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Evidence-based guideline: Diagnostic accuracy of CSF 14-3-3 protein in sporadic Creutzfeldt-Jakob disease

Posted Sep 20 2012 6:43pm
Special Article


Evidence-based guideline: Diagnostic accuracy of CSF 14-3-3 protein in sporadic Creutzfeldt-Jakob disease


Report of the Guideline Development Subcommittee of the American Academy of Neurology


Taim Muayqil, MBBS, FRCPC, Gary Gronseth, MD, FAAN and Richard Camicioli, MD, FRCPC


+ Author Affiliations


From the King Saud University (T.M.), Riyadh, Saudi Arabia; University of Kansas Medical Center (G.G.), Kansas City; and University of Alberta (R.C.), Edmonton, Canada.


Correspondence & reprint requests to American Academy of Neurology: guidelines@aan.com


View Complete Disclosures


Abstract


Objective: To assess the available evidence for the diagnostic accuracy of CSF testing for protein 14-3-3 in patients with suspected sporadic Creutzfeldt-Jakob disease (sCJD).


Methods: The authors performed a systematic review of the available literature from 1995 to January 1, 2011, to identify articles involving patients who were suspected of having sCJD and who had CSF analysis for protein 14-3-3. Studies were rated according to the American Academy of Neurology classification of evidence scheme for diagnostic studies, and recommendations were linked to the strength of the evidence. A pooled estimate of sensitivity and specificity was obtained for all studies rated Class II or higher. The question asked is “Does CSF 14-3-3 protein accurately identify Creutzfeldt-Jakob disease (CJD) in patients with sCJD?”


Results: The analysis was conducted on the basis of samples of 1,849 patients with suspected sCJD from 9 Class II studies. Assays for CSF 14-3-3 protein are probably moderately accurate in diagnosing sCJD: sensitivity 92% (95% confidence interval [CI] 89.8–93.6), specificity 80% (95% CI 77.4–83.0), likelihood ratio of 4.7, and negative likelihood ratio of 0.10.


Recommendation: For patients who have rapidly progressive dementia and are strongly suspected of having sCJD and for whom diagnosis remains uncertain (pretest probability ∼20%–90%), clinicians should order CSF 14-3-3 assays to reduce the uncertainty of the diagnosis (Level B). Received February 21, 2012. Accepted June 22, 2012. Copyright © 2012 by AAN Enterprises, Inc.







 
 
Wednesday, June 27, 2012


First US BSE Case Since 2006 Underscores Need for Vigilance


Neurology Today 21 June 2012







PO-028: Oral transmission of L-type bovine spongiform encephalopathy (L-BSE) in primate model Microcebus murinus


Nadine Mestre-Frances,1 Simon Nicot,2 Sylvie Rouland,1 Anne-Gaëlle Biacabe,2 Isabelle Quadrio,3 Armand Perret-Liaudet,3 Thierry Baron,2 Jean-Michel Verdier1 1IN SER M UM2; Montpellier, France; 2Anses; Lyon, France; 3Hopitaux Civils de Lyon; Lyon, France


An atypical form of bovine spongiform encephalopathy has been identified in cattle in Europe, North America and Japan and was designed as L-type BSE (L-BSE) due to the lower apparent molecular mass of the unglycosylated, protease-resistant prion protein (PrPres) detected by western blot compared with classical BSE. Experimental evidences from studies in transgenic mice expressing human PrP and in primate models suggest a higher risk of transmission to humans of the L-BSE form than for classical BSE agent. However, a major unresolved issue concerns the potential transmissibility of the L-BSE agent by oral route. To address this question, we infected mouse lemurs (Microcebus murinus), a non-human primate model, with L-BSE by intracerebral or oral route.


Four adult lemurs were intracerebrally (IC) inoculated with 5mg of L-BSE infected brain homogenate of an atypical French BSE case (02-2528). Four young and four adult animals were fed with 5 mg or 50 mg of infected brain. After sacrifice, the brain tissues were biochemically and immunocytochemically investigated for PrPres.


The 4 animals IC inoculated died at 19 and 22 months postinoculation (mpi). They developed blindness, tremor, abnormal posture, incoordinated movements, balance loss. Symptoms get worse according to the disease progression, until severe ataxia. Severe spongiosis was evidenced into the thalamus, the striatum, the mesencephalon, and the brainstem, whereas into the cortex the vacuolisation was weaker. Strong deposits of PrPres were detected into the thalamus, the striatum, and the hippocampus whereas in the cerebral cortex, PrPres was prominently accumulated in plaques.


