Predictors for advanced liver fibrosis in chronic hepatitis B virus infection with persistently normal or mildly elevated alanine aminotransferase

The aim of the present study was to evaluate the predictors for advanced liver fibrosis in patients with chronic hepatitis B virus (HBV) infection with persistently normal alanine aminotransferase (PNALT), or persistently or intermittently mildly elevated ALT (PIEALT). A total of 305 patients were included in the present study. Liver biopsies were evaluated using the METAVIR scoring system. Liver stiffness (LS) was measured using Fibroscan. Multivariate logistic regression and the area under the receiver operating characteristic curve (AUROC) were used to examine the diagnostic value of the predictors for advanced liver fibrosis. HBV DNA viral load in the PNALT group was significantly lower compared with the PIEALT group (4.57±1.68 vs. 5.71±1.69 log(10) IU/ml; P<0.001). Body mass index and LS were also significantly lower in the PNALT group compared with the PIEALT group (P<0.001). The proportion of patients with liver fibrosis was significantly higher in the PIEALT group compared with the PNATL group (P=0.001). High ALT levels were an independent predictor for liver fibrosis, with an odds ratio (OR) of 2.69 (P=0.002). Male sex (OR=0.34, P=0.007), high ALT levels (OR=2.37, P=0.029) and a high HBV DNA load (OR=1.39, P=0.005) were independent predictors for advanced liver fibrosis. The AUROC was 0.65 (P=0.003) when using ALT levels to predict advanced liver fibrosis. ALT levels at ≥0.88 upper limit of normal (ULN; 35 IU/l) were considered as positive for advanced liver fibrosis, the sensitivity and specificity were 87.8 and 47.4%, respectively. The AUROC was 0.64 (P=0.004) when using the HBV DNA value to predict advanced liver fibrosis. When an HBV DNA value of ≥4.99 log(10) IU/ml was considered as positive for advanced liver fibrosis, the sensitivity and specificity were 78.0 and 49.5%, respectively. The AUROC was 0.72 (P<0.001) when combining ALT, HBV DNA load and sex into a formulation to predict advanced liver fibrosis. When the formulation score at >-2.22 was considered as positive for advanced liver fibrosis, the sensitivity and specificity were 61.5 and 70.7%, respectively. Therefore, normal ALT levels do not always indicate the absence of hepatic fibrosis. A combination of ALT levels, sex and serum HBV DNA load may more effectively identify patients with CHB at high risk of developing fibrosis. These patients may benefit from liver biopsy.