Objectives: Despite the pathogenic role of the basal core promoter (BCP) and the precore mutations in chronic hepatitis B virus (HBV) infection, their role in the progression of liver disease is still controversial. We analyzed whether the accumulation of these mutations might enhance the progression of HBV-related chronic liver disease.
Methods: Forty consecutive patients at each clinical status were analyzed. Clinical statuses were as follows: HBeAg-positive asymptomatic carrier (HBeAg(+) ASC) (defined as HBeAg(+), anti-HBe(-), HBV-DNA(+) by hybridization, normal ALT); inactive HBsAg carrier; chronic hepatitis B; liver cirrhosis. The genotype and the BCP/precore regions were determined by PCR using genotype specific primers and direct sequencing, respectively.
Results: All patients except one were infected with genotype C. The A to T mutation at nucleotide 1762 and/or G to A mutation at nucleotide 1764 were found in 30% in HBeAg(+) ASC, 65.7% in inactive HBsAg carrier, 95% in chronic hepatitis B, and 90% in liver cirrhosis (p < 0.001). The prevalence of the G to A mutation at nucleotide 1896 was 5% in HBeAg(+) ASC, 22.5% in inactive HBsAg carrier, 32.5% in chronic hepatitis B, and 50% in liver cirrhosis, respectively (p < 0.001). The T to C/A mutation at nucleotide 1753 in the BCP and G to A mutation at nucleotide 1899 in the precore were more frequent in liver cirrhosis than in the other clinical statuses (p < 0.05).
Conclusion: Sequential accumulation of mutations in the BCP/precore has an important role in the progression of HBV-related liver disease.