Immunohistochemical verification of senile and kuru plaques in Creutzfeldt-Jakob disease and the allied disease

A critical review of atypical cerebellum-type Creutzfeldt-Jakob disease: its relationship to "new variant" CJD and bovine spongiform encephalopathy

Shortly after the appearance of bovine spongiform encephalopathy (BSE), Creutzfeldt-Jakob disease (CJD) was identified in young patients with nonclassical presentation such as difficulty in balancing and ataxia. The classical CJD in older patients starts with dementia. To distinguish between the two types, CJD in young persons has been termed "new variant" (nvCJD). The distinguishing features of classical CJD include initial presentation with dementia, confluent spongiform changes are very unusual in the cerebellum, and PrP plaques are rarely observed. For nvCJD, initially, difficulty with balancing and ataxia occurs, confluent spongiform changes are seen in the cerebellum, and a large number of PrP plaques are seen. The icelandic observation of sheep scrapie revealed a predominantly ataxic form of scrapie, termed Type II, rather than the itchy form termed Type I. Both types have been known to exist in Europe. Since the clinical signs of Type II scrapie in sheep with trembling and ataxia are similar to those seen in BSE and nvCJD, this suggests that Type II is the cause of BSE and nvCJD. Over 8 years, from 1989 to 1996, I examined the clinical histories of 33 CJD cases aged between the ages of 18 and 84. Six under the age of 40 and 15 over the age of 40 had leading clinical features such as difficulty in balancing and ataxia similar to those seen in the young cases classified as "nvCJD." Brains were examined from the six of 15 cases over the age of 40, which revealed similar pathology to that seen in young patients classified as "nvCJD." These findings suggest that all age groups are susceptible to the strain of the agent derived from BSE cattle.

Is ataxic gait the predominant presenting manifestation of Creutzfeldt-Jakob disease? Experience of 14 Chinese cases from Taiwan

Creutzfeldt-Jakob disease (CJD) is caused by an unusual prion protein. Rare CJD cases have been reported in Chinese individuals. This report describes the clinical manifestations of 14 Chinese individuals with clinically definite CJD from the National Taiwan University Hospital during the period 1976-1995. It is the largest case series of Chinese CJD up to now. All these patients fulfil the clinical definite diagnosis of CJD proposed by Brown et al. (1986), including rapidly evolving dementia, myoclonus, periodic electroencephalographic (EEG) activity (0.5-2 Hz) and death within 12 months. The clinical characteristics of the present series, including age at onset, sex ratio, duration, initial symptoms, neurological signs, EEG abnormalities, and neuroimaging studies were similar to those reported in other countries. However, there is a high incidence of initial ataxic gait as the presentation in our patients. Eight (57%) out of 14 patients initially had gait ataxia alone or in association with dementia. CJD should be considered in the differential provisional diagnosis of any middle-aged patient with a progressive ataxic syndrome.

Creutzfeldt-Jakob disease with Alzheimer-type A beta-reactive amyloid plaques

Creutzfeldt-Jakob disease and Gerstmann-Sträussler-Scheinker syndrome are classified as transmissible cerebral amyloidoses, in contrast to the non-transmissible amyloidoses of Alzheimer's disease type. While the aetiologies of Creutzfeldt-Jakob disease and Alzheimer's disease and the molecular composition of their amyloids are different, similar basic pathogenetic mechanisms operate in both diseases through synthesis and processing of amyloid precursor proteins, to produce an accumulation of amyloid deposits. We report here a case of Creutzfeldt-Jakob disease exhibiting numerous diffuse A beta immunoreactive plaques, thus presenting features of both Creutzfeldt-Jakob disease and Alzheimer's disease. The existence of such cases underlines the existence of a 'grey' area between the two types of amyloidoses.

