title: Quantitation of HBsAg predicts response to entecavir therapy in HBV genotype C patients.
abstract: OBJECTIVE
  To analysis the factors that predict the response to entecavir therapy in chronic hepatitis patients with hepatitis B virus (HBV) genotype C.
  
  
  METHODS
  Fifty patients [hepatitis B e antigen (HBeAg)-negative:HBeAg-positive = 26:24] with HBV genotype C, who received naïve entecavir therapy for > 2 years, were analyzed. Patients who showed HBV DNA levels ≥ 3.0 log viral copies/mL after 2 years of entecavir therapy were designated as slow-responders, while those that showed < 3.0 log copies/mL were termed rapid-responders. Quantitative hepatitis B surface antigen (HBsAg) levels (qHBsAg) were determined by the Architect HBsAg QT immunoassay. Hepatitis B core-related antigen was detected by enzyme immunoassay. Pre-C and Core promoter mutations were determined using by polymerase chain reaction (PCR). Drug-resistance mutations were detected by the PCR-Invader method.
  
  
  RESULTS
  At year 2, HBV DNA levels in all patients in the HBeAg-negative group were < 3.0 log copies/mL. In contrast, in the HBeAg-positive group, 41.7% were slow-responders, while 58.3% were rapid-responders. No entecavir-resistant mutants were detected in the slow-responders. When the pretreatment factors were compared between the slow- and rapid-responders; the median qHBsAg in the slow-responders was 4.57 log IU/mL, compared with 3.63 log IU/mL in the rapid-responders (P < 0.01). When the pretreatment factors predictive of HBV DNA-negative status at year 2 in all 50 patients were analyzed, HBeAg-negative status, low HBV DNA levels, and low qHBsAg levels were significant (P < 0.01). Multivariate analysis revealed that the low qHBsAg level was the most significant predictive factor (P = 0.03).
  
  
  CONCLUSIONS
  Quantitation of HBsAg could be a useful indicator to predict response to entecavir therapy.
authors.affiliation: Department of Gastroenterology, Nagoya Daini Red Cross Hospital, Nagoya, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Orito
authors.forename: Kei
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kanie
authors.forename: Tesshin
authors.initials: T
authors.lastname: Ban
authors.forename: Tomonori
authors.initials: T
authors.lastname: Yamada
authors.forename: Katsumi
authors.initials: K
authors.lastname: Hayashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D005838:Genotype; D006147:Guanine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000097:blood / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; C413685:entecavir; D006147:Guanine
keywords: Chronic hepatitis B; Core promoter mutation; Entecavir; Hepatitis B core-related antigen; Hepatitis B virus genotype C; Pre-C mutation; Quantitation of hepatitis B surface antigen; Slow-responders