GPT and chronic hepatitis B virus infection: The natural history of chronic HBV infection is classified into five phases: HBeAg-positive chronic HBV infection, HBeAg-positive chronic hepatitis B, HBeAg-negative chronic hepatitis B, HBeAg-negative chronic HBV infection, and HBsAg-negative phase, according to HBeAg, HBsAg, HBV DNA level, and alanine aminotransferase (ALT) value (Table 1) [2,3].