Presence of TT virus infection in chronic hepatitis patients from a hospital in New Delhi, India

Abstract

Background & objectives: The recent discovery of a novel parenterally transmitted, unenveloped, single-stranded DNA virus called TT virus (TTV) in chronic hepatitis patients with unclear pathogenesis throughout the world led us to investigate, its presence in chronic hepatitis patients attending a hospital in New Delhi, India, and to evaluate its role in liver disease. Methods: TT virus DNA was investigated in serum samples of 70 patients with various types of chronic hepatitis, and 100 healthy subjects from New Delhi, India by nested PCR using the primers that belonged to UTR (A) region of the genome. Results: TTV DNA was detected in 6 of 23 patients (26%) with type B chronic hepatitis, 3 of 20 patients (15%) with type C chronic hepatitis, and 12 of 100 subjects (12%) from healthy control group with normal liver function profile tests. None of the 27 non-B, non-C chronic hepatitis patients had TTV DNA positivity. The prevalence of TTV was significantly higher in type-B chronic hepatitis patients as compared to normal subjects (P < 0.05) but comparable to type C chronic hepatitis patients. The clinical course and biochemical profiles of type B, or type C chronic hepatitis patients co-infected with TTV did not differ significantly from those without TTV infection. Interpretation & conclusions: Interestingly, in chronic hepatitis patients, TTV was always associated with either hepatitis B or C virus indicating a likely parenteral route of transmission. All TTV-positive subjects in healthy control group showed normal clinical and biochemical profiles. Thus, the presence of TTV infection is unlikely to influence the course of chronic hepatitis related to hepatitis B virus (HBV) or hepatitis C virus (HCV) or cause liver diseases in healthy subjects.