Clinical and virological differences between hepatitis B virus genotypes B and C: a case-control study.

ABSTRACT

OBJECTIVE: The pathogenic significance of hepatitis B virus (HBV) genotypes is undefined. The aim of this study was to elucidate the differences in clinical and virologicalfeatures between HBV genotypes B and C by conducting a case-control study in Thai patients who were chronically infected with the virus. PATIENTS AND METHOD: HBV genotyping was assessed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) method in stored sera of 470 patients with chronic hepatitis B. Among these, 65 patients with HBV genotype B were enrolled and matched individually to those with HBV genotype C according to sex, age, and distribution of liver disease which included asymptomatic carrier, chronic hepatitis, cirrhosis and hepatocellular carcinoma. RESULTS: Serum alanine aminotransferase (ALT) was significantly higher in patients with genotype C than those with genotype B. Hepatitis B e antigen (HBeAg) was significantly more frequent in genotype C than genotype B patients (50.8 and 30.8%, respectively, p=0.03), but the levels of HBV DNA were comparable between them. Among patients who were positive for HBeAg, the mean age of genotype C patients tended to be older than genotype B patients. CONCLUSION: The present study demonstrated that patients with HBV genotype C had a significantly higher rate of HBeAg, experienced delayed HBeAg seroconversion and exhibited more severe liver disease compared to those with genotype B.