Continuous intraventricular infusion of pentosan polysulfate: Clinical trial against prion diseases

Prion diseases are progressive neurological disorders due to abnormal prion protein (PrP^Sc) deposition in the central nervous system. At present, there is no effective treatment available for any form of prion disease. Pentosan polysulfate (PPS) has been shown to prolong significantly the incubation period in mice with PrP^Sc infection when administered to the cerebral ventricles in preclinical trials. In human studies conducted in European countries and Japan, intraventricular PPS was administered to patients with different forms of prion disease and was well tolerated. We report 11 patients with prion disease treated with intraventricular PPS at Fukuoka University from 2004. Cases included three familial CJD (two with V180I mutation, one GSS with P102L mutation), two iatrogenic CJD, and six sporadic CJD cases. At present, average survival period after treatment was 24.2 months (range, 4–49). Seven cases died of sepsis and pneumonia. Subdural effusion with various degrees was seen on CT scan in most cases. Except for these, adverse effects did not occur in the treatment period. Although our preliminary study of the new treatment with PPS by continuous intraventricular infusion showed no apparent improvement of clinical features in patients with prion disease, the possibility of extended survival in some patients receiving long‐term PPS was suggested.     

Less protease‐resistant PrP in a patient with sporadic CJD treated with intraventricular pentosan polysulphate

Terada T, Tsuboi Y, Obi T, Doh‐ura K, Murayama S, Kitamoto T, Yamada T, Mizoguchi K. Less protease‐resistant PrP in a patient with sporadic CJD treated with intraventricular pentosan polysulphate.
Acta Neurol Scand: 2010: 121: 127–130.
© 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Treatment with intraventricular pentosan polysulphate (PPS) might be beneficial in patients with Creutzfeldt–Jakob disease. We report a 68‐year‐old woman with sporadic Creutzfeldt–Jakob disease who received continuous intraventricular PPS infusion (1–120 μg/kg/day) for 17 months starting 10 months after the onset of clinical symptoms. Treatment with PPS was well tolerated but was associated with a minor, transient intraventricular hemorrhage and a non‐progressive collection of subdural fluid. The patient’s overall survival time was well above the mean time expected for the illness but still within the normal range. Post‐mortem examination revealed that the level of abnormal protease‐resistant prion protein in the brain was markedly decreased compared with levels in brains without PPS treatment. These findings suggest that intraventricular PPS infusion might modify the accumulation of abnormal prion proteins in the brains of patients with sporadic Creutzfeldt–Jakob disease.     

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.     

Intraventricular pentosan polysulphate in human prion diseases: an observational study in the UK

Background, purpose and methods:  This observational study assessed the effect of continuous intraventricular infusion of pentosan polysulphate (PPS) in seven patients at different clinical centres in the UK.
Results:  Complications of intraventricular catheterization were frequent. PPS was well-tolerated over a wide dose range (11–110  μ g/kg/day) during the 6-month study. Four patients were assessed for the entire study period: one remained stable, two showed minimal deterioration and one progressed significantly.
Conclusion:  Mean survival of all patients was longer than reported values for natural history of specific prion disorders. Possible reasons for these findings are explored.     

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.     

An autopsied case of panencephalopathic‐type Creutzfeldt‐Jakob disease with mutation in the prion protein gene at codon 232 and type 1 prion protein

