Variant CJD infection in the spleen of a neurologically asymptomatic UK adult patient with haemophilia

SUMMARY

All UK patients with bleeding disorders treated with any UK-sourced pooled factor concentrates between 1980 and 2001 have been informed that they may be at an increased risk of infection with variant Creutzfeldt-Jakob disease (vCJD). We describe a study to detect disease-associated, protease-resistant prion protein (PrP(res)) in 17 neurologically aymptomatic patients with haemophilia considered to be at increased risk of vCJD. Materials from 11 autopsy and seven biopsy cases were analysed for PrP(res). The tissues available from each case were variable, ranging from a single biopsy sample to a wide range of autopsy tissues. A single specimen from the spleen of one autopsy case gave a strong positive result on repeated testing for PrP(res) by Western blot analysis. This tissue came from a 73-year-old male patient with no history of neurological disease, who was heterozygous (methionine/valine) at codon 129 in the prion protein gene. He had received over 9000 units of factor VIII concentrate prepared from plasma pools known to include donations from a vCJD-infected donor, and some 400,000 units not known to include donations from vCJD-infected donors. He had also received 14 units of red blood cells and had undergone several surgical and invasive endoscopic procedures. Estimates of the relative risks of exposure through diet, surgery, endoscopy, blood transfusion and receipt of UK-sourced plasma products suggest that by far the most likely route of infection in this patient was receipt of UK plasma products.

Immunohistochemistry for the prion protein: comparison of different monoclonal antibodies in human prion disease subtypes

Demonstration of the abnormal form of the prion protein (PrP) in the brain confirms the diagnosis of human prion disease (PrD). Using immunohistochemistry, we have compared ten monoclonal antibodies in PrD subtypes including sporadic and variant Creutzfeldt-Jakob disease (CJD), fatal familial insomnia, Alzheimer's disease (AD), and control brains. CJD subgroups were determined using Western blot analysis for the protease-resistant PrP type in combination with sequencing to determine the genotype at the methionine/valine polymorphism at codon 129 of the prion protein gene. None of the antibodies labeled given subgroups exclusively, but the intensity of immunoreactivity varied among morphologically distinct types of deposit. Fine granular or synaptic PrP deposits stained weakly or not at all with antibodies against the N-terminus of PrP, and were visible in one case only with 12F10 and SAF54. Coarser and plaque type deposits were immunolabeled with all antibodies. The immunostaining patterns appear characteristic for the disease subgroups. Labeling of certain neurons in all cases irrespective of disease, and staining at the periphery and/or throughout the senile plaques of AD patients were also noted. Antibodies such as 6H4 and 12F10 failed to give this type of labeling and are therefore less likely to recognise non-pathological PrP material in immunohistochemistry.

Prevalence of lymphoreticular prion protein accumulation in UK tissue samples

This study aims to provide an estimate of the number of individuals in the UK who may be incubating variant Creutzfeldt-Jakob disease and at risk of causing iatrogenic spread of the disease. Lymphoreticular accumulation of prion protein is a consistent feature of variant Creutzfeldt-Jakob at autopsy and has also been demonstrated in the pre-clinical phase. Immunohistochemical accumulation of prion protein in the lymphoreticular system remains the only technique that has been shown to predict neurological disease reliably in animal prion disorders. In this study, immunohistochemistry was used to demonstrate the presence of prion protein, with monoclonal antibodies KG9 and 3F4, in surgically removed tonsillectomy and appendicectomy specimens. The samples were collected from histopathology departments across the UK and anonymised prior to testing. Samples were tested from 16 703 patients (14 964 appendectomies, 1739 tonsillectomies), approximately 60% of whom were from the age group 20-29 years at operation. Twenty-five per cent of the samples were excluded from the final analyses because they contained inadequate amounts of lymphoid tissue. Three appendicectomy samples showed lymphoreticular accumulation of prion protein, giving an estimated prevalence of 3/12 674 or 237 per million (95% CI 49-692 per million). The pattern of lymphoreticular accumulation in two of these samples was dissimilar from that seen in known cases of variant Creutzfeldt-Jakob disease. Although it is uncertain whether immunohistochemical accumulation of prion protein in the lymphoreticular system is specific for variant Creutzfeldt-Jakob disease, it has not been described in any other disease, including other forms of human prion disease or a range of inflammatory and infective conditions. These findings reinforce the importance of measures taken by the UK Department of Health to reduce the risk of spread of variant Creutzfeldt-Jakob via blood products and surgical instruments, and of the urgency to proceed with large-scale screening of fresh tonsil specimens for the presence of prion protein.

