell (RBC) alloimmunization in sickle cell disease (SCD) patients are scarce in the Democratic Republic of the Congo (DRC) which is the third most affected country in the world by sickle cell disease. We aimed to determine the prevalence of red blood cell alloimmunization and alloantibody specificity in SCD patients in Kisangani (DRC). Materials and methods: We conducted a multi-hospital, multi-site based cross-sectional study among 125 SCD patients at Kisangani and 136 at the Centre Hospitalier Régional de la Citadelle (CHR) of Liège (Belgium). Data were collected using a survey form. Diagnostic con?rmation of SCD was made by high-performance liquid chromatography coupled to mass spectrometry. Alloantibodies were screened using the agglutination technique on gel cards and their specificity determined using 11 and/or 16 cell panels. Statistical analyses were carried out using SPSS. Results: The prevalence of RBC alloimmunization was 9.6% for samples collected at Kisangani versus 22.8% (including historical antibodies) at the CHR and increased to 10% at Kisangani versus 29.3% at the CHR when considering only patients transfused in the last five years prior to the study. At Kisangani as well as at CHR, the median age of alloimmunized patients was higher than that of non-alloimmunized patients, 15.5 years (IQR:4.8-19.8) vs 10 (IQR: 6.5-17) and 24 years (IQR:14-31) vs 17(IQR:12-24), respectively. The median number of blood units was higher in both Kisangani and CHR immunized patients compared to non-immunized patients, 8(IQR:5-11) vs 5(IQR:3-13) and 41(IQR:6-93) vs 6.5(3-37) respectively. At Kisangani(N=14), the most frequent antibodies were anti-D (28.6%), anti-C (21.4%), anti-M (14.3%,) and anti-N (14.3%) versus anti-E (13.6%), anti-S (13.6%), and anti-Lea (11.4%) at the CHR(N=44). Conclusion: Red blood cell alloimmunization is a common complication of transfusion therapy in SCD patients in the DRC and is mostly directed against the RH system. In a low income context in the DRC, blood transfusion with a minimum ABO, D, C, E antigen matching could significantly reduce the incidence of this complication. The authors do not declare any conflict of interest