Significance of TT virus detection in patients with viral hepatitis

Objective: To know the infection of TT virus(TTV) in patients with viral hepatitis, and to investigate the pathogenic effect of TTV in patients with non-A to G hepatitis. Methods: The sera, which were collected from 25 patients with viral hepatitis, were detected for TTV DNA by n-PCR using specific primers. The PCR products were cloned and sequenced. Results: Among 25 patients, 12 were TTV DNA positive. TTV DNA were detected in the sera form 8 of 18 patients with non-A to G hepatitis and their sera ALT levels were elevated. Sequence analysis indicated that there were high homology with Japanese strain. Conclusion: TTV infection exists in Xi' an area and TTV may have some pathogenic effects. There is coinfection or superinfection of TTV and HBV or HCV without acceleration of the disease which dose not make the patients condition worsened.