Abstract: Objective The aim of this study was to investigate the hepatic histological changes in adult individuals under 30 years old with chronic hepatitis B viral infection with normal serum alanine aminotransferase (ALT) levels. Methods A total of 108 individuals under 30 years old with chronic hepatitis B viral infection and with normal ALT levels were enrolled in our hospital between 2013 and 2023, and all underwent liver biopsies. The chronic hepatitis B was diagnosed based on the finding of liver histological activity index ≥G2 and/or liver fibrosis stage ≥S2, and those were classified into chronic HBV carriers who didn’t meet the requirement of CHB. The binary Logistic regression analysis was applied to screen the predictors of significant liver injuries, and the area under receiver operating characteristic curve (AUC) was used to predict the relevant indicators for significant liver inflammatory and fibrotic lesions. Results Out of the 108 individuals with chronic HBV infection, the liver histo-pathological examination found G1S1 in 73 cases, e.g., the HBV carriers, and G2/S2 in 30 cases and G3/S3 in 5 cases, e.g., the CHB in 35 cases; 65.7% of patients with CHB had positive hepatitis B viral infection family history, much higher than 13.7%(P＜0.05) in HBV carriers, and serum ALT level and HBV DNA load in patients with CHB were (30.3±6.7)U/L and 4.4(3.7, 5.8)lg IU/ml, both significantly higher than [(20.2±8.8)U/L and 3.5(2.9, 5.4) lg IU/ml, respectively, P＜0.05] in HBV carriers; the multivariate Logistic analysis showed that serum ALT level and HBV DNA load were the independent indicators for predicting significant liver injuries (P＜0.05); the AUC was 0.969, with the sensitivity and specificity of 88.6% and 95.9%, when the combination of serum ALT (the cut-off-value was 26.5 U/L) and HBV DNA load (the cut-off-value was 3.3 lgIU/ml) were applied to predict significant liver injuries, much superior to any of the two parameters alone (P＜0.05). Conclusion In adults under 30 years old with chronic HBV infection with normal serum ALT levels, when serum ALT level is greater than 27 U/L and serum HBV DNA load is greater than 2000 IU/ml, whether or not the antiviral therapy is given is worthy of further study.

Key words: Hepatitis B, Alanine aminotransferase, HBV DNA, Liver histopathology, HBV carriers