title: Test for detection of disease-associated prion aggregate in the blood of infected but asymptomatic animals.
abstract: We have developed a sensitive in vitro assay for detecting disease-associated prion aggregates by combining an aggregation-specific enzyme-linked immunosorbent assay (AS-ELISA) with the fluorescent amplification catalyzed by T7 RNA polymerase technique (FACTT). The new assay, named aggregation-specific FACTT (AS-FACTT), is much more sensitive than AS-ELISA and could detect prion aggregates in the brain of mice as early as 7 days after an intraperitoneal inoculation of PrP(Sc). However, AS-FACTT was still unable to detect prion aggregates in blood of infected mice. To further improve the detection limit of AS-FACTT, we added an additional prion amplification step (Am) and developed a third-generation assay, termed Am-A-FACTT. Am-A-FACTT has 100% sensitivity and specificity in detecting disease-associated prion aggregates in blood of infected mice at late but still asymptomatic stages of disease. At a very early stage, Am-A-FACTT had a sensitivity of 50% and a specificity of 100%. Most importantly, Am-A-FACTT also detects prion aggregates in blood of mule deer infected with the agent causing a naturally occurring prion disease, chronic wasting disease. Application of this assay to cattle, sheep, and humans could safeguard food supplies and prevent human contagion.
authors.affiliation: Institute of Pathology School of Medicine, Case Western Reserve University, Cleveland, Ohio 44107-1712, USA.
authors.forename: Binggong
authors.initials: B
authors.lastname: Chang
authors.forename: Xin
authors.initials: X
authors.lastname: Cheng
authors.forename: Shaoman
authors.initials: S
authors.lastname: Yin
authors.forename: Tao
authors.initials: T
authors.lastname: Pan
authors.forename: Hongtao
authors.initials: H
authors.lastname: Zhang
authors.forename: Poki
authors.initials: P
authors.lastname: Wong
authors.forename: Shin-Chung
authors.initials: SC
authors.lastname: Kang
authors.forename: Fan
authors.initials: F
authors.lastname: Xiao
authors.forename: Huimin
authors.initials: H
authors.lastname: Yan
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Li
authors.forename: Lisa L
authors.initials: LL
authors.lastname: Wolfe
authors.forename: Michael W
authors.initials: MW
authors.lastname: Miller
authors.forename: Thomas
authors.initials: T
authors.lastname: Wisniewski
authors.forename: Mark I
authors.initials: MI
authors.lastname: Greene
authors.forename: Man-Sun
authors.initials: MS
authors.lastname: Sy
mesh_terms: D000818:Animals; D003670:Deer; D007118:Immunoassay; D051379:Mice; D018620:PrPSc Proteins / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D017096:Prion Diseases / Q000097:blood* / Q000276:immunology / Q000662:veterinary*; D011328:Prions / Q000097:blood* / Q000737:chemistry / Q000276:immunology*
chemical_list: D018620:PrPSc Proteins; D011328:Prions