Consent for brain tissue donation after Intracerebral Haemorrhage: A Community-Based Study

Background Spontaneous intracerebral haemorrhage is a devastating form of stroke and its incidence increases with age. Obtaining brain tissue following intracerebral haemorrhage helps to understand its cause. Given declining autopsy rates worldwide, the feasibility of establishing an autopsy-based collection and its generalisability are uncertain. Methods We used multiple overlapping sources of case ascertainment to identify every adult diagnosed with intracerebral haemorrhage between 1st June 2010-31st May 2012, whilst resident in the Lothian region of Scotland. We sought consent from patients with intracerebral haemorrhage (or their nearest relative if the patient lacked mental capacity) to conduct a research autopsy. Results Of 295 adults with acute intracerebral haemorrhage, 110 (37%) could not be approached to consider donation. Of 185 adults/relatives approached, 91 (49%) consented to research autopsy. There were no differences in baseline demographic variables or markers of intracerebral haemorrhage severity between consenters and non-consenters. Adults who died and became donors (n = 46) differed from the rest of the cohort (n = 249) by being older (median age 80, IQR 76–86 vs. 75, IQR 65–83, p = 0.002) and having larger haemorrhages (median volume 23ml, IQR 13–50 vs. 13ml, IQR 4–40; p = 0.002). Conclusions Nearly half of those approached consent to brain tissue donation after acute intracerebral haemorrhage. The characteristics of adults who gave consent were comparable to those in an entire community, although those who donate early are older and have larger haemorrhage volumes

The application of in vitro cell-free conversion systems to human prion diseases

A key event in the pathogenesis of prion diseases is the conversion of the normal cellular isoform of the prion protein into the disease-associated isoform, but the mechanisms operating in this critical event are not yet fully understood. A number of novel approaches have recently been developed to study factors influencing this process. One of these, the protein misfolding cyclical amplification (PMCA) technique, has been used to explore defined factors influencing the conversion of cellular prion protein in a cell-free model system. Although initially developed in animal models, this technique has been increasingly applied to human prion diseases. Recent studies have focused on the role of different isoforms of the disease-associated human prion protein and the effects of the naturally occurring polymorphism at codon 129 in the human prion protein gene on the conversion process, improving our understanding of the interaction between host and agent factors that influence the wide range of phenotypes in human prion diseases. This technique also allows a greatly enhanced sensitivity of detection of disease-associated prion protein in human tissues and fluids, which is potentially applicable to disease screening, particularly for variant Creutzfeldt–Jakob disease. The PMCA technique can also be used to model human susceptibility to a range of prions of non-human origin, which is likely to prove of considerable future interest as more novel and potentially pathogenic prion diseases are identified in animal species that form part of the human food chain

Prions and the oral cavity

Prion diseases have recently emerged as a significant challenge to health-care workers, including those involved in dentistry. Abnormal prion proteins are resistant to complete inactivation by conventional sterilization techniques. In the last decade, a new form of prion disease emerged in the UK, termed "variant CJD", thought to be acquired by consumption of bovine spongiform encephalopathy-contaminated food products. At present, CJD is an invariably fatal disease with no immediate prospect of treatment or vaccination. Of concern with the variant form of CJD, unlike the more classic forms of the disease, is the appearance of significant levels of infectivity outside the central nervous system. This raises concerns for the potential transmission of prion proteins via surgical procedures from individuals in the asymptomatic stage of the disease. This article reviews the existing knowledge base on the nature of prions, their distribution in oral tissues, and the implications for dental treatment

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

Genotype-dependent molecular evolution of sheep Bovine Spongiform Encephalopathy (BSE) prionsin vitro affects their zoonotic potential

Background: The results of serial passage of BSE in sheep are unknown. Results: In vitro modeling shows a sheep genotype-dependent switch in prion protein type and loss of the ability to convert human prion protein. Conclusion: Molecular evolution of sheep BSE prions in vitro is genotype-dependent and affects zoonotic potential. Significance: Zoonotic risk might be predicted from cell-free modeling

Variably protease-sensitive prionopathy in the UK: a retrospective review 1991-2008

Variably protease-sensitive prionopathy is a newly described human prion disease of unknown aetiology lying out with the hitherto recognized phenotypic spectrum of Creutzfeldt-Jakob disease. Two cases that conform to the variably protease-sensitive prionopathy phenotype have been identified prospectively in the U.K. since the first description of the condition in 2008 in the U.S.A. To determine the incidence and phenotype of variably protease-sensitive prionopathy within a single well-defined cohort, we have conducted a retrospective review of patients referred to the National Creutzfeldt-Jakob Disease Research & Surveillance Unit during the period 1991-2008. The approach taken was to screen frozen brain tissue by western blotting for the form of protease-resistant prion protein that characterizes variably protease-sensitive prionopathy, followed by neuropathological and clinical review of candidate cases. Cases diagnosed as sporadic Creutzfeldt-Jakob disease with atypical neuropathology were also reviewed. Four hundred and sixty-five cases were screened biochemically, yielding four candidate cases of variably protease-sensitive prionopathy. One was discounted on pathological and clinical grounds, and one was a known case of variably protease-sensitive prionopathy previously reported, leaving two new cases, which were confirmed biochemically and neuropathologically as variably protease-sensitive prionopathy. A third new case that lacked frozen tissue was recognized retrospectively on neuropathological grounds alone. This means that five cases of variably protease-sensitive prionopathy have been identified (prospectively and retrospectively) during the surveillance period 1991-2011 in the U.K. Assuming ascertainment levels equivalent to that of other human prion diseases, these data indicate that variably protease-sensitive prionopathy is a rare phenotype within human prion diseases, which are themselves rare. Biochemical investigation indicates that the abnormal protease-resistant prion protein fragment that characterizes variably protease-sensitive prionopathy is detectable at low levels in some cases of sporadic Creutzfeldt-Jakob disease and conversely, that the form of abnormal prion protein that characterizes sporadic Creutzfeldt-Jakob disease can be found in certain brain regions of cases of variably protease-sensitive prionopathy, indicating molecular overlaps between these two disorders