Presence of valine at position 27 of the hepatitis B virus core gene is associated with severe liver inflammation in Chinese patients.

Although it is widely believed that cytotoxic T lymphocytes (CTL) are responsible for severe flares of chronic hepatitis B that lead to liver failure, the published evidence to support this hypothesis is weak. The frequency of the I27V mutation in the HBV core gene, which produces a core 18-27 peptide capable of binding HLA-A*02, was compared in Chinese patients with severe liver inflammation (n = 77, including 39 with acute-on-chronic liver failure), moderate liver inflammation (n = 44) and inactive disease (n = 45). The frequency with which V27 reverted to the wild-type I27 was compared in severe liver inflammation patients who were either HLA-A*02 positive (n = 5) or negative (n = 5). The frequency of patients with a V27 positive HBV was higher in severe than in moderate liver inflammation (23.4% vs. 6.8%, P = 0.02) or inactive disease (23.4% vs. 4.7%, P = 0.006). After a minimum of 3 months follow-up, the frequency of reversion of V27 to the wild-type I27 was higher in HLA-A*02 positive than negative patients (5/5 vs. 1/5, P = 0.05). In summary, this is the first data showing an association between a specific amino acid mutation (I27V) and severe liver inflammation in patients with chronic hepatitis B. This mutation would produce a peptide that is known to bind HLA-A*02 and stimulate CTL. The high frequency of reversion to wild-type I27 in HLA-A*02 positive subjects suggests that CTL recognizing this peptide exist, and is consistent with the possibility that they contribute to the pathophysiology of severe liver inflammation in chronic hepatitis B.