Variant Creutzfeldt-Jakob Disease Research Articles

Movement Disorders in Prionopathies: A Systematic Review.

BackgroundMovement disorders are frequent features of prionopathies. However, their prevalence and onset remain poorly described.MethodsWe performed a systematic review of case reports and case series of pathologically- and genetically confirmed prionopathies. Timing of symptom and movement disorder onset were documented. Continuous variables were compared between two groups using the Wilcoxon rank sum test and between multiple groups using Kruskal–Wallis test. Categorical variables were compared using Fisher’s exact test.ResultsA total of 324 cases were included in this analysis. Movement disorders were a common feature at the onset of symptoms in most prionopathies. Gait ataxia was present in more than half of cases in all types of prionopathies. The prevalence of limb ataxia (20%) and myoclonus (24%) was lower in Gerstmann–Sträussler–Scheinker disease compared to other prionopathies (p ≤ 0.004). Myoclonus was common but often a later feature in sporadic Creutzfeldt–Jakob disease (2 months before death). Chorea was uncommon but disproportionately prevalent in variant Creutzfeldt–Jakob disease (30% of cases; p < 0.001). In genetic Creutzfeldt–Jakob disease, E200K PRNP carriers exhibited gait and limb ataxia more often when compared to other mutation carriers.DiscussionMovement disorders are differentially present in the course of the various prionopathies. The movement phenomenology and appearance are associated with the type of prion disease and the PRNP genotype and likely reflect the underlying pattern of neurodegeneration. Reliance on myoclonus as a diagnostic feature of sporadic Creutzfeldt–Jakob disease may delay its recognition given its relatively late appearance in the disease course.

Quaking-induced conversion of prion protein on a thermal mixer accelerates detection in brains infected with transmissible spongiform encephalopathy agents.

Detection of misfolded prion protein, PrPTSE, in biological samples is important to develop antemortem tests for transmissible spongiform encephalopathies (TSEs). The real-time quaking-induced conversion (RT-QuIC) assay detects PrPTSE but requires dedicated equipment and relatively long incubation times when applied to samples containing extremely low levels of PrPTSE. It was shown that a microplate shaker with heated top (Thermomixer-C) accelerated amplification of PrPTSE in brain suspensions of 263K scrapie and sporadic Creutzfeldt-Jakob disease (sCJD). We expanded the investigation to include TSE agents previously untested, including chronic wasting disease (CWD), macaque-adapted variant CJD (vCJD) and human vCJD, and we further characterized the assays conducted at 42°C and 55°C. PrPTSE from all brains containing the TSE agents were successfully amplified using a truncated hamster recombinant protein except for human vCJD which required truncated bank vole recombinant protein. We compared assays conducted at 42°C on Thermomixer-C, Thermomixer-R (without heated top) and on a fluorimeter used for RT-QuIC. QuIC on Thermomixer-R achieved in only 18 hours assay sensitivity similar to that of RT-QuIC read at 60 hours (or 48 hours with sCJD). QuIC on Thermomixer-C required 24 hours to complete and the endpoint titers of some TSEs were 10-fold lower than those obtained with RT-QuIC and Thermomixer-R. Conversely, at 55°C, the reactions with sCJD and CWD on Thermomixer-C achieved the same sensitivity as with RT-QuIC but in shorter times. Human vCJD samples tested at higher temperatures gave rise to high reactivity in wells containing normal control samples. Similarly, reactions on Thermomixer-R were unsuitable at 55°C. The main disadvantage of Thermomixers is that they cannot track formation of PrP fibrils in real time, a feature useful in some applications. The main advantages of Thermomixers are that they need shorter reaction times to detect PrPTSE, are easier to use, involve more robust equipment, and are relatively affordable. Improvements to QuIC using thermal mixers may help develop accessible antemortem TSE tests.

