Clinical Usefulness of HBsAg Quantification in Patients with Chronic Hepatitis B Infection

Abstract

Context: Quantitative hepatitis B surface antigen (qHBsAg) levels have been shown to assist the management of patients with chronic hepatitis B virus (HBV) infection and reflect the level of transcriptional activity of covalently closed circular DNA (cccDNA). It has been indicated the importance of co-operative use of qHBsAg and HBV-DNA for diagnosis and monitoring of CHB treatment. Evidence Acquisition: In order to achieve a comprehensive approach in HBsAg quantification, an extensive search was done using relevant keywords in major medical libraries to collect, categorize, and summarize data in different sections. Results: A combination of qHBsAg < 1000 IU/mL and HBV-DNA < 2000 IU/mL can identify inactive carriers. qHBsAg levels are changed during the natural history of HBV infection that progressively declines from the immune tolerance to the inactive phase. Conclusions: The use of qHBsAg in chronic hepatitis B (CHB) patients may bring about important complementary information regarding HBV DNA during treatment and help predict the treatment outcome.