Specificity of lymphoreticular accumulation of prion protein for variant Creutzfeldt-Jakob disease

BACKGROUND

Immunocytochemical accumulation of prion protein (PrP) in lymphoid tissues is a feature of variant Creutzfeldt-Jakob disease (vCJD) that has been used both to aid in the diagnosis of patients and as a basis of large scale screening studies to assess the prevalence of preclinical disease in the UK. However, the specificity of this approach is unknown.

AIM

To assess the specificity of lymphoreticular accumulation of PrP for vCJD by examining a range of human diseases.

METHODS

Paraffin wax embedded lymphoreticular tissues from patients with several reactive conditions (58 cases), tumours (27 cases), vCJD (54 cases), and other human prion diseases (56 cases) were assessed. PrP accumulation was assessed by immunocytochemistry using two different monoclonal anti-PrP antibodies and a sensitive detection system.

RESULTS

All cases of vCJD showed widespread lymphoreticular accumulation of PrP; however, this was not seen in the other conditions examined.

CONCLUSION

Lymphoreticular accumulation of PrP, as assessed by immunocytochemistry, appears to be a highly specific feature of vCJD.

Peripheral tissue involvement in sporadic, iatrogenic, and variant Creutzfeldt-Jakob disease: an immunohistochemical, quantitative, and biochemical study

Human prion diseases are rare fatal neurodegenerative conditions that occur as acquired, familial, or idiopathic disorders. A key event in their pathogenesis is the accumulation of an altered form of the prion protein, termed PrP(Sc), in the central nervous system. A novel acquired human prion disease, variant Creutzfeldt-Jakob disease, is thought to result from oral exposure to the bovine spongiform encephalopathy agent. This disease differs from other human prion diseases in its neurological, neuropathological, and biochemical phenotype. We have used immunohistochemistry and Western blot techniques to analyze the tissue distribution and biochemical properties of PrP(Sc) in peripheral tissues in a unique series of nine cases of variant Creutzfeldt-Jakob disease. We have compared this with the distribution and biochemical forms found in all of the major subtypes of sporadic Creutzfeldt-Jakob disease and in a case of iatrogenic Creutzfeldt-Jakob disease associated with growth hormone therapy. The results show that involvement of the lymphoreticular system is a defining feature of variant Creutzfeldt-Jakob disease, but that the biochemical isoform of PrP(Sc) found is influenced by the cell type in which it accumulates.

Prion protein heterogeneity in sporadic but not variant Creutzfeldt-Jakob disease: U.K. cases 1991-2002

Human prion diseases can occur as an idiopathic disorder (sporadic Creutzfeldt-Jakob disease) or can be acquired, as is the case for variant Creutzfeldt-Jakob disease. These disorders are characterized by the accumulation of a protease-resistant form of the host-encoded prion protein termed PrP(Sc) in the brains of affected individuals. PrP(Sc) has been proposed to be the principal, if not sole, component of the infectious agent, with its accumulation in the central nervous system the primary event leading to neurodegeneration. A major question remains as to whether self-propagating structural differences in PrP(Sc) might account for the clinicopathological diversity evident in Creutzfeldt-Jakob disease and whether different prion protein types underlie the existence of different strains of causative agent. Here, we describe the results of a large-scale biochemical study of PrP(Sc) from autopsy-proved cases of variant Creutzfeldt-Jakob disease (n = 59) and compare these with cases of sporadic Creutzfeldt-Jakob disease (n = 170) in the United Kingdom over the period 1991 to 2002. The results show PrP(Sc) in variant Creutzfeldt-Jakob disease to be remarkably stereotyped. In contrast, considerable heterogeneity in PrP(Sc) exists both between and within cases of sporadic Creutzfeldt-Jakob disease.

