Serum HBsAg quantification to predict response to peginterferon therapy of e antigen positive chronic hepatitis B

P>Background On-treatment predictors of response to peginterferon can guide individualization of therapy in chronic hepatitis B virus infection. Aim To investigate the use of serum hepatitis B surface antigen quantification to predict sustained response. Methods Hepatitis B e antigen-positive chronic hepatitis B patients who received peginterferon for 32-48 weeks with or without lamivudine combination were studied. Sustained response was defined as hepatitis B e antigen seroconversion and chronic hepatitis B virus DNA < 10 000 copies/mL until 12 months post-treatment. Results Twenty-one of 92 (23%) patients achieved sustained response. At month 6, the area under receiver operating characteristics curve for hepatitis B surface antigen to predict sustained response was 0.77 (95% confidence interval 0.65-0.89, P < 0.001). An hepatitis B surface antigen cutoff at 300 IU/mL at month 6 could give the maximum combination of sensitivity (62%) and specificity (89%) to predict sustained response. Nine of 21 (43%) sustained responders vs. 9 of 71 (13%) nonsustained responders had > 1 log hepatitis B surface antigen reduction at month 6 (P < 0.001). Combined hepatitis B surface antigen < 300 IU/mL and > 1 log reduction at month 6 had sensitivity, specificity, positive and negative predictive values of 43%, 96%, 75% and 85% to predict sustained response, respectively. Conclusion On-treatment serum hepatitis B surface antigen can predict response to peginterferon therapy in chronic hepatitis B.