Hepatitis B virus subgenotypes and basal core promoter mutations in Indonesia

AIM:To identify the distribution of hepatitis B virus(HBV) subgenotype and basal core promoter(BCP) mutations among patients with HBV-associated liver disease in Indonesia.METHODS:Patients with chronic hepatitis (CH,n=61),liver cirrhosis (LC,n = 62),and hepatocellular carcinoma (HCC,n = 48) were included in this study.HBV subgenotype was identified based on S or preS gene sequence,and mutations in the HBx gene including the overlapping BCP region were examined by direct sequencing.RESULTS:HBV genotype B (subgenotypes B2,B3,B4,B5 and B7) the major genotype in the samples,accounted for 75.4%,71.0% and 75.0% of CH,LC and HCC patients,respectively,while the genotype C(subgenotypes C1,C2 and C3) was detected in 24.6%,29.0%,and 25.0% of CH,LC,and HCC patients,respectively.Subgenotypes B3 (84.9%) and C1 (82.2%) were the main subgenotype in HBV genotype B and C,respectively.Serotype adw2 (84.9%) and adrq+(89.4%) were the most prevalent in HBV genotype B and C,respectively.Double mutation (A1762T/G1764A) in the BCP was significantly higher in LC (59.7%) and HCC (54.2%) than in CH (19.7%),suggesting that this mutation was associated with severity of liver disease.The T1753V was also higher in LC (46.8%),but lower in HCC (22.9%) and CH (18.0%),suggesting that this mutation may be an indicator of cirrhosis.CONCLUSION:HBV genotype B/B3 and C/C1 are the major genotypes in Indonesia.Mutations in BCP,such as A1762T/G1764A and T1753V,might have an association with manifestations of liver disease.