A French cluster of Creutzfeldt–Jakob disease: a molecular analysis

We report the molecular and phenotypic analysis of a French cluster of three cases of Creutzfeldt-Jakob disease (CJD), two of them occurring in 1998 in the same village and the other in 1995 in a neighboring village. Analyses of the occurrence of these events in a close area with less than 3000 inhabitants over the 1992-1999 notification period confirmed that they are rare. This could be explained either by a common source of contamination or by the coincidental occurrence of either sporadic or genetic CJD. We applied genetic analysis and brain PrPres typing to explore these CJD cases. The three patients did not carry any mutation in their prion protein gene coding sequence. All were homozygous for methionine at the polymorphic codon 129. Brain tissue was available from two cases that died in 1998. The two patients showed different PrPres profiles on Western blot and distinct clinico-pathological features. These findings do not support the conclusion that in these three cases, CJD was acquired from a unique source of contamination and suggest that concurrent occurrence of sporadic CJD accounted for this CJD cluster.     

Cluster of Creutzfeldt–Jakob disease in France associated with the codon 200 mutation (E200K) in the prion protein gene

Between 1992 and 1995, the annual incidence of Creutzfeldt–Jakob disease (CJD) in one of the 96 French départments (adminstrative districts) was found to be about six times higher than the CJD national incidence. Among the 12 definite or probable CJD patients referred during this period within this département , nine originated from a small confined area (30 × 30 km) and seven patients carried the E200K mutation in their prion protein gene ( PRNP ). Genealogical data showed that these seven cases, together with three other ones previously referred during the 1970–82 period, probably belonged to different branches of the same family which could be traced to the beginning of the eighteenth century. Interestingly enough, all but two patients presented as sporadic cases before the genealogic and genetic studies. To our knowledge, this study is the first describing in France a focal accumulation of CJD associated with the PRNP E200K mutation.     

Panencephalopathic Creutzfeldt–Jakob disease in the Netherlands and the UK: clinical and pathological characteristics of nine patients

Aims: The panencephalopathic type of Creutzfeldt–Jakob disease (PECJD) has extensive abnormalities in cerebral white matter as well as the cortex. PECJD has rarely been described in Caucasians and debate continues on its classification and pathogenesis. We describe our experience of PECJD over a 14-year period of surveillance for CJD in the Netherlands and the UK. Methods: Between 1993 and 2006, nine cases of PECJD were identified. Clinical, histological and biochemical characteristics of all patients were analysed and compared; all cases were classified clinically as sporadic CJD. Results: The median age at onset was 57.8 years and median disease duration was 22 months. The average brain weight was 887 g. Most patients showed a two-stage clinical course with initial rapid deterioration to a state of akinetic mutism, which then persisted over a longer time scale. Neuropathological findings were characterized by severe global atrophy with status spongiosus. Cerebral white matter involvement tended to be associated with either disease duration or severity of cerebral cortical lesions. Five patients could be classified into the MM1 subtype of sporadic CJD, one patient into the MM2 subgroup and another into the MV2 subgroup. Two patients were heterozygous at codon 129 in the prion protein gene and contained both type 1 and type 2 PrP^res isoforms in the brain. Conclusions: We believe that white matter pathology in PECJD represents an end-stage pattern that reflects secondary degeneration due to widespread cortical neuronal loss that occurs in the early part of the disease, rather than representing a primary lesion.     

Creutzfeldt–Jakob disease risk and PRNP codon 129 polymorphism: necessity to revalue current data

The polymorphism at codon 129 (M129V) of the prion protein gene (PRNP) is a recognized genetic marker for susceptibility to Creutzfeldt-Jakob disease (CJD) in the Caucasians. The distribution of this polymorphism in healthy individuals provides an important starting point for the evaluation of CJD risk in the general population. Early studies of reference population cohorts demonstrated that methionine/valine heterozygosity was the most frequent genotype. These studies were performed in relatively small numbers of control subjects and do not correspond with the findings of more recent investigations. In this study, we present an analysis of the codon M129V distribution in 613 corneal donors, representing one of the largest control groups examined to date. Methionine homozygotes represented 48.1%, valine homozygotes 8.7% and methionine/valine heterozygotes 43.2%. While age-related difference was not significant, differentiation according to the gender showed significant difference. The observed highest proportion of methionine homozygotes and statistically significant difference between genders as well as comparison with results obtained in other countries underline the need to re-evaluate the generally used reference data on M129V, including consideration of the gender, age and geographical distribution.     