Prion protein accumulation in eyes of patients with sporadic and variant Creutzfeldt-Jakob disease

PURPOSE

Creutzfeldt-Jakob disease (CJD) primarily affects the brain. This study was conducted to assess the possible involvement of the eye in sporadic and variant CJD by testing for the presence of the disease-associated, protease-resistant isoform of the prion protein (PrP(Sc)) in ocular tissue.

METHODS

Human eyes from donors with CJD and non-prion neurodegenerative disease control eyes were studied. In situ hybridization and Western blot analysis were used to determine the normal pattern of cellular prion protein (PrP(C)) expression. Western blot analysis and immunohistochemistry were then used to determine the localization, abundance, and isotype of PrP(Sc) in eyes in CJD.

RESULTS

PrP(C) was expressed in the nuclear layers of the retina. In both the sporadic and variant forms of CJD, PrP(Sc) accumulated throughout the synaptic layers of the retina. The levels of PrP(Sc) found in the retina were comparable with those found in the brain. Lower levels of PrP(Sc) could be found in the optic nerve, but no PrP(Sc) was detectable in other ocular tissues. The glycoform ratio of PrP(Sc) in the retina did not correspond to that found in the brain.

CONCLUSIONS

Presumptive centrifugal spread of PrP(Sc) from the brain through the optic nerve occurs in two major types of CJD. PrP(Sc) is a marker of CJD infectivity. Given that routine decontamination may not remove PrP(Sc) from surgical instruments, a careful risk assessment should be made of possible iatrogenic spread of sporadic and variant CJD after surgery to the retina or optic nerve.

Ultrastructural analysis of the florid plaque in variant Creutzfeldt-Jakob disease

We report here the first description of florid plaques--the hallmark of variant Creutzfeldt-Jakob disease (vCJD). These plaques are composed of broad bundles of amyloid, are highly neuritic and exhibited astrocytes and microglial cells. Collectively, they are more similar to neuritic plaques of Alzheimer's disease than to kuru plaques of kuru--Creutzfeldt-Jakob disease--Gerstmann-Sträussler-Sheinker disease.

Pathological diagnosis of variant Creutzfeldt-Jakob disease

The neuropathological and biochemical features of the 89 histologically confirmed cases of variant Creutzfeldt-Jakob disease (vCJD) diagnosed up to the end of October 2001 in the UK are reviewed. Histology of the central nervous system, lymphoid tissues and other organs was accompanied by immunocytochemistry and Western blot analysis of the disease-associated form of the prion protein (PrP(RES)). All patients with vCJD were methionine homozygotes at codon 129 of the PrP gene. The pathology of vCJD showed relatively uniform morphological and immunocytochemical characteristics, which were distinct from other forms of CJD. PrP(RES) accumulation was widespread in lymphoid tissues in vCJD, but was not identified in other non-neural tissues. PrP(RES) in vCJD brain tissue showed a uniform glycotype pattern distinct from sporadic CJD. Given the increasingly widespread occurrence of bovine spongiform encephalopathy in Europe and Asia, there is a major need for widespread CJD surveillance. This should be accompanied by a multidisciplinary laboratory approach to the investigation and diagnosis of all forms of CJD, with the need to investigate autopsy tissues from suspected cases by the histological and biochemical techniques described herein.

