title: TT virus genotype changes frequently in multiply transfused patients with hemophilia but rarely in patients with chronic hepatitis C and in healthy subjects.
abstract: BACKGROUND
  TT virus (TTV), a novel DNA virus, was originally thought to be transmitted by transfusion. However, nonparenteral transmission is recently suspected to be a major mode of transmission. To investigate the possibility of reinfection with TTV in multiply transfused patients and to evaluate the significance of transfusion transmission of TTV in patients with hemophilia, serial changes in TTV genotype were investigated in three groups.
  
  
  METHODS
  Serial changes in TTV genotype were investigated in 16 multiply transfused patients with hemophilia, 16 age-matched patients with chronic hepatitis C, and 16 age-matched healthy subjects.
  
  
  RESULTS
  Mixed infection with multiple TTV genotypes was common in all groups. However, changes in TTV genotype were frequent in patients with hemophilia (15/16; 93.8%) but rare in patients with chronic hepatitis C and in healthy subjects (each group: 1/16; 6.3%).
  
  
  CONCLUSIONS
  Changes in TTV genotype were frequently observed in multiply transfused patients with hemophilia but not in patients with chronic hepatitis or in healthy subjects without risk of transfusion transmission. This difference may suggest that exposure to TTV or even reinfection occurs frequently in patients with hemophilia, which could be evidence of transfusion transmission of TTV in this population.
authors.affiliation: Department of Internal Medicine, Fujita Health University School of Medicine, Toyoake, Japan. hmtoyoda@net1.kdd.fr
authors.forename: H
authors.initials: H
authors.lastname: Toyoda
authors.forename: Y
authors.initials: Y
authors.lastname: Fukuda
authors.forename: I
authors.initials: I
authors.lastname: Nakano
authors.forename: Y
authors.initials: Y
authors.lastname: Katano
authors.forename: S
authors.initials: S
authors.lastname: Yokozaki
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: H
authors.initials: H
authors.lastname: Nakano
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: J
authors.initials: J
authors.lastname: Takamatsu
mesh_terms: D000293:Adolescent; D000328:Adult; D004266:DNA Virus Infections / Q000453:epidemiology / Q000635:transmission; D005838:Genotype; D006467:Hemophilia A / Q000628:therapy*; D019698:Hepatitis C, Chronic / Q000821:virology*; D006801:Humans; D007564:Japan; D015995:Prevalence; D012016:Reference Values; D022783:Torque teno virus / Q000235:genetics*; D065227:Transfusion Reaction