title: Factors associated with serum hepatitis B surface antigen levels and its on-treatment changes in patients under lamivudine therapy.
abstract: BACKGROUND
  We aimed to investigate factors associated with serum hepatitis B surface antigen (HBsAg) levels and its kinetics under lamivudine treatment in chronic hepatitis B patients.
  
  
  METHODS
  HBsAg levels were measured with the Architect HBsAg assay (Abbott laboratories, Abbott Park, IL, USA) in genotype B (HBV/B) or C (HBV/C) patients (n=218). Early HBsAg kinetics in 86 hepatitis B e antigen (HBeAg)-positive patients and long-term HBsAg changes in 45 patients with rapid and sustained viral suppression were further analysed.
  
  
  RESULTS
  Mean HBsAg levels were higher in male (n=181) than in female (n=37) patients (3.59 versus 3.23 log(10) IU/ml; P=0.036), and higher in 121 HBV/B than in 97 HBV/C patients (3.68 versus 3.34 log(10) IU/ml; P=0.006). In addition to HBV DNA loads (P<0.001), male gender (P=0.012) and HBV/B infection (P=0.035) were independently associated with higher HBsAg levels in antiviral-naive patients. HBsAg increases (0.00-0.87 log(10)) were found in 28/86 patients who obtained viral suppression under 12 weeks of lamivudine therapy. Higher baseline HBsAg levels (P=0.046), HBV/B infection (P=0.007) and faster HBV DNA declines (P=0.006) independently contributed to greater HBsAg decreases under 12 weeks treatment. An apparent dissociation between HBsAg and HBV DNA changes were found in 14/45 patients with rapid and sustained viral suppression, who had low baseline HBsAg levels and predominant HBV/C infection.
  
  
  CONCLUSIONS
  HBV/B and male gender were associated with higher HBsAg levels in antiviral-naive patients. Higher baseline HBsAg levels and HBV/B infection contributed to greater early HBsAg declines in HBeAg-positive patients, and might correlate with discordance between HBsAg and HBeAg or HBV DNA under long-term lamivudine treatment.
authors.affiliation: Institute of Hepatology, Department of Infectious Diseases, Key Laboratory for Organ Failure Research, Nanfang Hospital, Southern Medical University, Guangzhou, PR China.
authors.forename: Jinjun
authors.initials: J
authors.lastname: Chen
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Jinlin
authors.initials: J
authors.lastname: Hou
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D054316:Biomarkers, Pharmacological / Q000097:blood; D015331:Cohort Studies; D004279:DNA, Viral / Q000097:blood; D005260:Female; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000187:drug effects / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000097:blood / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D019259:Lamivudine / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male; D015999:Multivariate Analysis; D012737:Sex Factors; D016896:Treatment Outcome; D019562:Viral Load / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D054316:Biomarkers, Pharmacological; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; D019259:Lamivudine