Phase I/II safety study of transfusion of prion‐filtered red cell concentrates in transfusion‐dependent patients

Background and Objectives  Variant Creutzfeldt-Jakob (vCJD) is a fatal transfusion transmissible prion infection. No test for vCJD in the donor population is currently available. Therefore, prion removal by filtration of red cell concentrate (RCC) is an attractive option for prevention. Materials and Methods  Twenty patients were recruited with ethical permission, to receive clinically necessary transfusion containing one unit of pfRCC. Follow-up at 24 hours, 6 weeks and 6 months was undertaken. A second pfRCC was administered to 6 patients with similar follow up. pfRCC were prepared using the CE marked P-Capt device by the IBTS. Results  In 20 transfused patients undergoing one exposure to a prion filtered unit, no attributable adverse events were noted. A subset of these (n = 6) underwent re-exposure to a further filtered unit without incident. Conclusions  This phase 1/11 clinical study provides encouraging data on safety of prion filtration which can be used to plan more extensive studies on the use of filtered blood in adults and children.