Understanding the nature of PrP found in Appendix tissues in the UK population
Understanding the nature of PrP found in Appendix tissues in the UK population
Dr Marcelo M Barria1, Dr Diane Ritchie1, Dr Suzanne Sulieman1, Mr Fraser Brydon1, Dr Abigail Diack2, Dr Alison Green1
Variant Creutzfeldt-Jakob disease (vCJD) is an acquired form of CJD, primarily affecting younger individuals, which has resulted from the consumption of meat and meat products inadvertently contaminated with bovine spongiform encephalopathy (BSE). Like all forms of CJD, vCJD results in the build-up of an abnormal protein in the brain, the prion protein (PrPSc). The structure (biochemical pattern) of the prion protein that accumulates in vCJD patients differs to that of other forms of CJD and is referred to as “PrPSc type 2B”. In a further contrast to other forms of CJD, the abnormal prion protein can accumulate outside the brain in vCJD patients, in tissues such as appendix and tonsil, often several years before the appearance of clinical symptoms. This has raised public health concerns that a significant number of people may be infected with vCJD but have not developed any symptoms. Consequently, these individuals could potentially pass vCJD onto to others via contaminated surgical instruments, blood transfusions or through tissue and organ donation.
Three prevalence studies (Appendix I, II and III) looking for the presence of the abnormal prion protein in appendix tissue taken during routine appendectomies, have suggested that as many as 1 in 2000 of the UK population may be infected with vCJD. In the third of these studies (Appendix III), the presence of the prion protein in appendix samples from individuals considered to be at low or no risk from exposure to BSE has questioned whether the abnormal prion protein found in these appendix samples does truly represent vCJD.
Research
In 2017, the National CJD Research & Surveillance Unit (NCJDRSU) and the Roslin Institute at the University of Edinburgh, obtained funding from the Policy Research Programme, Department of Health and Social Care (PR-P DHSC) and the Scottish Government Department of Health to further investigate samples from two of the prevalence studies (Appendix II and III) and determine whether the abnormal prion protein found in the appendix samples is consistent with vCJD PrPSc type 2B and whether the protein was infectious.
Residual tissue from the Appendix II and III studies is scarce, and tissue that is available has been preserved for an extended period in paraffin wax, making the extraction and biochemical analysis of the protein in these samples problematic. To address these issues, Dr Marcelo Barria and Dr Suzanne Sulieman from the NCJDRSU developed a robust and novel protein extraction protocol and prion protein amplification technique known as the “highly sensitive Protein Misfolding Cyclic Amplification (hsPMCA)” that can detect and amplify very small amounts of PrPSc present in frozen tissues and in tissues preserved in paraffin wax. Bearing in mind the limited amount of residual tissue available from the Appendix II and III studies, we initially extracted and amplified PrPSc from the brain and appendix from a case of vCJD. Crucially, the protein extracted and amplified produced the characteristic vCJD PrPSc type “2B” pattern. Subsequently, the infectious nature of the hsPMCA amplified protein from these brain and appendix samples has been confirmed after transmission to mouse models (Dr Abigail Diack, Roslin Institute), producing a pattern of transmission in the mice that is consistent with vCJD.
With the success of these preliminary results, the PR-P DHSC and the Scottish Government Department of Health have extended the grant to enable us to examine the residual appendix samples from the Appendix II and III studies. These studies are underway and the findings will be published in due course.
We would like to take this opportunity to thank Mr Lester Firkins OBE. Lester recently retired from his position as the lay member and chair of our Steering Group committee. It has been a pleasure to work with Lester over the last few years and we will miss his enthusiasm, positivity and hard work.
We are looking for a new lay member for our Steering Group committee and if you are interested and wish to know more, please contact Alison Green at the NCJDRSU Alison.Green@ed.ac.uk.
We would like to thank all the contributors from the NCJDRSU and the Roslin Institute, and particularly, to the families of patients for their cooperation in this study.
The report is based on independent research commissioned and funded by the Policy Research Programme, Department of Health and Social Care and the Scottish Government [The National CJD Research and Surveillance Unit (NCJDRSU), PR- R17-0916-23001]. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the NIHR, the Department of Health and Social Care, the Scottish Government, ‘arms’ length bodies or
other government departments.
1The National CJD Research & Surveillance Unit, University of Edinburgh EH16 4SB
2 Roslin Institute, University of Edinburgh EH16 4SB
Prevalence in Britain of abnormal prion protein in human appendices before and after exposure to the cattle BSE epizootic
O. Noel Gill, Yvonne Spencer, Angela Richard-Loendt, Carole Kelly, David Brown, Katy Sinka, Nick Andrews, Reza Dabaghian, Marion Simmons, Philip Edwards, Peter Bellerby, David J. Everest, Mark McCall, Linda M. McCardle, Jacqueline Linehan, Simon Mead, David A. Hilton, James W. Ironside & Sebastian Brandner
Acta Neuropathologica (2020)Cite this article
Abstract
Widespread dietary exposure of the population of Britain to bovine spongiform encephalopathy (BSE) prions in the 1980s and 1990s led to the emergence of variant Creutzfeldt-Jakob Disease (vCJD) in humans. Two previous appendectomy sample surveys (Appendix-1 and -2) estimated the prevalence of abnormal prion protein (PrP) in the British population exposed to BSE to be 237 per million and 493 per million, respectively. The Appendix-3 survey was recommended to measure the prevalence of abnormal PrP in population groups thought to have been unexposed to BSE. Immunohistochemistry for abnormal PrP was performed on 29,516 samples from appendices removed between 1962 and 1979 from persons born between 1891 through 1965, and from those born after 1996 that had been operated on from 2000 through 2014. Seven appendices were positive for abnormal PrP, of which two were from the pre-BSE-exposure era and five from the post BSE-exposure period. None of the seven positive samples were from appendices removed before 1977, or in patients born after 2000 and none came from individuals diagnosed with vCJD. There was no statistical difference in the prevalence of abnormal PrP across birth and exposure cohorts. Two interpretations are possible. Either there is a low background prevalence of abnormal PrP in human lymphoid tissues that may not progress to vCJD. Alternatively, all positive specimens are attributable to BSE exposure, a finding that would necessitate human exposure having begun in the late 1970s and continuing through the late 1990s.
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Discussion The Appendix-3 Study was designed to measure the prevalence of abnormal PrP in appendices removed in operations performed before 1980 (historical), and after 2000 in those born since 1996 (new), i.e. in appendices taken from outside the population considered most at-risk of acquiring vCJD from BSE-related prions in the food chain. The overall prevalence of immunopositive samples found in these groups that were assumed to be unexposed to BSE was not lower than the prevalence in the most highly BSE-exposed cohort surveyed in the Appendix-2 Study. Examination of the available data on the appendectomy history of each human vCJD case to date showed that none of the positive appendices from this study (Appendix-3), nor the Appendix-2 Study [17], could have come from the 178 known vCJD cases in the UK.
The absence of a consistent difference between individual positive samples within Appendix-3 or between Appendix-2 and -3 is noteworthy. It might not have been possible to infer from these data alone that differences in immunostaining pattern of individual samples relate to source or strain, rather than host, or age of sample. Had we seen such differences it could have suggested different sources for the abnormal PrP detected.
One question is whether the IHC staining found in these prevalence studies was necessarily related to vCJD. The pattern of the staining observed in the positive specimens, however, is highly distinctive and consistent with that found in vCJD cases (both before and after onset of clinical symptoms). The abnormal accumulation of PrP in lymphoid tissue, as detected by immunohistochemistry, has only ever been found in humans with vCJD, and not in other human prion diseases such as sCJD [19, 20], and the transmitted forms of iatrogenic CJD [18] or Kuru [6, 10].
Two interpretations of the prevalence of abnormal PrP in different populations in Britain may be given. First, there is no significant difference in the prevalence of vCJD-related abnormal PrP between any of the appendix survey populations, i.e. there is a low background prevalence of abnormal PrP in human lymphoid tissues that may not progress to vCJD. This background prevalence is unrelated to the intensity and extent of dietary exposure to BSE. The alternative interpretation is that although there is no statistical difference in the prevalence of vCJD-related abnormal PrP across birth and exposure cohorts in the populations studied, the central estimates vary in a direction consistent with the changing intensity over time of the observed BSE epidemic in cattle. All positive specimens may therefore be attributable to BSE exposure.
This second interpretation, however, suggests that human exposure began in the late 1970s and continued through the late 1990s, albeit at a much lower rate than in the mid-1980s. Although cases of BSE were not described until 1986, back-calculation models indicate that cases could have been occurring, and infectivity possibly entering the food chain, for several years before the disease was identified in cattle [8, 46]. In addition, the origins of BSE have never been unequivocally established [40], so it could have been present at a very low prevalence for a long time prior to its amplification through the animal feed chain [46]. Cases of BSE continued to occur in animals born after the total feed ban put in place in the UK in July 1996, the reinforced feed ban in Ireland in October of the same year and the total feed ban in the rest of EU in 2001 [40], and such cases could provide one possible route of exposure for the vCJD cases identified in the post-1996 birth cohort.
Additionally, it has been demonstrated that sheep are susceptible to BSE [30, 44], and the disease can transmit between sheep under field conditions [31]. It has never been isolated from commercial sheep populations, but it has been observed in goats [43]. Sheep-passaged BSE can demonstrate increased ‘virulence’ on subsequent inter-species transmission [38, 44], and can cause disease indistinguishable from vCJD in transgenic mouse models [32, 38]. A non-bovine route of exposure is therefore hypothetically possible.
Neither interpretation, on its own, is entirely satisfactory and it is possible to speculate about a combination of both. There could be ‘background’ prevalence in all groups plus some additional prevalence associated with BSE in the most highly exposed population. Detailed appraisal of the histological findings, however, showed no consistent differences between the positive samples that might have indicated two or more different sources. A large study of a population entirely unexposed to BSE prions would be necessary to determine whether a background prevalence exists, and such a study would pose additional challenges to those faced when implementing the Appendix-3 survey.
Whichever interpretation is preferred, the contrast between the prevalence of abnormal PrP and the number of clinical vCJD cases seen to date (mid-2020) strongly suggests that possibly none of those in whom abnormal PrP is detected through an ante-mortem lymphoid tissue survey will develop any symptoms of prion disease.
New research proposals have been sought that utilise some of the archived additional slides and cuts of formalin fixed tissues from each positive appendix [Department of Health Policy Research Programme—Research call on vCJD 2016: https://clahrcprojects.co.uk/news/department-health-policy-research-programme-invitation-applications] (accessed March 2020). In response, laboratory investigations are underway to elucidate the nature of the immunopositive samples. One approach is using in vitro conversion models to amplify the abnormal prion prior to conducting Western blotting analysis and transmission studies in mice (Green A; personal communication). Another is attempting discrimination of vCJD infected from uninfected fixed tissues through DNA methylation array “profiling” (Mead S; personal communication).
A variety of risk management measures remain in place to limit the risks of person-to-person transmission of prions by blood transfusion or by re-use of surgical instruments in the general population. Whichever way the Appendix-3 Study is interpreted, the prevalence range of prion infection remains a concern, and maintenance of the full range of precautionary measures is a judgement that would need to be balanced against the costs and benefits of these risk reduction measures [1, 37, 42]. More specifically, it is reasonable to assume that the highest prevalence of asymptomatic infection is in the cohort that had greatest exposure to BSE and which contains all known clinical cases of vCJD, the 1961 to 1985 birth cohort [36]. The findings of the Appendix-3 Study, however, challenge the assumption that a specific cut-off date defines a low-risk population, i.e. those born after 1996. Therefore, the difference between the interpretations of the Appendix-3 prevalence has practical implications for risk management.
The discovery that not only PrP but also other proteopathic seeds such as amyloid-β can be iatrogenically transmitted between humans has in the last few years received significant attention [33]. Whilst experimental transmission of amyloid-β had been demonstrated for some years [12, 13, 34], the observation of human transmission of amyloid-β through contaminated human growth hormone [28, 33, 41] has prompted additional studies examining the potential transmission through other human-derived products such as dura mater transplants [14, 35], intravascular embolization material [3], and through surgical instruments [29]. The transmissibility into susceptible animals of amyloid-β contained in human growth hormone preparations has provided further evidence of the historic role of this product in the development of cerebral amyloid angiopathy (CAA), a potentially lethal vascular disease, in affected individuals [26, 39]. These observational and experimental studies have put new emphasis on the necessity of adequate surveillance of relevant human diseases, sensitive detection of proteopathic seeds other than PrP [27] and their effective decontamination, for example on surgical instruments and medical devices.
