Co-infections with torque teno viruses in HCV infection

Background/Aim: The potential role of co-infections with novel hepatitisviruses such as torque teno viruses (SENV and TTV) is not clear in HCVinfection. We determined the prevalence and clinical significance of theseagents in different forms of HCV infection. Patients: a total of 365 HCVinfected individuals have been studied. Out of them 33 were symptomfree HCV carriers with persistently normal alanine aminotransferase (ALT), 97suffered from chronic hepatitis C not treated with interferon (IFN)-basedtherapy, 48 patients (pts) had chronic hepatitis C and treated with IFN+ ribavirin (RBV) for one year, 76 pts previously treated with IFN+RBVand achieved sustained virological response (SVR) and 111 were non-responders to IFN +RBV. One hundred and eight healthy volunters served as controls for TTV studies and 40 for SENV investigations. Methods: HCVRNA was detected using Roche Cobas Amplicor Monitor 2.0 test, TTV DNA, SENV-D and SENV-H DNA by PCR method. Results: Prevalance of both SENV-D, SENV-H and TTV was higher in HCV pts than in healthy controls (SENV-D: 43.7% vs. 7.5%; SENV-H 66.6% vs. 35.0% and TTV: 77.7% vs. 18.5%, respectively). Both SENV and TTV carriers have lower serum ALT and higher HCV RNA levels than SENV negative and TTV negative pts. IFN+RBV treated pts with SVR, after the therapy showed lower frequency of SENV-D (10.5%) and TTV (3.9%) than not treated ones. HCV pts with SENV-D achieved lower SVR (33%) than SENV-D negative pts (45%). Conclusion: Torque teno viruses can be "accidental tourists" in HCV infection, and though they may interfere with HCV, their pathogenetic role in liver injury is questionable. They may be IFN (+RBV?) sensitive agents.