Handling of endoscopic equipment after use in the case of a patient with suspected prion disease

Prion diseases are slow-acting, neurodegenerative diseases found in humans and many species of animals. Although they occur very rarely in humans, currently, an increase in this type of disease is being observed, probably as a result of exposure to infectious prions causing BSE disease in cows. The aim of the procedures described in the article is to minimize the risk of human-to-human transfer of all forms of transmissible spongiform encephalopathy, including variant CJD (vCJD) by contaminated medical equipment. All diseases caused by prions, referred to as transmissible spongiform encephalopathies, are fatal. They are characterized by a long development period (up to several decades). Enormous problems are connected with the risk of transferring prions from patient to patient on the surface of instruments used in medical procedures. Laboratory tests indicate that standard disinfection and sterilization procedures may be insufficient to completely remove infectious proteins from contaminated instruments. One of the methods of infection prevention involves taking equipment used for surgery within the brain, tonsils or appendix, into quarantine until biopsy results of these organs have been received that exclude, as far as possible, asymptomatic carriage of prions. Whenever possible and justified, disposable-use instruments should be used for invasive surgery in patients with definite, clinically probable cases of CJD (vCJD). After use, these instruments should be incinerated.

Giving blood: providing treatment, providing knowledge

Abstract Background In France, 1,6 million donors contribute 3 million blood donations / year collected and tested by the French public transfusion service (Etablissement Français du Sang - EFS). At each donation, 2 ml plasma of are stored for 3 years for further testing if needed. In addition to providing life-saving blood products, blood donors may also provide knowledge through the sharing of their health data and bioresource collected at time of donation. Objective To describe how blood donors can provide knowledge in addition to blood products. Results Over the last 10 years, blood donors in France have enabled several studies performed by EFS in collaboration with research and reference laboratories as well as public health authorities. A linked assessment of Ab titers (+ clinical history) in donors having given blood before and after the 2009 H1N1 flu epidemic, as well as measles, rubella and hepatitis E virus seroprevalence studies (+ specific health questionnaires) have generated high value epidemiological data. Screening for arboviruses (such as Zika virus) and hepatitis A virus in donors during epidemics have increased knowledge of infectious spread and disease characteristics. Testing of plasma samples collected before variant Creutzfeldt-Jakob disease occurrence in two donors revealed the presence of circulating prion more than 1 year before diagnosis. A project to further take advantage of such a bio resource is underway. Upon occurrence and notification of a disease (or any pre-defined health event) in one of the 1,4 million repeat blood donors, all samples from prior donations would be gathered in a cohort of samples of all donors having notified an identical health event. Such cohorts would provide valuable samples to assess disease-specific biomarkers at pre-symptomatic phases. Conclusions Providing the opportunity to donors to give knowledge in addition to blood can result in production of high value biomedical data. Giving blood, being a public health actor. Key messages Blood donors may provide knowledge and bioresources in addition to blood products. Blood donors in France have enabled several large-scale epidemiological studies.

Role of prion protein glycosylation in replication of human prions by protein misfolding cyclic amplification

Prion diseases are transmissible neurological disorders associated with the presence of abnormal, disease-related prion protein (PrPD). The detection of PrPD in the brain is the only definitive diagnostic evidence of prion disease and its identification in body fluids and peripheral tissues are valuable for pre-mortem diagnosis. Protein misfolding cyclic amplification (PMCA) is a technique able to detect minute amount of PrPD and is based on the conversion of normal or cellular PrP (PrPC) to newly formed PrPD, sustained by a self-templating mechanism. Several animal prions have been efficiently amplified by PMCA, but limited results have been obtained with human prions with the exception of variant-Creutzfeldt–Jakob-disease (vCJD). Since the total or partial absence of glycans on PrPC has been shown to affect PMCA efficiency in animal prion studies, we attempted to enhance the amplification of four major sporadic-CJD (sCJD) subtypes (MM1, MM2, VV1, and VV2) and vCJD by single round PMCA using partially or totally unglycosylated PrPC as substrates. The amplification efficiency of all tested sCJD subtypes underwent a strong increase, inversely correlated to the degree of PrPC glycosylation and directly related to the matching of the PrP polymorphic 129 M/V genotype between seed and substrate. This effect was particularly significant in sCJDMM2 and sCJDVV2 allowing the detection of PK-resistant PrPD (resPrPD) in sCJDMM2 and sCJDVV2 brains at dilutions of 6 × 107 and 3 × 106. vCJD, at variance with the tested sCJD subtypes, showed the best amplification with partially deglycosylated PrPC substrate reaching a resPrPD detectability at up to 3 × 1016 brain dilution. The differential effect of substrate PrPC glycosylations suggests subtype-dependent PrPC–PrPD interactions, strongly affected by the PrPC glycans. The enhanced PMCA prion amplification efficiency achieved with unglycosylated PrPC substrates may allow for the developing of a sensitive, non-invasive, diagnostic test for the different CJD subtypes based on body fluids or easily-accessible-peripheral tissues.

