Abstract: Objective To explore the predictors for functional cure in HBeAg-negative chronic hepatitis B [HBeAg (-)CHB] patients treated with pegylated interferon α-2b (PEG-IFN α-2b). Methods A retrospective study was conducted on HBeAg (-)CHB patients treated with PEG-IFN α-2b from August 2016 to December 2020 in Taizhou People's Hospital, and they were divided into cured group and uncured group. Univariate and logistic multivariate analyses were used to screen out the predictors for the functional cure. ROC-AUC was used to evaluate the predictive efficacy. Patients were grouped according to the cut-off values of predictors derived from ROC-AUC, the accumulated rate of HBsAg seroclearance was estimated by Kaplan-Meier survival curves, and the Log-rank test was used to compare the differences. Results A total of 116 HBeAg (-)CHB patients were included. Median follow-up was 124.93(109.61～140.11)weeks, and the rate of functional cure was 31.03% (36/116). Univariate analysis found that the factors which had statistical differences included the baseline HBsAg level(Z=-6.283, P<0.001), the proportion of cirrhotic patients at baseline(χ²=8.344, P=0.004), HBsAg decline at week 12 and week 24(Z=-3.922 and -5.144 respectively, P<0.001 for all)and the peak value of transient ALT elevation during the treatment (Z=-6.081, P<0.001). Logistic multivariate regression analysis suggested that the baseline HBsAg levels(P=0.001), the magnitude of HBsAg decline at week 24 (P=0.001)and the peak value of transient ALT elevation (P=0.019)were independently associated with functional cure. The cut-off values of the baseline HBsAg, the decline of HBsAg at week 24 and the peak value of transient ALT elevation were 1.68 lg IU/mL, 1.28 lg IU/mL and 110.50 U/L, respectively. The AUCs of the above three factors alone and combined for predicting functional cure were 0.802, 0.855, 0.833 and 0.963, respectively. There were significant differences in the accumulated rate of HBsAg seroclearance between the groups with baseline HBsAg≤1.68 lg IU/mL and ＞1.68 lg IU/mL, the decline of HBsAg≥1.28 lg IU/mL and ＜1.28 lg IU/mL at week 24, the peak value of transient ALT elevation≥110.50 U/L and ＜110.50 U/L during the treatment (χ²=30.966, 42.925,28.463 respectively, P<0.001 for all). Conclusion For HBeAg (-)CHB patients with lower baseline HBsAg levels, the treatment of PEG-IFN α-2b could achieve a higher HBsAg seroclearance rate. Moreover, the functional cure rate could also elevate in patients with a significant HBsAg decline at week 24 and a higher peak value of transient ALT elevation during the treatment.

Key words: Chronic hepatitis B, Pegylated interferon, Functional cure, Hepatitis B surface antigens