In this study, we describe the clinicopathologic findings in a 68‐year‐old man with panencephalopathic‐type CJD with a substitution from methionine to arginine at codon 232 (M232R) in the prion protein (PrP) gene and type 1 PrP. Initial symptoms of the patient were a rapidly progressive memory disturbance and disorientation. The patient showed myoclonus and periodic sharp‐wave complexes on electroencephalogram in the early stages of disease. Diffusion‐weighted MRI along with the presence of both neuron‐specific enolase and 14‐3‐3 protein in the CSF showed similarities to classic‐type sporadic CJD. The patient reached the akinetic mutism state 2 months following the onset of symptoms and died after 13 months. Neuropathologic examination revealed panencephalopathic‐type CJD pathology including widespread neuron loss with severe hypertrophic astrocytosis and status spongiosus in the cerebral gray matter, particularly in the neocortex. Cerebral white matter and the cerebellum also showed severe involvement. Immunohistochemical staining for PrP showed diffuse gray matter staining, indicating synaptic‐type PrP deposition without plaque‐type. Two different clinical phenotypes of M232R CJD were recognized despite the presence of the same PrP genotype, and the present case is speculated to correspond to the rapid‐type.     

Human prion diseases: Molecular,cellular and population biology

The past 20 years have witnessed a dramatic resurgence of interest in a hitherto obscure neurodegenerative disease, Creutzfeldt‐Jakob disease (CJD). This was driven partly by the novelty of the prion hypothesis, which sought to provide an explanation for the pathogenesis of transmissible spongiform encephalopathies, involving a unique epigenetic mechanism, and partly by events in the UK, where an outbreak of a new prion disease in cattle (bovine spongiform encephalopathy or BSE) potentially exposed a large section of the UK population to prion infectivity through a dietary route. The numbers of cases of the resultant novel disease variant CJD (vCJD), have so far been limited and peaked in the UK in the year 2000 and have subsequently declined. However, the effects of BSE and vCJD have been far‐reaching. The estimated prevalence of vCJD infection in the UK is substantially higher than the numbers of clinical cases would suggest, posing a difficult dilemma for those involved in blood transfusion, tissue transplantation and cellular therapies. The clinico‐pathological phenotype of human prion diseases has come under close scrutiny and molecular classification systems have been developed to account for the different diseases and their phenotypic spectra. Moreover, enhanced human and animal surveillance and better diagnostic tools have identified new human and animal prion diseases. Lastly, as the prion hypothesis has gained widespread acceptance, the concepts involved have been applied to other areas, including extra‐chromosomal inheritance in fungi, long‐term potentiation in memory formation and the spread of molecular pathology in diverse conditions, such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Studies at the molecular and cellular level have helped to provide a better understanding of human prion diseases, aided pathological diagnosis and helped inform public health decision‐making.     

A case of sporadic Creutzfeldt‐Jakob disease with both plaque and synaptic‐type deposition of prion protein

We report a Japanese case of sporadic Creutzfeldt‐Jakob disease (CJD) with particular clinical course and neuropathological findings. A 74‐year‐old female exhibited parkinsonism and later, dementia, myoclonus as well as visual hallucinations, lacking periodic synchronous discharges in the electroencephalogram. The duration of her illness was 2 years, longer than typical CJD cases which average 8 months’ duration. Gray matter was severely affected, the Ammon’s horn and subicular cortex were well preserved and many kuru plaques were observed in the cerebellum using routine histological stainings. Immunohistochemistry for prion protein (PrP) using both formic acid and hydrolytic autoclaving pretreatment revealed numerous prion plaques throughout the brain together with intense synaptic‐type deposition of PrP^CJD (abnormal isoform of PrP) in all gray matter examined, particularly in the Ammon’s horn and subicular cortex. The definite combination of these two types of stain has never been reported previously in Japan other than in Gerstmann‐Sträussler– Scheinker syndrome. Relative resistance of the Ammon’s horn and subicular cortex to the PrP^CJD deposition is also discussed.     