Neuropathology of variant Creutzfeldt-Jakob disease

The clinical, neuropathological genetic and biochemical features of variant Creutzfeldt-Jakob disease (vCJD) are compared to the 926 other cases of suspected CJD referred to the National CJD Surveillance Unit laboratory from 1990-2001. Histological studies of the central nervous system, lymphoid tissues and other organs were accompanied by immunocytochemistry for prion protein (PrP); Western blot analysis of PrPRES was performed on frozen brain tissue. The pathology of vCJD showed relatively uniform morphological and immunocytochemical characteristics, with PrP accumulation in lymphoid tissues, but not in other non-neural tissues. PrPRES accumulation in vCJD showed a uniform glycotype pattern distinct from sporadic CJD. All cases of vCJD were methionine homozygotes at codon 129 of the PrP gene. In view of the spread of bovine spongiform encephalopathy in Europe and Japan, continuing surveillance is required for all forms of CJD, with histological and biochemical analysis of suspected cases to allow an accurate laboratory diagnosis.

Laboratory diagnosis of variant Creutzfeldt-Jakob disease

The neuropathological and biochemical features of 33 cases of variant Creutzfeldt-Jakob disease (vCJD) diagnosed up to the end of 1998 are analysed in relation to the 646 cases of suspected CJD referred to the CJD Surveillance Unit laboratory from 1990 to 1998. Morphological studies of the central nervous system, lymphoid tissues and other organs were accompanied by immunocytochemistry; Western blot analysis of PrPRES was performed on frozen brain tissue. The findings were analysed in relation to clinical and genetic data. The pathology of vCJD showed morphological and immunocytochemical characteristics distinct from other cases of CJD. PrP accumulation was widespread in lymphoid tissues in vCJD, but was not identified in other non-neural tissues. PrPRES accumulation in vCJD brain tissue showed a uniform glycotype pattern distinct from sporadic CJD. All analysed cases of vCJD were methionine homozygotes at codon 129 of the PrP gene. No evidence currently exists to suggest that cases of CJD diagnosed in individuals who are MV or VV at codon 129 of the PrP gene represent 'human bovine spongiform encaphalopathy (BSE)'. Continued surveillance is required to further investigate this possibility, with the need to investigate autopsy tissues from suspected cases by histological and biochemical techniques.

Protection of personnel and environment against Creutzfeldt-Jakob disease in pathology laboratories

Most neuropathology laboratories have been faced with the question of dealing with cases of Creutzfeldt-Jakob disease (CJD) which is a rare neurodegenerative disorder. Neuropathologists have been long aware of the transmissibility and unique properties of the agent which make it resistant to conventional inactivating reagents. The emergence of iatrogenic cases and of the bovine spongiform encephalopathy (BSE) crisis has induced anxiety among laboratory staff and raised questions about the efficiency of safety measures and procedures hitherto applied in pathology laboratories. This article aims at presenting an overview of the risk involved in handling CJD material. It gives practical advice and a key to more detailed procedures, guidelines and recommendations available in scientific literature and through government agencies. Neuropathologists and biochemists are at a higher potential risk than others since the diagnosing of CJD involves the handling of nervous tissue which contains the highest levels of infectivity.

Transmissions to mice indicate that 'new variant' CJD is caused by the BSE agent

There are many strains of the agents that cause transmissible spongiform encephalopathies (TSEs) or 'prion' diseases. These strains are distinguishable by their disease characteristics in experimentally infected animals, in particular the incubation periods and neuropathology they produce in panels of inbred mouse strains. We have shown that the strain of agent from cattle affected by bovine spongiform encephalopathy (BSE) produces a characteristic pattern of disease in mice that is retained after experimental passage through a variety of intermediate species. This BSE 'signature' has also been identified in transmissions to mice of TSEs of domestic cats and two exotic species of ruminant, providing the first direct evidence for the accidental spread of a TSE between species. Twenty cases of a clinically and pathologically atypical form of Creutzfeldt-Jakob disease (CJD), referred to as 'new variant' CJD (vCJD), have been recognized in unusually young people in the United Kingdom, and a further case has been reported in France. This has raised serious concerns that BSE may have spread to humans, putatively by dietary exposure. Here we report the interim results of transmissions of sporadic CJD and vCJD to mice. Our data provide strong evidence that the same agent strain is involved in both BSE and vCJD.

