Hepatitis B virus DNA in anti-HBe-positive asymptomatic carriers

Abstract

Objectives: We examined the level of hepatitis B virus (HBV) DNA and the mutations in the precore, core and polymerase regions of HBV in sera from anti-HBe-positive asymptomatic carriers (ASC).

Methods: The amount of HBV DNA was determined semiquantitatively by mutation site-specific assay in sera from 19 anti-HBe-positive ASC and 31 HBeAg-positive patients with chronic liver disease (CLD). The mutations in the precore, core and polymerase (terminal protein) regions, spanning 1,037 nucleotides, of HBV in sera from three cases each of anti-HBe-positive ASC, HBeAg-positive ASC and HBeAg-positive CLD were examined by directly sequencing the amplified HBV DNA.

Results: The level of HBV viremia in anti-HBe-positive ASC was significantly lower than that in HBeAg-positive CLD patients (p < 0.01). By sequence analysis, there were a few missense mutations detected in HBeAg-positive ASC and HBeAg-positive CLD patients. In contrast, many mutations, especially in the central or N-terminal half of the core region and N-terminal part of the polymerase region, were detected in anti-HBe-positive ASC.

Conclusion: Mutations not only in the precore/core region, but also in the polymerase region of HBV might cause damage to some important functions for efficient replication of HBV and be involved in the reduced amount of HBV in anti-HBe-positive ASC.