Hepatitis B virus genotypes, precore mutations, and basal core promoter mutations in HBV-infected Chinese patients with persistently normal alanine aminotransferase and low serum HBV-DNA levels

Hepatitis B virus (HBV) genotype and precore and basal core promoter (BCP) mutants in the patients with persistently normal alanine aminotransferase (ALT) and low serum HBV-DNA levels are unclear. The aim of this study was to determine HBV genotypes, precore and BCP mutations, and their association with chronic hepatitis and liver fibrosis in HBV-infected patients with persistently normal ALT, and low serum HBV-DNA levels in northeast China. Patients (n = 89) with normal ALT and serum HBV-DNA levels below 20000 IU/mL but detectable with real-time PCR were included in this study. HBV genotypes were determined by real-time PCR. The precore and BCP mutations were detected by sequencing. All the patients had biopsy results. Of the 89 patients, 11 (12.4%) were genotype B and 78 (87.6%) were genotype C. The most common mutations were G1896A (23.6%), G1764A (9.0%), and A1762T (6.7%). The prevalence of precore mutation was significantly higher in genotype B patients than in genotype C patients (54.5% vs. 19.2%, p < 0.01). There was no significant difference in the prevalence of BCP mutations between genotype B and genotype C (18.2% vs. 10.2%). Multivariate analysis showed that old age (> 40 years) and BCP mutations were independent predictors of liver necroinflammation and fibrosis. Thus, BCP mutations may be associated with liver necroinflammation and fibrosis in patients with persistently normal ALT and low serum HBV-DNA levels in northeast China.