Distribution and Quantitative Estimates of Variant Creutzfeldt-Jakob Disease Prions in Tissues of Clinical and Asymptomatic Patients
Volume 23, Number 6—June 2017
Research
Distribution and Quantitative Estimates of Variant Creutzfeldt-Jakob Disease Prions in Tissues of Clinical and Asymptomatic Patients
Jean Y. Douet, Caroline Lacroux, Naima Aron, Mark W. Head, Séverine Lugan, Cécile Tillier, Alvina Huor, Hervé Cassard, Mark Arnold, Vincent Beringue, James W. Ironside, and Olivier Andréoletti
Comments to Author Author affiliations: Institut National de la Recherche Agronomique, Toulouse, France (J.Y. Douet, C. Lacroux, N. Aron, S. Lugan, C. Tillier, A. Huor, H. Cassard, O. Andréoletti); University of Edinburgh, Edinburgh, Scotland, UK (M.W. Head, J.W. Ironside); Animal and Plant Health Agency, Loughborough, UK (M. Arnold); Institut National de la Recherche Agronomique, Jouy-en-Josas, France (V. Beringue) Suggested citation for this article
Abstract
In the United-Kingdom, ≈1 of 2,000 persons could be infected with variant Creutzfeldt-Jakob disease (vCJD). Therefore, risk of transmission of vCJD by medical procedures remains a major concern for public health authorities. In this study, we used in vitro amplification of prions by protein misfolding cyclic amplification (PMCA) to estimate distribution and level of the vCJD agent in 21 tissues from 4 patients who died of clinical vCJD and from 1 asymptomatic person with vCJD. PMCA identified major levels of vCJD prions in a range of tissues, including liver, salivary gland, kidney, lung, and bone marrow. Bioassays confirmed that the quantitative estimate of levels of vCJD prion accumulation provided by PMCA are indicative of vCJD infectivity levels in tissues. Findings provide critical data for the design of measures to minimize risk for iatrogenic transmission of vCJD.
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Discussion
Most previous studies with tissue from vCJD patients have failed to identify consistent accumulation of the vCJD agent outside the nervous and lymphoreticular systems. However, data obtained in this study clearly demonstrate the presence of vCJD prions in a wide and unexpected variety of peripheral tissues.
Natural scrapie and experimental BSE in sheep are 2 models of orally transmitted prion diseases (24,25). In both diseases, the agent accumulates in the lymphoreticular system and the enteric nervous system during the early preclinical phase of the incubation period. Moreover, an early and persistent prionemia is observed in asymptomatic infected animals (26,27). These features were also observed in vCJD in humans and in view of the likely origin of vCJD (oral exposure to BSE agent), these similarities have led to a consensus that BSE and scrapie in sheep and vCJD in human have a common pathogenesis (28).
Although vCJD prions in a variety tissues, such as bone marrow, kidney, salivary gland, skeletal muscle, pancreas, liver, or heart, might be surprising, each of these tissue has already been demonstrated to accumulate prion infectivity or abnormal prion protein in TSE-infected sheep (29–33). Because low levels of infectivity have been reported in blood fractions from a vCJD-affected patient, such widespread tissue positivity might be derived from residual blood, rather than from the solid tissue in these samples (16). However, this proposal seems unlikely because in whole blood PMCA amplification inhibitors preclude detection of endogenous vCJD agent by this method (11,34–36).
The patient in our study who was infected with a prion containing PRNP gene codon 129 Met/Val is 1 of only 2 identified vCJD agent–infected persons known to have died of other causes before onset clinical symptoms of vCJD, and the only person who provided consent to sample autopsy tissues for research. For this patient, all previous investigations did not detect abnormal prion protein or infectivity in the brain (12,37). The negative PMCA results we obtained for cerebral cortex, dorsal root ganglia, and trigeminal ganglia tissue from this patient are consistent with a lack of central nervous system involvement at the time of death. However, PMCA seeding activity in the pituitary gland was surprising in this instance.