EEG findings in dementia with Lewy bodies causing diagnostic confusion with sporadic Creutzfeldt–Jakob disease

Two patients with pathologically confirmed dementia with Lewy bodies (DLB) had electroencephalogram recordings reported to show periodic discharges suggestive or typical of Creutzfeldt-Jakob disease. These findings caused diagnostic confusion and necessitated appropriate precautions for prion disease at postmortem examination. Periodic sharp wave complexes have occasionally been reported in DLB and should not therefore dissuade one from the diagnosis when other clinical and neuropsychological features are consistent with validated diagnostic criteria.     

Creutzfeldt–Jakob disease presenting as progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder characterized by an akinetic rigid syndrome with vertical supranuclear ophthalmoplegia, early falls, and levodopa resistance. The pathological substrate of PSP consists of filamentous tau degenerative lesions affecting neurons and glia. Other disorders can present with a similar clinical picture, most commonly corticobasal degeneration and multiple system atrophy. Non-neurodegenerative disorders are rare causes of the PSP syndrome. In this report we describe clinical and pathological features of two cases of Creutzfeldt-Jakob disease (CJD) presenting with the PSP syndrome and discuss which features may help prevent misdiagnosis. To our knowledge, this is the first report of cases of CJD with autopsy confirmation that presented with a PSP syndrome.     

Iatrogenic Creutzfeldt–Jakob disease subsequent to dural graft: persisting risk after 1987

The first case of Creutzfeldt-Jakob disease (CJD) related to the use of a dura mater graft of cadaveric origin was identified in 1987 and this procedure is now considered as one of the main causes of iatrogenic CJD. Although the decontamination procedure for the preparation of graft material was modified, the product was withdrawn from the market in many countries a few years later and replaced by synthetic material. In this context, two patients treated in our institution developed CJD following a cadaveric dural graft performed after cerebral and lumbar trauma. Their clinical presentation, showing predominant cerebellar symptoms, late deterioration and myoclonic jerks, and a rapid disease course until death, was similar to that of previously reported cases involving the iatrogenic form. As the graft for one of the patients was performed in 1991 (several years after modification of the decontamination procedure), this fourth reported case suggests that the risk of iatrogenic CJD may have persisted in some patients treated after 1987, when grafts of cadaveric origin were totally abandoned.     

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 (PrP^CJD) in the central nervous system (CNS). Antibodies raised against PrP^CJD also react with its precursor protein, a soluble form of PrP (PrP^C), 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 PrP^CJD 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 PrP^CJD antibody produced the clearest immunochemical results and is presented as the consensus UK recommendation for PrP^CJD immunocytochemical procedures.     

Variant Creutzfeldt–Jakob disease: first two indigenous cases in Republic of Ireland. Case report and perspective

The first two cases of indigenous variant Creutzfeldt–Jakob disease (vCJD) in the Republic of Ireland are reported in two men, neither of whom had lived outside Ireland. Both diagnoses were made ante-mortem based on clinical presentation, brain imaging, positive 14-3-3 protein in one case, and tonsillar biopsy. We discuss some of the clinical aspects of vCJD and the significance of these cases in the Irish context.     

