The phenotypic profile of blood donors and recipients at the University Clinics of Kinshasa and the National Blood Transfusion Center of Kinshasa from November 2024 to July 2025

Introduction Blood transfusion is essential in the Democratic Republic of the Congo (DRC); however, comprehensive epidemiological data remain limited beyond the basic ABO and RhD systems. This study addresses this gap by providing data on extended Rhesus and Kell phenotyping. Purpose To determine the phenotypic distribution of ABO, Rhesus (D, C, c, E, e), and Kell blood group systems among blood donors and recipients at the University Clinics of Kinshasa and the National Blood Transfusion Center. Methods A descriptive cross-sectional study was conducted from November 2024 to July 2025. ABO blood group antigens were identified using both forward (cell) and reverse (serum) typing. Extended Rhesus and Kell antigens were determined using the direct serological method. Results A total of 240 samples from 214 subjects were analyzed (163 donors and 51 recipients). The mean age was 30.47 ± 15.08 years. The frequencies of blood groups O, A, B, and AB were 50.0%, 26.2%, 18.2%, and 5.6%, respectively. The RH1 (D) antigen was present in 95.3% of subjects. Extended phenotyping showed a high prevalence of RH4 (c) (99.5%) and RH5 (e) (96.7%) antigens. Haplotype analysis revealed a predominance of the R0 (Dce) complex (67.3%). All subjects were Kell-negative (100% KEL:-1). No statistically significant difference was observed in blood group distribution between donors and recipients (p > .05). Conclusion This study confirms the predominance of blood group O and the R0 haplotype in the Kinshasa population. However, the presence of C and E antigens in nearly one-quarter of participants, combined with universal Kell negativity, highlights a significant risk of alloimmunization in polytransfused patients. Implementing extended phenotyping is therefore essential to improve transfusion safety and clinical outcomes in the DRC.