title: A sensitive and quantitative assay for normal PrP in plasma.
abstract: Transmissible spongiform encephalopathies can be transmitted by blood transfusion. The risk of spreading the disease among the human population could be mitigated with the implementation of a blood screening assay. We developed a two-antibody assay for PrP detection in plasma using the ORIGEN technology with a protocol modification to improve the limit of detection and to increase the sample volume assayed. In the standard 200 microL format, the assay had a detection limit of 7-10 pg of recombinant PrP and 3 pg in 1 mL final volume implementation. PrP concentration measured in normal and scrapie-infected hamster brains was 7.5+/-0.9 and 57.3+/-9.6 microg/g, respectively. After a concentration step with an immuno-affinity resin, plasma PrP(c) was detected by Western blot and its concentration was measured at 3.5+/-0.8 ng/mL. From these data and assuming that blood has the same specific infectivity as brain, we estimated the concentration of abnormal PrP in hamster-infected plasma to be 32 f g/mL. The assay also detected abnormal brain PrP spiked into plasma although the limit of detection was affected. This is a novel and sensitive assay for the detection of PrP in plasma that could be developed into a platform for a plasma-based TSE test.
authors.affiliation: Veterans Affairs Medical Center and University of Maryland, Baltimore, MD 21201, United States. lgreg002@umaryland.edu
authors.forename: Luisa
authors.initials: L
authors.lastname: Gregori
authors.forename: Benjamin N
authors.initials: BN
authors.lastname: Gray
authors.forename: Elaine
authors.initials: E
authors.lastname: Rose
authors.forename: Daryl S
authors.initials: DS
authors.lastname: Spinner
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Kascsak
authors.forename: Robert G
authors.initials: RG
authors.lastname: Rohwer
mesh_terms: D000818:Animals; D015153:Blotting, Western; D006224:Cricetinae; D018562:Disease Transmission, Infectious / Q000517:prevention & control; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D010949:Plasma / Q000737:chemistry*; D017096:Prion Diseases / Q000517:prevention & control; D011328:Prions / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D011328:Prions