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Biomedical subjects

H A Kretzschmar

Publications and source records attributed to H A Kretzschmar.

At least 19 recordsLinked to original sources

Significant association of a M129V independent polymorphism in the 5' UTR of the PRNP gene with sporadic Creutzfeldt-Jakob disease in a large German case-control study.

BACKGROUND: A single nucleotide polymorphism (SNP) in the coding region of the prion protein gene (PRNP) at codon 129 has been repeatedly shown to be an associated factor to sporadic Creutzfeldt-Jakob disease (sCJD), but additional major predisposing DNA variants for sCJD are still unknown. Several previous studies focused on the characterisation of polymorphisms in PRNP and the prion-like doppel gene (PRND), generating contradictory results on relatively small sample sets. Thus, extensive studies are required for validation of the polymorphisms in PRNP and PRND. METHODS: We evaluated a set of nine SNPs of PRNP and one SNP of PRND in 593 German sCJD patients and 748 German healthy controls. Genotyping was performed using MALDI-TOF mass spectrometry. RESULTS: In addition to PRNP 129, we detected a significant association between sCJD and allele frequencies of six further PRNP SNPs. No significant association of PRND T174M with sCJD was shown. We observed strong linkage disequilibrium within eight adjacent PRNP SNPs, including PRNP 129. However, the association of sCJD with PRNP 1368 and PRNP 34296 appeared to be independent on the genotype of PRNP 129. We additionally identified the most common haplotypes of PRNP to be over-represented or under-represented in our cohort of patients with sCJD. CONCLUSION: Our study evaluated previous findings of the association of SNPs in the PRNP and PRND genes in the largest cohorts for association study in sCJD to date, and extends previous findings by defining for the first time the haplotypes associated with sCJD in a large population of the German CJD surveillance study.

5' Untranslated Regions↗

Sporadic Creutzfeldt-Jakob disease: clinical and diagnostic characteristics of the rare VV1 type.

BACKGROUND: Recently, six molecular subtypes of sporadic CJD (sCJD) have been identified showing differences regarding the disease course, neuropathologic lesion patterns, and sensitivity to diagnostic tools. Only isolated cases of the rare VV1 type have been reported so far. OBJECTIVE: To describe the clinical characteristics and neuropathologic lesion profiles in nine cases. METHODS: In the years 1993 until late 2003, 571 definite neuropathologically confirmed cases of sporadic CJD were identified in Germany. Of these, nine were homozygous for valine and displayed type 1 of the pathologic PrPSc in the brain (VV1 type). RESULTS: The authors describe eight men and one woman belonging to the VV1 type. All patients were relatively young at disease onset (median 44 years vs 65 years in all sCJD) with prolonged disease duration (median 21 months vs 6 months in all sCJD). During the initial stages, their main clinical signs were personality changes and slowly progressive dementia as well as focal neurologic deficits. None of the nine VV1 patients had periodic sharp-wave complexes (PSWCs) in the EEG. Only two out of seven displayed the typical signal increase of the basal ganglia on MRI, whereas signal increase of the cortex was seen in all patients. The 14-3-3 protein levels were elevated in CSF in all cases tested. CONCLUSIONS: The clinical diagnosis of the VV1 type of sCJD can be best supported by the 14-3-3 test and cortical signal increase on MRI. Because of the young age at onset vCJD is sometimes suspected as a differential diagnosis. MRI plays an important role in differentiating these two disease types and should be performed early during the disease course.

14-3-3 Proteins↗

A new family with frontotemporal dementia with intronic 10+3 splice site mutation in the tau gene: neuropathology and molecular effects.