Gerstmann-Sträussler-Scheinker disease showing beta-protein type cerebellar and cerebral amyloid angiopathy

Cerebral amyloid angiopathy is observed in several brain degenerative disorders, but this pathological condition has received little attention in Gerstmann-Sträussler-Scheinker disease (GSS). We report a 69-year-old man who showed the cardinal features of GSS together with typical and extensive congophilic angiopathy. Immunohistochemical studies revealed that the vast majority of the amyloid plaques present in the brain of this patient were consistently labeled by anti-prion protein (PrP) antibody. Double immunostaining disclosed many additional beta-protein immunoreactive plaque-like lesions, including a special type of "hybrid" plaque with colocalization of PrP and beta-protein (beta-PrP). The vascular amyloid deposits seen in both the cerebellum and cerebrum were immunoreactive only to anti-beta-protein antibody. It seems likely that the extensive deposition of beta-protein amyloid (including brain vascular amyloidosis) seen in this and other similar cases is part of pathology of GSS, although the possibility that this finding is due to ageing or concomitant Alzheimer's disease cannot be completely ruled out.

Iatrogenic Creutzfeldt-Jakob disease in three growth hormone recipients: a neuropathological study

Since 1985, several cases of Creutzfeldt-Jakob disease, occurring after a treatment by human cadaveric hormone have been reported. Three new iatrogenic cases observed in French patients (two children and one young adult) are described here. Neuropathological study displayed the classical aspects of previously reported sporadic cases of Creutzfeldt-Jakob disease in adults, including severe cortical spongiform change with numerous vacuoles within neuronal dendrites, diffuse astrogliosis and neuronal loss. In addition, the iatrogenic cases described here included two more unusual points: (i) they were homozygotic for the PrP gene on codon 129 and therefore a genetic predisposition could be suspected; (ii) numerous kuru plaques were scattered in the cerebral cortex, the subcortical white matter and in the cerebellar cortex. They were decorated with a PrP monoclonal antibody, but not with a beta A4 antibody. This last point underlines the similarities between iatrogenic Creutzfeldt-Jakob disease and kuru.

Prion protein preamyloid and amyloid deposits in Gerstmann-Sträussler-Scheinker disease, Indiana kindred

Gerstmann-Sträussler-Scheinker disease (GSS) is a familial neurological disorder pathologically characterized by amyloid deposition in the cerebrum and cerebellum. In GSS, the amyloid is immunoreactive to antisera raised against the prion protein (PrP) 27-30, a proteinase K-resistant peptide of 27-30 kDa that is derived by limited proteolysis from an abnormal isoform of a neuronal sialoglycoprotein of 33-35 kDa designated PrPSc. Polyclonal antibodies raised against synthetic peptides homologous to residues 15-40 (P2), 90-102 (P1), and 220-232 (P3) of the amino acid sequence deduced from hamster PrP cDNA were used to investigate immunohistochemically the distribution of PrP and PrP fragments in the brains of two patients from the Indiana kindred of GSS. Two types of anti-PrP-immunoreactive deposits were found: (i) amyloid deposits, which were exclusively labeled by anti-P1 antiserum to residues 90-102 of PrP, and (ii) preamyloid deposits, which were labeled by all anti-PrP antisera but did not exhibit the tinctorial and optical properties of amyloid. The latter appeared as diffuse immunostaining of the neuropil that targeted to areas in which amyloid deposits were most abundant. They were partially resistant to proteinase K digestion and consisted ultrastructurally of amorphous, flaky, electron-dense material. These findings substantiate our previous observation that the major amyloid component in the GSS Indiana kindred is an internal fragment of PrP and indicate that full-length abnormal isoforms of PrP and/or large PrP fragments accumulate in brain regions most affected by amyloid deposition. These findings support the view that in the GSS Indiana kindred a stepwise degradation of PrP occurs in situ in the process of amyloid fibril formation.

Ubiquitin-reactive axons have a widespread distribution and are unrelated to prion protein plaques in Creutzfeldt-Jakob disease

The amyloid plaques of Alzheimer disease (AD) are surrounded by dystrophic axons that contain ubiquitinated dense bodies. To investigate whether deposits of other types of amyloid cause axonal degeneration we studied 5 cases of Creutzfeldt-Jakob disease (CJD) with immunocytochemical methods using ubiquitin and prion protein (PrP) antisera. One of these cases contained PrP plaques in the cerebellum. In all cases dystrophic axons, which contain ubiquitinated dense bodies, were observed in neocortical and cerebellar grey matter, in absence of PrP-reactive amyloid deposits. Only a minority of PrP plaques present in the cerebellum was associated with ubiquitin positive neurites. The results indicate that, unlike in AD, the occurrence of ubiquitinated dystrophic axons is independent from amyloid deposition in CJD and is likely to be a primary phenomenon.

