Asian Hematology Research Journal

The H antigen is the precursor for the expression of A and B blood group antigens and is therefore essential for the ABO blood group system. Although H antigen is expressed in virtually all individuals, its absence characterizes the rare Bombay (Oh) phenotype, which has important implications for transfusion compatibility. Data on H-antigen expression among Nigerian ethnic populations remain limited. This study assessed the expression of H antigen among Ijaw undergraduate students of Niger Delta University, Bayelsa State, Nigeria. A cross-sectional study was conducted among 120 apparently healthy Ijaw undergraduate students of Niger Delta University between May and June 2026. Participants were selected using a convenience sampling technique. Venous blood samples were collected and H-antigen expression was determined using the conventional tube agglutination method with anti-H lectin reagent. Data were analysed using descriptive statistics and presented as frequencies and percentages. All 120 participants (100.0%) expressed the H antigen, while none (0.0%) was H-antigen negative. H-antigen expression was observed across participants from all eight Local Government Areas represented in the study. No participant demonstrated the serological pattern suggestive of H-antigen deficiency or the Bombay (Oh) phenotype. The finding is consistent with the rarity of the Bombay phenotype and provides baseline information on H-antigen expression among the Ijaw population in the Niger Delta region. Further studies involving larger and more diverse populations are recommended to provide broader estimates of H-antigen deficiency and the occurrence of the Bombay phenotype among Nigerians.