The presence of abnormal prion protein accumulation in the pituitary gland and other circumventricular organs before deposition of PrPres in surrounding brain has been reported in TSE-infected sheep (38). However, this phenomenon in animals does not represent the main route for neuroinvasion and is a probable consequence of hematogenous dissemination of the TSE agent through the fenestrated capillary system of the circumventricular organs, which is substantially more permeable than the other capillaries in the brain (blood–brain barrier). Therefore, this finding might be a consequence of the hematogenous route of secondary vCJD in this person (by transfusion of packed erythrocytes from a vCJD-infected donor), in contrast to the oral route of infection in primary clinical vCJD cases (12).
vCJD prions were detected in certain peripheral tissues from the patients infected with a prion containing the PRNP gene codon 129 Met/Val. Although distribution of vCJD seeding activity in lymphoreticular tissues was similar to that observed for symptomatic vCJD patients, several tissues that were positive in clinically affected patients were negative in this heterozygous asymptomatic person. These findings suggest that involvement of some peripheral tissues might occur at a later stage in the incubation period than others, or that they could involve recirculation of the agent from the central nervous system (i.e., centrifugal spread in a late state). However, we cannot discount the possibility that that these differences in tissue distribution are caused by the hematogenous route of infection in this person (as opposed to the probable oral route in patients with clinical vCJD) or the difference between the PRNP gene codon 129 genotype of the asymptomatic vCJD–affected person (PRNP gene codon 129 Met/Val) and persons with clinical vCJD (PRNP gene codon 129 Met/Met).
Irrespective of the actual explanation for these differences, the presence of vCJD agent in peripheral tissues of patients during preclinical and clinical stage of the disease indicates the potential for iatrogenic transmission of this fatal neurologic condition by surgical procedures. Furthermore, this finding shows that, for certain peripheral tissues, a level of infectivity equivalent to an end stage titer (and attendant risk) is reached at a preclinical stage.
Several hundred cases of iatrogenic CJD have been reported worldwide. These cases appear to result from transmission of sporadic CJD, and most cases have occurred in recipients of human dura mater grafts or after administration of human growth hormone extracted from cadaveric pituitaries (39). Although in sporadic CJD the distribution of the agent is largely restricted to the nervous system (central and peripheral), the wide distribution of the vCJD agent in the asymptomatic infected patient we report might serve to increase the range of medical procedures, including dentistry, organ transplant, and surgery involving nondisposable equipment, that might result in iatrogenic transmission of vCJD (40–43).
Nevertheless, >20 years after identification of the first vCJD patients, only 5 cases that are a probable consequence of iatrogenic vCJD transmission are known, all in the United Kingdom and associated with blood and blood products. These cases were caused by transfusion of non–leukocyte-depleted erythrocyte concentrates or by treatment involving large amounts of pooled plasma from the United Kingdom that were known to include donations from persons who later showed development of vCJD (12,44–46).
None of the 220 other vCJD cases identified worldwide have been linked to any other medical or dental procedure. Whereas this fact is reassuring, it would be unwise to disregard the threat that vCJD still poses for public health. Despite the relatively low number (n = 178) of vCJD clinical cases observed in the United Kingdom, the most recent epidemiologic studies indicate that ≈1 of 2,000 persons in the United Kingdom could be infected with the vCJD agent (as indicated by the presence of abnormal prion protein detected by immunohistochemical analysis of lymphoid follicles in the appendix). Each asymptomatic vCJD-infected person represents a potential source of secondary infection. The data in our report offer an opportunity for refining measures that were implemented in many countries to limit the risk for vCJD iatrogenic transmission. The apparent concordance between PMCA biochemical and infectivity bioassay data, and the higher analytical sensitivity of PMCA, suggest that future research need not rely exclusively on time-consuming and costly animal bioassay.
