Background: TT virus (TTV) is a recently discovered virus with a high DNA prevalence in different populations. Its role in pathogenesis is uncertain, particularly in immunocompromised patients.
Patients and methods: Prevalence of TTV-DNA was evaluated in a cohort of HIV-infected patients and in blood donors by nested PCR, using two different primer sets: T primers, derived from the open reading frame ORF1 region N22; B primers, derived from the untranslated region (UTR). Samples positive using T primers were also tested for TTV-DNA in peripheral blood mononuclear cells (PBMC) and followed up every 4 months.
Results: The overall prevalence of TTV-DNA in HIV-infected patients was 37/376 (9.8%) using T primers and 223/333 (67%) using B primers; prevalence was higher in males (167/237, 70.5% vs 56/96, 58.3%; p = 0.033) and sub-Saharan Africans (22/23, 95.6% vs 201/310, 64.8% in other areas). Discordance was also observed in blood donors: 3.8% prevalence using T primers and 51.4% using B primers (also higher in males: 57% vs 37%, p = 0.056). TTV-DNA was detected in PBMC in 20/23 (87%) TTV-positive sera. Two-thirds of the serum samples remained positive over a 2-year follow-up period.
Conclusion: TTV-DNA prevalence is higher when detected with primers derived from the UTR region and was highest in male and HIV-infected sub-Saharan Africans. TTV-DNA is frequently isolated in PBMC and chronic infection is common.