Hepatitis B e antigen-negative mutations in the precore and core promoter regions in Korean patients

Abstract

Most patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B have variants of the hepatitis B virus (HBV) that include mutations in the precore or core promoter regions of the HBV genome. The aim of this study was to investigate the patterns of precore and core promoter mutations and their relationship to HBeAg expression in Korean patients. Four hundred seventy-five Korean patients with chronic HBV infection between February 1995 and December 2003 were enrolled in this study. There were 236 HBeAg-positive and 239 HBeAg-negative patients. Blood samples were tested for HBsAg, anti-HBs, HBeAg, hepatitis B e antibody (anti-HBe), liver function tests, and serum HBV DNA. Mutations in the precore and core promoter regions were determined by direct sequencing. In the core promoter region, the C1740, C1753, T1762/A1764, and T1766 mutations were associated with HBeAg escape (all; P < 0.05). In the precore region, a higher frequency of the C1802, A1828, T1846, A1850, C1858, T1862, and A1896 mutations was found in HBeAg-negative patients (all; P < 0.05). In particular, the A1896 mutation was associated with high serum levels of ALT and HBV DNA in HBeAg-negative patients (P = 0.014 and 0.026, respectively). Mutations around the Kozak sequence (nucleotides 1809-1812) were found in 6.7% of patients and were not associated with undetectable HBeAg (P = 0.13). In Korean patients, various mutations in the precore and core promoter regions were associated with HBeAg escape and amelioration of hepatic inflammation in HBeAg- negative patients. Only the A1896 mutation contributed to HBeAg-negative chronic hepatitis B.