In conclusion, the Appendix-3 Study has not produced a clear answer to the question of whether the presence of abnormal PrP, as detected by IHC, in the British population is limited to those exposed to the BSE epizootic. The results raise the possibility of abnormal prion exposure both before the presumed BSE epizootic and after 1996 when exposure to BSE-related prions in the food chain in Britain was considered “extremely low”.
THURSDAY, APRIL 02, 2020
Prevalence in Britain of abnormal prion protein in human appendices before and after exposure to the cattle BSE epizootic
Pract Neurol 2010; 10: 250–251
Variant CJD: where has it gone, or has it?
Bob Will
The feared large scale epidemic of variant Creutzfeldt–Jakob disease (vCJD) has thankfully not materialised. The number of cases identified annually in the UK has been in decline since 1999 although there could still be a tail to the outbreak lasting for many years (fi gure). Internationally, the trend in the number of vCJD cases is also in decline and bovine spongiform encephalopathy (BSE) is now a rare disease, even in the UK. One explanation is that the measures introduced to control these diseases were effective; indeed, it is of interest that, to date, no case of vCJD in the UK was born after 1989 when the specified bovine offal ban was introduced whereas there have been three cases born after this date in other European countries where legislative measures to minimise human exposure to BSE were introduced some years later. However, BSE and vCJD control measures are very costly and there will be pressure in the coming years to withdraw or amend relevant legislation and guidance. An important question is whether there are continuing realistic concerns about public health in relation to vCJD and not simply, as has been suggested in the press, scaremongering by some researchers keen to maintain funding.
All probable and definite cases of vCJD internationally, in which genetic testing has been carried out (199/219), have been methionine (MM) homozygous at codon 129 of the prion protein gene. This is clearly a susceptibility factor for the development of clinical disease. However, two out of three prion protein positive appendices in a screening study of 12 674 routine appendix specimens were valine/valine (VV), and a clinically unaffected recipient of a vCJD implicated blood transfusion with disease associated prion protein in their spleen was a heterozygote (MV). This implies that there may be a population of individuals who are subclinically infected but who may never develop clinical disease within their lifespan, perhaps explaining, in part, the mismatch between the extensive human exposure to BSE in the food chain and the relatively limited number of clinical cases so far observed.
This has important implications for the risk of secondary transmission from person to person—for example, through contaminated surgical instruments or blood transfusion. According to one estimate, extrapolating from the estimated prevalence of subclinical infection, 1 in 10 000 blood donations have been derived from individuals who are infected with vCJD. The fact of transfusion transmission of vCJD is now established with three cases of vCJD developing symptoms 5–8 years after having received a blood transfusion from people who donated the blood 1.5–3.5 years before themselves developing the condition (in addition to the subclinical infection referred to above).1 Concerns have been heightened by the discovery of disease associated prion protein in the spleen of a person with haemophilia who had received factor VIII derived from a pool containing a vCJD donation.2 Furthermore, there is a signifi cant population who have been exposed to plasma products potentially contaminated with the vCJD agent but, to date, there is no evidence that clinical cases of vCJD have been caused by exposure to such treatments. One unresolved question is why there have not been more cases of vCJD linked to blood transfusion or plasma products and there is a pressing need to obtain more precise information on the prevalence of infection in the general population.
The recent identification of a possible clinical case of vCJD in an individual with an MV genotype3 reinforces the long held concern that there may be further waves of vCJD cases in individuals with a non-MM codon 129 genotype. Mathematical models suggest that the number of MV and VV cases will be limited and not exceed the primary MM outbreak, but predicting infectious outbreaks is an imprecise science, as may be inferred from the recent swine fl u epidemic which never materialised, at least not to the extent predicted. The adage that ‘Essentially, all models are wrong but some are useful’ (George Edwin Pelham Box, 2007), reinforces the need for caution in predicting the future course of the vCJD outbreak. There is also the possibility that the phenotype of vCJD may be influenced by the genetic background. It is reassuring therefore that the recent possible MV case was identified on the basis of the clinical features as this may indicate that any further such cases will also be recognised as vCJD.
However, there is clearly still a continuing need to look for new phenotypes of human prion disease. Novel forms of animal prion diseases have been identified in recent years, including atypical scrapie and the rare H and L forms of atypical BSE, probably as a result of the extensive abattoir testing of animal populations. Atypical BSE has been transmitted to a range of laboratory animals, and in a primate model the incubation period was shorter than with conventional BSE and the clinical and pathological phenotype different.4
The incubation period in human prion disease can extend to decades and there are continuing concerns and uncertainties that indicate that there are good reasons to continue research and surveillance in vCJD, despite the clear decline in the primary outbreak of vCJD.
Competing interests BW holds research grants in relation to CJD research and surveillance. Provenance and peer review Commissioned; not externally peer reviewed.
REFERENCES
1. Hewitt PE, Llewelyn CA, Mackenzie J, et al. Creutzfeldt–Jakob disease and blood transfusion: results of the UK Transfusion Medicine Epidemiological Review study. Vox Sang 2006;91:221–30.
2. Peden A, McCardle L, Head MW, et al. Variant CJD infection in the spleen of a neurologically asymptomatic UK adult patient with haemophilia. Haemophilia 2010;16:296–304.
3. Kaski D, Mead S, Hyare H, et al. Variant CJD in an individual heterozygous for PRNP codon 129. Lancet 2009;374:2128.
4. Comoy EE, Casalone C, Lescoutra-Etchegaray N, et al. Atypical BSE (BASE) transmitted from asymptomatic aging cattle to a primate. PLoS One 2008;3:e3017.
SATURDAY, JUNE 23, 2018
Diagnosis of Methionine/Valine Variant Creutzfeldt-Jakob Disease by Protein Misfolding Cyclic Amplification
Volume 24, Number 7—July 2018
Dispatch
Diagnosis of Methionine/Valine Variant Creutzfeldt-Jakob Disease by Protein Misfolding Cyclic Amplification
Daisy BougardComments to Author , Maxime Bélondrade, Charly Mayran, Lilian Bruyère-Ostells, Sylvain Lehmann, Chantal Fournier-Wirth, Richard S. Knight, Robert G. Will, and Alison J.E. Green
Author affiliations: Etablissement Français du Sang, Montpellier, France (D. Bougard, M. Bélondrade, C. Mayran, L. Bruyère-Ostells, C. Fournier-Wirth); University of Montpellier, Montpellier (S. Lehmann); University of Edinburgh, Edinburgh, Scotland, UK (R.S. Knight, R.G. Will, A.J.E. Green)
Abstract
A patient with a heterozygous variant of Creutzfeldt-Jakob disease (CJD) with a methionine/valine genotype at codon 129 of the prion protein gene was recently reported. Using an ultrasensitive and specific protein misfolding cyclic amplification–based assay for detecting variant CJD prions in cerebrospinal fluid, we discriminated this heterozygous case of variant CJD from cases of sporadic CJD.
Until recently, all clinical cases of vCJD for which the prion protein gene has been analyzed have been shown to be methionine homozygous at codon 129, a genotype present in almost 40% of Caucasian populations. The report of the first definite heterozygous methionine/valine vCJD patient who died in 2016 (3) underlined previous concern about a possible second wave of vCJD cases (4). The clinical features of this patient were more similar to those of patients with sporadic CJD (sCJD) than to those with vCJD. This patient had met the agreed surveillance diagnostic criteria for probable sCJD (5). However, vCJD was diagnosed during an autopsy; florid plaques were observed by histologic examination of the brain and peripheral detection of PrPTSE in lymphoid tissues. Western blot analysis of brain tissue confirmed a type 2B molecular profile of PrPTSE, which is characteristic for vCJD. A diagnostic test to identify methionine/valine heterozygous vCJD cases is urgently needed to enable discrimination between heterozygous vCJD and sCJD and in view of the potential reservoir of methionine/valine heterozygous asymptomatic vCJD carriers in the blood donor population. We developed a highly sensitive and specific assay that accurately detects vCJD prions in blood even before the occurrence of clinical signs (6). We adapted this assay, which was based on protein misfolding cyclic amplification (PMCA) (7), for specific detection of vCJD in cerebrospinal fluid (CSF) and confirmed the ability of this assay to differentiate patients with atypical heterozygous vCJD from patients with sCJD.
The Study
We blindly analyzed 98 CSF samples provided by the National CJD Research and Surveillance Unit (Edinburgh, Scotland, UK) and the Centre Hospitalier Universitaire de Montpellier (Montpellier, France) after obtaining appropriate consent. Clinicians distributed CSF samples into blinded panels from the United Kingdom and France; 41 from patients with vCJD; 23 from patients with sCJD; 1 from a patient with genetic CJD; and 33 from patients with non-CJD, including samples from patients with Alzheimer’s disease and patients with nonneurodegenerative diseases.
CSF samples were thawed at room temperature and used directly in PMCA. We performed PMCA amplification by using brains from humanized transgenic mice as substrate for normal prion protein. After successive rounds of 160 cycles of PMCA for 15 min and sonication for 20 s, we detected PrPTSE by using Western blot after digestion with proteinase K (6).
Of the 98 CSF samples analyzed, our assay identified 40 of 41 cases of clinical vCJD, including the methionine/valine heterozygous patient, thus showing a diagnostic sensitivity of 97.6% (95% CI 87.1%–99.9%) (Table). One CSF sample from a probable case of vCJD showed a negative result. After decoding by clinicians, we retested this sample in duplicate; it showed a positive result.
Our assay also showed high analytical specificity; 0 of 57 potentially cross-reacting CSF specimens from patients with sCJD, gCJD, Alzheimer's disease, and other nonneurodegenerative diseases showed a positive result (specificity 100% [95% CI 93.7%–100%]) (Table). The case-patient with methionine/valine heterozygous vCJD was specifically discriminated from the 12 methionine/valine heterozygous neuropathologically confirmed sCJD case-patients tested.
We then compared by using Western blot the PrPTSE molecular signature obtained for the clinical vCJD amplified samples from classical methionine homozygous cases and the new methionine/valine heterozygous vCJD case with that of the reference brain sample from a patient with vCJD (Figure). As expected, the profile obtained after PMCA amplification of the CSF from the methionine/valine heterozygous vCJD patient was similar to those obtained for methionine homozygous vCJD patients. The characteristic type 2 mobility and clear predominance of the diglycosylated isoform was obtained for all vCJD patients before or after amplification.
Conclusions
We report a specific detection method that enables clinical diagnosis of a heterozygous methionine/valine heterozygous vCJD patient. This patient was the first definite heterozygous patient described since the start of the vCJD epidemic in the United Kingdom in 1996 (3). Clinical diagnosis was difficult because clinical signs and symptoms, particularly cerebral appearance by magnetic resonance imaging, were suggestive of sCJD (3). The vCJD blood test (direct detection assay) developed by the Medical Research Council Prion Unit (London, UK) (8) showed a negative result for this case-patient. We found characteristic vCJD prion protein amplification in the CSF, which led to a specific diagnosis of vCJD because sCJD samples did not show positive results by PMCA. This result also demonstrates the possibility of amplifying methionine/valine heterozygous vCJD prion protein by PMCA with a substrate from humanized transgenic mice that overexpress homozygous methionine prion protein (9). However, PMCA analysis should be performed in a Biosafety Level 3 laboratory and requires highly experienced personnel.
Iatrogenic transmission of vCJD by blood transfusion has been documented in 3 recipients of nonleukodepleted erythrocyte concentrates from blood donors during development of disease (10). One additional probable case of vCJD transmission by blood transfusion was identified during an autopsy of a methionine/valine heterozygous patient who died from a nonneurologic disorder and in whom vCJD prion protein was detected in the spleen (11). The presence of infectivity in blood of the definite methionine/valine heterozygous vCJD patient involved in our study is uncertain and requires further investigation.
From a clinical point of view, prion amplification technologies, such as PMCA and real-time quaking-induced conversion (RT-QuIC), have already shown their sensitive detection of disease-related prion protein in biologic fluids (6,12–14). Independent studies have shown that detection of prion protein seeding activity in CSF by RT-QuIC might have a specificity of 99%–100% for diagnosis of sCJD (13,15). Application of RT-QuIC and PMCA for CSF samples might represent a suitable strategy for premortem discrimination between sCJD and vCJD including methionine/valine heterozygous case-patients, particularly for cases with a heterozygous codon 129 genotype in which clinical distinction between sCJD and vCJD is problematic.
