Hepatitis B virus genotypes and the response to lamivudine therapy

Hepatitis B virus (HBV) can be classified into eight major genotypes (A-H) that have mainly a geographic distribution. The HBV genotype may influence disease progression, HBeAg seroconversion rates, response to antiviral treatment. The aim of study was to analyze the distribution and frequency of genotypes in patients with chronic hepatitis B. Response to lamivudine 100 mg daily therapy was examined in respect to genotype. Sixty six patients (45 (68,2%) male, 21 (31,8%) female) with chronic hepatits B were enrolled. HBV genotypes were assigned before treatment with INNO-LiPA HBV Genotyping, Innogenetics, N. V., Ghent assay, which is a line probe test based on the reverse hybridization principle. In baseline and after 12 months of treatment serological markers of HBV infection, alanine aminotransferase (ALT) activities and HBV DNA serum levels were tested. Patients with chronic hepatitis B were infected predominantly with genotype A. HBV genotype distribution was: 78,8% for genotype A, 13,6% for genotype D, 1,5% for mixed infection with genotypes A and D. Distribution of genotypes A and D was asymmetrically regardless of sex, HBeAg status, ALT and HBV DNA levels. Four (6,1%) specimens had indeterminate A results by LiPA. There were no significant differences between patients with genotypes A and D regarding age and sex. There were also no significant differences between these two groups regarding rates of HBeAg and anti-HBe positivity, ALT activity and viral load. Twenty months of lamivudine (100 mg daily) therapy resulted in significant decreases in serum HBV DNA and ALT activities in patients with genotype A as well as with genotype D. After 12 months of treatment there were no statistical differences in HBeAg seroconversion rates, ALT activities, viral loads, frequency of HBeAg and anti-HBe between genotypes A and D.