Correlation with viral serotypes and clinical stages of liver disease

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J Med Virol 2002 Sep;68(1):50-9Related Articles, Links

Naturally occurring hepatitis B surface gene variants in chronic hepatitis B
virus infection: Correlation with viral serotypes and clinical stages of
liver disease.

Liu CJ, Kao JH, Shau WY, Chen PJ, Lai MY, Chen DS.

Department of Internal Medicine, National Taiwan University Hospital,
Taiwan.

Virus variants escaping from host immunity may be implicated in the
pathogenesis of hepatitis B virus (HBV) infection. In this cross-sectional
study, the association was evaluated of the frequency of amino acid
variation within the immunogenic epitopes of surface gene with different
disease stages of chronic HBV infection. The surface gene of HBV
encompassing the a determinant (amino acids 124-148) and the putative HLA class I restricted cytotoxic T lymphocyte (CTL) epitope (amino acids 28- 51) were amplified and directly sequenced in 33 asymptomatic carriers (Group I), 31 patients with chronic hepatitis (Group II), 22 with cirrhosis (Group III), and 36 with hepatocellular carcinoma (Group IV). The amino acid sequences were compared subsequently with the consensus sequences of HBV serotype adw or adr. The frequency of amino acid variation per site per sequence (FEQ) was analyzed by generalized estimating equation with Poisson model after stratification by clinical and virological features. The FEQ was 1.21% overall, and was highest in Group IV patients and in patients above 50 years of age. In contrast, nine Group IV patients aged below 50 years who were infected with serotype adw had an inversely higher FEQ than those above 50; the age effect among hepatocellular carcinoma patients was significantly different from that among non-cancerous patients (P = 0.04). Variation of amino acid clustered within a determinant and CTL epitope for serotype adw but was istributed at random for serotype adr. Mutation hotspots differed between serotypes adw and adr. The FEQ of HBV surface protein is correlated positively with advancing age and severity of liver disease, and certain variants may contribute to the persistence of HBV infection. J. Med. Virol. 68:50-59, 2002. Copyright 2002 Wiley-Liss, Inc.