title: Serum hepatitis B surface antigen levels predict surface antigen loss in hepatitis B e antigen seroconverters.
abstract: OBJECTIVE
  Loss of hepatitis B surface antigen (HBsAg) usually indicates that hepatitis B virus (HBV) infection has been cured. However, little is known about factors predicting HBsAg loss in patients who spontaneously clear hepatitis B e antigen (HBeAg).
  
  
  METHODS
  We studied 390 Taiwanese HBeAg-positive patients with chronic hepatitis who had spontaneously cleared HBeAg (seroconversion) during follow-up. Serum levels of HBV DNA and HBsAg were determined 1 year after HBeAg seroconversion, and their relationships with subsequent HBsAg loss were investigated.
  
  
  RESULTS
  In a mean follow-up of 7.4 years, the average annual rate of HBsAg loss was 0.62%. Serum levels of HBsAg and HBV DNA were inversely associated with HBsAg loss in a dose-response manner. Compared with patients with HBsAg levels ≥1000 IU/mL, the HBsAg loss rate was higher for those with HBsAg levels of 100 to 999 and <100 IU/mL, with hazard ratios of 4.4 (95% confidence interval, 1.1-17.0) and 24.3 (8.7-67.5), respectively. Among those who underwent HBsAg loss within 6 years of follow-up, serum HBsAg levels were a better predictor than HBV DNA levels by receiver operating characteristic curve analysis (area under the receiver operating characteristic curve, 0.90 vs 0.69; P = .012); an HBsAg level <100 IU/mL predicted HBsAg loss within 6 years with a diagnostic accuracy of 91.5%, sensitivity of 83.3%, specificity of 92.1%, positive predictive value of 45.5%, and negative predictive value of 98.6% in patients with an HBV DNA level <200 IU/mL.
  
  
  CONCLUSIONS
  Low serum levels of HBsAg, alone or in combination with HBV DNA levels, 1 year after HBeAg seroconversion can predict HBsAg loss in patients with HBV genotype B or C infection.
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: Chun-Jen
authors.initials: CJ
authors.lastname: Liu
authors.forename: Tung-Hung
authors.initials: TH
authors.lastname: Su
authors.forename: Chia-Chi
authors.initials: CC
authors.lastname: Wang
authors.forename: Chi-Ling
authors.initials: CL
authors.lastname: Chen
authors.forename: Pei-Jer
authors.initials: PJ
authors.lastname: Chen
authors.forename: Ding-Shinn
authors.initials: DS
authors.lastname: Chen
authors.forename: Jia-Horng
authors.initials: JH
authors.lastname: Kao
mesh_terms: D000328:Adult; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology*; D019694:Hepatitis B, Chronic / Q000097:blood*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012372:ROC Curve
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens