title: Quantitative hepatitis B surface antigen levels in patients with chronic hepatitis B after 2 years of entecavir treatment.
abstract: OBJECTIVE
  The role of quantitative hepatitis B surface antigen (HBsAg) levels in patients receiving oral antiviral therapy is controversial. We aimed to determine the HBsAg response in chronic hepatitis B patients treated with entecavir 0.5 mg daily for 2 years.
  
  
  METHODS
  A total of 166 patients were included. Liver biochemistry, hepatitis B virus (HBV) serological markers, HBV DNA, and quantitative HBsAg levels were performed at baseline, year 1, and year 2 after commencing entecavir. Additional HBsAg levels were measured at 12 and 24 weeks in patients with available sera.
  
  
  RESULTS
  In all, 68 patients were hepatitis B e-antigen (HBeAg) positive. Age, HBV DNA, and alanine aminotransferase (ALT) were significantly correlated with HBsAg levels at baseline (r=-0.429, 0.607, and 0.254, respectively, all P<0.05). The correlation with HBV DNA and ALT levels was reduced by entecavir treatment, and was lost after 2 years of treatment. There was an overall decline in HBsAg levels from baseline to year 1 to year 2 (3,377.4 vs. 2,316.5 vs. 1,903.0 IU/ml, respectively, P<0.001). However, at year 2, 102 patients (61%) had no significant changes (<0.5 log difference), 50 (30%) had significant decline (≥0.5 log decrease), whereas 14 (9%) had significant increase (≥0.5 log increase). Of the patients, 151 (91%) had undetectable HBV DNA; 25 (37%) underwent HBeAg seroconversion. Neither HBsAg at baseline nor early decline at weeks 12 or 24 was predictive of HBeAg seroconversion at 2 years.
  
  
  CONCLUSIONS
  Despite HBV DNA suppression, the majority did not show significant decline in HBsAg levels. Early decline of HBsAg levels at 12/24 weeks was not associated with HBV DNA suppression or HBeAg seroconversion.
authors.affiliation: Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong Special Administrative Region, China.
authors.forename: James
authors.initials: J
authors.lastname: Fung
authors.forename: Ching-Lung
authors.initials: CL
authors.lastname: Lai
authors.forename: John
authors.initials: J
authors.lastname: Young
authors.forename: Danny Ka-Ho
authors.initials: DK
authors.lastname: Wong
authors.forename: John
authors.initials: J
authors.lastname: Yuen
authors.forename: Wai-Kay
authors.initials: WK
authors.lastname: Seto
authors.forename: Man-Fung
authors.initials: MF
authors.lastname: Yuen
mesh_terms: D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D004279:DNA, Viral / Q000097:blood* / Q000187:drug effects; D004334:Drug Administration Schedule; D005260:Female; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000201:enzymology / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013997:Time Factors
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; C413685:entecavir; D006147:Guanine; D000410:Alanine Transaminase