A proportion of chronic hepatitis B virus (HBV) infection patients with normal alanine aminotransferase (ALT) should start antiviral therapy based on liver biopsy. We aim to evaluate the proportion of such patients, find noninvasive methods for identifying and then evaluate antiviral efficacy.

253 chronic HBV infection patients with normal ALT were analyzed at baseline and 57 patients with histological indication for antiviral therapy (Histology activity index ≥5 and/or Ishak fibrosis score ≥3) and 140 patients with elevated ALT received entecavir therapy and were followed-up to 78 weeks with a second liver biopsy in this multi-center study.

127 (50.2%) of 253 patients with normal ALT fulfilled histological indication for antiviral therapy. Aspartate aminotransferase (P=0.049), anti-hepatitis B virus core antibody (P=0.001) and liver stiffness measurement (P=0.000) were independent variables for identifying histological indication for antiviral therapy. A noninvasive model (AAF) performed best among independent variables and other noninvasive models with area under the operating characteristic curve of 0.887. Antiviral efficacy showed that 38 (66.7%) of 57 patients had undetectable HBV DNA. 12 (41.4%) of 29 patients who were hepatitis B e antigen (HBeAg)-positive at baseline achieved HBeAg loss and 3 (10.3%) achieved HBeAg seroconversion. 25 (43.9%) of 57 patients achieved histological response. Moreover, 57 patients with normal ALT had a similar antiviral therapy efficacy with 140 patients with elevated ALT (P>0.1) except proportion of inflammation improvement and histological response (P=0.005, P=0.049).

Half of chronic HBV patients with normal ALT should start antiviral therapy based on liver biopsy. A noninvasive model could be used as a reliable tool for antiviral therapy decision. Patients with normal or elevated ALT had a similar antiviral efficacy.