title: Quantitative hepatitis B surface antigen and hepatitis B e antigen titers in prediction of treatment response to entecavir.
abstract: Quantitative hepatitis B surface antigen (qHBsAg) and quantitative hepatitis B e antigen (qHBeAg) titers are emerging as useful tools for measuring viral loads and for predicting the virological response (VR) and serological response (SR) to pegylated interferon therapy. However, the clinical utility of these assays in patients taking entecavir (ETV) is largely unknown. Treatment-naive patients with chronic hepatitis B (CHB) who were taking ETV for 2 years were enrolled. The qHBsAg and qHBeAg levels were serially measured with the Architect assay. From 95 patients, 60.0% of whom were hepatitis B e antigen-positive [HBeAg(+)], 475 samples were analyzed. The median baseline log hepatitis B virus (HBV) DNA, log qHBsAg, and log qHBeAg values were 6.73 copies/mL (4.04-9.11 copies/mL), 3.58 IU/mL (1.17-5.10 IU/mL), and 1.71 Paul Ehrlich (PE) IU/mL (-0.64 to 2.63 PE IU/mL), respectively. For the prediction of VR (HBV DNA < 60 copies/mL at 24 months) in HBeAg(+) patients, baseline alanine aminotransferase (P = 0.013), HBV DNA (P = 0.040), and qHBsAg levels (P = 0.033) were significant. For the prediction of VR, the area under the curve for the baseline log qHBsAg level was 0.823 (P < 0.001); a cutoff level of 3.98 IU/mL (9550 IU/mL on a nonlogarithmic scale) yielded the highest predictive value with a sensitivity of 86.8% and a specificity of 78.9%. As for SR (HBeAg loss at 24 months), the reduction of qHBeAg was significantly greater in the SR(+) group versus the SR(-) group. The sensitivity and specificity were 75.0% and 89.8%, respectively, with a decline of 1.00 PE IU/mL at 6 months. With ETV therapy, the correlation between HBV DNA and qHBsAg peaked at 6 months in HBeAg(+) patients.
  
  
  CONCLUSIONS
  Both qHBsAg and qHBeAg decreased significantly with ETV therapy. The baseline qHBsAg levels and the on-treatment decline of qHBeAg in HBeAg(+) patients were proven to be highly useful in predicting VR and SR, respectively. The determination of qHBsAg and qHBeAg can help us to select the appropriate strategy for the management of patients with CHB. However, the dynamic interplay between qHBsAg, qHBeAg, and HBV DNA during antiviral therapy remains to be elucidated.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Ahn
authors.forename: Hyon Suk
authors.initials: HS
authors.lastname: Kim
authors.forename: Hana
authors.initials: H
authors.lastname: Park
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Chang
authors.forename: Do Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Seong Gyu
authors.initials: SG
authors.lastname: Hwang
authors.forename: Kyu Sung
authors.initials: KS
authors.lastname: Rim
authors.forename: Chae Yoon
authors.initials: CY
authors.lastname: Chon
authors.forename: Kwang-Hyub
authors.initials: KH
authors.lastname: Han
authors.forename: Jun Yong
authors.initials: JY
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D005260:Female; D006147:Guanine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000097:blood*; D019694:Hepatitis B, Chronic / Q000097:blood* / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; C413685:entecavir; D006147:Guanine