An Analysis of Media Reports on Key Issues of Mad Cow Disease in South Korea

Since 2008, South Korea has seen controversy over the risk of mad cow disease (bovine spongiform encephalopathy [BSE]) and its potential to lead to variant Creutzfeldt-Jakob disease (vCJD) in humans. National news organizations have covered the topic differently according to their ideological positions. This study sought to quantify these differences focusing on the five key BSE-related issues covered by the media as follows: 1) possibility of confusion between vCJD and degenerative brain disease, 2) vCJD incidence in humans, 3) risk of vCJD infection from eating beef from cattle aged 30 months or older, 4) scope of specified risk, and 5) vulnerability of South Koreans to BSE infection. Based on the analysis of media reports on each issue, we found that the progressive media tended to emphasize the risks of BSE more than the conservative media who promoted views opposing those of the progressive media. National public broadcasting companies tended to take a neutral position. Despite the scientific findings on each issue mentioned above, the South Korean press has failed to provide them to the public unbiasedly. We identified the need to reduce politicization and promote scientific approach in media coverage of the issues of mad cow disease in South Korea.

Scrapie susceptibility-associated indel polymorphism of shadow of prion protein gene (SPRN) in Korean native black goats

Prion diseases in sheep and goats are called scrapie and belong to a group of transmissible spongiform encephalopathies (TSEs) caused by the abnormal misfolding of the prion protein encoded by the prion protein gene (PRNP). The shadow of the prion protein gene (SPRN) is the only prion gene family member that shows a protein expression profile similar to that of the PRNP gene in the central nervous system. In addition, genetic susceptibility of the SPRN gene has been reported in variant Creutzfeldt–Jakob disease (CJD), bovine spongiform encephalopathy (BSE) and scrapie. However, genetic studies of the SPRN gene have not been carried out in Korean native black goats. Here, we investigated the genotype and allele frequencies of SPRN polymorphisms in 213 Korean native black goats and compared these polymorphisms with those previously reported for scrapie-affected animals. We found a total of 6 polymorphisms including 1 nonsynonymous single nucleotide polymorphism (SNP) and 1 synonymous SNP in the open reading frame (ORF) region and 3 SNPs and 1 indel polymorphism (c.495_496insCTCCC) in the 3′ untranslated region (UTR) by direct DNA sequencing. A significant difference in the allele frequency of the c.495_496insCTCCC indel polymorphism was found between the Italian scrapie-affected goats and the Korean native black goats (P < 0.001). Furthermore, there was a significant difference in the allele frequencies of the c.495_496insCTCCC indel polymorphism between Italian healthy goats and Korean native black goats (P < 0.001). To evaluate the biological impact of the novel nonsynonymous SNP c.416G > A (Arg139Gln), we carried out PROVEAN analysis. PROVEAN predicted the SNP as ‘Neutral’ with a score of −0.297. To the best of our knowledge, this is the first genetic study of the SPRN gene in Korean native black goats.

