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

Abstract

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.

Infusion of P‐Capt prion‐filtered red blood cell products demonstrate acceptable in vivo viability and no evidence of neoantigen formation

“…Analysis showed an absence of changes in RBC antigens after storage, and DAT and antibody screening for RBC antigens or neoantigens 6 weeks after infusion of autologous prion-filtered RBCs were negative. These results are in line with the data from Cahill and colleagues 16 who found no significant adverse events in a group of 20 patients transfused with 1 unit, including six who received transfusion of a second prion-filtered unit. Additional studies are required to rule out the development of antibody formation after repeated infusions and analysis of their impact on the RBC recovery in vivo.…”

“…The resin also demonstrated the ability to remove endogenous infectivity from hamster leukoreduced RBCs to below the limit of detection of the bioassay used to determine the infectivity titer 11 . RBC storage variables after leukoreduced RBCs were filtered with the P‐Capt prion filter and then stored with either plasma‐CPD or SAGM to outdate have been evaluated 16‐18 . All of the final variables (hemoglobin [Hb] g/unit, hematocrit [Hct], residual WBCs, total volume) as well as end of shelf life product variables (hemolysis, adenosine 5′‐triphosphate [ATP], 2,3‐diphosphoglycerate acid [2,3‐DPG], potassium, and pH) were within the UK and Council of Europe Guidelines 19,20 .…”

“…11 RBC storage variables after leukoreduced RBCs were filtered with the P-Capt prion filter and then stored with either plasma-CPD or SAGM to outdate have been evaluated. [16][17][18] 19,20 No effects on complement or coagulation factor activation were observed, and no platelet (PLT) activation was identified. 21 These results indicate that RBC stability is not adversely affected by exposure to the P-Capt prion filter.…”

Transfusion of prion‐filtered red cells does not increase the rate of alloimmunization or transfusion reactions in patients: results of the UK trial of prion‐filtered versus standard red cells in surgical patients (PRISM A)

“…P-Capt filtered red blood cell concentrates (PF-RCC) behaved normally in laboratory assays and had a normal antigenic profile (Murphy et al, 2009), and a study in 20 patients showed that exposure to 1-2 PF-RCC units did not generate any attributable adverse events (Cahill et al, 2010).…”

Evaluation of the protection of primates transfused with variant Creutzfeldt‐Jakob disease–infected blood products filtered with prion removal devices: a 5‐year update

“…The UK blood transfusion services confirmed the results demonstrating the P‐Capt's adequate profile for RBCC filtration and reinfusion in human transfusion . This device did neither show any detrimental effect on RBC stability nor induce any immunologic changes …”