Sigrid Poser

Classification of sporadic Creutzfeldt‐Jakob disease based on molecular and phenotypic analysis of 300 subjects

Phenotypic heterogeneity in sporadic Creutzfeldt‐Jakob disease (sCJD) is well documented, but there is not yet a systematic classification of the disease variants. In a previous study, we showed that the polymorphic codon 129 of the prion protein gene (PRNP), and two types of protease‐resistant prion protein (PrPSc) with distinct physicochemical properties, are major determinants of these variants. To define the full spectrum of variants, we have examined a series of 300 sCJD patients. Clinical features, PRNP genotype, and PrPSc properties were determined in all subjects. In 187, we also studied neuropathological features and immunohistochemical pattern of PrPSc deposition. Seventy percent of subjects showed the classic CJD phenotype, PrPSc type 1, and at least one methionine allele at codon 129; 25% of cases displayed the ataxic and kuru‐plaque variants, associated to PrPSc type 2, and valine homozygosity or heterozygosity at codon 129, respectively. Two additional variants, which included a thalamic form of CJD and a phenotype characterized by prominent dementia and cortical pathology, were linked to PrPSc type 2 and methionine homozygosity. Finally, a rare phenotype characterized by progressive dementia was linked to PrPSc type 1 and valine homozygosity. The present data demonstrate the existence of six phenotypic variants of sCJD. The physicochemical properties of PrPSc in conjunction with the PRNP codon 129 genotype largely determine this phenotypic variability, and allow a molecular classification of the disease variants. Ann Neurol 1999;46:224–233

Elevated levels of tau-protein in cerebrospinal fluid of patients with Creutzfeldt–Jakob disease

Creutzfeldt-Jakob disease (CJD) is a rare, fatal, neurodegenerative disease caused by a transmissible agent designated as proteinaceous infectious agent (prion). Searching for biochemical markers of CJD, we analysed cerebrospinal fluid (CSF) samples of 53 patients for tau-protein using an enzyme linked immunoassay (ELISA). In a group of 21 patients with definite CJD seen in the German case control study for CJD, tau-protein concentrations in CSF were significantly higher than in two control-groups of patients with other diseases (median 13,153 pg/ml, range 1,533-27,648 pg/ml; P = 0.0001). One group comprised 19 patients who were seen in the same study and were diagnosed as having other dementing diseases (tau concentration: median 558 pg/ml, range 233-1,769 pg/ml). The second control group comprised 13 patients from our hospital with no dementing disease (tau concentration: median 296 pg/ml, range 109-640 pg/ml). We conclude that determination of tau protein levels in CSF is a useful marker for laboratory diagnosis of CJD.

Tau protein and 14-3-3 protein in the differential diagnosis of Creutzfeldt–Jakob disease

Background: Diagnosis of Creutzfeldt–Jakob disease (CJD) is made according to the typical clinical picture and can be supported by a positive 14-3-3 CSF immunoblot. Promising results for the diagnostic sensitivity and specificity of tau-protein measurement in CSF already have been described in a smaller group of patients. Both tests in a larger group of patients with the differential diagnosis of CJD were evaluated. Methods: CSF of 297 patients under the differential diagnosis of CJD (109 definite, 55 probable, 39 possible; 85 others, 1 iatrogenic, 8 genetic), 23 nondemented control subjects, and 15 non-CJD patients with positive 14-3-3 immunoblots were analyzed. The 14-3-3 immunoblot bands were semiquantitatively rated as strong, medium, and weak. Tau-protein was analyzed using a commercially available ELISA. In addition, patients were neuropathologically classified according to prion protein type and polymorphism at codon 129. Results: A diagnostic sensitivity of 94%, a diagnostic specificity of 90%, and a positive predictive value of 92% were achieved for tau-protein at a cut-off of 1,300 pg/mL. These results are comparable with those of the 14-3-3 immunoblot. For patients with type II prion protein and methionine/valine or valine/valine polymorphism at codon 129, tau-protein has a higher diagnostic sensitivity than 14-3-3 protein. Tau-protein levels were significantly higher in patients with higher-rated 14-3-3 immunoblot bands. Conclusion: The differential diagnostic significance of the 14-3-3 immunoblot is similar to that of the tau-protein ELISA. The advantage of the tau-protein ELISA is that it is easy to use in routine laboratories. Patients with a negative 14-3-3 immunoblot already have measurable tau-protein levels. This increases information on 14-3-3—negative patients with CJD and especially on patients with other diseases.