Three Cases of Creutzfeldt-Jakob Disease with Visual Disturbances as Initial Manifestation

We report our findings in 3 cases of Creutzfeldt-Jakob disease (CJD) with visual disturbances as the initial manifestations. These cases were found to have the Heidenhain variant of CJD. Two cases initially presented with progressively blurred vision and homonymous hemianopia. The other case initially presented with blurred vision and a decrease in the central sensitivity in both eyes. These 3 cases developed neurological symptoms about 4 weeks after the onset of visual symptoms. All were diagnosed with the Heidenhain variant of CJD based on the clinical course and confirmed by positive assays of the cerebrospinal fluid for the 14-3-3 protein and tau protein. In addition, the diagnosis was confirmed by the findings of diffusion-weighted magnetic resonance imaging and electroencephalography. Patients can present with isolated visual symptoms which precede a decline in cognition by weeks due to the predominantly occipital lobe disease. The 3 patients were referred to the neurology department within 1 month of onset. The early diagnosis was necessary to avoid spread of the infection. In cases of suspected CJD, it is important to consult a neurologist quickly to make a definitive diagnosis of CJD. Ophthalmologists should be aware that visual impairments may be the first indication of CJD.

Study protocol for enhanced CJD surveillance in the 65+ years population group in Scotland: an observational neuropathological screening study of banked brain tissue donations for evidence of prion disease

IntroductionCreutzfeldt-Jakob disease (CJD) is a human prion disease that occurs in sporadic, genetic and acquired forms. Variant CJD (vCJD) is an acquired form first identified in 1996 in the UK....

Genetic Factors in Mammalian Prion Diseases.

Mammalian prion diseases are a group of neurodegenerative conditions caused by infection of the central nervous system with proteinaceous agents called prions, including sporadic, variant, and iatrogenic Creutzfeldt-Jakob disease; kuru; inherited prion disease; sheep scrapie; bovine spongiform encephalopathy; and chronic wasting disease. Prions are composed of misfolded and multimeric forms of the normal cellular prion protein (PrP). Prion diseases require host expression of the prion protein gene (PRNP) and a range of other cellular functions to support their propagation and toxicity. Inherited forms of prion disease are caused by mutation of PRNP, whereas acquired and sporadically occurring mammalian prion diseases are controlled by powerful genetic risk and modifying factors. Whereas some PrP amino acid variants cause the disease, others confer protection, dramatically altered incubation times, or changes in the clinical phenotype. Multiple mechanisms, including interference with homotypic protein interactions and the selection of the permissible prion strains in a host, play a role. Several non-PRNP factors have now been uncovered that provide insights into pathways of disease susceptibility or neurotoxicity.

Creutzfeldt-Jakob disease surveillance in Australia: update to 31 December 2018.

Nationwide surveillance of human prion diseases (also known as transmissible spongiform encephalopathies), the most common being Creutzfeldt-Jakob disease (CJD), is performed by the Australian National Creutzfeldt-Jakob Disease Registry (ANCJDR), based at the University of Melbourne. National surveillance encompasses the period since 1 January 1970, with prospective surveillance occurring from 1 October 1993. Over this prospective surveillance period considerable developments have occurred in relation to pre-mortem diagnostics, the delineation of new disease subtypes and a heightened awareness of prion diseases in health care settings. Surveillance practices of the ANCJDR have evolved and adapted accordingly. This report summarises the activities of the ANCJDR from 1 January to 31 December 2018. Since the ANCJDR began offering diagnostic cerebrospinal fluid (CSF) 14-3-3 protein testing in Australia in September 1997, the annual number of referrals has steadily increased. In 2018, 465 domestic CSF specimens were referred for 14-3-3 protein testing and 78 persons with suspected human prion disease were formally added to the national register. The majority of the 78 suspect case notifications remain as of 31 December 2018 classified as "incomplete" (42 cases), while eleven cases were excluded by either detailed clinical follow-up (one case) or neuropathological examination (ten cases); 15 cases were classified as "definite" and ten as "probable" prion disease. Sixty-two percent of all suspected human prion disease related deaths underwent neuropathological examination. No cases of variant CJD were confirmed.

