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 currentl y 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 pat ients with unselected pathologies, and no significant differences related t o 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 cirr hosis (30%) and rheumatoid arthritis (28%), Patients with other liver disea ses, systemic lupus erythematosus, or psoriasis or receiving hemodialysis h ad rates of infection similar to those in unselected patients. TTV-positive patients treated with interferon-alpha for underlying type C hepatitis sho wed no appreciable changes of TTV viremia levels. Type 1b was by far the mo st frequent viral genotype (92%), followed by types 2c (5%) and 1a (3%).