Prion protein immunocytochemistry--UK five centre consensus report

Creutzfeldt-Jakob disease (CJD) and other prion diseases are associated with the deposition of insoluble prion protein (PrPCJD) in the central nervous system (CNS). Antibodies raised against PrPCJD also react with its precursor protein, a soluble form of PrP (PrPC), which is widely distributed in the normal CNS. This cross-reactivity has in the past raised doubts as to the specificity and diagnostic reliability of PrP immunolocalization, especially in familial cases which are atypical clinically and which lack characteristic pathology findings. Following an MRC-funded workshop which focused on this problem, a multicentre prospective study was set up to identify a reliable protocol for PrPCJD immunocytochemistry. Five UK centres took part in this study and demonstrated consistent staining of plaques, vacuolar deposits in severe spongiform change, and perineuronal deposits using a variety of antibodies and enhancement procedures. A protocol using formic acid, guanidine thiocyanate, and hydrated autoclaving pre-treatment in conjunction with a monoclonal PrPCJD antibody produced the clearest immunochemical results and is presented as the consensus UK recommendation for PrPCJD immunocytochemical procedures.

Neuropathological phenotype and 'prion protein' genotype correlation in sporadic Creutzfeldt-Jakob disease

A systematic study of 'prion protein' genotype in cases of sporadic Creutzfeldt-Jakob disease showing amyloid plaques staining with anti-prion protein antibody has been performed. This revealed a relative excess of cases with valine at position 129 of the gene's open reading frame. The observation emphasises the importance of this site of common polymorphism in influencing the neuropathological phenotype in human spongiform encephalopathy.

Ubiquitin immunocytochemistry in human spongiform encephalopathies

The distribution of ubiquitin was studied by immunocytochemistry in eight cases of human spongiform encephalopathy and compared with the findings in seven age- and sex-matched cases of Alzheimer's disease and six non-demented control cases. The results were also compared with the immunocytochemical distribution of prion protein and the lysosomal aspartic protease cathepsin D. In the human spongiform encephalopathies, ubiquitin immunoreactivity was found in a punctate distribution at the periphery of prion protein amyloid plaques and in a finely granular pattern in the neuropil around and within areas of spongiform change. Cortical nerve cells contained scanty ubiquitinated dot-like inclusions, and occasional microglia around the areas of spongiform change also gave a positive staining reaction for ubiquitin, as did multiple irregular thread-like structures in the neuropil and white matter. The ubiquitin-containing structures at the plaque periphery in human spongiform encephalopathies resemble the neuritic processes at the periphery of the senile plaque in Alzheimer's disease. The granular positivity for ubiquitin associated with areas of spongiform change closely resembles the pattern of immunostaining seen with the antibodies to the prion protein and cathepsin D, consistent with the reported accumulation of ubiquitinated proteins and prion protein in lysosomes in the murine scrapie model. Further studies are required to investigate the role of lysosomes in this group of disorders, and to study the localization of other cell stress proteins and prion protein in spongiform encephalopathies.

The self-reported effects of PCP on human aggression

The elicitation of violent of psychotic behavior by phencyclidine (PCP) administration is well documented. There are indications, however, that behavioral responses to PCP may differ among PCP users as a function of background or personality characteristics. The present study examined 35 male jail inmates with histories of PCP use. Estimates of the nature and extent of drug use and self-reports of previous psychiatric hospitalizations were obtained in these subjects. The Buss-Durkee Hostility Inventory was modified to reflect behaviors under the two simulated conditions of "No PCP" and "PCP" use. Results showed that PCP use was related to increased levels of hostility in our subjects when present age, age of first use, the frequency of use and suspicion and assaultive behavior when not using PCP was considered. Also, subjects with a history of psychiatric hospitalizations reported higher levels of assault when using PCP than those without psychiatric histories. These data suggest that the self-reported behavioral results of PCP use are associated with certain personality traits and background features.