Dr. Bougard is a research scientist in charge of the Prion Group at Establissement Français du Sang of Montpellier, France. Her primary research interests include development of innovative tools for the prevention of transfusion risk associated with nonconventional agents.
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SUNDAY, DECEMBER 29, 2019
Variant CJD 18 years of research and surveillance Variant CJD
Abigail B Diack,Mark W Head,Sandra McCutcheon,Aileen Boyle,Richard Knight,James W Ironside, show all Pages 286-295 | Received 17 Mar 2014, Accepted 14 May 2014, Published online: 01 Nov 2014
Download citation https://doi.org/10.4161/pri.29237 CrossMark
Abstract
It is now 18 years since the first identification of a case of vCJD in the UK. Since that time, there has been much speculation over how vCJD might impact human health. To date there have been 177 case reports in the UK and a further 51 cases worldwide in 11 different countries. Since establishing that BSE and vCJD are of the same strain of agent, we have also shown that there is broad similarity between UK and non-UK vCJD cases on first passage to mice. Transgenic mouse studies have indicated that all codon 129 genotypes are susceptible to vCJD and that genotype may influence whether disease appears in a clinical or asymptomatic form, supported by the appearance of the first case of potential asymptomatic vCJD infection in a PRNP 129MV patient. Following evidence of blood transfusion as a route of transmission, we have ascertained that all blood components and leucoreduced blood in a sheep model of vCJD have the ability to transmit disease. Importantly, we recently established that a PRNP 129MV patient blood recipient with an asymptomatic infection and limited PrPSc deposition in the spleen could readily transmit disease into mice, demonstrating the potential for peripheral infection in the absence of clinical disease. This, along with the recent appendix survey which identified 16 positive appendices in a study of 32 441 cases, underlines the importance of continued CJD surveillance and maintaining control measures already in place to protect human health.
Keywords: prion, variant Creutzfeldt–Jakob disease, transmissible spongiform encephalopathy, prion protein
Volume 10 Number 26 published on: 12 August 2016
CJD/Emerging infections
Summary results of the third national survey of abnormal prion prevalence in archived appendix specimens
In July 2012, the Transmissible Spongiform Encephalopathies (TSE) Risk Assessment SubGroup of the Advisory Committee on Dangerous Pathogens (the successor national advisory committee to the Spongiform Encephalopathy Advisory Committee (SEAC)), considered the results of the second unlinked anonymous national survey of the prevalence of abnormal prion protein in human appendix samples (Appendix-II [1]), and concluded that a further similar survey should be conducted on tissues from population groups considered unexposed to BSE [2]. This third national survey (Appendix-III) of appendix specimens removed at operations prior to the BSE epizootic and appendix specimens from those born in 1996 or later, by which time measures had been put in place to protect the food chain, has now been concluded. This report provides a summary of the results of the Appendix-III survey prior to publication in due course of the complete data.
The Appendix-III survey examined by immunohistochemistry (IHC) appendices removed at operation and collected from 44 hospitals throughout England. Abnormal prion accumulation was detected within the follicular dendritic cells of seven appendices out of 29,516 suitable samples examined. Indirect comparison of available data showed that none of the positive appendices could have come from the 178 known vCJD cases in the UK. Two of the seven positive samples were from the 14,692 appendices removed at operations conducted in 1962 through 1979: both these positive samples were from the 5,865 appendices removed in 1977 through 1979. The other five positive samples were found in the 14,824 appendices from subjects born in 1996 or later and removed at operation in 2000 through 2014: all five were in the sub-group of 10,074 born in 1996 through 2000. Therefore, none of the seven positive appendices were in specimens removed before 1977 or in patients born in 2001 or later.
The planned statistical analysis found no difference between the prevalence observed in the Appendix-II survey of 493 per million (95% Confidence Interval (CI): 282 to 801 per million) and the Appendix-III prevalence in appendices removed between 1962 through 1979 of 136 per million (95%CI: 16 to 492 per million; exact p=0.08), nor with the Appendix-III prevalence in
Health Protection Report Vol. 10 No. 26 – 12 August 2016
appendices from those born in 1996 through 2000 of 337 per million (95%CI: 110 to 787 per million; exact p=0.64). Test accuracy calculations using the Appendix-III data suggest the IHC technique specificity is in the range of 99.975% to over 99.99%. Although specificity of this magnitude (99.99%) implies few false positives, if the true prevalence is very low, then the positive predictive value of the IHC technique will diminish. At the one in 7,000 prevalence observed in the Appendix-III survey of specimens removed in 1979 or earlier, the positive predictive value (PPV) will be 56%, for a specificity of 99.99% and a sensitivity of 90%, compared to a PPV of 82% at the one in 2,000 prevalence observed in the Appendix-II survey.
The Appendix-II and -III surveys were conducted by a collaboration of PHE, the Department of Neurodegenerative Diseases at the UCL Institute of Neurology, the Animal and Plant Health Agency, the National Creutzfeldt-Jakob Disease Research and Surveillance Unit, the Histopathology Department of Derriford Hospital in Plymouth, and the MRC Prion Unit.
In summary, the Appendix-III survey data have not produced a clear answer to the question of whether abnormal prions detected by IHC in the British population is limited to those exposed to the BSE epizootic, and various interpretations are possible. The survey results have been considered by the ACDP TSE Sub-Group and a position paper detailing the conclusions of the committee has been published online, simultaneously with this summary report [3].
References
1. Gill ON, Spencer Y, Richard-Loendt, A, Kelly C, Dabaghian R, Boyes L, et al (2013). Prevalent abnormal prion protein in human appendixes after bovine spongiform encephalopathy epizootic: large scale survey. BMJ 347: f5675, http://www.bmj.com/content/347/bmj.f5675. 2. Advisory Committee on Dangerous Pathogens TSE Risk Assessment Subgroup (July 2012).
Position Statement on occurrence of vCJD and prevalence of infection in the UK population. Available from: ACDP TSE subgroup minutes, agendas and papers, https://app.box.com/s/hhhhg857fjpu2bnxhv6e.
3. Advisory Committee on Dangerous Pathogens TSE Risk Assessment Subgroup (August 2016). “Appendix-III” position statement. Available from: ACDP TSE subgroup minutes, agendas and papers, https://app.box.com/s/hhhhg857fjpu2bnxhv6e.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/546883/hpr2616.pdf
SEAC 104/2
ESTIMATING THE PREVALENCE OF SUBCLINICAL vCJD
ISSUE
1. The prevalence of subclinical vCJD in the UK is highly uncertain. Current estimates are based on the Hilton et al data on abnormal prion protein (PrPvCJD) in stored appendix samples, however the National Anonymous Tonsil Archive (NATA) study is on-going, and a further study of appendices has been commissioned. In addition, a pilot to assess the feasibility of a post mortem study to test spleen tissue has also been commissioned. The NATA data are currently within the confidence intervals of the Hilton data, but there remains a possibility that once completed, the data from these studies might be discrepant.
2. All samples in the NATA survey (over 80,000) have tested negative by EIA. However, one of 10,000 samples re-tested by IHC has given a positive result in one follicle. Extensive further testing of this sample has produced negative results.
3. Prevalence of infective material in subclinical individuals is a key factor determining the risks of secondary vCJD transmission via surgery, or donated blood, tissues or organs. To assess these risks, presence of PrPvCJD has been used as a surrogate indicator of infectivity, though the relationship between the two is not fully established.
4. In addition, risk assessments have assumed that in principle, the same “prevalence” would drive all transmission risks. For example, if the prevalence of sub-clinical infection was “1 in x”, then 1 in every x surgical procedures encountering any lymphoid tissue (e.g. tonsil, appendix or spleen) would meet with infective material. Similarly, 1 in every x blood donations would be infective. At present, this means that assessments are based primarily on the Hilton et al appendix results. This approach may not be appropriate if the presence of PrPvCJD varies markedly by site, and possibly over time. Nor would one necessarily expect different “prevalence studies” to be mutually consistent.
5. The Committee is asked to consider the following questions:
snip...
http://www.seac.gov.uk/papers/104-2.pdf
SEAC 2008 ONE HUNDREDTH MEETING OF THE SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE
SEAC 2008
ONE HUNDREDTH MEETING OF THE SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE
The Spongiform Encephalopathy Advisory Committee held its 100th meeting in London on 25th April 2008, and discussed the following:
CURRENT ISSUES
SEAC was informed about:
• Two recently identified cases of variant Creutzfeldt-Jakob Disease (vCJD) in Spain. • Proposals for the future regulation of ‘high street’ dentistry outlined in a consultation issued recently by the Department of Health (DH)1. SEAC agreed to respond to the consultation, welcoming the proposals. • The detection of material of unknown animal origin in a batch of wheat feed distributed for use in livestock feed2.
ASSESSMENT OF THE PREVALENCE OF SUBCLINICAL vCJD SEAC was updated about the progress of the National Anonymous Tonsil Archive (NATA) and of discussions around a proposed post mortem tissue archive. These would provide data to estimate the prevalence of subclinical vCJD (vCJD infections that have yet to develop, or may never develop, into clinical disease). Approximately 55 000 NATA samples had been screened by the end of March 2008. Although none was positive for abnormal prion protein (PrPvCJD), some testing remains to be done on some samples. SEAC expressed disappointment that it is currently
1 DH (2008) The future regulation of health and adult social care in England: A consultation on the framework for the registration of health and adult social care providers.
http://www.dh.gov.uk/en/Consultations/Liveconsultations/DH_083625
2
http://www.food.gov.uk/news/newsarchive/2008/apr/feedcontam
2 © SEAC 2008
proving difficult to establish a post mortem tissue archive through collection of tissues from Coroners’ autopsies. In light of the current difficulties in establishing a post mortem tissue archive, DH asked for advice about how existing data from NATA might be combined with a completed survey of appendix samples3, which had found PrPvCJD in three out of about 11 000 samples. SEAC considered that the data from these studies are not, at the present time, discrepant. However, given the uncertainties about the tissue distribution of PrPvCJD during vCJD incubation, it would be hard to see how these data could be combined.
SEAC considered what further work might be done to obtain better estimates for the prevalence of subclinical vCJD including additional appendix studies and a post mortem tissue archive. SEAC strongly recommended that every avenue be pursued to establish such an archive.
The committee agreed to produce a statement.
THURSDAY, MAY 17, 2012
Iatrogenic Creutzfeldt-Jakob Disease, Final Assessment Volume 18, Number 6—June 2012
THURSDAY, JULY 02, 2020
Variant Creutzfeldt–Jakob Disease Diagnosed 7.5 Years after Occupational Exposure
Variant Creutzfeldt–Jakob Disease Diagnosed 7.5 Years after Occupational Exposure
Variant Creutzfeldt–Jakob disease was identified in a technician who had cut her thumb while handling brain sections of mice infected with adapted BSE 7.5 years earlier. The long incubation period was similar to that of the transfusion-transmitted form of the disease.
TO THE EDITOR:
We report a case of variant Creutzfeldt–Jakob disease (CJD) that was plausibly related to accidental occupational exposure in a technician who had handled murine samples contaminated with the agent that causes bovine spongiform encephalopathy (BSE) 7.5 years earlier.
In May 2010, when the patient was 24 years of age, she worked in a prion research laboratory, where she handled frozen sections of brain of transgenic mice that overexpressed the human prion protein with methionine at codon 129. The mice had been infected with a sheep-adapted form of BSE. During this process, she stabbed her thumb through a double pair of latex gloves with the sharp ends of a curved forceps used to handle the samples. Bleeding was noted at the puncture site.
In November 2017, she began having burning pain in the right shoulder and neck. The pain worsened and spread to the right half of her body during the following 6 months. In November 2018, an examination of a sample of cerebrospinal fluid (CSF) obtained from the patient was normal. Magnetic resonance imaging (MRI) of the brain showed a slight increase in the fluid-attenuated inversion recovery (FLAIR) signal in the caudates and thalami (Fig. S1A and S1B in the Supplementary Appendix, available with the full text of this letter at NEJM.org). In January 2019, she became depressed and anxious and had memory impairment and visual hallucinations. There was hypertonia on the right side of her body. At that time, an analysis of CSF for 14-3-3 protein was negative. In March 2019, MRI showed an increased FLAIR signal in pulvinar and dorsomedial nuclei of thalami (Fig. S1C through S1E).