Our results indicate the need for vCJD screening assays. After more than a decade of effort, several vCJD blood detection tests have reached a stage in their development that could enable their evaluation as screening or confirmatory assays (11,47,48). In particular, there is now a strong case for use of PMCA in a highly sensitive and specific blood test for vCJD, as indicated by our previous studies (11,16) and studies by Bougard et al. (35) and Concha-Marambio et al. (36). The relationship shown here between PrPres amplification by PMCA and detection of infectivity by bioassay indicates that PMCA seeding activity is a good surrogate marker of infectivity and could provide a sound basis for a vCJD blood test for use with blood or tissue donors.
Dr. Douet is a research scientist and assistant lecturer in ophthalmology at the National Veterinary School of Toulouse, Toulouse, France. His primary research interests are the pathogenesis of the prion disease with special emphasis on the iatrogenic risk of transmission.
Acknowledgment
This study was supported in part by the Department of Health Policy Research Programme and the Scottish Government. The National CJD Research and Surveillance Unit is supported by the Policy Research Program of the Department of Health and the Scottish Government (DH121/5061). The Edinburgh Brain Bank is supported by the Medical Research Council (MRC grant G0900580). The Unité Mixte de Recherche 1225, Ecole Nationale Vétérinaire de Toulouse was supported by the European Union FEDER/INTERREG (EFA282/13 TRANSPRION), the Institut National de la Recherche Agronomique Institut Carnot en Santé Animale, and an Agence Nationale Recherche grant (Unmasking Blood Prions; ANR-15-CE18-0028).
Volume 23, Number 6—June 2017 Synopsis
Sporadic Creutzfeldt-Jakob Disease in 2 Plasma Product Recipients, United Kingdom, P. Urwin et al.
View Summary
Two cases of sporadic CJD with clotting disorders have been identified, but this may represent a chance event.
please note next;
In summary, PrPsc was detectable at high levels in organs and tissues of the LRS only in BSE/vCJD infected animals (0.1% to 10% of the amounts found in the brains of the same animals). We interpreted these results as the BSE prion being highly lymphotropic in primates. These findings correlated indeed with the tonsils, spleens and appendices of vCJD patients being found positive for PrPsc18,19,20). We therefore proposed that LRS tissues be considered ‘high-risk’ in vCJD patients only.
However, lower amounts of PrPsc were detected in adrenals, muscles and intestinal tissue of macaques infected with BSE/vCJD as well as sCJD and iCJD, associated with peripheral nerves.
Levels were less than 10,000 times lower than brain PrPres levels (<0 .001="" div="" nbsp="">
*** We therefore proposed that these tissues be considered “low-risk” for all CJD patients.
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Review
Modeling Variant Creutzfeldt-Jakob Disease and Its Pathogenesis in Non-human Primates Corinne Lasmézas1)
1) Scripps Florida, 130 Scripps Way, Jupiter FL 33458, USA
Released 20170330 Received 20170123 Accepted 20170209
Keywords: prions, variant Creutzfeldt-Jakob disease, bovine spongiform encephalopathy, non-human primates, transmission, pathogenesis, blood Full Text PDF [7720K] Corresponding author: Corinne Lasmézas, Scripps Florida, 130 Scripps Way, Jupiter FL 33458, USA (E-mail: lasmezas (at) scripps.edu) The contents of this article reflect solely the view of the author(s).
Conflict of interest statement: The authors had no conflicts of interest to declare in this article.
This paper was presented at the Animal Prion Diseases Workshop “Updated Diagnosis and Epidemiology of Animal Prion Diseases for Food Safety and Security” supported by the OECD Co-operative Research Programme. (See “Food Safety” Vol.4 (2016), No.4, 103-4.)
