Amino acid residues of core region of hepatitis B virus. Asymptomatic carriers versus patients with liver disease.

Recent molecular biological studies have shown that mutations of hepatitis B virus (HBV) genes may have an important role in the pathogenesis of HBV-induced liver diseases. It has been suggested that the core antigen of HBV could be an immunologic target of cytotoxic T lymphocytes. In this study, nucleotide sequences encoding 183 amino acid residues of the core region of HBV were analysed in 4 asymptomatic healthy carriers and in 5 patients with chronic liver disease, in whom serum aminotransferase levels were fluctuating. A cluster of amino acid substitutions were found from codon 87 to 97 of the core region of HBV in all 5 patients with liver diseases. Such changes were not found in any of the asymptomatic carriers. These data suggest that the peptide sequence spanning 11 amino acid residues in this particular region may play an important role in the pathogenesis of B-viral liver disease, and could be an immunologic target of cytotoxic T lymphocytes.