Leptomeningeal melanoma and Creutzfeldt–Jakob disease in a patient with chronic lymphocytic leukaemia

A 78-year-old woman with known chronic lymphocytic leukaemia (CLL) was admitted to a psychiatric unit because of rapidly declining cognitive function. Clinical examination also revealed cerebellar signs and she later became akinetic and mute. She deteriorated and died of bronchopneumonia. The histology from the post-mortem confirmed the presence of CLL in the lymph nodes and she was also found to have diffuse leptomeningeal melanoma. In addition, there was extensive prion protein deposition in the cerebral cortex, but without significant spongiosis. The astrocytosis that was present appeared superficial only. Furthermore, prion protein appeared to be co-expressed with betaA4 in the form of plaques. The patient therefore had evidence of sporadic Creutzfeldt-Jakob disease (CJD) in addition to meningeal melanoma and CLL. This case further illustrates the importance of employing prion protein immunohistochemistry in suspected cases of CJD, especially where the histology is atypical.     

Immunohistochemical studies of the PrPCJD deposition in Creutzfeldt‐Jakob disease

The PrP^CJD deposition in eight brains of sporadic Creutzfeldt‐Jakob disease (CJD) was examined immunohistochemically using both hydrolytic autoclaving and formic acid pretreatment in order to understand the pathogenesis of CJD. Synaptic‐type PrP immunoreactivity was revealed in the gray matter in all cases and had a tendency to be weaker in devastated areas in cases with a longer duration of illness. However, in one particular case with numerous prion plaques, the degeneration was relatively mild while PrP^CJD immunoreactivity was intense despite the longest duration of illness among the examined cases. Deep layer accentuation of PrP^CJD immunoreactivity was observed in the cerebral cortices in most cases. This staining pattern, however, disappeared in a burnt‐out lesion exhibiting status spongiosus. The granular layer was damaged mostly in the cerebellum of the advanced cases. PrP^CJD and synaptophysin immunoreactivities decreased as the tissue degeneration progressed. Interestingly, the Purkinje cells had no positivity for PrP^CJD in all cases, although the neurons in relatively preserved cerebellum showed apparent positivity for synaptophysin. In the Ammon’s horn and subiculum the neurons were well preserved despite the marked immunoreactivity for PrP^CJD in all cases, although some cases demonstrated severe spongiform change. Approximately half of the cases showed intracytoplasmic inclusion body‐like immunoreactivity for PrP^CJD in neurons of the dentate nucleus. These findings suggest that PrP^CJD deposition may be an event that precedes neuronal degeneration evolving from deeper layers of the cerebral cortex. Although the Ammon’s horn and subiculum showed striking PrP^CJD deposition and spongiform change, neuronal loss did not take place, suggesting that deposited PrP^CJD itself seems not to be directly harmful to the neurons. Some investigators have assumed that microglia activated by PrP^CJD plays an important role in neuronal degeneration. Considering this, we speculate that microglia in the Ammon’s horn and subiculum may have a unique characteristic of not responding to PrP^CJD.     

Prion protein oligomers in Creutzfeldt‐Jakob disease detected by gel‐filtration centrifuge columns

Prion diseases are diagnosed by the detection of accumulation of abnormal prion protein (PrP) using immunohistochemistry or the detection of protease‐resistant abnormal PrP (PrP^res). Although the abnormal PrP is neurotoxic by forming aggregates, recent studies suggest that the most infectious units are smaller than the amyloid fibrils. In the present study, we developed a simplified method by applying size‐exclusion gel‐filtration chromatography to examine PrP oligomers without proteinase K digestion in Creutzfeldt‐Jakob disease (CJD) samples, and evaluated the correlation between disease severity and the polymerization degree of PrP. Brain homogenates of human CJD and non‐CJD cases were applied to the gel‐filtration spin columns, and fractionated PrP molecules in each fraction were detected by western blot. We observed that PrP oligomers could be detected by the simple gel‐filtration method and distinctly separated from monomeric cellular PrP (PrP^c). PrP oligomers were increased according to the disease severity, accompanied by the depletion of PrP^c. The separated PrP oligomers were already protease‐resistant in the case with short disease duration. In the cases with quite severe pathology the oligomeric PrP reached a plateau, which may indicate that PrP molecules could mostly develop into amyloid fibrils in the advanced stages. The increase of PrP oligomers correlated with the degree of histopathological changes such as spongiosis and gliosis. The decrease of monomeric PrP^c was unexpectedly obvious in the diseased cases. Dynamic changes of both oligomerization of the human PrP and depletion of normal PrP^c require further elucidation to develop a greater understanding of the pathogenesis of human prion diseases.     

