Quantitation of large, middle and small hepatitis B surface proteins in HBeAg‐positive patients treated with peginterferon alfa‐2a

Background & Aims Hepatitis B virus (HBV) contains three viral surface proteins, large, middle and small hepatitis B surface protein (LHBs, MHBs, SHBs). Proportions of LHBs and MHBs are lower in patients with inactive vs active chronic infection. Interferon alfa may convert hepatitis B e antigen (HBeAg)‐positive chronic hepatitis B (CHB) to an inactive carrier state, but prediction of sustained response is unsatisfactory. The aim of this study was to test the hypothesis that quantification of MHBs and LHBs may allow for a better prognosis of therapeutic response than total hepatitis B surface antigen (HBsAg) concentration. Methods Hepatitis B surface proteins were measured before and during peginterferon alfa‐2a therapy in serum from 127 Asian patients with HBeAg‐positive CHB. Sustained response was defined as HBeAg seroconversion 24 weeks post‐treatment. Results Mean total HBs levels were significantly lower in responders vs nonresponders at all time points (P 0.70). Conclusions Hepatitis B surface protein levels differ by HBV genotype. However, quantification of HBs proteins has no advantage over the already established HBsAg assays to predict response to peginterferon alfa‐2a therapy in HBeAg‐positive patients.