TT virus contaminates first-generation recombinant factor VIII concentrates

Recombinant factor VIII and factor IX concentrates, human-plasma-derived al bumin, and samples from previously untreated patients with hemophilia were examined for the presence of TT virus (TTV) by using polymerase chain react ion testing. Blood samples from the patients were obtained prospectively be fore and every 3 to 6 months after therapy was begun. TTV was detected in 2 3.5% of the recombinant-product lots and 55.5% of the albumin lots tested. Only first-generation factor VIII recombinant concentrates stabilized with human albumin were positive for TTV, whereas all second-generation (human p rotein-free) concentrates were negative for the virus. In 59% of patients t reated with either first- or second-generation recombinant factor concentra tes, TTV infection developed at some point after the initial infusion. Infe ction with TTV in these patients before and after treatment did not appear to be clinically important. Thus, first-generation recombinant factor VIII concentrates may contain TTV and the source of the viral contamination may be human albumin. (Blood. 2001;98:2571-2573) (C) 2001 by The American Socie ty of Hematology.