title: Change in serum hepatitis B surface antigen level and its clinical significance in treatment-naïve, hepatitis B e antigen-positive patients receiving entecavir.
abstract: OBJECTIVE
  We investigated changes in hepatitis B surface antigen (HBsAg) level and its correlation with clinical outcomes in treatment-naive chronic hepatitis B (CHB) patients undergoing entecavir therapy.
  
  
  METHODS
  Among 51 hepatitis B e antigen (HBeAg)-positive treatment-naive CHB patients receiving entecavir for more than 1 year, 28 were enrolled. HBsAg levels were measured at baseline, 6 months, and 12 months after treatment using the Architect HBsAg QT assay (Abbott, dynamic; range: 0.05 to 125,000 IU/mL). Serum alanine aminotransferase, HBeAg, anti-HBe, and hepatitis B virus (HBV) DNA (Cobas Taqman: low detection limit 1.84 log10 copies/mL) were measured at baseline and every 3 months. The HBsAg response was defined as an HBsAg level that decreased more than 1 log10 IU/mL from baseline level at 12 months after entecavir treatment.
  
  
  RESULTS
  Twenty-eight patients were treated for a median period of 21 months (range: 18 to 24 mo). Serum HBsAg level showed a mean of 4.0, 3.7, and 3.6 log10 IU/mL at pretreatment, 6, and 12 months, respectively, and declined significantly (P<0.001). Serum HBV DNA level showed a mean of 8.1, 3.1, and 2.4 log10 copies/mL at pretreatment, 6, and 12 months, respectively, and declined significantly (P<0.001). The decline in HBsAg level was significantly correlated with that of the HBV DNA level at 12 months from baseline (γ=0.391, P=0.044). Five patients showed an HBsAg response, and cumulative incidence of HBeAg loss at 1 year after entecavir treatment was 80% versus 30% in patients with an HBsAg response and those without, respectively (P=0.034).
  
  
  CONCLUSIONS
  Monitoring changes in quantitative HBsAg level could be a useful parameter for assessing the response to entecavir therapy in HBeAg-positive treatment-naive CHB patients.
authors.affiliation: Department of Internal Medicine, Gachon University of Medicine and Science Gil Medical Center, Incheon, Korea.
authors.forename: Young Kul
authors.initials: YK
authors.lastname: Jung
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Lee
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Lee
authors.forename: Eileen
authors.initials: E
authors.lastname: Yoon
authors.forename: Eun Suk
authors.initials: ES
authors.lastname: Jung
authors.forename: Seung Kwon
authors.initials: SK
authors.lastname: Hong
authors.forename: Moon Kyung
authors.initials: MK
authors.lastname: Joo
authors.forename: Jong Eun
authors.initials: JE
authors.lastname: Yeon
authors.forename: Jong Jae
authors.initials: JJ
authors.lastname: Park
authors.forename: Jae Seon
authors.initials: JS
authors.lastname: Kim
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Bak
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Byun
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006147:Guanine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000097:blood; D019694:Hepatitis B, Chronic / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; C413685:entecavir; D006147:Guanine