title: Hepatitis B virus activity in patients with anti-hepatitis C virus antibody positivity and hepatitis B antigen positivity.
abstract: BACKGROUND
  Co-infection with hepatitis B virus (HBV) and HCV seems to be relatively frequent. There might be a mutual influence on replication activity of HBV and HCV.
  
  
  OBJECTIVE
  To determine the HBV activity in patients with serum HCV RNA and HBsAg positivity and in those with confirmed anti-HCV antibody and HBsAg positivity but serum HCV RNA negativity.
  
  
  METHODS
  A total of 1,200 anti-HCV antibody positive samples were investigated. Samples of HCV RNA and HBsAg positive patients were compared with those of confirmed anti-HCV and HBsAg positive but serum HCV RNA negative patients. HBV activity was tested with the quantitative Cobas Amplicor HBV Monitor Test (Roche Diagnostic Systems, Pleasanton, CA).
  
  
  RESULTS
  Of all studied patients with chronic hepatitis C (serum HCV RNA positivity) only 1.0% were found to be HBsAg positive. In contrast, of all patients with confirmed anti-HCV positivity but serum HCV RNA negativity, 11.9% tested HBsAg positive. The median of HBV DNA levels of patients with serum HCV RNA positivity and HBeAg seroconversion (4.0 x 10(2) HBV DNA copies per ml) was found to be slightly lower than that of patients with serum HCV RNA negativity and HBeAg seroconversion (2.5 x 10(3) HBV DNA copies per ml; P>0.05). The median of HBV DNA levels of patients with serum HCV RNA positivity but without HBeAg seroconversion (1.1 x 10(4) HBV DNA copies per ml) was found to be significantly lower than that of patients with serum HCV RNA negativity but without HBeAg seroconversion (2.6 x 10(7) HBV DNA copies per ml; P<0.05).
  
  
  CONCLUSIONS
  A mutual effect on HBV and HCV replication could be observed. The molecular assay for quantification of serum HBV DNA was found to be useful for the routine diagnostic laboratory.
authors.affiliation: Institute of Laboratory Medicine, General Hospital St. Pölten, Propst Führer-Strasse 4, A-3100 St. Pölten, Austria. a.haushofer@kh-st-poelten.at
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Haushofer
authors.forename: René
authors.initials: R
authors.lastname: Hauer
authors.forename: Harald
authors.initials: H
authors.lastname: Brunner
authors.forename: Ursula
authors.initials: U
authors.lastname: Köller
authors.forename: Doris
authors.initials: D
authors.lastname: Trubert-Exinger
authors.forename: Walter Michael
authors.initials: WM
authors.lastname: Halbmayer
authors.forename: Josef
authors.initials: J
authors.lastname: Haas
authors.forename: Harald H
authors.initials: HH
authors.lastname: Kessler
mesh_terms: D006509:Hepatitis B / Q000097:blood* / Q000821:virology; D006510:Hepatitis B Antibodies / Q000097:blood*; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D015995:Prevalence; D012367:RNA, Viral / Q000097:blood / Q000302:isolation & purification; D015163:Superinfection
chemical_list: D006510:Hepatitis B Antibodies; D018937:Hepatitis C Antibodies; D012367:RNA, Viral