Abbreviations: BSE: Bovine Spongiform Encephalopathy; CNS: central nervous system; iCJD: iatrogenic Creutzfeldt-Jakob disease; IV: intravenous; LN: lymph nodes; LRS: lymphoreticular system; PrPsc: disease-associated prion protein; RBCs: red blood cells; sCJD: sporadic Creutzfeldt-Jakob disease; TSEs: transmissible spongiform encephalopathies; vCJD: variant Creutzfeldt-Jakob disease
Index
Abstract 1. Transmission of Bovine Spongiform Encephalopathy (BSE) to CynomolgusMacaques Reproduces vCJD: Establishment of a non-human Primate Model for vCJD 1.1. BSE, a New Disease in Cattle 1.2. vCJD in Humans and Transmission of BSE to Non-human Primates 1.3. Determination of the Minimal Infectious BSE Dose in Non-human Primates 1.4. Adaptation of the BSE Agent to Non-human Primates: Consequences for Human Health 2. The Cynomolgus Macaque as a model to Understand the Pathogenesis of Variant Creutzfeldt-Jakob Disease (vCJD) and Model Risk of Interhuman Transmission 2. 1. Distribution of Prions in Tissues and Organs of BSE/vCJD Macaques after Oral or Intravenous (IV) Inoculation 2. 2. Distribution of Prions in Tissues and Organs of vCJD, Sporadic and Iatrogenic CJD Infected Macaques 2.2. Blood Infectivity Studies in the Macaque vCJD Model Acknowledgments References Abstract In the early 90s’, Europe was shaken by the fear that the prions from “mad cow disease” (bovine spongiform encephalopathy) would transmit the disease to humans via beef products. In 1996, the first variant Creutzfeldt-Jakob (vCJD) patients were described, and the same year our Bovine Spongiform Encephalopathy (BSE) transmission studies to cynomolgus macaques demonstrated that the BSE prion was highly infectious for primates, inducing brain lesions identical to those observed in vCJD patients. These studies provided the first experimental evidence that vCJD was BSE in humans. Subsequent studies established the BSE/vCJD-infected cynomolgus macaque as a robust model to study the pathogenesis of vCJD. We showed rapid adaptation of BSE prions to primates upon subsequent passage, and their distribution in peripheral tissues and blood. Some key studies are summarized in the present paper.
Page top 1. Transmission of Bovine Spongiform Encephalopathy (BSE) to CynomolgusMacaques Reproduces vCJD: Establishment of a non-human Primate Model for vCJD 1.1. BSE, a New Disease in Cattle In 1987, a new prion disease affecting dairy cattle was described in the United Kindom1). Affected cows presented signs of aggressiveness, anxiety, ataxia and were finally found recumbent. The disease was rapidly classified in the group of “transmissible spongiform encephalopathies”, or TSEs, due to the transmissibility of the disease2), as well as the similarities of the neuropathological lesions and molecular hallmark with those found in sheep scrapie and human CJD: neuronal death, spongiform changes, and accumulation of misfolded and aggregated prion protein (termed PrPsc)3). PrPsc is the infectious form of the host prion protein PrP. It is also called a prion (for “proteinaceaous infectious particle4)) or TSE agent. The number of affected cows increased rapidly to top at a 37,280 diagnosed animals in the year of 1992 (OIE data). Thankfully, British epidemiologists recognized that BSE was due to the consumption of prion-tainted meat and bone meal (MBM)5), and the first feed-ban was implemented in 1988, prohibiting the feeding of ruminants with ruminant-derived MBM.
1.2. vCJD in Humans and Transmission of BSE to Non-human Primates In 1991, BSE was reported in a domestic cat that presumably was contaminated via pet food6). Transmission of scrapie from small ruminants to cats had never been described, raising concern that BSE might be more pathogenic than scrapie not only for cats, but also for humans. In order to probe the cow-to-primates species barrier of the BSE agent, we inoculated cynomolgus macaques (Macaca fascicularis) with BSE-infected cow brains at the French Atomic Energy Commision (CEA).
In 1996, 10 young individuals were described in the UK and one in France, harboring an unusual form of CJD that was coined variant CJD (vCJD)7,8). Besides patients being exceptionally young (adolescents and young adults, while sporadic CJD (sCJD) affects people over the age of 60), they exhibited unusual symptoms. Early symptoms were dysaesthesia, behavioral symptoms, depression, ataxia, with myoclonus appearing later on, contrasting with the cognitive course of the disease (memory impairment, dementia) preceding motor impairment, which is most frequently observed in sCJD. Moreover, vCJD patients presented specific neuropathological features with spongiosis and neuronal loss most evident in the basal ganglia and thalamus, and the presence of PrP amyloid plaques (abundant in the cerebral cortex and cerebellum) that were surrounded by vacuoles, giving them a flower-like appearance. These peculiar plaques were called florid plaques7).
