clinical usefulness of hbsag quantification in patients with chronic hepatitis b infection

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.