Creutzfeldt–Jakob disease surveillance in Australia: update to December 2017

Nationwide surveillance of human prion diseases (also known as transmissible spongiform encephalopathies), the most common being Creutzfeldt–Jakob disease (CJD), is performed by the Australian National Creutzfeldt–Jakob Disease Registry (ANCJDR), based at the University of Melbourne. National surveillance encompasses the period since 1970, with prospective surveillance occurring from 1993 onwards. Over this prospective surveillance period considerable developments have occurred, especially in relation to pre-mortem diagnostics, the delineation of new disease subtypes and a heightened awareness of prion diseases in the health care setting. The surveillance practices of the ANCJDR have evolved and adapted accordingly. Since the ANCJDR began offering cerebrospinal fluid (CSF) 14-3-3 protein testing in Australia in September 1997, the annual number of referrals has steadily increased to a maximum of 508 in 2017. The number of CSF test referrals in 2017 represents a 20% increase compared to that of 2016. In 2017, there was an overall stabilisation of the annual incidence rate of confirmed prion disease in Australia at expected levels; 72 persons with suspected human prion disease were added to the national register, with 72% of all suspected CJD cases undergoing neuropathological examination. The majority of the 72 suspected cases added to the register are as of 31 December 2017 still classified as “incomplete” (47 cases), while four cases were excluded by either detailed clinical follow-up (1 case) or neuropathological examination (3 cases); 19 cases were classified as definite and two as probable prion disease. No cases of variant CJD (vCJD) were confirmed.

Looking at the Past, Learning for the Future

Case Reports: Open Access 2014 | Vol 1: e101Medicine in the past records history, in the present a dialogue, and for the future, there are untold advances. A reflection on the pace of such change underlines progress. Just two to three decades have seen new entities, treatments, management, and curricula arise. Medical school applications are as popular as ever for aspiring doctors. What has changed is the gender balance with more females gaining entry in this modern age than ever before, often being a majority in a class [1]. Discus-sion in the clinical field is robust and inspired. Genomics has arrived and will continue to reform the practice of medicine. To talk about DNA-double helices is almost banal, and yet at the time, the discovery was life changing. Now we have new jargon with phrases like Single Nucleotide Polymorphisms or “SNPs”, and Environmental Shotgun Sequencing (ESS). Rap-id development of information technology and bioengineer-ing applied to the medical field too has transformed care, not forgetting progressive modalities of treating cancers. Healthy controversy persists and discussion of screening with Prostate Specific Antigen (PSA) testing still continues. Nations differ on their concepts of hazards to individuals exposed to new variant Creutzfeldt-Jakob disease (nvCJD). Residents potentially exposed to nvCJD by the consumption of home grown beef, who hail from the United Kingdom, France, and Western Europe are considered too risky to ac-cept as good faith blood donors in North America [2].The world and the Centers for Disease Control and Preven-tion (CDC), Atlanta, GA, in the US quietly wait for a predicted outbreak of a pandemic flu infection, anticipating catastroph-ic rates of death making even the First World War’s outbreak seem rather small. Highly pathogenic avian influenza (HPAI) known as H7N9 has evolved to jump from birds to humans, and worse, perpetuated from human to human thereafter. Neuraminidase inhibitors proved a good find against HPAI, but SARS and later MERS caused new scares. Now we have Ebola to consider, with sporadic cases appearing in countries distant to its source of origin. In the background, HIV in the sub-Saharan region, tuberculosis and malaria run rampant [3]. The 2011 tsunami in Japan caused utter devastation, with nearly 16,000 deaths, with a further 3200 untraceable [4]. But the fallout from Fukushima Daiichi’s nuclear power plant will leave vestigial effects locally, if not impact the global en-vironment. Critics blame authorities and companies building the plant too close to the coast, Japan being renowned for violent earthquakes. Viable Smallpox virus was recently dis-covered discarded but retrieved in time before any accidental contamination occurred. The question asked is “how did that error happen?” The prospect of a smallpox outbreak in an immune weak global population defies description. No two nations are alike in their approach to health care, but all have the same ideal objectives – to provide good service, economically and effectively. Obamacare has enfranchised tens of millions for access to health care, and it is hard to be-lieve that many still oppose such insured access. The National Health Service (NHS) in the United Kingdom, a great insti-tution, continues to struggle with capacity. So where does the responsibility for health care begin? With the state say some, at home say others, and what about health education at schools? Would that not be a timely place to learn about self-care, and provide education on how a country’s health system operates? Will Emergency Departments savor any respite for routine complaints when dealing with major trauma, or do physicians in primary care need to step up, be empowered with triaging capabilities and overhaul initial access to ter-tiary care? With the global population now at 7.2 billion, an exponential rise to 9.6 billion by 2050 is predicted [5], and what then?Diabetes mellitus could be argued to be the modern world’s biggest scourge. The average delay from onset to diagnosis has fallen slightly from 7.2 to 6.2 years. The clinical effects of nephropathy, retinopathy, peripheral neuropathy, micro- and macro-vasculopathy, and poor oral health with gum disease not always highlighted prominently remain serious debilities. Periodontal disease is now the 6th most prevalent disorder globally, affecting 743 million people [6]. Time to be proactive or accept the risk of becoming toothless. Recall that it was only in 1921 or under a hundred years ago, that insulin was finally discovered. Everyone remembers Banting and Best, MacLeod, but fewer may recall Collip, and even fewer will mention Paulesco who all contributed to insulin’s research [7].

