title: Effect of TT virus co-infection on interferon response in chronic hepatitis C patients.
abstract: OBJECTIVE
  TT virus (TTV) is a single stranded DNA virus found in serum of patients with post-transfusion non-A to -G hepatitis. TTV-DNA has been investigated in sera of patients with various liver diseases. This study aimed at finding whether co-infection with TTV in HCV patients, may influence the effect of interferon (IFN) in complete elimination of HCV, and analysed the correlation between HCV and TTV by semi-quantification of both HCV RNAs and TTV DNA.
  
  
  METHODS
  In 28 chronic hepatitis C (CH-C) patients with TTV co-infection, the presence of TTV DNA was checked in sera six months before and after the end of IFN therapy.
  
  
  RESULTS
  Five out of 28 patients became negative for both HCV-RNA and TTV-DNA following IFN therapy. But 10 out of 28 patients persistently remained positive for both. Among the remaining 13 patients, 5 tested negative for HCV-RNA but positive for TTV-DNA. Post IFN therapy changes in serum alanine aminotransferase (ALT) levels did not appear to be influenced by the presence of TTV co-infection. HCV-RNA was found to be the most important predictor of IFN response in CH-C patients with TTV co-infection. TTV DNA level in sera had no correlation with IFN response. In addition, there was no relationship between HCV RNA and TTV DNA.
  
  
  CONCLUSIONS
  Based on these results, it can be concluded that the effectiveness of IFN in eliminating HCV does not seem to be influenced by co-infection.
authors.affiliation: Department of Internal Medicine, Center for Liver Diseases, Kawasaki Hospital, Kawasaki Medical School, 2-1-80 Nakasange, Okayama City 700-8505, Japan. kh-kanzo@po.rweb.ne.jp
authors.forename: Miwa
authors.initials: M
authors.lastname: Kawanaka
authors.forename: Gouichi
authors.initials: G
authors.lastname: Niiyama
authors.forename: Sabina
authors.initials: S
authors.lastname: Mahmood
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ifukube
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yoshida
authors.forename: Hideki
authors.initials: H
authors.lastname: Onishi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Hanano
authors.forename: Toshio
authors.initials: T
authors.lastname: Ito
authors.forename: Gotaro
authors.initials: G
authors.lastname: Yamada
mesh_terms: D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000627:therapeutic use*; D004266:DNA Virus Infections / Q000150:complications* / Q000188:drug therapy* / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D007372:Interferons / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000032:analysis; D022783:Torque teno virus / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D012367:RNA, Viral; D007372:Interferons; D000410:Alanine Transaminase