Mortality from Creutzfeldt–Jakob disease and related disorders in Europe, Australia, and Canada

Background: An international study of the epidemiologic characteristics of Creutzfeldt–Jakob disease (CJD) was established in 1993 and included national registries in France, Germany, Italy, the Netherlands, Slovakia, and the United Kingdom. In 1997, the study was extended to Australia, Austria, Canada, Spain, and Switzerland. Methods: Data were pooled from all participating countries for the years 1993 to 2002 and included deaths from definite or probable CJD of all etiologic subtypes. Results: Four thousand four hundred forty-one cases were available for analysis and included 3,720 cases of sporadic CJD, 455 genetic cases, 138 iatrogenic cases, and 128 variant cases. The overall annual mortality rate between 1999 and 2002 was 1.67 per million for all cases and 1.39 per million for sporadic CJD. Mortality rates were similar in all countries. There was heterogeneity in the distribution of cases by etiologic subtype with an excess of genetic cases in Italy and Slovakia, of iatrogenic cases in France and the UK, and of variant CJD in the UK. Conclusions: This study has established overall epidemiologic characteristics for Creutzfeldt–Jakob disease (CJD) of all types in a multinational population–based study. Intercountry comparisons did not suggest any relative change in the characteristics of sporadic CJD in the United Kingdom, and the evidence in this study does not suggest the occurrence of a novel form of human bovine spongiform encephalopathy infection other than variant CJD. However, this remains a possibility, and countries currently unaffected by variant CJD may yet have cases.

Cytokine mRNA levels in mononuclear blood cells from patients with multiple sclerosis

We determined the cytokine messenger RNA (mRNA) expression pattern of blood mononuclear cells in 45 patients with the relapsing-remitting form of MS and 32 patients with other neurologic diseases. Using a semiquantitative polymerase chain reaction method, we detected significantly higher levels of tumor necrosis factor-alpha and lymphotoxin mRNA in patients with relapsing compared to those with stable disease (p < 0.001), but transforming growth factor-beta and interleukin-10 mRNA expressions were higher in patients with stable disease.

Decreased β-amyloid1-42 in cerebrospinal fluid of patients with Creutzfeldt-Jakob disease

Objectives: Decreased levels of Aβ1-42 are found in CSF of patients with AD. Because early stages of Creutzfeldt-Jakob disease (CJD) and AD share several clinical features, we investigated Aβ1-42 levels in CSF of these groups, inferring that this might give additional help in differentiating patients with CJD from AD patients. Methods: We investigated 27 patients with CJD, 14 patients with AD, 19 patients with other dementias, and 20 nondemented controls (NDC) for Aβ1-42 in CSF. Twenty-four of the 27 CJD patients were neuropathologically verified. All the neuropathologically verified patients presented with a type 1 prion protein pattern. CJD patients were all homozygous for methionine at codon 129. Except in five CJD patients, no β-amyloid plaques were seen. Additionally, APOE status was determined in patients with CJD. Results: Levels of Aβ1-42 in CSF were decreased in patients with AD as well as in CJD. Levels of Aβ1-42 in CSF of patients with CJD and AD were significantly different from the other dementia and NDC groups. There was no substantial difference between the CJD and AD groups (p = 0.66). Decreased levels of Aβ1-42 did not correlate with the APOE ε4 load in patients with CJD. Conclusion: Low levels of Aβ1-42 in CSF do not exclude a diagnosis of CJD. Decreased levels of Aβ1-42 in CSF can occur without β-amyloid plaque formation in the brain. However, the underlying mechanism of this phenomenon must be elucidated.

Case-control study of risk factors of Creutzfeldt-Jakob disease in Europe during 1993-95

