Friday, July 29, 2011

Real-time quaking-induced conversion A highly sensitive assay for prion detection

Real-time quaking-induced conversion A highly sensitive assay for prion detection

Ryuichiro Atarashi,1,* Kazunori Sano,1,2 Katsuya Satoh1 and Noriyuki Nishida1,2 1Department of Molecular Microbiology and Immunology; Graduate School of Biomedical Sciences; 2Global COE Program; Nagasaki University; Nagasaki, Japan

We recently developed a new in vitro amplification technology, designated “real-time quaking-induced conversion (RT-QUIC),” for detection of the abnormal form of prion protein (PrPSc) in easily accessible specimens such as cerebrospinal fluid (CSF). After assessment of more than 200 CSF specimens from Japanese and Australian patients, we found no instance of a false positive, and more than 80% accuracy for the correct diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). Furthermore, the RT-QUIC can be applied to other prion diseases, including scrapie, chronic wasting disease (CWD) and bovine spongiform encephalopathy (BSE), and is able to quantify prion seeding activity when combined with an end-point dilution of samples. These results indicate that the RT-QUIC, with its high sensitivity and specificity, will be of great use as an early, rapid and specific assay for prion diseases.


Further Progress in RT-QUIC Technology Recently, Caughey’s group demonstrated that our RT-QUIC could be successfully applied to the detection of hamster and sheep scrapie, deer chronic wasting disease (CWD) and vCJD.28,29 Additionally, our team has been able to detect BSE at a sensitivity equivalent to that of sCJD (manuscript in preparation). In addition, the RT-QUIC can rapidly determine the relative prion concentration when used in combination with end-point dilution analysis.29 In another very recent study, Caughey’s team showed that enrichment of PrPSc in plasma by immunoprecipitation employing the PrP aggregate-specific monoclonal IgM antibody 15B3 greatly enhances the sensitivity of RT-QUIC, especially when coupled with a substrate replacement step.28 Together, these studies demonstrated the wide-ranging application of RT-QUIC to clinical and basic research on human and animal prion diseases.


Key words: RT-QUIC, real-time quaking-induced conversion, prion, CJD, Creutzfeldt-Jakob disease, CSF, cerebrospinal fluid

Submitted: 06/10/11

Accepted: 06/28/11 DOI:

*Correspondence to: Ryuichiro Atarashi; Email:

see full text ;

Oral.42: Prion Seeding Activity in Cerebrospinal Fluid from Sporadic Creutzfeldt-Jakob Disease Patients Using Real-Time QuIC Analysis: A Potential New Diagnostic Test?

Lynne I. McGuire,1,† Alexander H. Peden,1 Nigel Appleford,2 Gary Mallinson,2 Christina Orru,3 Jason Wilham,3 Greg Raymond,3 Mary Andrews,1 Mark W. Head,1 Byron Caughey,3 Robert Will,1 Richard Knight1 and Alison Green,1

1 NCJDSU, University of Edinburgh; Edinburgh, UK; 2 Bristol Institute for Transfusion Sciences, NHS Blood and Transplant; Bristol, UK; 3 Laboratory of Persistent Viral Disease, NIAID Rocky Mountain Laboratories, National Institutes of Health; Hamilton, MT USA†Presenting author; Email:

Since its introduction into the diagnostic criteria for sporadic CJD in 1998, the analysis of cerebrospinal fluid (CSF) for 14-3-3 has become a widely accepted investigation in patients with suspected sporadic CJD. However, a number of reports have raised concerns about its lack of specificity. This has prompted the search for a more specific and disease-related pre-mortem diagnostic test for sporadic CJD. The ability of PrPSc to convert PrPC into protease-resistance isoforms has been exploited using a variety of techniques such as protein misfolding cyclic amplification (PMCA) and quaking induced conversion (QuIC). A recent adaptation of QuIC (real-time QuIC) has been described which incorporates thioflavin T (ThT) in the reaction mixture. The ThT binds to the aggregated PrP causing a change in the ThT emission spectrum that can be monitored in real-time. Recent studies have shown that CSF samples from hamsters inoculated with experimental scrapie, sheep with scrapie and patients with sporadic CJD can be correctly identified using real-time QuIC.1,2 We now describe the findings of an investigation into the value of real-time QuIC in the diagnosis of sCJD. A blinded panel of CSF samples from 56 neuropathologically confirmed cases of sCJD and from 53 patients who were initially suspected of having sCJD but who were found to have an alternative diagnosis were analyzed. Of the 56 patients with sCJD 51 were found to give a positive response with real-time QuIC. In contrast only one patient from the control group was found to be positive. The sensitivity and specificity was 91% and 98%, respectively. The corresponding sensitivity and specificity of CSF 14-3-3 was 91% and 55%, respectively. These results suggest that real-time QuIC has the potential to be a more specific pre-mortem CSF test for sCJD than CSF 14-3-3.