Human prion diseases.

Prion diseases are rapidly progressive neurodegenerative conditions that can be difficult to diagnose and are transmissible under specific circumstances. The authors will provide background regarding prion disease and focus on diagnostic tools. Prion disease is caused by misfolded prion protein. The three possible causes of prion disease include sporadic (85%), genetic (10-15%), and acquired (<1%). Acquired prion diseases include kuru, iatrogenic, and variant Creutzfeldt-Jakob disease. Prion diseases differ in their clinical manifestation, neuropathology, and diagnostic test results. A variety of recent diagnostic tools have evolved that allow more reliable antemortem diagnosis of prion disease such as brain MRI and cerebrospinal fluid real-time quaking-induced conversion. Special infectivity guidelines must be followed when dealing with central nervous system tissue, but only standard precautions are needed for routine clinical care of patients with prion disease. The only way to definitely diagnose prion disease and determine its type is via neuropathologic examination. However, brain MRI and cerebrospinal fluid real-time quaking-induced conversion have drastically increased diagnostic accuracy and are important tests to use when evaluating patients with suspected prion disease.

Tracking and clarifying differential traits of classical- and atypical L-type bovine spongiform encephalopathy prions after transmission from cattle to cynomolgus monkeys.

Classical- (C-) and atypical L-type bovine spongiform encephalopathy (BSE) prions cause different pathological phenotypes in cattle brains, and the disease-associated forms of each prion protein (PrPSc) has a dissimilar biochemical signature. Bovine C-BSE prions are the causative agent of variant Creutzfeldt-Jakob disease. To date, human infection with L-BSE prions has not been reported, but they can be transmitted experimentally from cows to cynomolgus monkeys (Macaca fascicularis), a non-human primate model. When transmitted to monkeys, C- and L-BSE prions induce different pathological phenotypes in the brain. However, when isolated from infected brains, the two prion proteins (PrPSc) have similar biochemical signatures (i.e., electrophoretic mobility, glycoforms, and resistance to proteinase K). Such similarities suggest the possibility that L-BSE prions alter their virulence to that of C-BSE prions during propagation in monkeys. To clarify this possibility, we conducted bioassays using inbred mice. C-BSE prions with or without propagation in monkeys were pathogenic to mice, and exhibited comparable incubation periods in secondary passage in mice. By contrast, L-BSE prions, either with or without propagation in monkeys, did not cause the disease in mice, indicating that the pathogenicity of L-BSE prions does not converge towards a C-BSE prion type in this primate model. These results suggest that, although C- and L-BSE prions propagated in cynomolgus monkeys exhibit similar biochemical PrPSc signatures and consist of the monkey amino acid sequence, the two prions maintain strain-specific conformations of PrPSc in which they encipher and retain unique pathogenic traits.