At the same time as the first vCJD patients were being described, we were examining the brains of our 3 macaques that had all come down with disease 3 years after intracerebral (IC) inoculation with BSE-infected cow brain. Clinical signs were characterized by behavioral signs such as depression or edginess, as well as truncal ataxia (broad-based gait, tremors) and myoclonus. Neuropathological examination of the brains of the BSE-macaques revealed the presence of florid plaques and other neuropathological features similar to those observed in vCJD patients (Fig. 1). Florid plaques were not present in the brains of macaques inoculated with Kuru or sCJD, and thus were considered specific for infection by the BSE prion. Moreover, PrPsc in BSE-infected macaques and vCJD patients exhibited a similar electrophoretic pattern by western blot (Fig. 1).
In summary, macaques infected by BSE reproduced the behavioral and motor symptoms, the neuropathology and the biochemical signature of vCJD in humans. This study provided the first experimental evidence supporting that vCJD was due to human infection by the BSE agent9), and an experimental model to study the new disease.
1.3. Determination of the Minimal Infectious BSE Dose in Non-human Primates
In a concerted European effort involving 5 laboratories including ours, the BSE-macaque model was then used to evaluate the minimal amount of BSE-infected material necessary to induce vCJD in primates. Results so far show that 5g of infectious BSE cattle brain is sufficient to induce the disease in all recipient animals by the oral route, with 500 mg yielding an incomplete attack rate10,11). The ID50 of BSE cattle brain is 200 mg for cattle12). These results suggest a low species barrier between cattle and non-human primates.
1.4. Adaptation of the BSE Agent to Non-human Primates: Consequences for Human Health
The macaque BSE model provided an opportunity to evaluate the possible risk for humans of secondary inter-human transmission of the BSE/vCJD prion. Accidental human-to-human transmissions of sCJD, resulting in iatrogenic CJD (iCJD) has occurred in several unfortunate circumstances (described in ref.13). One of them was the infection of children with CJD-contaminated human growth hormone (hGH) extracted from cadaveric hypophyses. These iCJD patients had been treated for short stature by injection of hGH in childhood, and 226 of them died of iCJD as young adults, mainly in France and the USA13). Other dramatic iCJD cases had been linked to the surgical implantation of dura-mater grafts, resulting in 228 deaths13). A few cases were also due to corneal grafts and intracranial electrodes. Although all known iCJD cases prior to 2004 had been linked to contamination with central nervous system (CNS) tissue, the possibility existed that the BSE agent would harbor a different distribution in primates than the sCJD agent, thus representing a higher risk of transmission via organ/tissue grafts, contamination of surgical instruments or even blood transfusion.
As a first step for risk assessment, we transmitted the BSE prion from macaque to macaque via different routes. We also established a dose-response (incubation time) for the IC route to provide a baseline for subsequent infectivity measurement studies. This experiment showed that the BSE agent adapts rapidly to primates, as incubation periods shortened from 3 to 1.5 years upon secondary passage at the highest dose14). It also showed that, for a given amount of BSE material (40 mg BSE brain homogenate), the incubation period was the same whether inoculation was done by the IC or the intravenous (IV) route.
2. The Cynomolgus Macaque as a model to Understand the Pathogenesis of Variant Creutzfeldt-Jakob Disease (vCJD) and Model Risk of Interhuman Transmission
2. 1. Distribution of Prions in Tissues and Organs of BSE/vCJD Macaques after Oral or Intravenous (IV) Inoculation
We compared second passage macaques inoculated with BSE prions by the oral or IV routes15). PrPsc was detected by immunohistochemistry and by ELISA after “scrapie associated fibril” (SAF) purification15). In addition to the brain, we detected PrPsc in spleen, tonsils, intestine and sciatic nerve in amounts that did not depend on the inoculation route, with the exceptions of the spleen where PrPsc amounts were up to 4% the amounts found in the brain after IV inoculation, and up to 0.2% those of the brain after oral dosing15).
