Detection of pre-S/S gene mutants in chronic hepatitis B carriers with concurrent hepatitis B surface antibody and hepatitis B surface antigen

Hepatitis B virus (HBV) with various mutations has been reported. The frequ ency of the natural occurrence of such variants and whether the heterogenei ty of these genomic regions correlates with a specific serologic pattern of concurrent hepatitis B surface antigen (HBsAg) and hepatitis B surface ant ibody (anti-HBs) were investigated. We analyzed the perS/S regions of HBV i n six asymptomatic HBV carriers who were seropositive for both HBsAg and an ti-HBs (group A), four hepatocellular carcinoma (HCC) patients with concurr ent HBsAg and anti-HBs (group B), and five asymptomatic HBV carriers withou t anti-HBs as controls (group C). PreS/S regions of HBV-DNA were amplified by polymerase chain reaction (PCR), cloned, and sequenced. The results show ed that, in some of the samples, a few deletions and numerous point mutatio ns were presented in preS/S regions. One of the HBV carriers with anti-HBs (group A) and an HCC patient with anti-HBs (group B) had point mutations in the "a" determinant, resulting in conversion from Ile-126 of wild type to Asn-126. The patients with anti-HBs (groups A and B) had a significantly gr eater divergence rate of amino acid for the preS/S gene compared with contr ols. Our results suggested that the HBV mutants observed in the preS/S gene may have led to changes in the immunogenicity of the viral particles, and thus influence the viral behavior and clinical course. Therefore, some HBV patients with concurrent HBsAg and anti-HBs may be HBV S mutants.