title: Removal of prion challenge from an immune globulin preparation by use of a size-exclusion filter.
abstract: BACKGROUND
  A size-exclusion filter (Viresolve 180, Millipore Corp.) was tested for its ability to remove transmissible spongiform encephalopathies prion protein from an immune globulin preparation during ultrafiltration.
  
  
  METHODS
  Hamster-adapted 263K scrapie brain homogenate (SBH) was spiked into Rh0(D) immune globulin (human) at 1 in 300 and 1 in 1000 dilutions. Before spiking, the SBH was treated with detergent, sonicated, and filtered through serial 0.45-, 0.22-, and 0.1-microm filters to present a rigorous filter challenge. Process variables were monitored throughout the ultrafiltration to ensure that the spiked material did not compromise the membrane flux. Removal of scrapie prion protein (PrP(Sc)) material was determined by use of a sensitive Western blot assay.
  
  
  RESULTS
  The turbid SBH became completely translucent after sonication and passage through the 0.45-, 0.22-, and 0.1-microm filters. The filtration of the immune globulin containing PrP(Sc) material was more difficult to perform than was filtration of immune globulin spiked with the normal cellular isoform. Even during tangential flow filtration, the fibril material prevented the PrP(Sc)-spiked immune globulin from passing as readily through the filter. Western blot results indicated a removal of greater than or equal to 2.5 log PrP(Sc), while remaining within the normal filtration limits.
  
  
  CONCLUSIONS
  The composition, physical condition, and the amount of SBH introduced have significant effects on the filtration of the immune globulin and the log removal values obtained. By use of a detergent-treated, sonicated, and filtered preparation of SBH, it was demonstrated that the Viresolve 180 effectively removes PrP(Sc) from the immune globulin.
authors.affiliation: Immunohematology/RhoGAM, R & D Ortho-Clinical Diagnostics, Raritan, New Jersey 08869, USA. rvanholt@ocdus.jnj.com
authors.forename: Robert W
authors.initials: RW
authors.lastname: Van Holten
authors.forename: Stephen
authors.initials: S
authors.lastname: Autenrieth
authors.forename: Jeri Ann
authors.initials: JA
authors.lastname: Boose
authors.forename: W T
authors.initials: WT
authors.lastname: Hsieh
authors.forename: Sherri
authors.initials: S
authors.lastname: Dolan
mesh_terms: D000818:Animals; D006224:Cricetinae; D004867:Equipment Design; D006440:Hemofiltration / Q000295:instrumentation*; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry*; D018620:PrPSc Proteins / Q000302:isolation & purification*; D017096:Prion Diseases / Q000821:virology*; D012608:Scrapie / Q000821:virology
chemical_list: D007136:Immunoglobulins; D018620:PrPSc Proteins