Methylenetetrahydrofolate reductase 677 T allele protects against persistent HBV infection in West Africa

Background/Aims Homocysteine metabolism is linked to DNA methylation, a mechanism potentially involved in the course of hepatitis B virus (HBV) infection. We evaluated the association of determinants of homocysteine metabolism with the outcome of HBV infection. Methods Four hundred and fifty-five healthy adults from Togo and Benin were tested for HBV serologic markers, HLA DR alleles, folate, vitamin B12, methylenetetrahydrofolate reductase (MTHFR) 677 C→T, 1298 A→C and methionine synthase 2756 A→G polymorphisms. Results Seventy-eight percent of the study population was anti-HBc positive. Among them, 202 (56.9%) were anti-HBs positive and 58 (16.3%) were HBsAg positive. After stepwise logistic regression, the MTHFR 677 T allele was independently associated with persistence of detectable anti-HBs antibodies (OR: 2.47; 95% CI: 1.29–4.71; p = 0.006). The mean HBV DNA level was significantly lower in HBsAg positive subjects carrying the 677 T allele than in those with the 677 CC genotype (1000 ± 1406 vs. 2,400,000 ± 214,000 copies/ml, p = 0.005). Beninese origin and HLA-DRB1*09 allele were the other determinants independently associated with favorable outcome of HBV infection. Conclusions The methylenetetrahydrofolate reductase 677 T allele seems to protect against chronic HBV infection in young African adults.