Impact of rs3077 (HLA-DPA1 gene) on chronic hepatitis B virus carriage in Cotonou

Hepatitis B Virus (HBV) is a major global health concern, particularly in sub-Saharan Africa, where infection rates are notably high. Despite this, data on the host genetic contributors to HBV infection, such as the single nucleotide polymorphism rs3077 (HLA-DPA1 gene), are unavailable in this region. To contribute to closing this gap, the present study explored the association between rs3077 and chronic hepatitis B virus (HBV) carriage. We used a cross-sectional study design, incorporating both descriptive analyses of chronic HBV carriers and analytical assays for rs3077 genotyping. The study included 48 melanoderma subjects with chronic HBV from the hepato-gastroenterology department of CNHU Hospital. These were matched by age and sex with 49 HBV-negative control subjects, selected from blood donors at the Atlantic-Littoral section of the Blood Donor Agency (ANTS). Both cases and controls underwent RT-PCR genotyping. The average age of chronic HBV carriers was 41.21±12.34 years, with the most prevalent age group being 31 to 43 years, accounting for 33.33% of the population. Considering potential transmission modes, the T allele was identified as a protective factor in the dominant model (Odds Ratio [OR] 0.046; 95% Confidence Interval [CI] 0.005 - 0.136). Conversely, the C allele was found to be a risk factor in both recessive (OR 47.162; 95% CI 6.754 - 203.063) and codominant models (OR 49.782; 95% CI 7.218 - 213.609). This study reveals that the C and T alleles of rs3077 have distinct roles in chronic hepatitis B virus carriage among individuals in Cotonou. Specifically, the C allele seems to be a risk factor, while the T allele appears to confer a protective effect. This finding emphasizes the importance of host genetic variation in HBV susceptibility and provides valuable insights for future research and potential targeted healthcare strategies in regions with high HBV prevalence.