title: Infection by an unenveloped DNA virus associated with non-A to -G hepatitis in Japanese blood donors with or without elevated ALT levels.
abstract: BACKGROUND
  An unenveloped, single-stranded DNA virus named TT virus has been found in association with elevated alanine aminotransferase (ALT) levels in recipients of transfusions and has been detected frequently in patients with acute or chronic hepatitis of non-A to -G etiology in Japan. DNA of the TT virus was searched for in blood donors with or without elevated ALT levels.
  
  
  METHODS
  A total of 861 blood donors without previous transfusions and who were negative for markers of hepatitis B or C virus infection were tested. DNA of the TT virus was detected by polymerize chain reaction with hemi-nested primers.
  
  
  RESULTS
  TT virus DNA was detected in 62 of 280 (22.1% [95% CI: 18.1-26.6]) donors with elevated ALT levels (mean +/- SD, 89.3 +/- 36.4 U/L; range, 61-301 U/L), which is significantly more frequently (p<0.02) than its detection in 91 of 581 (15.7% [95% CI: 13.2-18.4]) donors with normal ALT (< or = 45 U/L). The frequency of TT virus DNA increased with age, in donors with and without elevated ALT.
  
  
  CONCLUSIONS
  The detection of TT virus DNA, at a frequency higher in donors with elevated ALT than in those without, strengthens the association of TT virus with non-A to -G hepatitis.
authors.affiliation: Japanese Red Cross Yamaguchi Blood Center, Yamaguchi.
authors.forename: K
authors.initials: K
authors.lastname: Itoh
authors.forename: K
authors.initials: K
authors.lastname: Hirakawa
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.forename: M
authors.initials: M
authors.lastname: Ukita
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: N
authors.initials: N
authors.lastname: Sawada
authors.forename: F
authors.initials: F
authors.lastname: Tsuda
authors.forename: Y
authors.initials: Y
authors.lastname: Miyakawa
authors.forename: M
authors.initials: M
authors.lastname: Mayumi
mesh_terms: D000293:Adolescent; D000328:Adult; D000410:Alanine Transaminase / Q000097:blood*; D001782:Blood Donors; D004266:DNA Virus Infections / Q000453:epidemiology / Q000209:etiology* / Q000821:virology; D005260:Female; D006525:Hepatitis, Viral, Human / Q000209:etiology* / Q000821:virology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012698:Serologic Tests; D065227:Transfusion Reaction
chemical_list: D000410:Alanine Transaminase