Variant Creutzfeldt-Jakob disease strain is identical in individuals of two PRNP codon 129 genotypes.

Variant Creutzfeldt-Jakob disease strain is identical in individuals of two PRNP codon 129 genotypes.

A Case of Heidenhain Variant Creutzfeldt-Jakob Disease Presenting with Isolated Homonymous Quadrantanopia and Corresponding Nuclear Imaging Findings (P1.9-020)

A Case of Heidenhain Variant Creutzfeldt-Jakob Disease Presenting with Isolated Homonymous Quadrantanopia and Corresponding Nuclear Imaging Findings (P1.9-020)

Variant Creutzfeldt-Jakob disease strain is identical in individuals of two PRNP codon 129 genotypes.

In 2004, a subclinical case of variant Creutzfeldt-Jakob disease in a PRNP 129 methionine/valine heterozygous individual infected via blood transfusion was reported, and we established that the spleen from this individual was infectious. Since host genetics is an important factor in strain modification, the identification of variant Creutzfeldt-Jakob disease infection in a PRNP 129 methionine/valine heterozygous individual has raised the possibility that the properties of the variant Creutzfeldt-Jakob disease agent could change after transmission to this different genetic background and concerns that this could lead to a more virulent strain of variant Creutzfeldt-Jakob disease. The variant Creutzfeldt-Jakob disease strain has to date been characterized only in methionine homozygous individuals, therefore to establish whether the strain characteristics of variant Creutzfeldt-Jakob disease had been modified by the host genotype, spleen material with prion protein deposition from a PRNP 129 methionine/valine individual was inoculated into a panel of wild-type mice. Three passages in mice were undertaken to allow stabilization of the strain characteristics following its passage into mice. In each passage, a combination of clinical signs, neuropathology (transmissible spongiform encephalopathy vacuolation and prion protein deposition) were analysed and biochemical analysis carried out. While some differences were observed at primary and first subpassage, following the second subpassage, strain characteristics in the methionine/valine individual were totally consistent with those of variant Creutzfeldt-Jakob disease transmitted to 129 methionine/methionine individuals thus demonstrated no alteration in strain properties were imposed by passage through the different host genotype. Thus we have demonstrated variant Creutzfeldt-Jakob disease strain properties are not affected by transmission through an individual with the PRNP methionine/valine codon 129 genotype and thus no alteration in virulence should be associated with the different host genotype.

PMCA-replicated PrPD in urine of vCJD patients maintains infectivity and strain characteristics of brain PrPD: Transmission study

The presence of abnormal, disease-related prion protein (PrPD) has recently been demonstrated by protein misfolding cyclic amplification (PMCA) in urine of patients affected with variant Creutzfeldt-Jakob disease (vCJD), a prion disease typically acquired from consumption of prion contaminated bovine meat. The complexity and multistage process of urine excretion along with the obligatory use of PMCA raise the issue of whether strain characteristics of the PrPD present in vCJD brains, such as infectivity and phenotype determination, are maintained in urine excreted PrPD and following amplification by PMCA. We inoculated transgenic mice expressing normal human PrP with amplified urine and brain homogenate achieving the same 100% attack rate, similar incubation periods (in both cases extremely long) and histopathological features as for type and severity of the lesions. Furthermore, PrPD characteristics analyzed by immunoblot and conformational stability immunoassay were indistinguishable. Inoculation of raw vCJD urine caused no disease, confirming the extremely low concentration of PrPD in vCJD urine. These findings show that strain characteristics of vCJD brain PrPD, including infectivity, are preserved in PrPD present in urine and are faithfully amplified by means of PMCA; moreover, they suggest that the PrPD urine test might allow for the diagnosis and identification of disease subtype also in sporadic CJD.

Surveillance for variant CJD: should more children with neurodegenerative diseases have autopsies?

ObjectivesTo report investigations performed in children with progressive neurodegenerative diseases reported to this UK study.DesignSince 1997 paediatric surveillance for variant Creutzfeldt-Jakob disease (vCJD) has been performed by identifying children aged...