Clinical features of variant Creutzfeldt-Jakob disease

Altered properties of amyloidogenic prion protein in genetic Creutzfeldt-Jakob disease with PRNP V180I mutation in response to pentosan polysulfate

Genetic Creutzfeldt-Jakob disease (gCJD) with V180I prion protein gene (PRNP) mutation shows weaker prion protein (PrP) deposition histologically compared with sporadic CJD, and it is more difficult to detect protease-resistant prion protein in immunoblotting. However, we previously reported the autopsy case of a patient with V180I gCJD who was treated with pentosan polysulfate sodium (PPS); this case had increased protease-resistant PrP deposition. It has been suggested that PPS might reduce protease-resistant PrP; however, the detailed pharmacological and histopathological effects of PPS in humans remain unknown. We examined autopsied human brain tissue from four cases with V180I gCJD that were added to our archives between 2011 and 2021: two cases treated with PPS and two cases without PPS. We conducted a neuropathological assessment, including immunohistochemistry for PrP. We also performed immunoblotting for PrP on homogenate samples from each brain to detect protease-resistant PrP using both a conventional procedure and size-exclusion gel chromatography for the purification of oligomeric PrP. Both PPS-treated cases showed long survival time over 5 years from onset and increased PrP deposition with a characteristic pattern of coarse granular depositions and congophilic PrP microspheres, whereas the cases without PPS showed around 1-year survival from onset and relatively mild neuronal loss and synaptic PrP deposition. Although cortical gliosis seemed similar among all cases, aquaporin 4-expression as a hallmark of astrocytic function was increased predominantly in PPS cases. Immunoblotting of non-PPS cases revealed protease-resistant PrP in the oligomeric fraction only, whereas the PPS-treated cases showed clear signals using conventional procedures and in the oligomeric fraction. These unique biochemical and histopathological changes may reflect the progression of V180I gCJD and its modification by PPS, suggesting the possible existence of toxic PrP-oligomer in the pathophysiology of V180I gCJD and beneficial effects of PPS toward the aggregation and detoxication of toxic PrP-oligomer.

Variant Creutzfeldt-Jakob Disease Presenting as New-onset Psychosis

The case of a patient with a first presentation psychotic episode secondary to variant Creutzfeldt-Jakob Disease (vCJD) is presented. While psychiatric symptoms are considered a prominent feature of vCJD, they may precede characteristic neurological symptoms, which can delay diagnosis. The psychotic symptoms in this case differed in quality from typical psychotic presentations, which could have helped with earlier diagnosis. The patient's symptomatology suggested that errors in cognition and perception were largely contributing to his psychiatric symptoms. These errors appeared to be the result of prion destruction of relevant brain structures that may either be directly or secondarily involved in psychiatric disorders. The findings in this case can help elucidate how vCJD symptoms deviate from established guidelines for diagnosing primary psychiatric disorders.

[Psychiatric manifestations by prions. A narrative review]

Prion diseases are a group of rare and rapidly progressive neurodegenerative conditions that may cause neuropsychiatric symptoms. This group of diseases has been described since the 18(th) century, but they were recognized decades later, when it became clear that the humans were affected by infected animals. There was controversy when the problem was attributed to a single protein with infective capacity. The common pathological process is characterized by the conversion of the normal cellular prion protein into an abnormal form. In humans, the illness has been classified as idiopathic, inherited and acquired through exposure to exogenous material containing abnormal prions. The most prominent neurological manifestation of prion diseases is the emergence of a rapidly progressive dementia, mioclonus associated with cerebellar ataxia and also extra pyramidal symptoms. Psychiatric symptoms occur in early stages of the illness and can contribute to timely diagnosis of this syndrome. Psychiatric symptoms have traditionally been grouped in three categories: affective symptoms, impaired motor function and psychotic symptoms. Such events usually occur during the prodromal period prior to the neurological manifestations and consists in the presence of social isolation, onset of delusions, irritability/aggression, visual hallucinations, anxiety and depression, and less frequent first-rank symptoms among others. Definite diagnosis requires post mortem examination. The possibility that a large number of cases may occur in the next years or that many cases have not been considered with this diagnosis is a fact. In our opinion, psychiatrists should be aware of symptoms of this disease. The main objective of this research consisted of assessing the correlation between this disturbance and neuro-psychiatric symptoms and particularly if this psychiatric manifestations integrate a clinical picture suggestive for the diagnosis of these diseases, but firstly reviewed taxonomic, pathogenic and pathological aspects. The authors of this project also added an element in relation to some diagnostic considerations based on scientific evidence. For the search controlled descriptors applied to the research for indexing scientific articles in databases were used. The electronic data bases used were PubMed, EMBASE and also PsycInfo. The descriptors were prion diseases, psychotic disorders, depression, mood disorders, pathology, classification, prion protein, history, neurological manifestations, and psychiatric manifestations. The selection criteria for the material were qualitative. To conclude, and based on the extensive literature review, the authors propose that the period where the evidence is more robust for mental impaired is named "psychiatric symptoms phase, which can be extended for a few months, being the psychiatric affective symptoms the most characteristic of this phase. In conclusion, we considered that the identification of these symptoms in a patient with risk factors for developing the disease will contribute to the early identification, and would regulate the guidelines in suspected diagnosis of this group of disorders. The intention is provide a better quality of life to the sick people.

