Roles of TT virus infection in various types of chronic hepatitis

An unenveloped single-stranded virus, which might be a causative agent for posttransfusion non-A-G hepatitis, was recently found and named 'TT virus' (TTV). There is still controversy over the role of TTV in chronic hepatitis . Therefore, we have examined the prevalence of TTV in various types of chr onic hepatitis in Japan. TTV DNA was detected in 11 of 40 patients (27.5%) with non-B, non-C chronic hepatitis, 13 of 46 patients (28.3%) with type B chronic hepatitis, 21 of 55 patients (38.2%) with type C chronic hepatitis, and 41 of 131 subjects (31.3%) with normal liver function tests. The posit ivity rate for TTV DNA tended to increase with age. The detection rate did not differ statistically between non-B, non-C chronic hepatitis and type B or type C chronic hepatitis, or normal subjects. The distribution of TTV ge notypes was not significantly different among them. Clinical characteristic s of the chronic illness were similar for patients with or without TTV in a ll hepatitis groups. The etiologic role of TTV in chronic hepatitis is not confirmed from the statistical and clinical standpoint. Copyright (C) 2001 S. Karger AG, Basel.