Comparative ultrastructural neuropathology of naturally occurring bovine spongiform encephalopathy and experimentally induced scrapie and Creutzfeldt-Jakob disease

We report the ultrastructural neuropathology of bovine spongiform encephalopathy (BSE), a recently described slow virus disease first recognized in Friesian/Holstein cattle, and compare it to that of experimental scrapie and Creutzfeldt-Jakob disease. The spongiform change, which was most pronounced in the central grey matter of the midbrain, consisted of membrane-bound vacuoles within neuronal processes, containing curled membrane fragments, secondary chambers and vesicles. Axons and dendrites accumulated whorls of neurofilaments and other subcellular organelles, such as mitochondria and dense bodies, which were entrapped within the filamentous masses. Other neurites accumulated electron-dense bodies, and still others electron-lucent cisterns and branching tubules. Membrane-bound neuronal inclusions, composed of tubules measuring 10 nm in diameter, were found in axonal terminals. Tubulovesicular structures were loosely packed and were occasionally surrounded by a common membrane, a finding previously described only in natural scrapie in sheep. Except for the intraneuronal inclusions, all of the ultrastructural features of BSE resembled those found in scrapie and Creutzfeldt-Jakob disease.

Immunoreactivity of cerebral amyloidosis is enhanced by protein denaturation treatments

We investigated paraffin-embedded brain sections from three patients with Gerstmann-Sträussler syndrome and three patients with Alzheimer's disease or senile dementia of Alzheimer type using anti-human prion protein antisera and anti-beta/A4 protein antisera after protein denaturation treatments. After incubation with guanidine-thiocyanate, trichloroacetate, and phenol, the immunoreactivity of kuru plaques and senile plaques was enhanced to the same level as the formic acid treatment. These treatments revealed small compact amyloid deposits, amyloid deposits surrounding the plaque cores, and diffuse plaques. Most of these chemicals changed the congophilia of both amyloids. It is possible that these treatments denature amyloid fibril proteins and break down the structure of amyloid fibrils, thus revealing buried epitopes.

PrP amyloid plaques in Creutzfeldt-Jakob disease of short duration: immunohistochemical studies of 5 cases from Poland

We report here PrP-immunohistochemistry performed on brains from CJD cases from Poland. Only one of five definitive CJD cases exhibited typical PrP-immunoreactive kuru-like plaques and this was case of a short duration. We thus confirm the low frequency of PrP plaques in CJD of Eastern and Central European origin.

Ubiquitin immunoreactivity in kuru plaques in Creutzfeldt-Jakob disease

Cerebellar kuru plaques in 2 cases of Creutzfeldt-Jakob disease were studied immunohistochemically. Similar to cerebellar senile plaques in Alzheimer's disease, many kuru plaques contained ubiquitin-positive, tau-negative small granular elements, presumably representing dystrophic neurites. Our results suggest that similar mechanisms are involved in neuritic changes in cerebellar plaques in Creutzfeldt-Jakob and Alzheimer's diseases despite differences of amyloid proteins in the plaques.

The pathogenesis and progression of the pathological changes of Alzheimer's disease

In this paper, it is argued that the earliest morphological changes of Alzheimer's disease involve the formation of the senile plaque. Key molecular events in this process implicate a deposition of amyloid (A4) protein and an accumulation of an oligosaccharide. These 'preplaques' do not contain neurites, and may first appear in the hippocampus and amygdala, but later involving all association areas of cortex. They may be caused by a capillary defect leading to an altered blood-brain barrier function. The amyloid protein later increases, becomes arranged in a beta-pleated manner recognizable by thioflavin and at this stage plaques also usually contain paired helical filaments within neurites. Similar filaments also form the neurofibrillary tangles of affected perikarya, appearing initially within the large neurones of the entorhinal cortex, but later affecting neurones widely throughout the hippocampus, amygdala, cortex and subcortex. Tangle accumulation leads to impairment of neurone function, development of clinical dementia and ultimately, cell death. Progression of this process leads to extensive cortical plaque and also of those anatomically projecting to the affected cortex.