The patient was found to be homozygous for methionine at codon 129 of the prion protein gene without mutation. An analysis of a sample of CSF on real-time quaking-induced conversion analysis was negative for a diagnosis of sporadic CJD. However, an analysis of plasma and CSF by means of protein misfolding cyclic amplification was positive for the diagnosis of variant CJD (Figure 1A and 1B). The patient died 19 months after the onset of symptoms. Neuropathological examination confirmed the diagnosis of variant CJD (Figure 1C and 1D). Western blot analysis showed the presence of type 2B protease-resistant prion protein in all sampled brain areas. The clinical characteristics of the patient and the postmortem neuropathological features were similar to those observed in 27 patients with variant CJD who had previously been reported in France.1 (Additional details are provided in the Supplementary Appendix.)
There are two potential explanations for this patient’s condition. Oral transmission from contaminated cattle products cannot be ruled out because the patient was born at the beginning of the French BSE outbreak in cattle. However, the last two patients who had confirmed variant CJD with methionine homozygosity at codon 129 in France and the United Kingdom died in 2014 and 2013, respectively, which makes oral transmission unlikely. In France, the risk of variant CJD in 2019 was negligible or nonexistent in the post-1969 birth cohort.2
Percutaneous exposure to prion-contaminated material is plausible in this patient, since the prion strain that she had handled was consistent with the development of variant CJD.3 The 7.5-year delay between the laboratory accident and her clinical symptoms is congruent with the incubation period in the transfusion-transmitted form of the disease. The ability of this strain to propagate through the peripheral route has been documented, and experimental studies with scrapie strains have shown that scarification and subcutaneous inoculation are effective routes.4,5 The last known Italian patient with variant CJD, who died in 2016, had had occupational contact with BSE-infected brain tissues, although subsequent investigation did not disclose a laboratory accident (Pocchiari M, Italian Registry of CJD: personal communication). Thus, the last two cases of variant CJD outside the United Kingdom have been associated with potential occupational exposure. Such cases highlight the need for improvements in the prevention of transmission of variant CJD and other prions that can affect humans in the laboratory and neurosurgery settings, as outlined in the Supplementary Appendix.
Jean-Philippe Brandel, M.D. Assistance Publique–Hôpitaux de Paris, Paris, France
M. Bustuchina Vlaicu, M.D. Groupe Hospitalier Nord-Essonne, Orsay, France
Audrey Culeux, B.Sc. INSERM Unité 1127, Paris, France
Maxime Belondrade, M.Sc. Daisy Bougard, Ph.D. Etablissement Français du Sang, Montpellier, France
Katarina Grznarova, Ph.D. Angeline Denouel, M.Sc. INSERM Unité 1127, Paris, France
Isabelle Plu, M.D. Elodie Bouaziz-Amar, Pharm.D., Ph.D. Danielle Seilhean, M.D., Ph.D. Assistance Publique–Hôpitaux de Paris, Paris, France
Michèle Levasseur, M.D. Groupe Hospitalier Nord-Essonne, Orsay, France
Stéphane Haïk, M.D., Ph.D. INSERM Unité 1127, Paris, France stephane.haik@upmc.fr
Supported by a grant (ANR-10-IAIHU-06) from Programme d’Investissements d’Avenir and Santé Publique France.
Disclosure forms provided by the authors are available with the full text of this letter at NEJM.org.
July 2, 2020 N Engl J Med 2020; 383:83-85 DOI: 10.1056/NEJMc2000687
Supplementary Appendix
This appendix has been provided by the authors to give readers additional information about their work. Supplement to: Brandel J-P, Vlaicu MB, Culeux A, et al. Variant Creutzfeldt–Jakob disease diagnosed 7.5 years after occupational exposure. N Engl J Med 2020;383:83-5. DOI: 10.1056/NEJMc2000687
Full case report
A woman, born in 1986, with only a medical history of dental avulsion and the removal of a nevus started to complain, in November 2017, of burning pain in the right shoulder and the right side of the neck. Over the next 6 months, the pain worsened and spread to the right half-body including the buttocks, the back of the thigh and the foot sole, and the face with ear pain. After several consultations, a first hospital assessment was carried out in November 2018. CSF examination was normal and brain MRI interpreted as normal despite slight high signals in the caudate nucleus and thalami (Supplementary figure 1). The diagnosis of Lyme disease was suspected and treatment with ceftriaxone was initiated. Pain persisted and the patient who was showing signs of depression was referred to a psychiatrist for antidepressant treatment. Memory impairment was noted by relatives in January 2019 and the patient was admitted to a neurology department in February 2019. Right extrapyramidal hypertonia, visual hallucinations and memory problems of recent events were observed. Neurological alterations were associated with severe anxiety. Inflammatory markers, biological and immunological assessments were normal. Serology for conventional agents was negative. Detection of anti-neuronal, anti-thyroid peroxidase, anti-thyroglobulin and anti-thyroidstimulating hormone receptor antibodies yielded negative results. Vitamin B1 and B6 levels were within normal limits. Standard CSF analysis was normal and 14-3-3 protein detection was negative. MRI from mid-March 2019 showed a high signal on the FLAIR sequences in the pulvinar and dorsomedian nuclei of the thalamus, bilaterally, more intense than those observed in the striatum (Supplementary figure 1). A generally slow activity was observed on EEGs. PRNP analysis revealed a homozygous methionine-methionine (MM) genotype at codon 129 without mutation. At this time, the patient fulfilled criteria of probable vCJD. Two different protein misfolding amplification methods were performed. As predicted in a suspected case of vCJD, RT-QuIC detection in the CSF gave a negative result.1 A PMCA test, recently validated for the diagnosis of vCJD in plasma and CSF was performed.2,3 PMCA detection was positive in plasma and CSF. Evolution was marked by the
3
worsening of cognitive impairment, a small step with balance disorders and an extrapyramidal syndrome.
The patient died 19 months after disease onset.
Neuropathological examination confirmed the diagnosis of vCJD by showing typical florid plaques in the cerebral cortex and cerebellum. Spongiform changes, gliosis and neuronal loss were predominantly observed in the subcortical gray matter. In addition, PrP immunohistochemistry showed multicentric plaques, clumpses, peri-cellular and peri-vascular PrP deposition (Supplementary figure 2). Western blot detection of PrPres was positive and type 2B PrPres was consistently detected in all studied brain areas.
The epidemiological survey revealed that the patient had been employed from 2009 to 2012 in a laboratory involved in prion research. In particular, she has worked on transgenic animal models expressing human and bovine PrP and infected with strains of human or bovine prions. The patient had two work accidents. In May 2010, she stabbed her thumb with sharp ends curved forceps used to handle brain frozen sections of humanized transgenic mice infected with a sheep-adapted BSE agent. The mouse brain handled at the time of the accident was from a secondary intra-cerebral subpassage of sheep BSE in transgenic mice overexpressing a methionine 129-human PrP. To note transmission studies indicate a low or absent transmission barrier to sheep BSE in human M129-PrP mice. The neuropathological phenotype is similar to that observed in mice infected with cattle BSE or vCJD suggesting that sheep-BSE could act as a causal vCJD agent especially in codon 129-methionine homozygotes.
4,5 The patient immediately noticed a bleeding wound. After leaving the level 3 biosafety laboratory, the wounded finger was cleaned with water and immersed for more than ten minutes in a freshly diluted 2% sodium hypochlorite solution. The second accident occurred in September 2011 in a conventional laboratory with no contact with infectious prion material. No other risk factors were identified with the exception, as most French people in her age cohort, a dietary exposure from 1986 to 1996 to bovine products with a BSE risk.
4
Methods
Clinical and epidemiological data As with all other cases of French vCJD, a direct interview with the patient’s family was conducted. Clinical data were extracted from the medical records and further information was collected using the European network (EuroCJD) questionnaire. The data collected were gender, age at onset and death, clinical features, results of investigations, and specific medical risk factors. These included history of growth hormone therapy, transplantation, surgery, blood transfusion, blood products therapy (albumin, immunoglobulin, clotting factors), vaccinations, professional activity, and stays in UK. The reports of the two accidents at work were collected. Additional data were obtained from the authorities of the research institute. They explained precisely how the patient had been injured, the biological materials handled and how the wounds had been disinfected and treated. Genetic analysis The prion protein gene (PRNP) was analyzed as described previously to obtain the genotype at codon 129 and to exclude a pathogenic mutation.6 An informed consent for genetic analysis was obtained from the patient's husband.
Neuropathological analysis
Samples were taken from 1cm-thick coronal sections after two months of fixation in 10% formalin as described previously.7 After formic acid treatment, specimens were embedded in paraffin. Threemicrometer-thick sections were stained with hematoxylin and eosin and Periodic Acid–Schiff (PAS) methods. PrP immunohistochemistry was performed using the 12F10 mouse monoclonal antibody.8,9 Biochemical analysis PrPres analysis by Western blot was performed from frozen samples of the brain. Tissue homogenization, digestion with proteinase K, purification, electrophoresis and immunoblotting were
5
done as described previously.10 The biochemical classification according to Parchi and colleagues was used.11
Amplification methods
RT-QuIC analysis in the CSF was performed using hamster full-length (23–231) recombinant PrP as previously described.12 Thirty µl of CSF per well were added and analysis was performed in quadruplicate using a BMG-LABTECH Omega. PMCA amplification in plasma and CSF was performed as described by using brains from transgenic mice overexpressing human M129-PrP as substrate.2,3 For plasma samples, a capture of abnormal PrP using plasminogen-coated magnetic nanobeads was performed before serial amplification. Each round of PMCA comprised 80 cycles of 30 min incubation/20 s sonication. Implications If one considers our patient as a case of a documented accidental transmission of CJD in a research laboratory, several important points should be stressed:
- A single puncture without hollow needle containing infectious material is sufficient to transmit prions in human even with a short contact.
- The incubation period is similar to that seen in MM patients with transfusion-transmitted vCJD, suggesting that the level of accidentally delivered infectious dose is in the same range as that contained in a unit of non-leukodepleted red blood cells.
- Immersing this type of lesion in a freshly diluted 2% sodium hypochlorite solution was not sufficient to prevent contamination. Important consequences in terms of prevention of occupational risks and public health issue associated with prions should be underlined:
6
- Individual protection against accidental wounds should be reinforced in research laboratories, neuropathology department and autopsy rooms. Neurosurgery teams should take the risk into account, especially when a cortical biopsy is performed to explore patients with unexplained encephalopathy. This implies accurate information and training of exposed professionals.
- The efficacy of decontamination procedures to be applied in case of accidental exposure has not been demonstrated using adequate in vivo models of transmission. A more aggressive postexposure management is to be defined and validated experimentally.
- The mechanisms of prion neuro-invasion in this specific scenario are unknown and may involve prion propagation through (1) the peripheral innervation of digital pulp, (2) an up-take by phagocytes driving prion replication in the lymphoid system followed by propagation via the autonomous nervous system or (3) blood transport.
- No preventive treatment is available to date. While a few approaches that may limit peripheral prion propagation and neuro-invasion have been proposed (such as corticoids and pentosan polysulfate), their efficiency in such a transmission pattern and in the use of relevant prion strains has to be confirmed.
7
References
1. Zanusso G, Monaco S, Pocchiari M, Caughey B. Advanced tests for early and accurate diagnosis of Creutzfeldt-Jakob disease. Nat Rev Neurol 2016;12:325-33.
2. Bougard D, Brandel JP, Belondrade M, et al. Detection of prions in the plasma of presymptomatic and symptomatic patients with variant Creutzfeldt-Jakob disease. Science translational medicine 2016;8:370ra182.
3. Bougard D, Belondrade M, Mayran C, et al. Diagnosis of Methionine/Valine Variant Creutzfeldt-Jakob Disease by Protein Misfolding Cyclic Amplification. Emerging infectious diseases 2018;24:1364-6.
4. Plinston C, Hart P, Chong A, et al. Increased susceptibility of human-PrP transgenic mice to bovine spongiform encephalopathy infection following passage in sheep. Journal of virology 2011;85:1174-81.
5. Joiner S, Asante EA, Linehan JM, et al. Experimental sheep BSE prions generate the vCJD phenotype when serially passaged in transgenic mice expressing human prion protein. J Neurol Sci 2018;386:4-11.
6. Laplanche JL, Delasnerie-Lauprêtre N, Brandel JP, et al. Molecular genetics of prion diseases in France. Neurology 1994;44:2347-51.
7. Hauw JJ, Sazdovitch V, Laplanche JL, et al. Neuropathologic variants of sporadic CreutzfeldtJakob disease and codon 129 of PrP gene. Neurology 2000;54:1641-6.