2. 2. Distribution of Prions in Tissues and Organs of vCJD, Sporadic and Iatrogenic CJD Infected Macaques
We also infected macaques with vCJD, sCJD, iCJD16). As determined earlier, BSE and vCJD prions correspond to the same prion strain, and one or the other denomination is used depending on the species of origin for the brain tissue used as inoculum. All prion strains were inoculated in the same manner (intracerebral and intratonsillar combined), in order to be able to directly compare tissue distribution of PrPsc between strains.
Disease-associated PrP deposits were detected by immunocytochemistry in various organs. They were found in the Peyer’s patches of the gut and other lymphoreticular system (LRS) tissue of BSE/vCJD infected animals (Fig. 2). By PET-blot, we showed that these deposits corresponded to proteinase K-resistant PrP, a biochemical subset of PrPsc. Interestingly, not all Peyer’s patches of a single animal were PrPsc positive (Fig. 2), showing that PrPsc-negative LRS tissue biopsies may lead to false negative diagnostic results.
Pathological PrP deposits were also detected in the enteric nervous system in macaques infected with all prion strains. Fig. 3 shows the localization of pathological PrP in the pericarya of neurons of the myenteric plexus, as well as in small nerve fibers of the inner muscular layer of the intestine.
Pathological PrP deposits were also found in peripheral nerves and in muscle for all CJD strains (Table 1). In the peripheral nerves, they were found mostly at the surface of Schwann cells (Fig. 4). In muscle, they were localized to specific foci in the vicinity of nerve fibers (Fig. 5). Our results suggest that the heterogeneous, patchy distribution of pathological PrP deposits in muscles corresponds to the distribution zones of motor end plates. This study provides a possible explanation for the variably positive detection of pathological PrP in muscle samples of sCJD patients17).
PrPsc amounts were also measured semi-quantitatively using a sensitive biochemical detection method including phosphotungstic acid precipitation as a concentration method, and western blot or ELISA detection16). This method revealed the presence of PrPsc in the spleen of the sCJD infected macaque and tonsils of the iCJD infected macaque, but no PrPsc could be detected in lymph nodes and Peyer’s patches of these animals, a result most likely due to the presence of PrPsc amounts at the threshold of detection in the LRS of sCJD and iCJD macaques, and sampling variations. These results are summarized in Table 1.
In summary, PrPsc was detectable at high levels in organs and tissues of the LRS only in BSE/vCJD infected animals (0.1% to 10% of the amounts found in the brains of the same animals). We interpreted these results as the BSE prion being highly lymphotropic in primates. These findings correlated indeed with the tonsils, spleens and appendices of vCJD patients being found positive for PrPsc18,19,20). We therefore proposed that LRS tissues be considered ‘high-risk’ in vCJD patients only.
However, lower amounts of PrPsc were detected in adrenals, muscles and intestinal tissue of macaques infected with BSE/vCJD as well as sCJD and iCJD, associated with peripheral nerves.
Levels were less than 10,000 times lower than brain PrPres levels (<0 .001="" div="" nbsp="">
