title: Responsiveness to interferon alpha treatment in patients with chronic hepatitis C coinfected with hepatitis G virus.
abstract: OBJECTIVE
  Patients with chronic hepatitis C are often coinfected with the new identified Flaviviridae-like agent, termed hepatitis G virus (HGV). The aim of the study was to investigate the responsiveness of hepatitis G virus to interferon alpha and to evaluate whether a hepatitis G virus coinfection negatively influences the outcome of treatment in chronic hepatitis C.
  
  
  METHODS
  One hundred and fifteen patients with histologically proven chronic hepatitis C were treated with interferon alpha and investigated for the presence of hepatitis G virus coinfection by nested polymerase chain reaction with primers from the helicase region of hepatitis G virus. All patients received at least 3 MU (range 3-6) interferon alpha thrice weekly for at least 6 months (mean 8, range 6-12). Polymerase chain reaction products of seven pre- and post-treatment hepatitis G virus positive patients were directly sequenced for identification of sequence variability during the follow-up.
  
  
  RESULTS
  Eighteen (16%) patients were coinfected with hepatitis G virus. Although nine (50%) of these patients became HGV RNA negative during interferon alpha therapy, only three patients (17%) remained HGV RNA negative at the end of follow-up (mean 24 months). The rate of sustained response of chronic hepatitis C was not significantly different between patients with hepatitis C virus infection and HCV/HGV coinfection (19% vs 28%). Severity of liver disease as determined by alanine aminotransferase levels, histology and hepatitis C virus viremia was not significantly different in patients with hepatitis C virus or HCV/HGV coinfection. Sequence analysis of the helicase region revealed that our isolates all belonged to the hepatitis G virus and not to the GBV-C like genotype. No amino acid exchanges during the observation period of up to 48 months were observed, indicating that this region is highly conserved.
  
  
  CONCLUSIONS
  The responsiveness of hepatitis G virus to interferon alpha in chronic HCV/HGV coinfected patients is similar to that observed in chronic hepatitis C. Hepatitis G virus coinfection seems not to interfere with the efficacy of interferon alpha treatment in patients with chronic hepatitis C.
authors.affiliation: Virchow-Klinikum, Department of Internal Medicine, Humboldt-University, Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Berg
authors.forename: U
authors.initials: U
authors.lastname: Dirla
authors.forename: U
authors.initials: U
authors.lastname: Naumann
authors.forename: H G
authors.initials: HG
authors.lastname: Heuft
authors.forename: S
authors.initials: S
authors.lastname: Küther
authors.forename: H
authors.initials: H
authors.lastname: Lobeck
authors.forename: E
authors.initials: E
authors.lastname: Schreier
authors.forename: U
authors.initials: U
authors.lastname: Hopf
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000627:therapeutic use*; D001483:Base Sequence; D002908:Chronic Disease; D005260:Female; D018067:Flaviviridae / Q000302:isolation & purification*; D005500:Follow-Up Studies; D006526:Hepatitis C / Q000628:therapy* / Q000821:virology; D006525:Hepatitis, Viral, Human / Q000628:therapy* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents