title: Removal of exogenous (spiked) and endogenous prion infectivity from red cells with a new prototype of leukoreduction filter.
abstract: BACKGROUND
  Two recent probable cases of transmission of a variant of human Creutzfeldt-Jakob disease (vCJD) through blood transfusion suggest that the disease can be transmitted through transfusion of blood components from presymptomatic blood donors. In the absence of a preclinical screening test, removal of the infectious agent by processing is the only means by which risk to recipients of blood from donors with inapparent vCJD infections can be eliminated.
  
  
  METHODS
  In the endogenous infectivity study, a pool of 500 mL of whole blood was collected into CP2D anticoagulant from 263K-strain scrapie-infected hamsters, processed into 300 mL of red cells (RBCs), and then passed through a prion removal filter. Pre- and postfiltration samples were tested for PrP(sc) by Western blot and for infectivity by inoculation of healthy hamsters. In the exogenous (spiking) infectivity study, 30 mL of 10 percent (wt/vol) scrapie-infected brain homogenates was added to 270 mL of human RBCs and then filtered. Levels of PrP(sc) and infectivity were determined by Western blot and bioassay.
  
  
  RESULTS
  In the endogenous infectivity study, the prefiltered RBCs transmitted disease to 6 of 43 animals, whereas the postfiltered RBCs did not transmit disease to any of 35 animals, and a barely visible prefiltration PrP(sc) Western blot signal was reduced below the level of detection in the postfiltration sample. In the exogenous (spike) study, infectivity was reduced by 3.7 log LD50 per mL, from 9.2 to 5.5 log LD50 per mL.
  
  
  CONCLUSIONS
  The new filter was effective in removing both infectivity and PrP(sc) from RBCs. The use of this type of filter should reduce the risk of vCJD transmission through blood transfusion.
authors.affiliation: Pall Medical, Pall Corp., Port Washington, New York 11050, USA. Sam_Coker@Pall.com
authors.forename: Samuel
authors.initials: S
authors.lastname: Sowemimo-Coker
authors.forename: Regina
authors.initials: R
authors.lastname: Kascsak
authors.forename: Anzi
authors.initials: A
authors.lastname: Kim
authors.forename: Fabiola
authors.initials: F
authors.lastname: Andrade
authors.forename: Susan
authors.initials: S
authors.lastname: Pesci
authors.forename: Richard
authors.initials: R
authors.lastname: Kascsak
authors.forename: Clifford
authors.initials: C
authors.lastname: Meeker
authors.forename: Richard
authors.initials: R
authors.lastname: Carp
authors.forename: Paul
authors.initials: P
authors.lastname: Brown
mesh_terms: D000818:Animals; D001681:Biological Assay; D015153:Blotting, Western; D006224:Cricetinae; D005374:Filtration / Q000379:methods; D047589:Leukocyte Reduction Procedures / Q000379:methods*; D008647:Mesocricetus; D018620:PrPSc Proteins / Q000097:blood* / Q000302:isolation & purification*; D017096:Prion Diseases / Q000097:blood* / Q000517:prevention & control*
chemical_list: D018620:PrPSc Proteins