title: Analysis of HCV co-infection with occult hepatitis B virus in patients undergoing IFN therapy.
abstract: OBJECTIVE
  Occult hepatitis B virus (HBV) infection is characterized by the presence of HBV DNA in the absence of hepatitis B surface antigen (HBsAg) in the patient serum. Although such infections have been identified in patients with chronic hepatitis C, the clinical significance of those co-infections is still not understood. Our aim was, therefore, to assess the prevalence and clinical consequences of occult HBV infection in chronic hepatitis C patients undergoing antiviral therapy.
  
  
  METHODS
  The study population consisted of 53 HBsAg-negative patients with chronic hepatitis C treated with IFN/ribavirin or IFN/ribavirin/amantadine. Nine patients experienced a viral breakthrough (BT), 30 were non-responders (NR) and 14 were responders (R). HBV-DNA detection by PCR was performed using primers specific for the S region of the HBV genome and HCV-RNA detection by PCR with primers localised in both the 5'NC and core region of HCV genome, before, during and after treatment. Viral genome sequences were also studied.
  
  
  RESULTS
  Occult HBV genomes were found in the serum of four of 53 (7.5%) patients, unrelated to anti-HBc status. No significant differences in biochemical, virological, or histological markers, age, duration of infection, were observed in patients with or without HBV DNA. There was an inverse correlation in the evolution of HBV DNA and HCV RNA levels. Direct sequencing showed that S gene of occult HBV presented mutations in the "a" determinant while no specific mutation in the core region of HCV was observed. None of the four patients co-infected with HBV and HCV were responders to anti-HCV therapy.
  
  
  CONCLUSIONS
  In our clinical setting, the prevalence of occult HBV co-infection among patients with chronic hepatitis C was low and independent of the presence of markers of previous HBV infection. Further studies in larger cohort of patients are warranted to determine if occult HBV co-infection may be involved in HCV resistance to combination therapy.
authors.affiliation: INSERM UNIT 271, 151 cours Albert Thomas, 69424 Lyon Cedex 03, France.
authors.forename: E
authors.initials: E
authors.lastname: Khattab
authors.forename: I
authors.initials: I
authors.lastname: Chemin
authors.forename: I
authors.initials: I
authors.lastname: Vuillermoz
authors.forename: C
authors.initials: C
authors.lastname: Vieux
authors.forename: S
authors.initials: S
authors.lastname: Mrani
authors.forename: O
authors.initials: O
authors.lastname: Guillaud
authors.forename: C
authors.initials: C
authors.lastname: Trepo
authors.forename: F
authors.initials: F
authors.lastname: Zoulim
mesh_terms: D000328:Adult; D000547:Amantadine / Q000627:therapeutic use; D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood / Q000737:chemistry; D024882:Drug Resistance, Viral; D005260:Female; D005602:France; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D006515:Hepatitis B virus / Q000235:genetics / Q000302:isolation & purification; D019694:Hepatitis B, Chronic / Q000150:complications* / Q000188:drug therapy*; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000188:drug therapy*; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000097:blood / Q000737:chemistry; D011994:Recombinant Proteins; D012254:Ribavirin / Q000627:therapeutic use; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D019562:Viral Load
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012367:RNA, Viral; D011994:Recombinant Proteins; D012254:Ribavirin; D000547:Amantadine