TTV infection in patients with acute hepatitis of defined aetiology and in acute non-A-E hepatitis

Background/Aims: Recently, the presence of a novel nonenveloped single-stranded DNA virus (TTV) has been associated with either acute or chronic hepatitis of unknown aetiology, suggesting a possible aetiological role. The aim of this study was to evaluate the prevalence, the significance and the clinical impact of TTV infection in patients with acute viral hepatitis of defined aetiology and in patients with non-A-E acute hepatitis. Methods: TTV-DNA was tested by hemi-nested PCR in serum samples collected from 121 patients during and after acute hepatitis (103 with acute viral hepatitis of defined aetiology and 18 with acute non-A-E hepatitis) and in 30 healthy controls. Results: Overall, the rate of TTV infection was 12.6% (13/103) in patients with acute hepatitis of defined aetiology, 16.6% (3/18) in patients with non-A-E acute hepatitis and 6.6% (2/30) in the healthy control group, (p=n.s). TTV-DNA was detected in the following proportions: hepatitis B, 13.2% (7/53); hepatitis C, 16.6% (4/24); hepatitis A, 4.7% (1/21); hepatitis E 20% (1/5). Moreover, acute hepatitis with and without TTV infection/coinfection were comparable in terms of both liver biochemistry and chronicity rate. The results of TTV re-testing after serial dilutions of six TTV-DNA positive serum samples during and after the peak of liver transaminases failed to demonstrate a correlation between liver damage and viral titre. Conclusions: The prevalence of TTV infection appeared to be comparable in patients with non-A-E hepatitis, in acute hepatitis of defined aetiology and in the control group. Hence, an aetiological role of TTV for acute hepatitis of unknown aetiology seems questionable. Moreover, TTV infection does not modify the natural history of acute hepatitis of defined aetiology.