8. Haik S, Faucheux BA, Sazdovitch V, et al. The sympathetic nervous system is involved in variant Creutzfeldt-Jakob disease. Nature medicine 2003;9:1121-3.
9. Privat N, Laffont-Proust I, Faucheux BA, et al. Human prion diseases: from antibody screening to a standardized fast immunodiagnosis using automation. Mod Pathol 2008;21:140-9.
8
10. Levavasseur E, Laffont-Proust I, Morain E, et al. Regulating factors of PrP glycosylation in Creutzfeldt-Jakob disease--implications for the dissemination and the diagnosis of human prion strains. PloS one 2008;3:e2786.
11. Parchi P, Notari S, Weber P, et al. Inter-laboratory assessment of PrPSc typing in creutzfeldtjakob disease: a Western blot study within the NeuroPrion Consortium. Brain pathology 2009;19:384- 91.
12. McGuire LI, Poleggi A, Poggiolini I, et al. Cerebrospinal fluid real-time quaking-induced conversion is a robust and reliable test for sporadic creutzfeldt-jakob disease: An international study. Annals of neurology 2016;80:160-5.
snip...
Variant Creutzfeldt–Jakob Disease Diagnosed 7.5 Years after Occupational Exposure
Variant Creutzfeldt–Jakob disease was identified in a technician who had cut her thumb while handling brain sections of mice infected with adapted BSE 7.5 years earlier. The long incubation period was similar to that of the transfusion-transmitted form of the disease.
THURSDAY, JULY 02, 2020
Variant Creutzfeldt–Jakob Disease Diagnosed 7.5 Years after Occupational Exposure
Wednesday, July 28, 2021
France issues moratorium on prion research after fatal brain disease strikes two lab workers
Volume 26, Number 8—August 2020
Sporadic Creutzfeldt-Jakob Disease among Physicians, Germany, 1993–2018 high proportion of physicians with sCJD were surgeons
Saturday, January 23, 2021
Improved surveillance of surgical instruments reprocessing following the variant Creutzfeldt-Jakob disease crisis in England: findings from a 3-year survey
SUNDAY, JULY 19, 2020
Joseph J. Zubak Orthopaedic surgeon passed away Monday, July 6, 2020, Creutzfeldt-Jakob Disease (CJD)
snip...
Thursday, July 29, 2021
TSE PRION OCCUPATIONAL EXPOSURE VIA ANIMAL OR HUMAN, iatrogenic transmission, nvCJD or sCJD, what if?
Potential Exposure to Creutzfeldt-Jakob Disease VA Connecticut Healthcare System West Haven, Connecticut
VA OIG releases findings of potential CJD exposure
July 2, 2014
Tuesday, November 30, 2021
Second death in France in a laboratory working on prions
Wednesday, February 3, 2021
Wide distribution of prion infectivity in the peripheral tissues of vCJD and sCJD patients
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
snip...
76/10.12/4.6
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC.
Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK
National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
WEDNESDAY, JANUARY 12, 2022
Bovine Spongiform Encephalopathy BSE TSE Prion Origin USA, what if?
ARS RESEARCH Generation of human chronic wasting disease in transgenic mice
Publication Acceptance Date: 9/8/2021
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Generation of human chronic wasting disease in transgenic mice
Author item WANG, ZERUI - Case Western Reserve University (CWRU) item QIN, KEFENG - University Of Chicago item CAMACHO, MANUEL - Case Western Reserve University (CWRU) item SHEN, PINGPING - Case Western Reserve University (CWRU) item YUAN, JUE - Case Western Reserve University (CWRU) item Greenlee, Justin item CUI, LI - Jilin University item KONG, QINGZHONG - Case Western Reserve University (CWRU) item MASTRIANNI, JAMES - University Of Chicago item ZOU, WEN-QUAN - Case Western Reserve University (CWRU)
Submitted to: Acta Neuropathologica Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/8/2021 Publication Date: N/A Citation: N/A
Interpretive Summary: Prion diseases are invariably fatal neurologic diseases for which there is no known prevention or cure. Chronic wasting disease (CWD) is the prion disease of deer and elk and is present in farmed and free ranging herds throughout North America. To date there is no clear evidence that the CWD agent could be transmitted to humans. This manuscript describes the use of an in vitro technique, cell-free serial protein misfolding cyclic amplification (sPMCA), to generate a CWD prion that is infectious to transgenic mice expressing the human prion protein. This study provides the first evidence that CWD prions may be able to cause misfolding in the human prion protein. This information will impact medical experts and those involved in making policy for farmed cervids and wildlife.
Technical Abstract: Chronic wasting disease (CWD) is a cervid spongiform encephalopathy or prion disease caused by the infectious prion or PrPSc, a misfolded conformer of cellular prion protein (PrPC). It has rapidly spread in North America and also has been found in Asia and Europe. In contrast to the zoonotic mad cow disease that is the first animal prion disease found transmissible to humans, the transmissibility of CWD to humans remains uncertain although most previous studies have suggested that humans may not be susceptible to CWD. Here we report the generation of an infectious human PrPSc by seeding CWD PrPSc in normal human brain PrPC through the in vitro cell-free serial protein misfolding cyclic amplification (sPMCA). Western blotting confirms that the sPMCA-induced proteinase K-resistant PrPSc is a human form, evidenced by a PrP-specific antibody that recognizes human but not cervid PrP. Remarkably, two lines of humanized transgenic (Tg) mice expressing human PrP-129Val/Val (VV) or -129Met/Met (MM) polymorphism develop prion disease at 233 ± 6 (mean ± SE) days post-inoculation (dpi) and 552 ± 27 dpi, respectively, upon intracerebral inoculation with the sPMCA-generated PrPSc. The brain of diseased Tg mice reveals the electrophoretic profile of PrPSc similar to sporadic Creutzfeldt-Jakob disease (sCJD) MM1 or VV2 subtype but different neuropathological patterns. We believe that our study provides the first evidence that CWD PrPSc is able to convert human PrPC into PrPSc in vitro and the CWD-derived human PrPSc mimics atypical sCJD subtypes in humanized Tg mice.
''The brain of diseased Tg mice reveals the electrophoretic profile of PrPSc similar to sporadic Creutzfeldt-Jakob disease (sCJD) MM1 or VV2 subtype but different neuropathological patterns.''
''We believe that our study provides the first evidence that CWD PrPSc is able to convert human PrPC into PrPSc in vitro and the CWD-derived human PrPSc mimics atypical sCJD subtypes in humanized Tg mice.''
Published: 26 September 2021
Generation of human chronic wasting disease in transgenic mice
Zerui Wang, Kefeng Qin, Manuel V. Camacho, Ignazio Cali, Jue Yuan, Pingping Shen, Justin Greenlee, Qingzhong Kong, James A. Mastrianni & Wen-Quan Zou
Acta Neuropathologica Communications volume 9, Article number: 158 (2021)
Abstract
Chronic wasting disease (CWD) is a cervid prion disease caused by the accumulation of an infectious misfolded conformer (PrPSc) of cellular prion protein (PrPC). It has been spreading rapidly in North America and also found in Asia and Europe. Although bovine spongiform encephalopathy (i.e. mad cow disease) is the only animal prion disease known to be zoonotic, the transmissibility of CWD to humans remains uncertain. Here we report the generation of the first CWD-derived infectious human PrPSc by elk CWD PrPSc-seeded conversion of PrPC in normal human brain homogenates using in vitro protein misfolding cyclic amplification (PMCA). Western blotting with human PrP selective antibody confirmed that the PMCA-generated protease-resistant PrPSc was derived from the human PrPC substrate. Two lines of humanized transgenic mice expressing human PrP with either Val or Met at the polymorphic codon 129 developed clinical prion disease following intracerebral inoculation with the PMCA-generated CWD-derived human PrPSc. Diseased mice exhibited distinct PrPSc patterns and neuropathological changes in the brain. Our study, using PMCA and animal bioassays, provides the first evidence that CWD PrPSc can cross the species barrier to convert human PrPC into infectious PrPSc that can produce bona fide prion disease when inoculated into humanized transgenic mice.
Snip...
It is worth noting that the annual number of sporadic CJD (sCJD) cases in the USA has increased, with the total number of suspected and confirmed sCJD cases rising from 284 in 2003 to 511 in 2017 (https://www.cdc.gov/prions/cjd/occurrence-transmission.html). The greatly enhanced CJD surveillance and an aging population in the USA certainly contributed to the observed increase in annual sCJD case numbers in recent years, but the possibility cannot be excluded that some of the increased sCJD prevalence is linked to CWD exposure.
In the present study, using serial protein misfolding cyclic amplification (sPMCA) assay we generate PrPSc by seeding CWD prions in normal human brain homogenates. Importantly, we reveal that two lines of humanized Tg mice expressing human PrP-129VV and 129MM develop prion diseases upon intracerebral inoculation of the abnormal PrP generated by sPMCA. We believe that our study provides the first opportunity to dissect the clinical, pathological and biochemical features of the CWD-derived human prion disease in two lines of humanized Tg mice expressing two major human PrP genotypes, respectively.
***> ''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
***> In conclusion, sensory symptoms and loss of reflexes in Gerstmann-Sträussler-Scheinker syndrome can be explained by neuropathological changes in the spinal cord. We conclude that the sensory symptoms and loss of lower limb reflexes in Gerstmann-Sträussler-Scheinker syndrome is due to pathology in the caudal spinal cord. <***
***> The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology.<***
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <***
***> All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals.<***
***> In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids.'' Scientific opinion on chronic wasting disease (II) <***
''The brain of diseased Tg mice reveals the electrophoretic profile of PrPSc similar to sporadic Creutzfeldt-Jakob disease (sCJD) MM1 or VV2 subtype but different neuropathological patterns.''
''We believe that our study provides the first evidence that CWD PrPSc is able to convert human PrPC into PrPSc in vitro and the CWD-derived human PrPSc mimics atypical sCJD subtypes in humanized Tg mice.''
Published: 26 September 2021
Generation of human chronic wasting disease in transgenic mice
Zerui Wang, Kefeng Qin, Manuel V. Camacho, Ignazio Cali, Jue Yuan, Pingping Shen, Justin Greenlee, Qingzhong Kong, James A. Mastrianni & Wen-Quan Zou
Acta Neuropathologica Communications volume 9, Article number: 158 (2021)
Abstract
Chronic wasting disease (CWD) is a cervid prion disease caused by the accumulation of an infectious misfolded conformer (PrPSc) of cellular prion protein (PrPC). It has been spreading rapidly in North America and also found in Asia and Europe. Although bovine spongiform encephalopathy (i.e. mad cow disease) is the only animal prion disease known to be zoonotic, the transmissibility of CWD to humans remains uncertain. Here we report the generation of the first CWD-derived infectious human PrPSc by elk CWD PrPSc-seeded conversion of PrPC in normal human brain homogenates using in vitro protein misfolding cyclic amplification (PMCA). Western blotting with human PrP selective antibody confirmed that the PMCA-generated protease-resistant PrPSc was derived from the human PrPC substrate. Two lines of humanized transgenic mice expressing human PrP with either Val or Met at the polymorphic codon 129 developed clinical prion disease following intracerebral inoculation with the PMCA-generated CWD-derived human PrPSc. Diseased mice exhibited distinct PrPSc patterns and neuropathological changes in the brain. Our study, using PMCA and animal bioassays, provides the first evidence that CWD PrPSc can cross the species barrier to convert human PrPC into infectious PrPSc that can produce bona fide prion disease when inoculated into humanized transgenic mice.
Snip...
It is worth noting that the annual number of sporadic CJD (sCJD) cases in the USA has increased, with the total number of suspected and confirmed sCJD cases rising from 284 in 2003 to 511 in 2017 (https://www.cdc.gov/prions/cjd/occurrence-transmission.html). The greatly enhanced CJD surveillance and an aging population in the USA certainly contributed to the observed increase in annual sCJD case numbers in recent years, but the possibility cannot be excluded that some of the increased sCJD prevalence is linked to CWD exposure.
In the present study, using serial protein misfolding cyclic amplification (sPMCA) assay we generate PrPSc by seeding CWD prions in normal human brain homogenates. Importantly, we reveal that two lines of humanized Tg mice expressing human PrP-129VV and 129MM develop prion diseases upon intracerebral inoculation of the abnormal PrP generated by sPMCA. We believe that our study provides the first opportunity to dissect the clinical, pathological and biochemical features of the CWD-derived human prion disease in two lines of humanized Tg mice expressing two major human PrP genotypes, respectively.
i thought i might share some news about cwd zoonosis that i got, that i cannot share or post to the public yet, i promised for various reasons, one that it will cause a shit storm for sure, but it was something i really already knew from previous studies, but, i was told that ;
==================
''As you can imagine, 2 and 5 (especially 5) may raise alarms. The evidence we have for 4 are not as strong or tight as I would like to have. At this point, please do not post any of the points publicly yet, but you can refer to points 1-3 in private discussions and all 5 points when discussing with relevant public officials to highlight the long-term risks of CWD zoonosis.''