A traceback phenomenon can reveal the origin of prion infection

The transmission of prions to animals with incongruent prion protein (PrP) gene (referred to as cross‐sequence transmission) results in a relatively long incubation period and can generate a new prion strain with unique transmissibility designated as a traceback phenomenon. For example, cross‐sequence transmission of bovine spongiform encephalopathy (BSE) prions to human generated variant Creutzfeldt‐Jakob disease (vCJD) prions which retained the transmissibility to mice expressing bovine PrP. This finding suggests that traceback studies could enable us to identify the origin of prions. There are two distinct phenotypes in dura mater graft‐associated Creutzfeldt‐Jakob disease (dCJD), with the majority represented by a non‐plaque‐type of dCJD (np‐dCJD) and the minority by a plaque‐type of dCJD (p‐dCJD). To identify the origin of p‐dCJD, we performed a traceback study using mice expressing human PrP with methionine homozygosity (129M/M) or valine homozygosity (129V/V) at polymorphic codon 129. The characteristics of p‐dCJD such as the accumulation of abnormal isoform of PrP (PrP^Sc) intermediate in size between type 1 and type 2, and plaque‐type PrP deposition in the brain were maintained after transmission to the 129M/M mice. Furthermore, the 129V/V mice were more susceptible to p‐dCJD prions than the 129M/M mice and produced type 2 PrP^Sc that were identical in size to those from the 129V/V mice inoculated with sporadic CJD prions from a patient with 129V/V and type 2 PrP^Sc (sCJD‐VV2). In addition, we performed intracerebral transmission of sCJD‐VV2 prions to the 129M/M mice as an experimental model for p‐dCJD. These 129M/M mice showed the accumulation of the intermediate type PrP^Sc and plaque‐type PrP deposition in the brain. These results suggest that p‐dCJD could be caused by cross‐sequence transmission of sCJD‐VV2 prions to individuals with the 129M/M genotype.     

Autopsy case of Creutzfeldt–Jakob disease with Met/Val heterozygosity at codon 129 and type 1 protease‐resistant prion protein presenting some florid‐type plaques and many Kuru plaques in the cerebellum

We report an atypical case of CJD. The clinical course was similar to a classic CJD phenotype, but histopathological study revealed several florid‐type plaques in the amygdale and abundant Kuru plaques in the cerebellum that are atypical of classic CJD. Molecular analysis showed methionine/valine heterozygosity at codon 129 and no pathogenic mutation in the coding region of the prion protein gene. Western immunoblots revealed type 1 protease‐resistant prion protein (PrPres), and a ration analysis of PrPres showed a high ratio of the diglycosylated form and a low ratio of the non‐glycosylated form. Our case could not be precisely classified in any of Parchi’s six variants. It suggests the existence of some factors that determine the phenotypic variability other than the codon 129 genotypes in the PrP gene or the physicochemical properties of PrPres.     

An autopsied case of V180I Creutzfeldt‐Jakob disease presenting with panencephalopathic‐type pathology and a characteristic prion protein type

A 73‐year‐old Japanese woman showed slowly progressive aphasia, apraxia and dementia. She had no family history of prion disease or dementia. One year later she showed parkinsonism and corticobasal degeneration was initially suspected. On MRI, the left temporal neocortex seemed swollen on T2‐weighted images in the initial stage, and a later high‐signal intensity region was observed in the cerebral cortex in diffusion‐weighted images. The patient developed myoclonus and an akinetic mutism state 15 months and 22 months after onset, respectively. Consecutive electroencephalography revealed no periodic sharp‐wave complexes. Prion protein (PrP) gene analysis revealed a valine to isoleucine point mutation at codon 180, and methionine homozygosity at codon 129. This patient's clinical symptoms and disease course were atypical for Creutzfeldt–Jakob disease (CJD), and a stable state with nasal tube‐feeding lasted several years. She died of respiratory failure at the age of 81, 102 months after the onset. Autopsy revealed widespread spongiform degeneration with weak synaptic‐type PrP deposition, confirming the diagnosis of genetic CJD. Neurons in the cerebral cortex were relatively preserved in number and hypertrophic astrocytosis was generally moderate for such long‐term disease, but cerebral white matter showed diffuse severe myelin pallor with tissue rarefaction suggestive of panencephalopatic‐type pathology. The cerebellar cortex was relatively well preserved with observation of mild spongiform change in the molecular layer, moderate neuron loss in the Purkinje neuron layer, and scattered small plaque‐like PrP deposition. Western blot analysis of protease‐resistant PrP showed a characteristic pattern without a diglycoform band. V180I CJD is an interesting form of genetic CJD with regards to the clinicopathologic, molecular and genetic findings.     

