title: Transfusion-associated TT virus infection and its relationship to liver disease.
abstract: TT virus (TTV) has been proposed as the causative agent of non-A to E hepatitis. We studied the association between TTV viremia and biochemical evidence of hepatitis in blood donors and prospectively-followed patients. TTV was found in 7.5% of 402 donors and in 11.0% of 347 patients before transfusion. The rate of new TTV infections was 4.7% in 127 nontransfused, and 26.4% in 182 transfused patients (P <.0001). The risk of infection increased with the number of units transfused (P <.0001). The rate of new TTV infections in 13 patients with non-A to E hepatitis (23.2%) was almost identical to the rate in 124 patients who were transfused, but did not develop hepatitis (21.8%). Of 45 patients with acute hepatitis C, 40.0% were simultaneously infected with TTV. TTV did not worsen the biochemical severity (mean ALT: 537 in TTV+; 550 in TTV-) or persistence of hepatitis C. In non-A to E cases, the mean ALT was 182 in those TTV-positive and 302 in TTV-negatives. No consistent relationship between alanine transaminase level and TTV DNA level was observed in 4 patients with long-term, sequential samples. Of 21 viremic subjects, 67% cleared TTV within 5 years (38% in 1 year); 33% were viremic throughout follow-up extending to 22 years. We conclude that TTV is a very common, often persistent infection that is transmitted by transfusion and by undefined nosocomial routes. We found no association between TTV and non-A to E hepatitis and no effect of TTV on the severity or duration of coexistent hepatitis C. TTV may not be a primary hepatitis virus.
authors.affiliation: Department of Transfusion Medicine, National Institutes of Health, Bethesda, MD, USA.
authors.forename: A
authors.initials: A
authors.lastname: Matsumoto
authors.forename: A E
authors.initials: AE
authors.lastname: Yeo
authors.forename: J W
authors.initials: JW
authors.lastname: Shih
authors.forename: E
authors.initials: E
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Kiyosawa
authors.forename: H J
authors.initials: HJ
authors.lastname: Alter
mesh_terms: D001782:Blood Donors; D004267:DNA Viruses / Q000302:isolation & purification*; D004279:DNA, Viral / Q000097:blood*; D004219:District of Columbia / Q000453:epidemiology; D006508:Hepatitis Antibodies / Q000097:blood; D006525:Hepatitis, Viral, Human / Q000453:epidemiology* / Q000635:transmission*; D006801:Humans; D009316:National Institutes of Health (U.S.); D011183:Postoperative Complications / Q000821:virology; D012367:RNA, Viral / Q000097:blood; D012011:Red Cross; D019616:Thoracic Surgical Procedures / Q000009:adverse effects*; D065227:Transfusion Reaction; D014481:United States
chemical_list: D004279:DNA, Viral; D006508:Hepatitis Antibodies; D012367:RNA, Viral