BACKGROUND Creutzfeldt-Jakob disease (CJD) is a transmissible spongiform encephalopathy. Genetic and iatrogenic forms have been recognised but most are sporadic and of unknown cause. We have studied risk factors for CJD as part of the 1993-95 European Union collaborative studies of CJD in Europe. METHODS The 405 patients with definite or probable CJD who took part in our study had taken part in population-based studies done between 1993 and 1995 in Belgium, France, Germany, Italy, the Netherlands, and the UK. Data on putative risk factors from these patients were compared with data from 405 controls. FINDINGS We found evidence for familial aggregation of CJD with dementia due to causes other than CJD (relative risk [RR] 2.26, 95% CI 1.31-3.90). No significant increased risk of CJD in relation to a history of surgery and blood transfusion was shown. There was no evidence for an association between the risk of CJD and the consumption of beef, veal, lamb, cheese, or milk. No association was found with occupational exposure to animals or leather. The few positive findings of the study include increased risk in relation to consumption of raw meat (RR 1.63 [95% CI 1.18-2.23]) and brain (1.68 [1.18-2.39]), frequent exposure to leather products (1.94 [1.13-3.33]), and exposure to fertiliser consisting of hoofs and horns (2.32 [1.38-2.91]). Additional analyses, for example stratification by country and of exposures pre-1985 and post-1985, suggest that these results should be interpreted with great caution. INTERPRETATION Within the limits of the retrospective design of the study, our findings suggest that genetic factors other than the known CJD mutations may play an important part in CJD. Iatrogenic transmission of disease seems rare in this large population-based sample of patients with CJD. There is little evidence for an association between the risk of CJD and either animal exposure, or consumption of processed bovine meat or milk products for the period studied.

Cerebrospinal fluid concentration of neuron-specific enolase in diagnosis of Creutzfeldt-Jakob disease

Neuron-specific enolase (NSE) is among the biochemical markers in cerebrospinal fluid reported to be useful in the differential diagnosis of Creutzfeldt-Jakob disease from other dementing illnesses. In a group of 58 patients with definite and probable Creutzfeldt-Jakob disease, NSE concentrations (median 94.0, interquartile range 256 ng/mL) were significantly higher (p < 0.001) than in 26 control patients (9.5, 15.5 ng/mL). At a cut-off of 35 ng/mL an optimum sensitivity of 80% with a specificity of 92% for the diagnosis of Creutzfeldt-Jakob disease by NSE in cerebrospinal fluid was obtained.

Current clinical diagnosis in Creutzfeldt‐Jakob disease: Identification of uncommon variants

According to the recently established molecular basis for phenotypic heterogeneity of sporadic Creutzfeldt‐Jakob disease (CJD), six different phenotypes are characterized by the size of the protease‐resistant fragment of the pathological prion protein (types 1 and 2) and homozygosity or heterozygosity for methionine or valine at codon 129 of the prion protein gene (designated by MM1, MM2, MV1, MV2, VV1, and VV2). In the present investigation, we analyzed the value of commonly used clinical tests (electroencephalogram [EEG], detection of 14‐3‐3 protein in cerebrospinal fluid [CSF], and hyperintensity of the basal ganglia in magnetic resonance imaging) for the clinical diagnosis in each CJD phenotype. The detection of periodic sharp and slow wave complexes in the EEG is reliable in the clinical diagnosis of MM1 and MV1 patients only. The CSF analysis for 14‐3‐3 protein showed high sensitivity in all analyzed subgroups with the exception of MV2 patients. Valine‐homozygous patients had a negative EEG, but most had detectable levels of neuronal proteins in the CSF. The sensitivity of the magnetic resonance imaging was 70%, irrespective of the subgroup, but was particularly reliable in the clinical diagnosis of MV2 patients. The widening spectrum of diagnostic techniques in CJD is not only useful in the increased accuracy of the clinical diagnosis but should also lead to the identification of more atypical cases of sporadic CJD. Ann Neurol 2000;48:323–329

Diagnostic value of periodic complexes in Creutzfeldt–Jakob disease

In 1996, our group published objective electroencephalogram (EEG) criteria to define periodic sharp‐wave complexes (PSWCs) suggestive for Creutzfeldt–Jakob disease (CJD). These criteria have since then been strictly applied in all cases reported to us as possible CJD in the course of the German CJD surveillance study. Furthermore, EEG analysis of the records was performed without any additional information on complementary clinical and laboratory data. In this study, we investigated sensitivity, specificity, and the predictive values of these EEG criteria exclusively in cases in which autopsy confirmed (n = 150) or excluded (n = 56) CJD. EEG criteria were positive in 64% (n = 96) of the CJD cases and falsely positive in 9% (n = 5) of other dementias. The resulting figures for sensitivity, specificity, and positive and negative predictive values were 64%, 91%, 95%, and 49%, respectively. In the falsely positive cases, Alzheimers disease (n = 4) and vascular dementia (n = 1) were the underlying diseases. However, only in one of these five cases both clinical and EEG data would have led to the false‐positive result to diagnose probable CJD. These data prove the high diagnostic value of our objective EEG criteria in CJD. Ann Neurol 2004