Clinicopathological phenotype of codon 129 valine homozygote sporadic Creutzfeldt-Jakob disease

The naturally occurring polymorphism at codon 129 of the human prion protein gene (PRNP) influences susceptibility to sporadic Creutzfeldt-Jakob Disease (CJD); the majority of the patients are methionine homozygotes at this locus, while valine homozygotes represent only 10% of cases. The aim was to study the clinical and neuropathological phenotype of sporadic CJD in valine homozygotes, to estimate the reliability of current clinical diagnostic criteria, and to identify any consistent and distinct features. Twelve cases of sporadic CJD with a codon 129 valine homozygote genotype were identified at the National CJD Surveillance Unit in Edinburgh. In addition to a retrospective clinical analysis, tissue blocks were stained by conventional techniques and by immunocytochemistry for prion protein. Frozen brain tissue was available from five cases for Western blot analysis of PrPRES, which in all cases showed a type 2 mobility. The cases included four males and eight females, average age 63.6 years, with a mean duration of illness of 6 months. Eleven patients presented with ataxia, and none had the characteristic EEG changes found in sporadic CJD. The neuropathological phenotype comprised spongiform change and prion protein immunopositivity most marked in the subcortical grey matter and cerebellum, prion protein positive plaque-like deposits in all regions, laminar deposition of prion protein in the cerebral cortex, and hippocampal involvement (which is seldom reported in sporadic CJD). In conclusion, these cases exhibited a fairly uniform phenotype, which is relatively distinct from sporadic CJD in methionine homozygotes, and thus diagnosis may be difficult using existing clinical criteria.     

Defining the limits of prion disease

The term prion disease applies to any disease in which there is an accumulation in brain of the abnormal isoform of prion protein, known as PrP^sc. These diseases include all the transmissible spongiform encephalopathies of humans and animals and their related atypical forms. Although there are clear clinical and neuropathological indicators in the majority of cases, the atypical forms present particular diagnostic difficulties because their clinical presentation may closely resemble much more common forms of dementia. On pathological examination the brain may show no spongiform encephalopathy, and attempts at transmission are often not successful in these cases. There are various biochemical and immunohistochemical ways in which prion disease can be detected. Some of these require the use of fresh/frozen tissue which is often not available unless prion disease is already suspected. Some previously unsuspected cases have been detected by genetic analysis of the PrP gene. This approach must be used with caution since there are several rare polymorphisms in the PrP gene which are not pathogenic and possession of a pathogenic mutation does not prevent the occurrence of more common neurological disorders at an earlier age, some of which may be treatable.     

A quantitative study of the pathological changes in the cerebellum in 15 cases of variant Creutzfeldt–Jakob disease (vCJD)

Aims : To determine in the cerebellum in variant Creutzfeldt–Jakob disease (vCJD): (i) whether the pathology affected all laminae; (ii) the spatial topography of the pathology along the folia; (iii) spatial correlations between the pathological changes; and (iv) whether the pathology was similar to that of the common methionine/methionine Type 1 subtype of sporadic CJD. Methods : Sequential cerebellar sections of 15 cases of vCJD were stained with haematoxylin and eosin, or immunolabelled with monoclonal antibody 12F10 against prion protein (PrP) and studied using spatial pattern analysis. Results : Loss of Purkinje cells was evident compared with control cases. Densities of the vacuolation and the protease-resistant form of prion protein (PrP^Sc) (diffuse and florid plaques) were greater in the granule cell layer (GL) than the molecular layer (ML). In the ML, vacuoles and PrP^Sc plaques occurred in clusters regularly distributed along the folia with larger clusters of vacuoles and diffuse plaques in the GL. There was a negative spatial correlation between the vacuoles and the surviving Purkinje cells in the ML. There was a positive spatial correlation between the vacuoles and diffuse PrP^Sc plaques in the ML and GL. Conclusions : (i) all laminae were affected by the pathology, the GL more severely than the ML; (ii) the pathology was topographically distributed along the folia especially in the Purkinje cell layer and ML; (iii) pathological spread may occur in relation to the loop of anatomical connections involving the cerebellum, thalamus, cerebral cortex and pons; and (iv) there were pathological differences compared with methionine/methionine Type 1 sporadic CJD.     

