title: Clinical utility of quantitative HBsAg in natural history and nucleos(t)ide analogue treatment of chronic hepatitis B: new trick of old dog.
abstract: Using commercial quantitative assays, quantitative hepatitis B surface antigen (qHBsAg) has improved our understanding and management of chronic hepatitis B (CHB). The HBsAg level is highest in the immune tolerance phase, starts to decline during the immune clearance phase, and decreases slowly but progressively after hepatitis B e antigen (HBeAg) seroconversion. The HBsAg level is lowest in individuals with an inactive carrier state but higher in those who develop HBeAg-negative hepatitis. It has been shown that a reduction of HBsAg by 1 log IU/mL or more reflects improved host immune control of HBV infection. A combination of HBsAg <1000 IU/mL and HBV-DNA <2000 IU/mL can identify a 3-year inactive state in a genotype D HBeAg-negative carrier population. In the Asian-Pacific region, where HBV genotypes B and C are dominant, HBsAg levels of ≤10-100 IU/mL predict HBsAg loss over time. As to the prediction of disease progression, low-viremic carriers with HBsAg >1000 IU/mL have been shown to be at higher risks of HBeAg-negative hepatitis, cirrhosis, and hepatocellular carcinoma than those with HBsAg <1000 IU/mL. Although qHBsAg has been widely used in CHB patients receiving pegylated interferon therapy, the HBsAg decline is slow and does not correlate with HBV-DNA levels during nucleos(t)ide analogue (NUC) therapy. However, a rapid HBsAg decline during NUC therapy may identify patients who will finally clear HBsAg. A 6- to 12-monthly assessment of HBsAg level could be considered during NUC therapy. Taking these lines of evidence together, qHBsAg can complement HBV-DNA levels to optimize the management of CHB patients in our daily clinical practice.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan.
authors.forename: Tai-Chung
authors.initials: TC
authors.lastname: Tseng
authors.forename: Jia-Horng
authors.initials: JH
authors.lastname: Kao
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use*; D002353:Carrier State / Q000097:blood; D004279:DNA, Viral / Q000097:blood*; D018450:Disease Progression; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000096:biosynthesis / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000276:immunology; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D019694:Hepatitis B, Chronic / Q000097:blood* / Q000188:drug therapy*; D006801:Humans; D009705:Nucleosides; D009711:Nucleotides; D011237:Predictive Value of Tests
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; D009705:Nucleosides; D009711:Nucleotides