title: Baseline hepatitis B surface antigen quantitation can predict virologic response in entecavir-treated chronic hepatitis B patients.
abstract: OBJECTIVE
  Several anti-viral drugs are approved for the treatment of hepatitis B virus (HBV) infection. However, whether quantitative hepatitis B surface antigen (qHBsAg) can predict the therapeutic response during long-term entecavir treatment remains unclear.
  
  
  METHODS
  Fifty-five chronic hepatitis B (CHB) patients who received entecavir for more than 2 years were enrolled. The serum qHBsAg level was measured by HBsAg II quant immunoassay. A significant decline in the qHBsAg level was defined as > 1 log reduction from baseline to 6 months of entecavir treatment.
  
  
  RESULTS
  Of the 55 patients (41 males and 14 females with a mean age of 48.3 ± 11.4 years), 23 patients were positive for hepatitis B e antigen (HBeAg). The median treatment period was 34 months, and ranged from 26 months to 43 months. A total of 288 serum samples were used to determine the qHBsAg levels. At year 3 of entecavir therapy, one (1.8%) patient had HBsAg seroclearance. A high qHBsAg level was defined as greater than 10,000 IU/mL. Patients with a high baseline qHBsAg level had a lower rate of virologic response at year 1 (37.5% vs. 89.7%, p < 0.001) and year 2 (56.2% vs. 94.9%, p = 0.001). In this study population, 14.5% had a significant decline of the qHBsAg level. A significant decline could not predict HBeAg loss in HBeAg-positive or virologic response in all patients.
  
  
  CONCLUSIONS
  The baseline serum qHBsAg level can predict virologic response in entecavir-treated CHB patients. However, a significant decline in the qHBsAg level cannot predict serologic or virologic response of entecavir treatment.
authors.affiliation: Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Chia-Chi
authors.initials: CC
authors.lastname: Wang
authors.affiliation: Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Tai-Chung
authors.initials: TC
authors.lastname: Tseng
authors.affiliation: Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Pin-Chao
authors.initials: PC
authors.lastname: Wang
authors.affiliation: Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and School of Medicine, Tzu Chi University, Hualien, Taiwan. Electronic address: YOYO@tzuchi.com.tw.
authors.forename: Hans Hsienhong
authors.initials: HH
authors.lastname: Lin
authors.affiliation: Graduate Institute of Clinical Medicine and Hepatitis Research Center, National Taiwan University College of Medicine and Hospital, Taiwan.
authors.forename: Jia-Horng
authors.initials: JH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D006147:Guanine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000097:blood*; D006515:Hepatitis B virus; D019694:Hepatitis B, Chronic / Q000175:diagnosis / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; C413685:entecavir; D006147:Guanine
keywords: entecavir; hepatitis B e antigen; hepatitis B virus; quantitative hepatitis B surface antigen