TT virus is present in a high frequency of Italian hemophilic patients transfused with plasma-derived clotting factor concentrates

The prevalence of the blood-borne TT virus (TTV) in Italian hemophiliacs tr eated with different preparations of factor VIII was determined. Of the 178 hemophilic patients (mean age, 29 years), TTV-DNA was found in 123 (69%), in comparison to 22 of 100 (22%) blood donors (P < .0001). Of the 123 patie nts who tested positive for rm, significant numbers were also infected with human hepatitis viruses and/or human immunodeficiency virus (HIV): 31% had rm and hepatitis C virus (HCV), 22% had TTV, and at least 2 of the 4 known human blood-borne viruses tested, whereas 15% had TTV alone. The risk of a cquiring TTV alone was only slightly higher in recipients of unmodified pla sma factor concentrates (78%, odds ratio, 1.24; 95% confidence interval [Cl ], 0.27 to 5.79) than in patients treated with virus inactivated concentrat es (67%), whereas the risk was significantly lower in recipients of recombi nant factors (11%, odds ratio, 0.09; 95% CI, 0.01 to 0.52), Serum alanine a minotransferase (ALT) levels were elevated in 2 of 27 patients (7%) with TT V alone compared with 43 of 56 patients (77%) coinfected with TTV and HCV a nd compared with 16 of 21 patients (76%) with HCV alone. Taken together, th ese results indicate that rm frequently infects Italian hemophiliacs treate d with plasma-derived factor VIII concentrates, both unmodified and virus-i nactivated. Our results do not suggest a causal effect of TTV on chronic li ver disease in these patients. (C) 1999 by The American Society of Hematolo gy.