Abstract: Objective The aim of this study was to investigate serum B-cell activating factor (BAFF) levels in predicting antiviral response of pegylated interferon alpha (Peg-IFN-α) in inactive HBsAg carriers(IHCs). Methods 54 IHCs were recruited in our hospital between January 2018 and August 2020,and all were treated with Peg-IFN-α for 48 weeks and followed-up for 24 weeks. Serum BAFF levels were measured by ELISA. The Logistic regression analysis was applied to analyze the factors affecting antiviral response, and the area under the receiver-operating characteristic curve (AUC) were applied to evaluate the performance of serum BAFF levels in predicting antiviral response. Results At the end of 72 weeks, the complete response (CR) was obtained in 24 cases (44.4%), and were not obtained in 30 cases (55.6%); there was no significant difference as respect to baseline serum BAFF levels [(670.9±105.9) pg/mL vs. (612.7±183.8)pg/mL, P>0.05] between the two groups; at the end of 12 weeks and 24 weeks, serum BAFF levels in responders were (805.8±197.6)pg/mL and (895.3±227.4)pg/mL, both significantly higher than [(675.3±190.8)pg/mL and (724.4±218.0)pg/mL, respectively, P<0.05] in non-responders; the multivariate Logistic regression analysis showed that baseline serum HBsAg, HBV DNA<20 IU/mL, serum BAFF levels at week 12 and week 24 were the independent factors impacting the antiviral response; the ROC analysis demonstrated that the AUC=0.722, with the sensitivity (Se) of 79.2% and specificity (Sp) of 66.7%, when serum BAFF level greater than 704.3 pg/mL at week 12 was set as the cut-off-value, and the AUC=0.725, with Se of 75.0% and Sp of 70.0%, when serum BAFF level greater than 741.9 pg/mL at week 24 was set as the cut-off-value in predicting antiviral response in patients receiving Peg-IFN-α treatment. Conclusion The CR is nearly 40% in IHCs receiving Peg-IFN-α treatment, and the surveillance of serum BAFF levels might guide the regimen going or stopping.

Key words: Hepatitis B, Inactive HBsAg carriers, Pegylated interferon-alpha, B-cell activating factor, Response