TT virus infection during chronic hepatitis C

OBJECTIVE: The pathogenic role of TT virus (TTV) is not well known, especia lly during chronic hepatitis C virus (HCV) infection. We retrospectively in vestigated the presence of TTV DNA in the plasma of patients with chronic H CV infection and compared the characteristics of TTV-DNA-positive and -nega tive groups. METHODS: Between November 1996 and November 1998, 234 patients were include d. Inclusion criteria were persistently elevated serum alanine aminotransfe rase (ALT) levels, anti-HCV and HCV-RNA positivity, and seronegativity for hepatitis B virus and human immunodeficiency virus markers. TTV DNA was amp lified in nested polymerase chain reaction with TTV-specific primers, and p roducts were analyzed by agarose-gel electrophoresis. Data were analyzed us ing the chi(2), Fisher's exact test, or Mann-Whitney test, as appropriate. RESULTS: TTV DNA was detected in 19 (8.1%; 95% confidence interval: 4.6-11. 6%) patients. TTV-DNA-positive: and TTV-DNA-negative patients did not diffe r statistically for age, gender ratio, source of HCV infection, HCV disease duration, biological parameters, histological grade, HCV-RNA load, or HCV genotype. Although nonsignificant (p = 0.21), there was a trend for a highe r prevalence of TTV DNA in patients with an unknown cause of HCV infection (4/22, 18.2%) than in intravenous drug users (4/84; 4.8%), in those exposed to potential risk factors (4/49; 8.2%), or in those having received blood transfusion (7/79; 8.9%). CONCLUSIONS: Because the rates of HCV replication and the severity of liver lesions in TTV-DNA-negative and -positive patients were similar, the hepat ic pathogenicity of TTV in chronic hepatitis C patients is questionable. (C ) 2000 by Am. Coll. of Gastroenterology).