Creutzfeldt-Jakob disease in Mexico

Creutzfeldt-Jakob disease (CJD) is classified within the group of transmissible spongiform encephalopathies (TSE). It is a rapidly progressive illness that affects mental functions. The average age of onset is 50 years. Various tests can help orient the clinical diagnosis, but the confirmatory test is still the post mortem analysis. The aim of this study was to describe the epidemiological, clinical and histopathological characteristics of patients diagnosed as suffering from CJD, at the National Institute of Neurology and Neurosurgery of Mexico (NINN). An observational, descriptive and transversal study was conducted. We collected information concerning these cases from the Departments of Epidemiology and Pathology, as well as the clinical charts of the patients with a diagnosis of CJD. Fifteen cases were registered of which three CJD cases were definite, five probable cases were identified, and seven were possible. The average age of the patients was 49 years. Two definite cases were female and one was male. It is important to improve the systems for surveillance of this type of disease and, furthermore, to permit greater accessibility to laboratories where the procedures necessary for supporting diagnosis can be followed.

Neuroimaging findings in human prion disease

Imaging occupies an important role in the investigation of dementia and neurodegenerative disease. The role of imaging in prion disease used to be one of exclusion of other conditions. Over the past decade, the non-invasive nature of MRI, the improved range of magnetic resonance sequences and the availability of clinical and neuropathological correlation have led to a more prominent position of MRI and its inclusion in the diagnostic criteria for variant Creutzfeldt-Jakob disease. As experience of imaging in human prion disease increases, patterns of change related to strain and genotype may improve the diagnostic potential of imaging in the future, may reduce the need for more invasive testing and prove useful in future therapeutic trials. This paper reviews the current knowledge of imaging appearances in human prion disease.

Bovine spongiform encephalopathy: the effect of oral exposure dose on attack rate and incubation period in cattle

The dose–response of cattle exposed to the bovine spongiform encephalopathy (BSE) agent is an important component of modelling exposure risks for animals and humans and thereby, the modulation of surveillance and control strategies for BSE. In two experiments calves were dosed orally with a range of amounts of a pool of brainstems from BSE-affected cattle. Infectivity in the pool was determined by end-point titration in mice. Recipient cattle were monitored for clinical disease and, from the incidence of pathologically confirmed cases and their incubation periods (IPs), the attack rate and IP distribution according to dose were estimated. The dose at which 50 % of cattle would be clinically affected was estimated at 0.20 g brain material used in the experiment, with 95 % confidence intervals of 0.04–1.00 g. The IP was highly variable across all dose groups and followed a log-normal distribution, with decreasing mean as dose increased. There was no evidence of a threshold dose at which the probability of infection became vanishingly small, with 1/15 (7 %) of animals affected at the lowest dose (1 mg).

Depressive disorder with psychotic symptoms as psychiatric presentation of sporadic Creutzfeldt-Jakob disease: a case report

Creutzfeldt-Jakob disease (CJD) is a rare neurodegenerative disease and shows a wide range of early clinical manifestation. We report the case of Ms. A, a 50-year-old woman, who exhibited an atypical psychiatric presentation of CJD at the beginning of the disease, as a depressive disorder with psychotic features. We discuss this case, the clinical attitudes that can lead to misdiagnose such presentation of CJD with other psychiatric diseases, and propose to repeat complementary investigations when the diagnostic is evocated, even if these tests are often negative or nonspecific in the early stages of CJD.

Cerebroventricular infusion of pentosan polysulphate in human variant Creutzfeldt-Jakob disease

Variant Creutzfeldt-Jakob disease (CJD) is a transmissible spongiform encephalopathy believed to be caused by the bovine spongiform encephalopathy agent, an abnormal isoform of the prion protein (PrP(sc)). At present there is no specific or effective treatment available for any form of CJD. Pentosan polysulphate (PPS), a large polyglycoside molecule with weak heparin-like activity, has been shown to prolong the incubation period of the intracerebral infection when administered to the cerebral ventricles in a rodent scrapie model. PPS also prevents the production of further PrP(sc) in cell culture models. These properties of PPS prompted its cerebroventricular administration in a young man with vCJD. Long-term continuous infusion of PPS at a dose of 11 microg/kg/day for 18 months did not cause drug-related side effects. Follow-up CT scans demonstrated progressive brain atrophy during PPS administration. Further basic and clinical research is needed in order to address the issue of efficacy of PPS in vCJD and in other prion diseases.

