[Quantitative analysis of hepatitis B surface antigen as a clinical marker]

There are 1.5 million hepatitis B virus (HBV) infected patients in Japan. Anti-viral therapy is important for chronic hepatitis B patients to prevent hepatocellular carcinoma. Recently, HBs antigen (HBsAg) quantification has been reported to be useful for not only HBV screening but also for monitoring of anti-viral treatment. In this paper, we evaluated the clinical utility of quantitative assay of HBsAg by HISCL HBsAg kit. Although there can be a significant difference in age, HBeAg positive/negative and viral genotype, there is not in the disease stage. Moreover, the weak correlation was confirmed between HBsAg and HBV-DNA levels with or without anti-virus treatment. In the clinical practice, as HBV-DNA becomes undetectable immediately by anti-viral therapy such as entecavir, it may be difficult to evaluate the efficacy. The monitoring of the HBsAg concentration in addition to HBV-DNA would be useful for the evaluation. Hence, the clinical role of HBsAg concentration could spread widely in Japan.