*** We therefore proposed that these tissues be considered “low-risk” for all CJD patients.
Our results expanded upon observations made in vCJD patients that PrPsc is detectable in tonsils, emphasizing that BSE prions are largely lymphotropic in primates, and may replicate in lymph notes, tonsils, spleen and Peyer’s patches before the symptomatic phase. Our subsequent studies confirmed that lymph node biopsies of BSE-inoculated macaques were positive for PrPsc prior to the onset of clinical signs (see below). In another study, gut-associated lymphoid tissue and gut-draining lymph nodes were found positive for PrPsc within one year of oral infection of macaques with cattle BSE21). On the other hand, distribution of PrPsc in muscle of macaques inoculated with vCJD, sCJD and iCJD suggests a centrifugal spread of prions from the CNS to muscle motor plates via motor nerves, occurring after CNS invasion by prions. In addition, it is probable that centripetal spread of prions via peripheral nerves also occurs in earlier stages of infection stochastically from various points of entry, even in the absence of prior LRS replication. We demonstrated this paradigm earlier in severely immunodeficient (SCID) mice infected with mouse-adapted scrapie22). Moreover, spread from the gut to the CNS via autonomic nerve fibers has been shown in experimental scrapie and BSE23,24,25). Fig. 6 illustrates the distribution and proposed propagation of prions in our non-human primate model.
2.2. Blood Infectivity Studies in the Macaque vCJD Model The lymphotropic properties of BSE prions raised the important question of the presence of infectivity in blood of vCJD patients.
We initiated a large blood transfusion study where whole blood, white blood cells or plasma from either vCJD patients or BSE/vCJD macaques was injected by IV or IC to recipient macaques. This experiment led to most macaques surviving over prolonged periods of time (>10 years), and few coming down with BSE/vCJD or intercurrent illnesses. These studies continued after the author of this manuscript left the CEA. Interim transmission results are shown in Fig. 7, and some important observations were as follows. Blood depleted for red blood cells (RBC) from a vCJD patient (7.5 mL) injected intravenously did not result in any clinical disease in the recipient macaque after 10 years, yet this animal harbored positive IHC staining in the inguinal lymph nodes (LNs). Another macaque, who had received 25 mL of RBC-depleted blood intravenously from another vCJD patient, died suddenly at 42 months after inoculation, and harbored PrPsc positive inguinal LNs. Two other animals, that received 500 µL of buffy coat (BC) from vCJD patients by IC, were still alive 10 years after inoculation (with PrPsc positive LNs, Fig. 7A). A whole blood transfusion of 40 mL from a vCJD macaque (who died 3 years after intracerebral + intratonsillar inoculation of human vCJD brain homogenate) induced clinical signs of vCJD in the recipient macaque 66 months after the transfusion. Inguinal lymph nodes biopsies had been positive since 45 months, i.e. 75% of the incubation period (Fig. 7B). Other macaques transfused with blood from BSE-macaques survived more than 10 years, but some had positive LNs (Fig. 7C). Another notable result was the transmission of BSE infection by the plasma from a macaque that had been dosed orally with cattle BSE 27.5 months earlier. The donor macaque died with a behavioral syndrome of self-injury 117 months after challenge with a diagnosis of probable BSE, hence infectivity was present in its blood at a quarter of the incubation period (Fig. 7D).
In 2004, the first transfusion-related case of vCJD was described in a patient who had been transfused with non-leucoreduced red blood cells from a donor who developed vCJD 3.5 years after the donation26). A total of four transfusion-related vCJD transmissions have been reported to date27).
Acknowledgments
I thank the many people who supported and participated in this work at the CEA: Dominique Dormont, Jean-Philippe Deslys, Christian Herzog, Nathalie Lescoutra, Nicole Salès, Emmanuel Comoy, René Rioux. I also thank Ray Bradley and Michael Dawson for providing BSE-infected cattle brain homogenates. I am thankful to Robert Will and Nicolas Kopp for providing vCJD samples, and to James Ironside for his collaboration on the neuropathology of BSE-infected macaques. I am grateful to my European collaborators Maurizio Pocchiari, Gerhard Hunsmann, Johannes Löwer, Pär Bierke, Loredana Ingrosso, Uwe Hahmann, Dirk Motzkus, Edgar Holznagel, for their friendship and for embarking on this challenging project.
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FRIDAY, APRIL 21, 2017
URGENT GLOBAL UPDATE BLOOD, TISSUE, CJD, nvCJD, GSS, BSE, CWD, SCRAPIE, TSE, PRION
kind regards, terry
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