Institute of Digestive Disease, The Chinese University of Hong Kong; Hong Kong SAR, China.
Department of Medicine and Therapeutics, The Chinese University of Hong Kong; Hong Kong SAR, China.
State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong; Hong Kong SAR, China.
The natural history of chronic hepatitis B (CHB) is complex and may run through different immune phases that may overlap. In particulars, the immune-tolerant phase is the most interesting and not as well understood as we thought. The concept of true immune tolerance have been under challenged from immunology points of view. The major international guidelines have not yet reached a consensus on the definition of the immune-tolerant phase. While positive hepatitis B e antigen (HBeAg), high serum hepatitis B virus (HBV) DNA and normal serum alanine aminotransferase (ALT) levels are the three key features of this phase, some guidelines also put age into consideration. A new nomenclature, Phase 1 or HBeAg-positive chronic HBV infection, is given by the latest European Association for the Study of the Liver (EASL) published in April 2017. While current guidelines advise against starting antiviral treatment for immune-tolerant CHB patients, some new data suggest treating such patients may reduce the risk of liver fibrosis progression and hepatocellular carcinoma.