Incidence and clinical implication of TT virus in patients with hepatitis and its frequency in blood donors in India.

Background: Transfusion Transmitted Virus (TTV), also known as Torque Teno Virus is a new novel viral agent which appears to correlate with some acute and chronic hepatitis cases and may produce liver damage under specific circumstances. Aim of this study was to detect TT virus by real-time PCR, study its clinical implications and effects of its co-infection in HBV and HCV chronic liver diseases.

Methods: The study population comprised 50 acute hepatitis, 50 chronic hepatitis patients and 100 voluntary blood donors. All samples were tested for serum bilirubin, AST, ALT and alkaline phosphatase levels and for all available viral markers for hepatitis. The detection of TT viral genome was carried out by real-time PCR using TTV sequences as reported by Takahashi et al with modifications on the basis of database of the DDBJ/EMBL/GenBank (GenBank accession no. AB008394).

Result: Serum was positive for TTV in 72% of volunteer blood donors, 77.4% (24/31) of hepatitis A cases, 87.6% (36/41) of HBV-positive, 77% (10/13) of HCV-positive, and 92.8% (13/14) of non-B, non-C cases. Co-infection of TTV with other hepatitis viruses was detected in some patients.

Conclusion: TTV is a frequent virus detected in patients with various types of viral hepatitis, in cases of hepatitis without obvious viral agent, and from the healthy population in India. Rate of TTV was found to be significantly higher (92.8%) for Non A-E hepatitis group.