Mutations in the tau gene cause familial frontotemporal dementia with parkinsonism linked to chromosome 17 characterized by filamentous tau protein deposits. Here we describe the clinical and neuropathological features of a case from a newly identified family with an intron 10+3-splice site mutation in the tau gene. The proband presented with severe personality changes and stereotyped speech followed by parkinsonian symptoms. He died at age 56 after a disease duration of approximately 6 years. At autopsy, there was marked frontotemporal degeneration with abundant tau-immunoreactive neuronal and glial inclusions widespread in the cortex and brainstem. RT-PCR analysis revealed a 3.7-fold increase of tau transcripts with exon 10, resulting in an 1.7-fold higher expression level of 4-repeat tau isoforms in soluble tau fractions when compared to control brains and exclusively 4-repeat tau isoforms in the sarcosyl-insoluble tau fractions. In accordance with the hypothesis that the overexpression leads to saturation of microtubule binding sites and an increase of unbound 4-repeat tau isoforms which assemble into filaments, the neuronal and glial inclusions in this case were exclusively composed of 4-repeat tau isoforms. The clinical and neuropathological data of this family are compared with results from the two other published families with the intron 10 + 3 mutation, the MSTD and the SOT 254 family.

Base Sequence↗

Immunoglobulins and virus-specific antibodies in patients with Creutzfeldt-Jakob disease.

OBJECTIVES: Cerebrospinal fluid (CSF) pattern in patients with neuropathologically diagnosed Creutzfeldt-Jakob disease was analyzed. MATERIAL AND METHODS: Routine tests included white blood cells count, protein, albumin, immunoglobulins and the presence of oligoclonal immunoglobulin G (IgG) in the CSF as well as the calculation of intrathecal synthesis of immunoglobulins by standard methods. In addition, antibodies against neurotropic viruses such as measles, rubella, varicella zoster and herpes simplex were measured and the specific antibody index was calculated. RESULTS: A blood-CSF barrier dysfunction was observed in six of 25 cases. In CSF/serum quotient diagrams, no patient had intrathecally synthesized immunoglobulins, but in two of 25 patients oligoclonal bands were detected. Two patients had intrathecally synthesized antibodies against varicella zoster and three against herpes simplex virus. CONCLUSION: In conclusion, in the routine diagnosis, the CSF in CJD is normal in most cases. In some patients, abnormalities include the blood-CSF barrier dysfunction, mild pleocytosis, oligoclonal bands and intrathecally synthesized viral antibodies.

Antibodies, Viral↗

Breaking an absolute species barrier: transgenic mice expressing the mink PrP gene are susceptible to transmissible mink encephalopathy.

Transmissible mink encephalopathy (TME) is a rare disease of the North American mink, which has never been successfully transmitted to laboratory mice. We generated transgenic mice expressing the mink prion protein (PrP) and inoculated them with TME or the mouse-adapted scrapie strain 79A. TME infected mink PrP-transgenic mice on a murine PrP knockout background. The absolute species barrier between the infectious agent of TME and mice was therefore broken. Following TME and 79A infection of mice carrying both mink and murine PrP(C), only proteinase-resistant PrP homologous to the incoming agent was detectable. The presence of the murine PrP(C) prolonged the incubation time of TME substantially.

Animals↗

Pattern of interleukin-6 receptor complex immunoreactivity between cortical regions of rapid autopsy normal and Alzheimer's disease brain.

Involvement of the interleukin-6 receptor complex (IL-6RC) in neuroregulatory and immunological processes of the brain and particularly in Alzheimer's disease (AD) has been hypothesized. The functionally active IL-6RC consists of the cytokine IL-6, which acts through the ligand binding IL-6R and the signal transducing gp130. Using a new immunocytochemical protocol on rapid autopsy cryostat brain sections we studied the expression of the IL-6RC in Braak IV-V staged AD patients compared to normal age-matched controls (HC) across five different cortical regions. Inter-rater reliability of the method was high. The "baseline" expression in normal human brain was determined for IL-6,IL-6R and gp130 in all cortical regions. In normal tissue IL-6 expression was lower in parietal cortex. Higher IL-6R expression was shown in frontal, occipital and parietal cortex, lower expression in temporal cortex and cerebellum. In AD IL-6 expression levels were generally increased in parietal cortex and decreased in occipital cortex compared to controls. IL-6R expression levels were strongly increased in AD frontal and occipital cortex and decreased in temporal cortex and cerebellum. Our findings indicate an altered cortical immunoreactivity pattern of the functional IL-6RC in AD supporting the hypothesis of a disease-related role of IL-6 in AD pathophysiology.

Aged↗

Signs of rapidly progressive dementia in a case of intravascular lymphomatosis.