The orally inoculated animals showed similar clinical symptoms occurring between 27 and 34 mpi. Disease was characterized by progressive prostration, loss of appetite and poor appearance of the fur. Only one adult animal showed disequilibrium. PrPres was strongly accumulated only in the striatum and thalamus and weakly into the cortex. No plaques were evidenced. Two animals that were orally challenged at the age of two years are still alive and healthy 34 months after inoculation. The western blot analysis showed uniform molecular profiles, irrespective of the route or dose of infection, and included notably a PrPres form with low apparent molecular mass (~19 kDa) similar to the PrPres in the original cattle brain. However, the PrPres profile in lemurs was characterized by a higher proportion of di- and mono-glycosylated species (up to 95% of the total signal) than in the bovine L-BSE inoculum (~80%). In addition, small amounts of PrPres were detected by western blotting in the spleen of three animals (one intra-cerebrally inoculated and two fed with 5 mg of cattle brain).


Here, we demonstrate that the L-BSE agent can be transmitted by oral route from cattle to young and adult mouse lemurs. In comparison to IC inoculated animals, orally challenged lemurs were characterized by longer survival periods as expected with this route of infection.








EFSA Journal 2011 The European Response to BSE: A Success Story


snip...


EFSA and the European Centre for Disease Prevention and Control (ECDC) recently delivered a scientific opinion on any possible epidemiological or molecular association between TSEs in animals and humans (EFSA Panel on Biological Hazards (BIOHAZ) and ECDC, 2011). This opinion confirmed Classical BSE prions as the only TSE agents demonstrated to be zoonotic so far but the possibility that a small proportion of human cases so far classified as "sporadic" CJD are of zoonotic origin could not be excluded. Moreover, transmission experiments to non-human primates suggest that some TSE agents in addition to Classical BSE prions in cattle (namely L-type Atypical BSE, Classical BSE in sheep, transmissible mink encephalopathy (TME) and chronic wasting disease (CWD) agents) might have zoonotic potential.



snip...











see follow-up here about North America BSE Mad Cow TSE prion risk factors, and the ever emerging strains of Transmissible Spongiform Encephalopathy in many species here in the USA, including humans ;








Wednesday, August 01, 2012


Behavioural and Psychiatric Features of the Human Prion Diseases: Experience in 368 Prospectively Studied Patients









Monday, August 06, 2012


Atypical neuropathological sCJD-MM phenotype with abundant white matter Kuru-type plaques sparing the cerebellar cortex








 
Monday, August 20, 2012



CASE REPORTS CREUTZFELDT-JAKOB DISEASE: AN UNDER-RECOGNIZED CAUSE OF DEMENTIA










Tuesday, June 26, 2012


Creutzfeldt Jakob Disease Human TSE report update North America, Canada, Mexico, and USDA PRION UNIT as of May 18, 2012


type determination pending Creutzfeldt Jakob Disease (tdpCJD), is on the rise in Canada and the USA








Monday, August 6, 2012


TAFS BSE in USA August 6, 2012


BSE in USA









Saturday, May 26, 2012


Are USDA assurances on mad cow case 'gross oversimplification'?


SNIP...


What irks many scientists is the USDA’s April 25 statement that the rare disease is “not generally associated with an animal consuming infected feed.”


The USDA’s conclusion is a “gross oversimplification,” said Dr. Paul Brown, one of the world’s experts on this type of disease who retired recently from the National Institutes of Health. "(The agency) has no foundation on which to base that statement.”


“We can’t say it’s not feed related,” agreed Dr. Linda Detwiler, an official with the USDA during the Clinton Administration now at Mississippi State.


In the May 1 email to me, USDA’s Cole backed off a bit. “No one knows the origins of atypical cases of BSE,” she said


The argument about feed is critical because if feed is the cause, not a spontaneous mutation, the California cow could be part of a larger outbreak.


SNIP...






==============================================


Saturday, August 4, 2012


Final Feed Investigation Summary - California BSE Case - July 2012




=============================================


SUMMARY REPORT CALIFORNIA BOVINE SPONGIFORM ENCEPHALOPATHY CASE INVESTIGATION JULY 2012


Summary Report BSE 2012


Executive Summary




Saturday, August 4, 2012


Update from APHIS Regarding Release of the Final Report on the BSE Epidemiological Investigation






Sunday, August 26, 2012


Detection of PrPSc in peripheral tissues of clinically affected cattle after oral challenge with BSE






2011 Monday, September 26, 2011


L-BSE BASE prion and atypical sporadic CJD







TSS
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