High Prevalence of TT Virus Viremia in Italian Patients, Regardless of Age, Clinical Diagnosis, and Previous Interferon Treatment

The pathogenic potential of the newly discovered TT virus (TTV) is currently a matter of conjecture. Its presence was investigated in the serum of 660 patients, by polymerase chain reaction. TTV was detected in 50% of 221 patients with unselected pathologies, and no significant differences related to age, sex, or organ disease were noted. TTV was present at a significantly higher rate in hemophiliacs (73%) and at lower rates in patients with cirrhosis (30%) and rheumatoid arthritis (28%). Patients with other liver diseases, systemic lupus erythematosus, or psoriasis or receiving hemodialysis had rates of infection similar to those in unselected patients. TTV-positive patients treated with interferon-alpha for underlying type C hepatitis showed no appreciable changes of TTV viremia levels. Type 1b was by far the most frequent viral genotype (92%), followed by types 2c (5%) and 1a (3%).