Intravascular lymphomatosis (IVL), a rare type of non-Hodgkin's lymphoma, is an uncommon cause of progressive dementia, usually followed by death within a few months of onset of clinical disease. Often this aggressive tumor is only diagnosed at autopsy, because of misleading clinical features mimicking a broad spectrum of syndromes and the absence of circulating lympoma cells in the blood, bone marrow or cerebrospinal fluid in many cases. Here we present IVL in a 78-year-old woman with findings leading to the clinical diagnosis of vascular dementia with sudden beginning and positive 14-3-3 protein in the CSF, commonly reported in Creutzfeldt-Jakob disease (CJD).

14-3-3 Proteins↗

Follow-up investigations in cerebrospinal fluid of patients with dementia with Lewy bodies and Alzheimer's disease.

Measuring proteins in cerebrospinal fluid (CSF) has gained wide acceptance for the differential diagnosis of dementia. Some groups have already extended these investigations in Alzheimer's disease (AD) by asking how stable these markers are in follow-up analysis, if they depend on the stage of disease and whether they can be used to monitor the progression and biological effects of treatment. We evaluated 21 patients with dementia with Lewy bodies (DLB) and 19 patients with AD, on two occasions, with regard to levels of tau protein, tau protein phosphorylated at threonine 181 (p-tau), Abeta42, Abeta40 and S-100B protein, using a set of commercially available assays. Tau protein levels were lower in DLB in first and second LP compared to AD and decreased during course of both groups. P-tau levels were increased in AD and DLB and decreased during follow-up. Abeta42 and Abeta40 remained relatively stable during follow-up but we found a slight increase of the median Abeta42 level in DLB, whereas in AD, Abeta42 tends to decrease during follow-up. S-100B protein increased during follow-up in both diseases. The protein dynamics in DLB and AD are relatively similar. S-100B protein may be a useful marker for follow-up in neurodegenerative diseases but has to be analysed in longer follow-up periods. Tau protein may be used to differentiate between DLB and AD. Follow-up CSF analyses are of limited value for the differentiation of AD and DLB. We conclude that more specific markers have to be established for the differentiation and follow-up of these diseases.

Acetylcholinesterase↗

Loss of glycosylation associated with the T183A mutation in human prion disease.

A heterozygous T183A mutation in the prion protein (PrP) gene, PRNP, was identified in a patient with histopathologically confirmed spongiform encephalopathy. Clinically, this form of prion disease was characterized by early-onset dementia as the predominant sign, along with global cerebral atrophy and hypometabolism. The age at onset was 40 years and the disease duration was 4 years. Additional neurological signs including cerebellar ataxia and EEG abnormalities were absent until late stages of the disease. The T183A mutation was not found in non-affected family members. This mutation results in the removal of one of the two consensus sites for glycosylation of PrP. Neuropathological examination revealed severe spongiform degeneration and neuronal loss in the neocortex, putamen and claustrum, small plaque-like PrP-immunoreactive deposits in the molecular layer of the cerebellum, and faint intracellular cytoplasmic PrP immunoreactivity. Western blot analysis of the patient's brain tissue showed protease K-resistant PrP with a definite preponderance of the monoglycosylated form. The additional appearance of a band representing diglycosylated PrPSc strongly suggests that non-mutated PrP also acquires protease resistance in the present setting. Cell culture experiments confirmed previous reports on intracellular retention of the mutant protein in vitro. This is the second report of a disease-causing T183A mutation of PrP, and the clinical, histological and genetic observations strongly suggest that T183A is a disease-causing mutation.

Adult↗

Predictors of survival in sporadic Creutzfeldt-Jakob disease and other human transmissible spongiform encephalopathies.

A collaborative study of human transmissible spongiform encephalopathies has been carried out from 1993 to 2000 and includes data from 10 national registries, the majority in Western Europe. In this study, we present analyses of predictors of survival in sporadic (n = 2304), iatrogenic (n = 106) and variant Creutzfeldt-Jakob disease (n = 86) and in cases associated with mutations of the prion protein gene (n = 278), including Gerstmann-Sträussler-Scheinker syndrome (n = 24) and fatal familial insomnia (n = 41). Overall survival for each disease type was assessed by the Kaplan-Meier method and the multivariate analyses by the Cox proportional hazards model. In sporadic disease, longer survival was correlated with younger age at onset of illness, female gender, codon 129 heterozygosity, presence of CSF 14-3-3 protein and type 2a prion protein type. The ability to predict survival based on patient covariates is important for diagnosis and counselling, and the characterization of the survival distributions, in the absence of therapy, will be an important starting point for the assessment of potential therapeutic agents in the future.