An autopsy case of Creutzfeldt‐Jakob disease with a V180I mutation of the PrP gene and Alzheimer‐type pathology

We report an autopsy case of Creutzfeldt‐Jakob disease with a codon 180 point mutation of the prion protein gene (PRNP). A 77‐year‐old woman developed gait instability, followed by dementia and limb/truncal ataxia. She became akinetic and mute 18 months and died of pneumonia 26 months after the disease onset. Analysis of the PRNP gene revealed a codon 180 point mutation. Post‐mortem examination revealed marked spongiosis, neuronal loss, and astrocytic gliosis in the cerebral cortex. Mild to moderate spongiosis and neuronal loss were observed in the limbic cortex and basal ganglia. There was no spongiform change in the hippocampus, brain stem or cerebellum. Many senile plaques and neurofibrillary tangles were found, and the Braak stages were stage C and stage IV, respectively. Immunostaining for prion protein (PrP) revealed granular (synaptic‐type) and patchy PrP deposition in the cerebral cortex and especially in the hippocampus. Most patchy PrP deposits were colocalized with amyloid β plaques, but some of them were isolated. The relatively strong PrP deposition and coexistence of Alzheimer‐type pathology of this case are remarkable. We suppose that amyloid β plaques might act as a facilitating factor for PrP deposition.     

An autopsied case of Creutzfeldt‐Jakob disease with mutation in the prion protein gene codon 232 and type 1+2 prion protein

A 68‐year‐old Japanese man gradually showed abnormal behavior and gait disturbance with bradykinesia. Slowly progressive dementia, including memory disturbance and disorientation, was also observed. Cerebral cortical hyperintensity on diffusion‐weighted MRI was observed 6 months after onset. The patient progressed to an akinetic mutism state with mild myoclonus, and atypical periodic sharp‐wave complexes were observed by electroencephalogram 13 months after onset. He was clinically suspected of having atypical CJD and died after 19 months total disease duration. The brain weighed 1160 g and showed mild atrophy of the cerebrum and cerebellum with ventricular dilatation. Spongiform changes with varying vacuole size and gliosis was extensive in the cerebral cortex and basal ganglia. Neuron loss in the cerebral cortex, basal ganglia and thalamus was relatively mild. The cerebellum showed mild spongiform changes of the molecular layer and mild neuron loss in the Purkinje cell layer. PrP immunostaining showed mainly coarse‐type combined with diffuse synaptic‐type PrP deposition in the cerebral gray matter. Some perivacuolar‐type PrP deposition was also present. Numerous plaque‐type PrP depositions were observed in the molecular layer of the cerebellum. Analysis of the PrP gene revealed a methionine‐to‐arginine (Met‐to‐Arg) substitution at codon 232 (M232R) with Met homozygosity at codon 129. Western blot analysis of protease‐resistant PrP indicated type 2 dominant PrP combined with type 1. Genetic CJD with M232R substitution in the PrP gene has only been reported in Japan. Although two clinical phenotypes (rapid‐type and slow‐type) were suggested in the M232R CJD cases (despite the presence of the same PrP genotype), the pathological and molecular backgrounds have not been well understood because there have only been a few autopsied case reports. This is the first case report of M232R CJD presenting with 1 + 2 PrP.     

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.     

