Editorial: Measurement of HBsAg concentration during antiviral therapy of hepatitis B: who, when, and why.

Abstract

The measurement of hepatitis B surface antigen (HBsAg) concentration in serum is now under evaluation in treatment trials for hepatitis B. HBsAg kinetics differ during interferon and nucleoside analog treatment. A rapid decline in HBsAg concentration during interferon therapy has been associated with a higher chance for sustained virological response. By contrast, a much slower decline often occurs during nucleoside analog therapy and limits the ability of this test to be a useful prognostic indicator during the first year or two of treatment.