Adolescent↗

Sporadic Creutzfeldt-Jakob disease: magnetic resonance imaging and clinical findings.

OBJECTIVE: To assess if clinical features, prion protein codon 129, and molecular subtype correlate with MRI basal ganglia hyperintensity in sporadic Creutzfeldt-Jakob disease (CJD). METHODS: The authors studied 219 patients including 153 confirmed CJD cases for their neurologic symptoms and MRI findings. The MRI was assessed by a blinded investigator for the presence of high signal intensity on T2-weighted images in the basal ganglia. RESULTS: Patients with basal ganglia high signal on T2-weighted images were more likely to present with rapid progressive dementia in an early stage and shorter disease duration (median 6.7 months and 8.6 months). Surprisingly, among the CJD cases, patients without signal increase of the basal ganglia were shown to have a higher frequency of extrapyramidal disturbances (82% vs 70%). More striking differences were found for symptoms such as depression and sensory disturbances, which were more frequent among cases without signal increase. MRI was more likely to be diagnostic in patients with MV2 molecular subtype. CONCLUSIONS: Selected clinical and pathologic features correlate with the presence of basal ganglia high signal on T2-weighted MRI in patients with definite or probable CJD.

Adult↗

Efficacy of flupirtine on cognitive function in patients with CJD: A double-blind study.

BACKGROUND: In cell culture experiments, flupirtine maleate (FLU), a triaminopyridine compound, was able to protect neuronal cells from apoptotic cell death induced by prion protein fragments and beta-amyloid peptides. As FLU is a clinically safe drug, the authors started a double-blind placebo-controlled study in patients with Creutzfeldt-Jakob disease (CJD). METHODS: Twenty-eight patients with CJD were randomized to an oral treatment with either FLU (n = 13) or matching placebo (PLA; n = 15). For inclusion and continuing the study, the patients had to achieve at least 50% in two of the subscales of the dementia tests employed. A battery of standardized questionnaires was employed to monitor the progression of the disease. The main outcome variable was the cognitive part of the Alzheimer's Disease Assessment Scale (ADAS-Cog); the difference between baseline and the best score under treatment was defined as the primary efficacy variable for hypothesis testing. RESULTS: CJD types were homogeneously distributed among the treatment groups. Patients treated with FLU showed significantly less deterioration in the dementia tests than patients treated with PLA. The mean change in ADAS-Cog (baseline to best) was +8.4 (+/-15.3) in the FLU group and +20.6 (+/-15.1) in the PLA group (p = 0.02, one-sided t-test). CONCLUSIONS: FLU has beneficial effects on cognitive function in patients with CJD. These positive results also may suggest a treatment potential of FLU in other neurodegenerative disorders. However, further studies are necessary.

Adult↗

CSF lactate dehydrogenase activity in patients with Creutzfeldt-Jakob disease exceeds that in other dementias.

The diagnosis of Creutzfeldt-Jakob disease (CJD) is still made by exclusion of other dementias. We now evaluated lactate dehydrogenase (LDH) in the cerebrospinal fluid (CSF) as a possible additional diagnostic tool. CSF LDH levels of patients with CJD (n = 26) were compared with those in other dementias (n = 28). LDH isoenzymes were determined in a subset (n = 9). Total LDH and isoenzyme LDH-1 were significantly higher, whereas the fractions of LDH-2 and LDH-3 were significantly lower in CJD patients. We conclude that in addition to established CSF parameters, LDH and its isoenzymes might serve as a further help to discriminate between CJD and other dementias.

Aged↗

Early age of onset in fatal familial insomnia. Two novel cases and review of the literature.