====================
so, i figure your as about as official as it gets, and i think this science is extremely important for you to know and to converse about with your officials. it's about to burn a whole in my pocket. this is about as close as it will ever get for cwd zoonosis to be proven in my time, this and what Canada Czub et al found with the Macaques, plus an old study from cjd surveillance unit back that showed cjd and a 9% increase in risk from folks that eat venison, i will post all this below for your files Sir. i remember back in the BSE nvCJD days, from when the first BSE case in bovine was confirmed around 1984 maybe 83, i forget the good vets named that screwed it up first, Carol something, but from 83ish to 95 96 when nvCJD was linked to humans from BSE in cattle, so that took 10 to 15 years. hell, at that rate, especially with Texas and cwd zoonsis, hell, i'll be dead before it's official, if ever, so here ya go Sir. there was a grant study on cwd zoonosis that had been going on for some time, i followed it over the years, then the grant date for said study had expired, so, i thought i would write the good Professor about said study i.e. Professor Kong, CWRU et al. i will post the grant study abstract first, and then after that, what reply i got back, about said study that i was told not to post/publish...
CWD ZOONOSIS GRANT FIRST;
===============
Cervid to human prion transmission
Kong, Qingzhong
Case Western Reserve University, Cleveland, OH, United States
Abstract Prion disease is transmissible and invariably fatal. Chronic wasting disease (CWD) is the prion disease affecting deer, elk and moose, and it is a widespread and expanding epidemic affecting 22 US States and 2 Canadian provinces so far. CWD poses the most serious zoonotic prion transmission risks in North America because of huge venison consumption (>6 million deer/elk hunted and consumed annually in the USA alone), significant prion infectivity in muscles and other tissues/fluids from CWD-affected cervids, and usually high levels of individual exposure to CWD resulting from consumption of the affected animal among often just family and friends. However, we still do not know whether CWD prions can infect humans in the brain or peripheral tissues or whether clinical/asymptomatic CWD zoonosis has already occurred, and we have no essays to reliably detect CWD infection in humans. We hypothesize that: (1) The classic CWD prion strain can infect humans at low levels in the brain and peripheral lymphoid tissues; (2) The cervid-to-human transmission barrier is dependent on the cervid prion strain and influenced by the host (human) prion protein (PrP) primary sequence; (3) Reliable essays can be established to detect CWD infection in humans; and (4) CWD transmission to humans has already occurred. We will test these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in vitro approaches.
Aim 1 will prove that the classical CWD strain may infect humans in brain or peripheral lymphoid tissues at low levels by conducting systemic bioassays in a set of humanized Tg mouse lines expressing common human PrP variants using a number of CWD isolates at varying doses and routes. Experimental human CWD samples will also be generated for Aim 3.
Aim 2 will test the hypothesis that the cervid-to-human prion transmission barrier is dependent on prion strain and influenced by the host (human) PrP sequence by examining and comparing the transmission efficiency and phenotypes of several atypical/unusual CWD isolates/strains as well as a few prion strains from other species that have adapted to cervid PrP sequence, utilizing the same panel of humanized Tg mouse lines as in Aim 1.
Aim 3 will establish reliable essays for detection and surveillance of CWD infection in humans by examining in details the clinical, pathological, biochemical and in vitro seeding properties of existing and future experimental human CWD samples generated from Aims 1-2 and compare them with those of common sporadic human Creutzfeldt-Jakob disease (sCJD) prions.
Aim 4 will attempt to detect clinical CWD-affected human cases by examining a significant number of brain samples from prion-affected human subjects in the USA and Canada who have consumed venison from CWD-endemic areas utilizing the criteria and essays established in Aim 3. The findings from this proposal will greatly advance our understandings on the potential and characteristics of cervid prion transmission in humans, establish reliable essays for CWD zoonosis and potentially discover the first case(s) of CWD infection in humans.
Public Health Relevance There are significant and increasing human exposure to cervid prions because chronic wasting disease (CWD, a widespread and highly infectious prion disease among deer and elk in North America) continues spreading and consumption of venison remains popular, but our understanding on cervid-to-human prion transmission is still very limited, raising public health concerns. This proposal aims to define the zoonotic risks of cervid prions and set up and apply essays to detect CWD zoonosis using mouse models and in vitro methods. The findings will greatly expand our knowledge on the potentials and characteristics of cervid prion transmission in humans, establish reliable essays for such infections and may discover the first case(s) of CWD infection in humans.
Funding Agency Agency National Institute of Health (NIH) Institute National Institute of Neurological Disorders and Stroke (NINDS) Type Research Project (R01) Project # 1R01NS088604-01A1 Application # 9037884 Study Section Cellular and Molecular Biology of Neurodegeneration Study Section (CMND) Program Officer Wong, May Project Start 2015-09-30 Project End 2019-07-31 Budget Start 2015-09-30 Budget End 2016-07-31 Support Year 1 Fiscal Year 2015 Total Cost $337,507 Indirect Cost $118,756
snip...
Professor Kongs reply to me just this month about above grant study that has NOT been published in peer reveiw yet...
=================================
Here is a brief summary of our findings:
snip...can't post, made a promise...tss
On Sat, Apr 3, 2021 at 12:19 PM Terry Singeltary <flounder9@verizon.net> wrote:
snip...
end...tss
==============
CWD ZOONOSIS THE FULL MONTY TO DATE
International Conference on Emerging Diseases, Outbreaks & Case Studies & 16th Annual Meeting on Influenza March 28-29, 2018 | Orlando, USA
Qingzhong Kong
Case Western Reserve University School of Medicine, USA
Zoonotic potential of chronic wasting disease prions from cervids
Chronic wasting disease (CWD) is the prion disease in cervids (mule deer, white-tailed deer, American elk, moose, and reindeer). It has become an epidemic in North America, and it has been detected in the Europe (Norway) since 2016. The widespread CWD and popular hunting and consumption of cervid meat and other products raise serious public health concerns, but questions remain on human susceptibility to CWD prions, especially on the potential difference in zoonotic potential among the various CWD prion strains. We have been working to address this critical question for well over a decade. We used CWD samples from various cervid species to inoculate transgenic mice expressing human or elk prion protein (PrP). We found infectious prions in the spleen or brain in a small fraction of CWD-inoculated transgenic mice expressing human PrP, indicating that humans are not completely resistant to CWD prions; this finding has significant ramifications on the public health impact of CWD prions. The influence of cervid PrP polymorphisms, the prion strain dependence of CWD-to-human transmission barrier, and the characterization of experimental human CWD prions will be discussed.
Speaker Biography Qingzhong Kong has completed his PhD from the University of Massachusetts at Amherst and Post-doctoral studies at Yale University. He is currently an Associate Professor of Pathology, Neurology and Regenerative Medicine. He has published over 50 original research papers in reputable journals (including Science Translational Medicine, JCI, PNAS and Cell Reports) and has been serving as an Editorial Board Member on seven scientific journals. He has multiple research interests, including public health risks of animal prions (CWD of cervids and atypical BSE of cattle), animal modeling of human prion diseases, mechanisms of prion replication and pathogenesis, etiology of sporadic Creutzfeldt-Jacob disease (CJD) in humans, normal cellular PrP in the biology and pathology of multiple brain and peripheral diseases, proteins responsible for the α-cleavage of cellular PrP, as well as gene therapy and DNA vaccination.
SUNDAY, JULY 25, 2021
North American and Norwegian Chronic Wasting Disease prions exhibit different potential for interspecies transmission and zoonotic risk
''Our data suggest that reindeer and red deer from Norway could be the most transmissible CWD prions to other mammals, whereas North American CWD prions were more prone to generate human prions in vitro.''
MONDAY, JULY 19, 2021
***> U Calgary researchers at work on a vaccine against a fatal infectious disease affecting deer and potentially people
Prion Conference 2018 Abstracts
BSE aka MAD COW DISEASE, was first discovered in 1984, and it took until 1995 to finally admit that BSE was causing nvCJD, the rest there is history, but that science is still evolving i.e. science now shows that indeed atypical L-type BSE, atypical Nor-98 Scrapie, and typical Scrapie are all zoonosis, zoonotic for humans, there from.
HOW long are we going to wait for Chronic Wasting Disease, CWD TSE Prion of Cervid, and zoonosis, zoonotic tranmission to humans there from?
Studies have shown since 1994 that humans are susceptible to CWD TSE Prion, so, what's the hold up with making CWD a zoonotic zoonosis disease, the iatrogenic transmissions there from is not waiting for someone to make a decision.
Prion Conference 2018 Abstracts
P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States
Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1)
(1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.
Background
Chronic wasting disease (CWD) is a prion disease of deer and elk that has been identified in freeranging cervids in 23 US states. While there is currently no epidemiological evidence for zoonotic transmission through the consumption of contaminated venison, studies suggest the CWD agent can cross the species barrier in experimental models designed to closely mimic humans. We compared rates of human prion disease in states with and without CWD to examine the possibility of undetermined zoonotic transmission.
Methods
Death records from the National Center for Health Statistics, case records from the National Prion Disease Pathology Surveillance Center, and additional state case reports were combined to create a database of human prion disease cases from 2003-2015. Identification of CWD in each state was determined through reports of positive CWD tests by state wildlife agencies. Age- and race-adjusted mortality rates for human prion disease, excluding cases with known etiology, were determined for four categories of states based on CWD occurrence: highly endemic (>16 counties with CWD identified in free-ranging cervids); moderately endemic (3-10 counties with CWD); low endemic (1-2 counties with CWD); and no CWD states. States were counted as having no CWD until the year CWD was first identified. Analyses stratified by age, sex, and time period were also conducted to focus on subgroups for which zoonotic transmission would be more likely to be detected: cases <55 years old, male sex, and the latter half of the study (2010-2015).
Results
Highly endemic states had a higher rate of prion disease mortality compared to non-CWD states (rate ratio [RR]: 1.12, 95% confidence interval [CI] = 1.01 - 1.23), as did low endemic states (RR: 1.15, 95% CI = 1.04 - 1.27). Moderately endemic states did not have an elevated mortality rate (RR: 1.05, 95% CI = 0.93 - 1.17). In age-stratified analyses, prion disease mortality rates among the <55 year old population were elevated for moderately endemic states (RR: 1.57, 95% CI = 1.10 – 2.24) while mortality rates were elevated among those ≥55 for highly endemic states (RR: 1.13, 95% CI = 1.02 - 1.26) and low endemic states (RR: 1.16, 95% CI = 1.04 - 1.29). In other stratified analyses, prion disease mortality rates for males were only elevated for low endemic states (RR: 1.27, 95% CI = 1.10 - 1.48), and none of the categories of CWD-endemic states had elevated mortality rates for the latter time period (2010-2015).
Conclusions
While higher prion disease mortality rates in certain categories of states with CWD in free-ranging cervids were noted, additional stratified analyses did not reveal markedly elevated rates for potentially sensitive subgroups that would be suggestive of zoonotic transmission. Unknown confounding factors or other biases may explain state-by-state differences in prion disease mortality.
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P172 Peripheral Neuropathy in Patients with Prion Disease
Wang H(1), Cohen M(1), Appleby BS(1,2)
(1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio.
Prion disease is a fatal progressive neurodegenerative disease due to deposition of an abnormal protease-resistant isoform of prion protein. Typical symptoms include rapidly progressive dementia, myoclonus, visual disturbance and hallucinations. Interestingly, in patients with prion disease, the abnormal protein canould also be found in the peripheral nervous system. Case reports of prion deposition in peripheral nerves have been reported. Peripheral nerve involvement is thought to be uncommon; however, little is known about the exact prevalence and features of peripheral neuropathy in patients with prion disease.
