title: A prion reduction filter does not completely remove endogenous prion infectivity from sheep blood.
abstract: BACKGROUND
  Variant Creutzfeldt-Jakob disease (vCJD) is a transmissible spongiform encephalopathy affecting humans, acquired initially through infection with bovine spongiform encephalopathy (BSE). A small number of vCJD cases have been acquired through the transfusion of blood from asymptomatic donors who subsequently developed vCJD. Filter devices that selectively bind the infectious agent associated with prion disease have been developed for removal of infection from blood. This study independently assessed one such filter, the P-CAPT filter, for efficacy in removing infectivity associated with the BSE agent in sheep blood. The sheep BSE model has previously been used to evaluate the distribution of infectivity in clinically relevant blood components. This is the first study to assess the ability of the P-CAPT filter to remove endogenous infectivity associated with blood components prepared from a large animal model.
  
  
  METHODS
  Paired units of leukoreduced red blood cells (LR-RBCs) were prepared from donors at the clinical stage of infection and confirmed as having BSE. One cohort of recipients was transfused with LR-RBCs alone, whereas a parallel cohort received LR and P-CAPT-filtered RBCs (LR-RBCs-P-CAPT).
  
  
  RESULTS
  Of 14 recipients, two have been confirmed as having BSE. These sheep had received LR-RBCs and LR-RBCs-P-CAPT from the same donor.
  
  
  CONCLUSIONS
  The results indicate that, after leukoreduction and P-CAPT filtration, there can still be sufficient residual infectivity in sheep RBCs to transmit infection when transfused into a susceptible recipient.
authors.affiliation: Neurobiology Division, The Roslin Institute, University of Edinburgh.
authors.forename: Sandra
authors.initials: S
authors.lastname: McCutcheon
authors.affiliation: Neurobiology Division, The Roslin Institute, University of Edinburgh.
authors.forename: A Richard
authors.initials: AR
authors.lastname: Alejo Blanco
authors.affiliation: Neurobiology Division, The Roslin Institute, University of Edinburgh.
authors.forename: Boon Chin
authors.initials: BC
authors.lastname: Tan
authors.affiliation: Animal and Plant Health Agency, Lasswade Laboratory, Edinburgh, UK.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: González
authors.affiliation: Animal and Plant Health Agency, Lasswade Laboratory, Edinburgh, UK.
authors.forename: Stuart
authors.initials: S
authors.lastname: Martin
authors.affiliation: Bristol Institute for Transfusion Sciences, Bristol, UK.
authors.forename: Gary
authors.initials: G
authors.lastname: Mallinson
authors.affiliation: Bristol Institute for Transfusion Sciences, Bristol, UK.
authors.forename: Nigel E
authors.initials: NE
authors.lastname: Appleford
authors.affiliation: University of Edinburgh and SNBTS, Edinburgh, UK.
authors.forename: Marc L
authors.initials: ML
authors.lastname: Turner
authors.affiliation: Neurobiology Division, The Roslin Institute, University of Edinburgh.
authors.forename: Jean C
authors.initials: JC
authors.lastname: Manson
authors.affiliation: Neurobiology Division, The Roslin Institute, University of Edinburgh.
authors.forename: E Fiona
authors.initials: EF
authors.lastname: Houston
mesh_terms: D000818:Animals; D002417:Cattle; D004912:Erythrocytes; D006440:Hemofiltration / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D017096:Prion Diseases / Q000097:blood* / Q000517:prevention & control; D011328:Prions / Q000097:blood / Q000302:isolation & purification; D012756:Sheep
chemical_list: D011328:Prions