1. Atarashi R, Satoh K, Sano K, Fuse T, Yamanaka H, Yamaguchi N, et al. Ultrasensitive human prion detection in cerebrospinal fluids by real-time quaking induced conversion. Prion 2010; 4:214

2. Wilham JM, Orru CD, Benssen RA, Atarashi R, Sano K, Race B, et al. Rapid end-point quantitation of prion seeding activity with sensitivity comparable to bioassays. PLoS 2010; 6:1-15

i guess the next question would be, is the USDA et al going to use _any_ test in numbers large enough to detect TSE in the bovine ???

Thursday, July 28, 2011

An Update on the Animal Disease Traceability Framework July 27, 2011

Saturday, July 23, 2011



Saturday, June 25, 2011

Transmissibility of BSE-L and Cattle-Adapted TME Prion Strain to Cynomolgus Macaque


Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.


The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...

Sunday, June 26, 2011

Risk Analysis of Low-Dose Prion Exposures in Cynomolgus Macaque

Thursday, June 23, 2011

Experimental H-type bovine spongiform encephalopathy characterized by plaques and glial- and stellate-type prion protein deposits

Wednesday, June 15, 2011

Galveston, Texas - Isle port moves through thousands of heifers headed to Russia, none from Texas, Alabama, or Washington, due to BSE risk factor

Thursday, February 10, 2011

TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY REPORT UPDATE CANADA FEBRUARY 2011 and how to hide mad cow disease in Canada Current as of: 2011-01-31

Friday, March 4, 2011

Alberta dairy cow found with mad cow disease

Monday, June 20, 2011 2011

Annual Conference of the National Institute for Animal Agriculture ATYPICAL NOR-98 LIKE SCRAPIE UPDATE USA

Thursday, July 14, 2011

Histopathological Studies of “CH1641-Like” Scrapie Sources Versus Classical Scrapie and BSE Transmitted to Ovine Transgenic Mice (TgOvPrP4)

Monday, June 27, 2011

Comparison of Sheep Nor98 with Human Variably Protease-Sensitive Prionopathy and Gerstmann-Sträussler-Scheinker Disease

Thursday, June 2, 2011

USDA scrapie report for April 2011 NEW ATYPICAL NOR-98 SCRAPIE CASES Pennsylvania AND California

Wednesday, July 06, 2011

Swine Are Susceptible to Chronic Wasting Disease by Intracerebral Inoculation

(see tonnage of mad cow feed in commerce USA...tss)

Monday, June 27, 2011

Zoonotic Potential of CWD: Experimental Transmissions to Non-Human Primates

Thursday, May 26, 2011

Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey

Journal of the American Dietetic Association Volume 111, Issue 6 , Pages 858-863, June 2011.

Tuesday, June 14, 2011

Clinical research in CJD at a U.S. clinical prion research center: CJD Quinacrine Study results and improved diagnosis of prion disease

Saturday, March 5, 2011


Tuesday, April 26, 2011

sporadic CJD RISING Text and figures of the latest annual report of the NCJDRSU covering the period 1990-2009 (published 11th March 2011)

Wednesday, June 29, 2011

TSEAC Meeting August 1, 2011 donor deferral Saudi Arabia vCJD risk blood and blood products

Friday, June 17, 2011

Treatable neurological disorders misdiagnosed as Creutzfeldt-Jakob disease

Saturday, January 22, 2011

Alzheimer's, Prion, and Neurological disease, and the misdiagnosis there of, a review 2011

Wednesday, July 20, 2011

Canadian Researchers Receive $2.9 Million to Protect Against Prion Disease Outbreaks, Develop Novel Therapies to Treat Alzheimer's, Parkinson's and ALS


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