title: Assessment of prion reduction filters in decreasing infectivity of ultracentrifuged 263K scrapie-infected brain homogenates in "spiked" human blood and red blood cells.
abstract: BACKGROUND
  The safety of red blood cells (RBCs) is of concern because of the occurrence of four transfusion-transmitted variant Creutzfeldt-Jakob disease (vCJD) cases in the United Kingdom. The absence of validated screening tests requires the use of procedures to remove prions from blood to minimize the risk of transmission. These procedures must be validated using infectious prions in a form that is as close as possible to one in blood.
  
  
  METHODS
  Units of human whole blood (WB) and RBCs were spiked with high-speed supernatants of 263K scrapie-infected hamster brain homogenates. Spiked samples were leukoreduced and then passed through prion-removing filters (Pall Corporation). In another experiment, RBCs from 263K scrapie-infected hamsters were treated as above, and residual infectivity was measured by bioassay.
  
  
  RESULTS
  The overall removal of infectivity by the filters from prion-spiked WB and RBCs was approximately two orders of magnitude. No infectivity was detected in filtered hamster RBCs endogenously infected with scrapie.
  
  
  CONCLUSIONS
  The use of prion-removing filters may help to reduce the risk of transfusion-transmitted vCJD. To avoid overestimation of prion removal efficiency in validation studies, it may be more appropriate to use supernates from ultracentrifugation of scrapie-infected hamster brain homogenate rather than the current standard brain homogenates.
authors.affiliation: Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Cardone
authors.forename: Samuel
authors.initials: S
authors.lastname: Sowemimo-Coker
authors.forename: Hanin
authors.initials: H
authors.lastname: Abdel-Haq
authors.forename: Marco
authors.initials: M
authors.lastname: Sbriccoli
authors.forename: Silvia
authors.initials: S
authors.lastname: Graziano
authors.forename: Angelina
authors.initials: A
authors.lastname: Valanzano
authors.forename: Vito Angelo
authors.initials: VA
authors.lastname: Berardi
authors.forename: Roberta
authors.initials: R
authors.lastname: Galeno
authors.forename: Maria
authors.initials: M
authors.lastname: Puopolo
authors.forename: Maurizio
authors.initials: M
authors.lastname: Pocchiari
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology*; D006224:Cricetinae; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D004912:Erythrocytes / Q000737:chemistry*; D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D008851:Micropore Filters / Q000592:standards*; D011328:Prions / Q000302:isolation & purification*; D012608:Scrapie / Q000517:prevention & control* / Q000635:transmission; D014461:Ultracentrifugation / Q000295:instrumentation / Q000379:methods
chemical_list: D011328:Prions