We reviewed autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017. We collected information regarding prion protein diagnosis, demographics, comorbidities, clinical symptoms, physical exam, neuropathology, molecular subtype, genetics lab, brain MRI, image and EMG reports. Our study included 104 patients. Thirteen (12.5%) patients had either subjective symptoms or objective signs of peripheral neuropathy. Among these 13 patients, 3 had other known potential etiologies of peripheral neuropathy such as vitamin B12 deficiency or prior chemotherapy. Among 10 patients that had no other clear etiology, 3 (30%) had familial CJD. The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%). The Majority of cases wasere male (60%). Half of them had exposure to wild game. The most common subjective symptoms were tingling and/or numbness of distal extremities. The most common objective finding was diminished vibratory sensation in the feet. Half of them had an EMG with the findings ranging from fasciculations to axonal polyneuropathy or demyelinating polyneuropathy.
Our study provides an overview of the pattern of peripheral neuropathy in patients with prion disease. Among patients with peripheral neuropathy symptoms or signs, majority has polyneuropathy. It is important to document the baseline frequency of peripheral neuropathy in prion diseases as these symptoms may become important when conducting surveillance for potential novel zoonotic prion diseases.
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P177 PrP plaques in methionine homozygous Creutzfeldt-Jakob disease patients as a potential marker of iatrogenic transmission
Abrams JY (1), Schonberger LB (1), Cali I (2), Cohen Y (2), Blevins JE (2), Maddox RA (1), Belay ED (1), Appleby BS (2), Cohen ML (2)
(1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.
Background
Sporadic Creutzfeldt-Jakob disease (CJD) is widely believed to originate from de novo spontaneous conversion of normal prion protein (PrP) to its pathogenic form, but concern remains that some reported sporadic CJD cases may actually be caused by disease transmission via iatrogenic processes. For cases with methionine homozygosity (CJD-MM) at codon 129 of the PRNP gene, recent research has pointed to plaque-like PrP deposition as a potential marker of iatrogenic transmission for a subset of cases. This phenotype is theorized to originate from specific iatrogenic source CJD types that comprise roughly a quarter of known CJD cases.
Methods
We reviewed scientific literature for studies which described PrP plaques among CJD patients with known epidemiological links to iatrogenic transmission (receipt of cadaveric human grown hormone or dura mater), as well as in cases of reported sporadic CJD. The presence and description of plaques, along with CJD classification type and other contextual factors, were used to summarize the current evidence regarding plaques as a potential marker of iatrogenic transmission. In addition, 523 cases of reported sporadic CJD cases in the US from January 2013 through September 2017 were assessed for presence of PrP plaques.
Results
We identified four studies describing 52 total cases of CJD-MM among either dura mater recipients or growth hormone recipients, of which 30 were identified as having PrP plaques. While sporadic cases were not generally described as having plaques, we did identify case reports which described plaques among sporadic MM2 cases as well as case reports of plaques exclusively in white matter among sporadic MM1 cases. Among the 523 reported sporadic CJD cases, 0 of 366 MM1 cases had plaques, 2 of 48 MM2 cases had kuru plaques, and 4 of 109 MM1+2 cases had either kuru plaques or both kuru and florid plaques. Medical chart review of the six reported sporadic CJD cases with plaques did not reveal clinical histories suggestive of potential iatrogenic transmission.
Conclusions
PrP plaques occur much more frequently for iatrogenic CJD-MM cases compared to sporadic CJDMM cases. Plaques may indicate iatrogenic transmission for CJD-MM cases without a type 2 Western blot fragment. The study results suggest the absence of significant misclassifications of iatrogenic CJD as sporadic. To our knowledge, this study is the first to describe grey matter kuru plaques in apparently sporadic CJD-MM patients with a type 2 Western blot fragment.
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P180 Clinico-pathological analysis of human prion diseases in a brain bank series
Ximelis T (1), Aldecoa I (1,2), Molina-Porcel L (1,3), Grau-Rivera O (4), Ferrer I (5), Nos C (6), Gelpi E (1,7), Sánchez-Valle R (1,4)
(1) Neurological Tissue Bank of the Biobanc-Hospital ClÃnic-IDIBAPS, Barcelona, Spain (2) Pathological Service of Hospital ClÃnic de Barcelona, Barcelona, Spain (3) EAIA Trastorns Cognitius, Centre Emili Mira, Parc de Salut Mar, Barcelona, Spain (4) Department of Neurology of Hospital ClÃnic de Barcelona, Barcelona, Spain (5) Institute of Neuropathology, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Barcelona (6) General subdirectorate of Surveillance and Response to Emergencies in Public Health, Department of Public Health in Catalonia, Barcelona, Spain (7) Institute of Neurology, Medical University of Vienna, Vienna, Austria.
Background and objective:
The Neurological Tissue Bank (NTB) of the Hospital Clínic-Institut d‘Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain is the reference center in Catalonia for the neuropathological study of prion diseases in the region since 2001. The aim of this study is to analyse the characteristics of the confirmed prion diseases registered at the NTB during the last 15 years.
Methods:
We reviewed retrospectively all neuropathologically confirmed cases registered during the period January 2001 to December 2016.
Results:
176 cases (54,3% female, mean age: 67,5 years and age range: 25-86 years) of neuropathological confirmed prion diseases have been studied at the NTB. 152 cases corresponded to sporadic Creutzfeldt-Jakob disease (sCJD), 10 to genetic CJD, 10 to Fatal Familial Insomnia, 2 to GerstmannSträussler-Scheinker disease, and 2 cases to variably protease-sensitive prionopathy (VPSPr). Within sCJD subtypes the MM1 subtype was the most frequent, followed by the VV2 histotype.
Clinical and neuropathological diagnoses agreed in 166 cases (94%). The clinical diagnosis was not accurate in 10 patients with definite prion disease: 1 had a clinical diagnosis of Fronto-temporal dementia (FTD), 1 Niemann-Pick‘s disease, 1 Lewy Body‘s Disease, 2 Alzheimer‘s disease, 1 Cortico-basal syndrome and 2 undetermined dementia. Among patients with VPSPr, 1 had a clinical diagnosis of Amyotrophic lateral sclerosis (ALS) and the other one with FTD.
Concomitant pathologies are frequent in older age groups, mainly AD neuropathological changes were observed in these subjects.
Discussion:
A wide spectrum of human prion diseases have been identified in the NTB being the relative frequencies and main characteristics like other published series. There is a high rate of agreement between clinical and neuropathological diagnoses with prion diseases. These findings show the importance that public health has given to prion diseases during the past 15 years. Continuous surveillance of human prion disease allows identification of new emerging phenotypes. Brain tissue samples from these donors are available to the scientific community. For more information please visit:
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P192 Prion amplification techniques for the rapid evaluation of surface decontamination procedures
Bruyere-Ostells L (1), Mayran C (1), Belondrade M (1), Boublik Y (2), Haïk S (3), Fournier-Wirth C (1), Nicot S (1), Bougard D (1)
(1) Pathogenesis and control of chronic infections, Etablissement Français du Sang, Inserm, Université de Montpellier, Montpellier, France. (2) Centre de Recherche en Biologie cellulaire de Montpellier, CNRS, Université de Montpellier, Montpellier, France. (3) Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.
Aims:
Transmissible Spongiform Encephalopathies (TSE) or prion diseases are a group of incurable and always fatal neurodegenerative disorders including Creutzfeldt-Jakob diseases (CJD) in humans. These pathologies include sporadic (sCJD), genetic and acquired (variant CJD) forms. By the past, sCJD and vCJD were transmitted by different prion contaminated biological materials to patients resulting in more than 400 iatrogenic cases (iCJD). The atypical nature and the biochemical properties of the infectious agent, formed by abnormal prion protein or PrPTSE, make it particularly resistant to conventional decontamination procedures. In addition, PrPTSE is widely distributed throughout the organism before clinical onset in vCJD and can also be detected in some peripheral tissues in sporadic CJD. Risk of iatrogenic transmission of CJD by contaminated medical device remains thus a concern for healthcare facilities. Bioassay is the gold standard method to evaluate the efficacy of prion decontamination procedures but is time-consuming and expensive. Here, we propose to compare in vitro prion amplification techniques: Protein Misfolding Cyclic Amplification (PMCA) and Real-Time Quaking Induced Conversion (RT-QuIC) for the detection of residual prions on surface after decontamination.
Methods:
Stainless steel wires, by mimicking the surface of surgical instruments, were proposed as a carrier model of prions for inactivation studies. To determine the sensitivity of the two amplification techniques on wires (Surf-PMCA and Surf-QuIC), steel wires were therefore contaminated with serial dilutions of brain homogenates (BH) from a 263k infected hamster and from a patient with sCJD (MM1 subtype). We then compared the different standard decontamination procedures including partially and fully efficient treatments by detecting the residual seeding activity on 263K and sCJD contaminated wires. We completed our study by the evaluation of marketed reagents endorsed for prion decontamination.
Results:
The two amplification techniques can detect minute quantities of PrPTSE adsorbed onto a single wire. 8/8 wires contaminated with a 10-6 dilution of 263k BH and 1/6 with the 10-8 dilution are positive with Surf-PMCA. Similar performances were obtained with Surf-QuIC on 263K: 10/16 wires contaminated with 10-6 dilution and 1/8 wires contaminated with 10-8 dilution are positive. Regarding the human sCJD-MM1 prion, Surf-QuIC allows us to detect 16/16 wires contaminated with 10-6 dilutions and 14/16 with 10-7 . Results obtained after decontamination treatments are very similar between 263K and sCJD prions. Efficiency of marketed treatments to remove prions is lower than expected.
Conclusions:
Surf-PMCA and Surf-QuIC are very sensitive methods for the detection of prions on wires and could be applied to prion decontamination studies for rapid evaluation of new treatments. Sodium hypochlorite is the only product to efficiently remove seeding activity of both 263K and sCJD prions.
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WA2 Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice
Schatzl HM (1, 2), Hannaoui S (1, 2), Cheng Y-C (1, 2), Gilch S (1, 2), Beekes M (3), SchulzSchaeffer W (4), Stahl-Hennig C (5) and Czub S (2, 6)
(1) University of Calgary, Calgary Prion Research Unit, Calgary, Canada (2) University of Calgary, Faculty of Veterinary Medicine, Calgary, Canada, (3) Robert Koch Institute, Berlin, Germany, (4) University of Homburg/Saar, Homburg, Germany, (5) German Primate Center, Goettingen, Germany, (6) Canadian Food Inspection Agency (CFIA), Lethbridge, Canada.
To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years. After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were found in spinal cord and brain of euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and preclinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles. Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate. The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology. Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP. The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.
See also poster P103
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.
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WA16 Monitoring Potential CWD Transmission to Humans
Belay ED
Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA.
The spread of chronic wasting disease (CWD) in animals has raised concerns about increasing human exposure to the CWD agent via hunting and venison consumption, potentially facilitating CWD transmission to humans. Several studies have explored this possibility, including limited epidemiologic studies, in vitro experiments, and laboratory studies using various types of animal models. Most human exposures to the CWD agent in the United States would be expected to occur in association with deer and elk hunting in CWD-endemic areas. The Centers for Disease Control and Prevention (CDC) collaborated with state health departments in Colorado, Wisconsin, and Wyoming to identify persons at risk of CWD exposure and to monitor their vital status over time. Databases were established of persons who hunted in Colorado and Wyoming and those who reported consumption of venison from deer that later tested positive in Wisconsin. Information from the databases is periodically cross-checked with mortality data to determine the vital status and causes of death for deceased persons. Long-term follow-up of these hunters is needed to assess their risk of development of a prion disease linked to CWD exposure.
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P166 Characterization of CJD strain profiles in venison consumers and non-consumers from Alberta and Saskatchewan
Stephanie Booth (1,2), Lise Lamoureux (1), Debra Sorensen (1), Jennifer L. Myskiw (1,2), Megan Klassen (1,2), Michael Coulthart (3), Valerie Sim (4)
(1) Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg (2) Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg (3) Canadian CJD Surveillance System, Public Health Agency of Canada, Ottawa (4) Division of Neurology, Department of Medicine Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton.