MM1‐type sporadic Creutzfeldt‐Jakob disease with 1‐month total disease duration and early pathologic indicators

A 62‐year‐old man presented with abnormal behavior and cognitive impairment. Diffusion‐weighted images (DWI) obtained on MRI showed extensive hyperintense regions in the cerebral cortex and striatum. Myoclonus was recognized, and the patient died 1 month after the onset; his condition did not reach the akinetic mutism state. The brain weighed 1300 g and showed no apparent atrophy. Extensive spongiform changes were observed in the cerebral neocortex, striatum, thalamus and cerebellar cortex, but gliosis was mild or absent. Neuropil rarefaction and neuron loss were not apparent. Mild proliferation of anti‐ GFAP‐positive astrocytes was observed in the cerebral cortex, but unaffected regions were noted. Regions without spongiform changes and GFAP‐positive astrocytes included the hippocampal formation and subiculum. PrP immunostaining showed extensive diffuse synaptic‐type PrP deposition in the gray matter, including the hippocampal region, but it was also mild. PrP gene analysis revealed no mutation with methionine homozygosity at polymorphic codon 129. Western blot analysis of proteinase K‐resistant PrP indicated type 1 PrP^Sc. The clinicopathological findings of the present case confirm several hypotheses: (i) the earliest pathologic evidence observed by HE staining in CJD are spongiform changes; (ii) DWI hyperintense regions indicate these spongiform changes; and (iii) regions without spongiform changes, gliosis and proliferation of GFAP‐positive astrocytes, but with PrP deposition, exist in the early disease stage.     

“Preclinical” MSA in definite Creutzfeldt‐Jakob disease

Multiple system atrophy (MSA) is a sporadic alpha‐synucleinopathy clinically characterized by variable degrees of parkinsonism, cerebellar ataxia and autonomic dysfunction. The histopathological hallmark of MSA is glial cytoplasmic inclusion (GCI). It is considered to represent the earliest stage of the degenerative process in MSA and to precede neuronal degeneration. Sporadic Creutzfeldt‐Jakob disease (sCJD) is a fatal, rapidly progressive dementia generally associated with ataxia, pyramidal and extrapyramidal symptoms and myoclonus. Definite diagnosis needs neuropathological demonstration of variable degrees of spongiform degeneration of neuropil, neuronal loss, astro‐ and microgliosis, and the presence of abnormal deposits of the misfolded prion protein PrP^res. Both diseases, CJD and MSA are infrequent among neurodegenerative diseases. In the present report we describe clinical and neuropathological findings of a previously healthy 64‐year‐old woman who developed symptoms of classical CJD. At post mortem examination, the brain showed in addition to classical methionine/methionine PrP^res type 1 (MM1) sCJD changes and moderate Alzheimer‐type pathology, features of “preclinical” MSA with minimal histopathological changes. These were characterized by discrete amounts of alpha‐synuclein immunoreacive glial cytoplasmic inclusions in the striato‐nigral system, isolated intraneuronal inclusions in pigmented neurons of the substantia nigra, as well as some vermiform intranuclear inclusions. To our knowledge, this is the first report on the coexistence of definite sCJD and “minimal changes” MSA in the same patient.     

Rhythmic pupillary oscillation in Creutzfeldt‐Jakob disease associated with the Glu/Lys mutation of prion protein codon 200

We report two Creutzfeldt‐Jakob disease (CJD) patients with rhythmic pupillary and palpebral oscillation who had a mutation of prion protein codon 200 that resulted in the substitution of lysine for glutamate (Glu/Lys). Alternating dilation and constriction of the pupils combined with elevation and descent of the eyelids occurred in correspondence with periodic sharp wave complexes (PSWCs) on the electroencephalogram and with myoclonus of the head, face, and extremities. The onset of pupillary dilation and palpebral elevation coincided with the PSWCs. Initiation of these rhythmic pupillary and palpebral movements may depend on sympathetic activity, but the site of the generator is unclear. Such rhythmic pupillary and palpebral oscillation may be a feature of rapidly progressive CJD with predominant right hemispheric involvement. © 2009 Movement Disorder Society