Fatal familial insomnia (FFI) is a prion disease exhibiting the PRNP D178N/129M genotype. Features of this autosomal dominant illness are progressive insomnia, dysautonomia, myoclonus, cognitive decline and motor signs associated with thalamic nerve cell loss and gliosis. In contrast to the new variant of Creutzfeldt-Jakob disease (vCJD) the onset of FFI is in middle to late adulthood. We report two male patients who belong to a large German FFI kindred. They were examined clinically, and postmortem neuropathological examination was carried out in collaboration with the German reference centre for prion disease. Additionally, the prion protein gene (PRNP) was analysed. To identify further patients with disease onset under 30 years of age a comprehensive literature review was carried out. Two male patients presented with typical symptoms of FFI at the age of 23 and 24 years. In their kindred, the age of onset has never before been under 44 years of age. Our literature review identified five additional early onset cases who died at age 21 to 25 years. In all 22 reviewed FFI families the median manifestation age was 49.5 years. Although phenotypic variability of FFI is common, age of onset under 30 years has been considered to be a hallmark of vCJD with a mean manifestation at 27 years of age. Our findings underline that in addition to vCJD, FFI must be considered in cases of young-onset prion disease. This has considerable impact on clinical management and genetic counselling.

Adult↗

Bcl-2 expression inversely correlates with tumour cell differentiation in medulloblastoma.

Medulloblastoma (MB) is a cerebellar primitive neuroectodermal tumour that occurs predominantly in childhood. It can be mainly divided into classical and desmoplastic tumours, but differential diagnosis is often difficult. Patients' prognosis is poor and neuropathological markers that reliably predict outcome are still missing. In a series of 104 MBs including 80 tumours of the classical and 24 tumours of the desmoplastic variant we studied the number of apoptotic figures and the expression of the proto-oncogene bcl-2, an anti-apoptotic protein known to affect tumour cell proliferation. We observed a strong correlation between the expression of bcl-2 with patients' age (P < 0.001) as well as with the desmoplastic subtype (P < 0.001). Here, protein expression was found to be restricted to internodular, less differentiated, highly proliferative areas. In classical MB, bcl-2 was detected only in 23% of cases and was highly inversely correlated with the expression of synaptophysin (P < 0.001) indicating that bcl-2 is predominantly expressed by undifferentiated classical MB. With regard to prognosis the expression of bcl-2 tended to correlate with poor outcome in classical MB but not in desmoplastic MB, although not to a statistically significant extension (P = 0.06). On the other hand, a high number of apoptotic figures in the tumour tissue was found to indicate poor prognosis independent of the histological subtype (P < 0.05).

Adolescent↗

[Clinically atypical CJD: diagnostic relevance of cerebrospinal fluid markers and molecular genetic analysis?].

HISTORY AND CLINICAL FINDINGS: A 66-year-old woman with known remitting depressive episodes was admitted to a psychiatric hospital where a severe major depression was diagnosed. The patient failed to respond to SSRI medication. In addition, she developed a pronounced speech disturbance and gait ataxia. Therefore she was referred to the department of neurology 5 months after disease onset. She presented with a predominant cerebellar syndrome. Because of a severe dysarthria testing of cognitive functions were impossible. INVESTIGATIONS: EEG revealed a general slowing of the basic activity. Periodic sharp wave complexes were not seen during the entire disease course. Cerebrospinal fluid analysis (CSF) was normal with regard to cell count and blood-csf-barrier function. 14- 3-3 proteins were detected in CSF, and CSF levels of tau-protein and neuron-specific enolase were strongly elevated. A point mutation was detected at codon 196 (E196K) of the prion proteine gene. In addition, codon 129 was found homozygous for valine. TREATMENT AND COURSE: During the following 10 weeks the patient developed pyramidal and extrapyramidal signs, myoclonus and akinetic mutism. Complications were decubital ulcers and infections of the urinary tract. The myoclonus slightly regressed following treatment with benzodiazepines. The patient died 9 months after disease onset. CONCLUSION: A rapid disease course and typical changes of surrogate markers in CSF may support the in-vivo diagnosis of CJD despite incomplete clinical criteria (e. g. lack of dementia). In such cases, detection of mutations by molecular genetic analysis is of importance to further support the diagnosis of CJD.

Aged↗