Diagnosing prion diseases: needs, challenges and hopes

Prion diseases are among the most intriguing infectious diseases and are associated with unconventional proteinaceous infectious agents known as prions. Prions seem to lack nucleic acid and propagate by transmission of protein misfolding. The nature of prions and their unique mode of transmission present challenges for early diagnosis of prion diseases. In this article, state-of-the-art prion diagnostic techniques, together with the new strategies that are being used to develop sensitive, early and non-invasive diagnoses for these diseases are reviewed.

Presentation of a case of variant CJD in general dental practice

This case report describes the initial presentation of variant CJD to a general dental practitioner. The case highlights the importance of prompt referral of patients presenting with a history of atypical facial symptoms.

Prospects for the development of pre-mortem laboratory diagnostic tests for Creutzfeldt-Jakob disease

At present the diagnosis of Creutzfeldt-Jakob disease (CJD) and related transmissible spongiform encephalopathies in humans is based on clinical criteria and (at post-mortem) the histopathological and immunological examination of brain tissue. The misfolded prion protein, PrPSc, is the single most significant marker, but its recognition by standard serological methods is complicated by its antigenic similarity to the normal prion protein, PrPC. Although there are commercial diagnostic assays available for bovine spongiform encephalopathy using brain specimens taken at slaughter, there are no suitable pre-mortem assays for cattle and none either for pre-mortem human disease. Especially in view of the recent report of variant CJD transmission by blood transfusion, it is important that tests for pre-symptomatic infections are developed. This will safeguard the blood supply and, for example, prevent the transmission of CJD in neurosurgery. This paper reviews the current and prospective approaches to the pre-mortem diagnosis of CJD, in particular its variant form.

Prions and the human transmissible spongiform encephalopathies

The last 5 years have seen the emergence of a new disease in humans (vCJD), mainly in the United Kingdom. This emergence has been accompanied by an explosion of scientific data on a novel group of the responsible infectious agents called prions and has profound implications for infection control and transfusion policies. Also of concern is the finding of prions in neural, gingival, pulpal, and salivary tissue in animal models and significant titers of infectivity from extraneural organs (particularly, in cases of vCJD, in lymphoreticular tissues). There is limited information on the presence of prion proteins in the oral tissues from human studies. Because of the differences in patterns of disease in animal models and in strains of prion protein, it is difficult to extrapolate directly these findings to humans, but it illustrates a potential for transmission by way of the dental route. High levels of infectivity may be present in tissues early in the incubation period and before clinical signs and symptoms. The dental profession must turn its attention to the routine decontamination of dental instruments to ensure that these procedures are performed to the highest regulatory standard. Clinicians and manufacturers must work closely together to develop instruments that are either single use or can be presented in a form that can be more easily decontaminated. Clinicians must pay close attention to manufacturers' decontamination instructions and must not reuse items designated as single use, such as endodontic files. Improvements in compliance with these requirements will not only reduce the risk of transmission of TSEs but also other less tenacious infectious agents.

Towards cellular receptors for prions

Transmissible spongiform encephalopathies (TSE) are attributed to the conversion of the cellular prion protein (PrP(c)) into an abnormal isoform (PrP(sc)). This can be caused by the invasion of living organisms by infectious particles, or be inherited due to mutations on the PrP(c) gene. One of the most intriguing problems of prion biology is the inability to generate the infectious agent in vitro. This argues strongly that other cellular proteins besides those added in test tubes or found in cellular preparations are necessary for infection. Despite recent progress in the understanding of prion pathology, the subcellular compartments in which the interaction and conversion of PrP(c) into PrP(sc) take place are still controversial. PrP(c) interacts with various macromolecules at the cell membrane, in endocytic compartments and in the secretory pathway, all of which may play specific roles in the internalisation of PrP(sc) and conversion of PrP(c). A specific interacting protein required for the propagation of prions was originally proposed as a prion receptor, and later referred to as a ligand, a cofactor, protein X, or a partner. However, current studies indicate that PrP(c) associates with multi-molecular complexes, which mediate a variety of functions in distinct cellular compartments. It is proposed that a deeper understanding of the mechanics of such interactions, coupled to a better knowledge of the corresponding signalling pathways and ensuing cellular responses, will have a major impact on the prevention and treatment of TSE.