Chronic wasting disease (CWD) is spreading rapidly through wild cervid populations in the Canadian provinces of Alberta and Saskatchewan. While this has implications for tourism and hunting, there is also concern over possible zoonotic transmission to humans who eat venison from infected deer. Whilst there is no evidence of any human cases of CWD to date, the Canadian CJD Surveillance System (CJDSS) in Canada is staying vigilant. When variant CJD occurred following exposure to BSE, the unique biochemical fingerprint of the pathologic PrP enabled a causal link to be confirmed. However, we cannot be sure what phenotype human CWD prions would present with, or indeed, whether this would be distinct from that see in sporadic CJD. Therefore we are undertaking a systematic analysis of the molecular diversity of CJD cases of individuals who resided in Alberta and Saskatchewan at their time of death comparing venison consumers and non-consumers, using a variety of clinical, imaging, pathological and biochemical markers. Our initial objective is to develop novel biochemical methodologies that will extend the baseline glycoform and genetic polymorphism typing that is already completed by the CJDSS. Firstly, we are reviewing MRI, EEG and pathology information from over 40 cases of CJD to select clinically affected areas for further investigation. Biochemical analysis will include assessment of the levels of protease sensitive and resistant prion protein, glycoform typing using 2D gel electrophoresis, testing seeding capabilities and kinetics of aggregation by quaking-induced conversion, and determining prion oligomer size distributions with asymmetric flow field fractionation with in-line light scattering. Progress and preliminary data will be presented. Ultimately, we intend to further define the relationship between PrP structure and disease phenotype and establish a baseline for the identification of future atypical CJD cases that may arise as a result of exposure to CWD.
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Source Prion Conference 2018 Abstracts
Volume 24, Number 8—August 2018 Research Susceptibility of Human Prion Protein to Conversion by Chronic Wasting Disease Prions
Marcelo A. BarriaComments to Author , Adriana Libori, Gordon Mitchell, and Mark W. Head Author affiliations: National CJD Research and Surveillance Unit, University of Edinburgh, Edinburgh, Scotland, UK (M.A. Barria, A. Libori, M.W. Head); National and OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada (G. Mitchell)
Abstract Chronic wasting disease (CWD) is a contagious and fatal neurodegenerative disease and a serious animal health issue for deer and elk in North America. The identification of the first cases of CWD among free-ranging reindeer and moose in Europe brings back into focus the unresolved issue of whether CWD can be zoonotic like bovine spongiform encephalopathy. We used a cell-free seeded protein misfolding assay to determine whether CWD prions from elk, white-tailed deer, and reindeer in North America can convert the human prion protein to the disease-associated form. We found that prions can convert, but the efficiency of conversion is affected by polymorphic variation in the cervid and human prion protein genes. In view of the similarity of reindeer, elk, and white-tailed deer in North America to reindeer, red deer, and roe deer, respectively, in Europe, a more comprehensive and thorough assessment of the zoonotic potential of CWD might be warranted.
snip...
Discussion Characterization of the transmission properties of CWD and evaluation of their zoonotic potential are important for public health purposes. Given that CWD affects several members of the family Cervidae, it seems reasonable to consider whether the zoonotic potential of CWD prions could be affected by factors such as CWD strain, cervid species, geographic location, and Prnp–PRNP polymorphic variation. We have previously used an in vitro conversion assay (PMCA) to investigate the susceptibility of the human PrP to conversion to its disease-associated form by several animal prion diseases, including CWD (15,16,22). The sensitivity of our molecular model for the detection of zoonotic conversion depends on the combination of 1) the action of proteinase K to degrade the abundant human PrPC that constitutes the substrate while only N terminally truncating any human PrPres produced and 2) the presence of the 3F4 epitope on human but not cervid PrP. In effect, this degree of sensitivity means that any human PrPres formed during the PMCA reaction can be detected down to the limit of Western blot sensitivity. In contrast, if other antibodies that detect both cervid and human PrP are used, such as 6H4, then newly formed human PrPres must be detected as a measurable increase in PrPres over the amount remaining in the reaction product from the cervid seed. Although best known for the efficient amplification of prions in research and diagnostic contexts, the variation of the PMCA method employed in our study is optimized for the definitive detection of zoonotic reaction products of inherently inefficient conversion reactions conducted across species barriers. By using this system, we previously made and reported the novel observation that elk CWD prions could convert human PrPC from human brain and could also convert recombinant human PrPC expressed in transgenic mice and eukaryotic cell cultures (15).
A previous publication suggested that mule deer PrPSc was unable to convert humanized transgenic substrate in PMCA assays (23) and required a further step of in vitro conditioning in deer substrate PMCA before it was able to cross the deer–human molecular barrier (24). However, prions from other species, such as elk (15) and reindeer affected by CWD, appear to be compatible with the human protein in a single round of amplification (as shown in our study). These observations suggest that different deer species affected by CWD could present differing degrees of the olecular compatibility with the normal form of human PrP.
The contribution of the polymorphism at codon 129 of the human PrP gene has been extensively studied and is recognized as a risk factor for Creutzfeldt-Jakob disease (4). In cervids, the equivalent codon corresponds to the position 132 encoding methionine or leucine. This polymorphism in the elk gene has been shown to play an important role in CWD susceptibility (25,26). We have investigated the effect of this cervid Prnp polymorphism on the conversion of the humanized transgenic substrate according to the variation in the equivalent PRNP codon 129 polymorphism. Interestingly, only the homologs methionine homozygous seed–substrate reactions could readily convert the human PrP, whereas the heterozygous elk PrPSc was unable to do so, even though comparable amounts of PrPres were used to seed the reaction. In addition, we observed only low levels of human PrPres formation in the reactions seeded with the homozygous methionine (132 MM) and the heterozygous (132 ML) seeds incubated with the other 2 human polymorphic substrates (129 MV and 129 VV). The presence of the amino acid leucine at position 132 of the elk Prnp gene has been attributed to a lower degree of prion conversion compared with methionine on the basis of experiments in mice made transgenic for these polymorphic variants (26). Considering the differences observed for the amplification of the homozygous human methionine substrate by the 2 polymorphic elk seeds (MM and ML), reappraisal of the susceptibility of human PrPC by the full range of cervid polymorphic variants affected by CWD would be warranted.
In light of the recent identification of the first cases of CWD in Europe in a free-ranging reindeer (R. tarandus) in Norway (2), we also decided to evaluate the in vitro conversion potential of CWD in 2 experimentally infected reindeer (18). Formation of human PrPres was readily detectable after a single round of PMCA, and in all 3 humanized polymorphic substrates (MM, MV, and VV). This finding suggests that CWD prions from reindeer could be more compatible with human PrPC generally and might therefore present a greater risk for zoonosis than, for example, CWD prions from white-tailed deer. A more comprehensive comparison of CWD in the affected species, coupled with the polymorphic variations in the human and deer PRNP–Prnp genes, in vivo and in vitro, will be required before firm conclusions can be drawn. Analysis of the Prnp sequence of the CWD reindeer in Norway was reported to be identical to the specimens used in our study (2). This finding raises the possibility of a direct comparison of zoonotic potential between CWD acquired in the wild and that produced in a controlled laboratory setting. (Table).
The prion hypothesis proposes that direct molecular interaction between PrPSc and PrPC is necessary for conversion and prion replication. Accordingly, polymorphic variants of the PrP of host and agent might play a role in determining compatibility and potential zoonotic risk. In this study, we have examined the capacity of the human PrPC to support in vitro conversion by elk, white-tailed deer, and reindeer CWD PrPSc. Our data confirm that elk CWD prions can convert the human PrPC, at least in vitro, and show that the homologous PRNP polymorphisms at codon 129 and 132 in humans and cervids affect conversion efficiency. Other species affected by CWD, particularly caribou or reindeer, also seem able to convert the human PrP. It will be important to determine whether other polymorphic variants found in other CWD-affected Cervidae or perhaps other factors (17) exert similar effects on the ability to convert human PrP and thus affect their zoonotic potential.
Dr. Barria is a research scientist working at the National CJD Research and Surveillance Unit, University of Edinburgh. His research has focused on understanding the molecular basis of a group of fatal neurologic disorders called prion diseases.
Acknowledgments We thank Aru Balachandran for originally providing cervid brain tissues, Abigail Diack and Jean Manson for providing mouse brain tissue, and James Ironside for his critical reading of the manuscript at an early stage.
This report is independent research commissioned and funded by the United Kingdom’s Department of Health Policy Research Programme and the Government of Scotland. The views expressed in this publication are those of the authors and not necessarily those of the Department of Health or the Government of Scotland.
Author contributions: The study was conceived and designed by M.A.B. and M.W.H. The experiments were conducted by M.A.B. and A.L. Chronic wasting disease brain specimens were provided by G.M. The manuscript was written by M.A.B. and M.W.H. All authors contributed to the editing and revision of the manuscript.
Prion 2017 Conference Abstracts
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1
University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen
This is a progress report of a project which started in 2009.
21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves.
Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice.
At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS ABSTRACTS REFERENCE
8. Even though human TSE‐exposure risk through consumption of game from European cervids can be assumed to be minor, if at all existing, no final conclusion can be drawn due to the overall lack of scientific data. In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids. It might be prudent considering appropriate measures to reduce such a risk, e.g. excluding tissues such as CNS and lymphoid tissues from the human food chain, which would greatly reduce any potential risk for consumers. However, it is stressed that currently, no data regarding a risk of TSE infections from cervid products are available.
SATURDAY, FEBRUARY 23, 2019
Chronic Wasting Disease CWD TSE Prion and THE FEAST 2003 CDC an updated review of the science 2019
TUESDAY, NOVEMBER 04, 2014
Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: risk behaviours and health outcomes 2005–2011
Authors, though, acknowledged the study was limited in geography and sample size and so it couldn't draw a conclusion about the risk to humans. They recommended more study. Dr. Ermias Belay was the report's principal author but he said New York and Oneida County officials are following the proper course by not launching a study. "There's really nothing to monitor presently. No one's sick," Belay said, noting the disease's incubation period in deer and elk is measured in years. "
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases {the following was written but with a single line marked through it ''first passage (by this route)}....TSS
resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculum (?saline). Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in ALL of these species with the shortest incubation period in the ferret.
snip....
Prion Infectivity in Fat of Deer with Chronic Wasting Disease▿
Brent Race#, Kimberly Meade-White#, Richard Race and Bruce Chesebro* + Author Affiliations
In mice, prion infectivity was recently detected in fat. Since ruminant fat is consumed by humans and fed to animals, we determined infectivity titers in fat from two CWD-infected deer. Deer fat devoid of muscle contained low levels of CWD infectivity and might be a risk factor for prion infection of other species.
Prions in Skeletal Muscles of Deer with Chronic Wasting Disease
Here bioassays in transgenic mice expressing cervid prion protein revealed the presence of infectious prions in skeletal muscles of CWD-infected deer, demonstrating that humans consuming or handling meat from CWD-infected deer are at risk to prion exposure.
*** now, let’s see what the authors said about this casual link, personal communications years ago, and then the latest on the zoonotic potential from CWD to humans from the TOKYO PRION 2016 CONFERENCE.
see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ???? “Our conclusion stating that we found no strong evidence of CWD transmission to humans”
From: TSS
Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam,
In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091). Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
-----Original Message-----
From: Sent: Sunday, September 29, 2002 10:15 AM
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
Thursday, April 03, 2008
A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008 Apr 3;39(4):41 A prion disease of cervids: Chronic wasting disease Sigurdson CJ.
snip...
*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,
snip... full text ;
> However, to date, no CWD infections have been reported in people.
sporadic, spontaneous CJD, 85%+ of all human TSE, did not just happen. never in scientific literature has this been proven.
if one looks up the word sporadic or spontaneous at pubmed, you will get a laundry list of disease that are classified in such a way;
sporadic = 54,983 hits https://www.ncbi.nlm.nih.gov/pubmed/?term=sporadic
spontaneous = 325,650 hits https://www.ncbi.nlm.nih.gov/pubmed/?term=spontaneous
key word here is 'reported'. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can't, and it's as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it's being misdiagnosed as sporadic CJD. ...terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
> However, to date, no CWD infections have been reported in people.
key word here is ‘reported’. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can’t, and it’s as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it’s being misdiagnosed as sporadic CJD. …terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
CWD TSE PRION AND ZOONOTIC, ZOONOSIS, POTENTIAL
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ References: <3daf5023 .4080804="" wt.net="">
Dear Terry,
An excellent piece of review as this literature is desparately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported. Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler ===============
''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994
Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss) These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...
Table 9 presents the results of an analysis of these data.
There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).
Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.
There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).
The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).
The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
BSE Inquiry Steve Dealler
Management In Confidence
BSE: Private Submission of Bovine Brain Dealler
snip...see full text;
MONDAY, FEBRUARY 25, 2019
***> MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
FRIDAY, DECEMBER 24, 2021
Creutzfeldt Jakob Disease CJD TSE Prion Update December 25, 2021
MONDAY, JANUARY 31, 2022
Validation of Revised International Creutzfeldt-Jakob Disease Surveillance Network Diagnostic Criteria for Sporadic Creutzfeldt-Jakob Disease Singeltary Comment Submission
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. | 11:50 AM
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