Hepatitis B virus DNA level as predictor of response to therapy with interferon-alpha-2b (PDferon) in chronic hepatitis B infection

Background: To evaluate the strength of association and to determine the best prediction of response in terms of sensitivity and specificity among quantitative baseline HBV-DNA levels in blood serum in patients with chronic hepatitis B (CHB) infection who treated with interferon-alpha-2b. Patients and methods: Totally, 78 CHB patients with serum HBV-DNA > 105 copies/mL were treated with interferonalpha- 2b (PDferon: Pooyesh Darou, Tehran, Iran) for 52 weeks as 5 MU Sc. for 24 weeks in HBeAg(+) and 48 weeks for HBeAg(-) at baseline of study in Tehran, Iran. Serum HBV-DNA level using Cobas Amplicor HBV Monitor test and HBeAg status were assessed at baseline and end of 6-months follow-up. Sustained response (SR) (n=42, 56%) was defined by HBeAg seroconversion (n=12), or with a decrease in HBV-DNA > 105 copies/mL to undetectable value (n=33), or chemical response (n=20). Results: Higher pretreatment HBV-DNA levels have a significant relationship with better response to treatment in HBeAg (+) (R=0.7, p=0.04). Positivity of HBeAg in SR was a better predictor of chemical response in our patients, when compared to HBeAg negative (SR: 85% vs. 15%, respectively). At end of follow up, HBeAg (-) patients revealed more decrease in HBV-DNA levels than HBeAg (+) (412 vs. 290 ×105 copies/ml, p < 0.05). Sensitivity of HBV-DNA in HBeAg (+) was more than HBeAg(-) (75% vs. 62%), but specificity was less in HBeAg(+) (58% vs. 45%). Area under ROC was 0.63 in HBeAg (-). Conclusion: Higher pretreatment HBV-DNA levels have a significant relationship with better response to treatment in HBeAg positive patients of CHB. Although HBV-DNA in HBeAg negative was decreased significantly from baseline to end of follow-up, monitoring with sensitive quantitative baseline HBV-DNA measurement in these patients was not a better predictor of SR than HBeAg positive.