Review: Creutzfeldt-Jakob disease: prion protein type, disease phenotype and agent strain

The human transmissible spongiform encephalopathies or human prion diseases are one of the most intensively investigated groups of rare human neurodegenerative conditions. They are generally held to be unique in terms of their complex epidemiology and phenotypic variability, but they may also serve as a paradigm with which other more common protein misfolding disorders might be compared and contrasted. The clinico-pathological phenotype of human prion diseases appears to depend on a complex interaction between the prion protein genotype of the affected individual and the physico-chemical properties of the neurotoxic and transmissible agent, thought to comprise of misfolded prion protein. A major focus of research in recent years has been to define the phenotypic heterogeneity of the recognized human prion diseases, correlate this with molecular-genetic features and then determine whether this molecular-genetic classification of human prion disease defines the biological properties of the agent as determined by animal transmission studies. This review seeks to survey the field as it currently stands, summarize what has been learned, and explore what remains to be investigated in order to obtain a more complete scientific understanding of prion diseases and to protect public health.     

Phenotypic variability in the brains of a family with a prion disease characterized by a 144-base pair insertion in the prion protein gene

The use of prion protein (PrP) immunohistochemistry in neuropathology has allowed identification of prion diseases with otherwise atypical histological features. The brains from family members with familial prion diseases can show marked histological variation. A histological and immunohistochemical study was performed on 10 brains of patients with a familial prion disease caused by a 144-base pair (bp) insertion in the prion protein gene. The histology from the cases showed variability in the severity of spongiform change and astrocytosis in both the cerebellum and the cerebrum. There was also variability in the density of microglial cells. The PrP immunohistochemistry revealed that in nine cases there was a similar patch-like deposition of PrP within the molecular layer of the cerebellum. Although in the cerebellum there did seem to be some correlation between the severity of spongiform change, astrocytosis and the density of microglial cells, there was no such correlation between any of these three parameters and the density of PrP staining. There was deposition of beta-amyloid precursor protein (beta-APP) in the cerebellum, suggesting that disrupted axonal transport had a possible role in the evolution of the disease. The cases illustrate the histological variability that can occur in familial prion diseases despite similarity in PrP staining. They also reveal that the relationship between PrP deposition and cerebral or cerebellar damage might be complex.     

Enhanced Aquaporin‐4 immunoreactivity in sporadic Creutzfeldt‐Jakob disease

Aquaporin‐4 (AQP‐4) is a water channel protein located on the plasma membrane of astrocytes and is regulated under various conditions. In the present study, a series of brains with sporadic Creutzfeldt‐Jakob disease (sCJD) were investigated to determine the possible contribution of AQP‐4 in the development of sCJD pathology. Six cases of subacute spongiform encephalopathy (SSE) and four cases of panencephalopathic (PE)‐type sCJD were included. Increased AQP‐4 immunoreactivity compared to that in controls was observed in all sCJD patients, particularly in the cerebral neocortex and cerebellar cortex. AQP‐4 immunoreactivity was present in the cell bodies and processes of protoplasmic astrocytes in SSE and around cell bodies and processes of hypertrophic astrocytes in PE‐type sCJD. Analysis of serial sections showed the development of sCJD pathology, particularly in neocortical lesions, as follows: PrP deposition; spongiform change and gliosis; enhanced staining for AQP‐4; hypertrophic astrocytosis; and neuronal loss and tissue rarefaction. Strong AQP‐4 immunoreactivity was present in burnt‐out lesions such as those of status spongiosus. These results indicate that increased AQP‐4 expression in sCJD is an early pathologic event and appears to remain until the late disease stage. We suggest that increased expression of AQP‐4 is a pathologic feature of sCJD.