[Role of TT virus in pathogenesis of liver diseases--the prevalence of TTV in patients and healthy individuals].

Primarily TTV has been thought as an etiologic agent of post transfusion non-A to -G hepatitis. TTV can replicate in liver and bone marrow cells. The presence of TTV has been found in the serum of patients with acute as well as chronic hepatitis of known etiology. Patients with acute hepatitis A, B, C and hepatitis caused by EBV or CMV all have TTV viremia in a frequency up to 60%. In chronic viral hepatitis TTV was present in a wide range of 7-94.4%. Treatment of viral hepatitis patients with interferon alfa and rybawiryn leads to eradication of TTV viremia in 50% cases. TTV infection in hepatocellular carcinoma ranged from 8.1% up to 100% patients. In hepatitis of unknown etiology TTV infection was observed in 26% to 71% cases. In liver cirrhosis TTV infection has been evidenced in 10% to 66% patients. Some authors postulated that the frequency of TTV increased with the number of blood or blood products transfusions. Coinfection of TTV has been found in 34.9%-76% of HIV positive persons. The study of medical staff revealed no difference in TTV viremia with healthy individual control. TTV is widespread in healthy general population. Therefore based on so far published results the association between TTV infection and hepatitis is questionable.