A combination of total tau and neurofilaments discriminates between neurodegenerative and primary psychiatric disorders.

BACKGROUND AND PURPOSE: Neuropsychiatric symptoms are commonly observed in neurodegenerative diseases. No biomarker is currently available to diagnose psychiatric conditions. As a consequence, the distinction between psychiatric and neurodegenerative disorders can be challenging in daily practice. METHODS: This retrospective study included a cohort of 64 primary psychiatric patients (PSY) and 162 patients suffering from various neurodegenerative disorders (NDG). Total tau (t-Tau), phosphorylated tau (p-Tau), Aß1-42 peptide (Aß1-42) and neurofilament light chain protein (NfL) were analysed in cerebrospinal fluid. The discrimination between PSY and NDG patients was assessed using both individual and combined analysis of cerebrospinal fluid markers. RESULTS: Cerebrospinal fluid t-Tau and NfL exhibited the best diagnostic performances: they were able to discriminate between PSY and each subgroup of NDG patients. t-Tau had the highest sensitivity (93.8%) but a poor specificity (67.3%). Indeed, some NDG subgroups exhibited low t-Tau levels comparable to PSY patients. A sequential combination t-Tau + NfL improved the characterization of patients, especially in these particular subgroups, increasing specificity up to 89.6% without modification of sensitivity. Finally, this combination of markers led to a high classification rate of 90.7% for the whole cohort of patients. CONCLUSION: The sequential combination t-Tau + NfL enables the biological detection of neurodegeneration in patients with psychiatric features. This association of markers seems to be a promising strategy for a differential diagnosis in clinical practice between primary psychiatric conditions and neurodegenerative disorders, thus improving medical care of patients.

Detection of CSF 14-3-3 Protein in Sporadic Creutzfeldt-Jakob Disease Patients Using a New Automated Capillary Western Assay.

Sporadic Creutzfeldt-Jakob disease (sCJD) is a fatal rapidly progressive dementia. The detection of 14-3-3 protein in cerebrospinal fluid (CSF) is included in the WHO diagnostic criteria for the pre-mortem diagnosis of CJD. The aim of this study is to assess CSF 14-3-3 protein analytical and diagnostic performances using a new automated capillary Western technology (Simple Western technology-SW). For the validation of this assay, samples from a cohort of 268 patients suspected from sCJD were analyzed: 77 sCJD (including 40 definite sCJD) and 191 non-CJD samples were tested using both SW and the current Western Blot (WB) assays. Automated capillary Western determination provided better analytical performances than WB with a lower intra- and inter-assay variability. Analytical interferences such as hemolysis and high total protein concentration known to lead to false positive WB results were also assessed using SW assay: unfortunately, these interferences still remain confounders of CSF 14-3-3 protein determination. Finally, automated capillary Western assay's sensitivity and specificity were superior to those of WB assay (93.5 and 95.3%, respectively, compared to 92.2 and 84.8% for WB). In conclusion, with a shorter time of analysis than WB assays' (4 h versus 1.5 day), automated capillary Western assay is an excellent routine alternative method to the currently performed WB assay for CSF 14-3-3 protein detection in patients suspected of sporadic Creutzfeldt-Jakob disease.

How to control the recombinant prion protein adhesion for successful storage through modification of surface properties.

Depletion of neuroproteins on the inner walls of storage tubes influences the accuracy of tests used for identification of various neurodegenerative disorders. In this paper, a strategy is described for surface modification of Eppendorf tubes leading to non-adhesive properties towards the recombinant human prion proteins (PrPrec(hum)). Tubes were pre-activated by helium plasma and grafted with three diverse coatings: pure poly(N-isopropylacrylamide) (PNIPAM), PNIPAM admixed with either neutral PEG(20)sorbitan monolaurate (PEG(20)) or positively charged cetyl trimethylammonium bromide (CTAB) at varying plasma activation times and polymer to surfactant ratios. New functionalized surfaces were analyzed by goniometry, streaming potential measurement and X-ray photoelectron spectroscopy, whereas the protein adhesion was monitored by enzyme linked immunosorbent assays and confocal microscopy. The mapping of PrPrec(hum) adhesion associated with surface analyses enabled us to determine that no or negligible depletion of PrPrec(hum) can be obtained by surfaces possessing basic component in the range between 50 and 60 mJ m(-2) and streaming potential ζ(7.4) - -50 mV.

Improvement of the detection of neurodegenerative Alzheimer's disease through a specific surface chemistry applied onto the inner surface of the titration well.

The main objective of this paper was to illustrate the enhancement of the sensitivity of the ELISA titration of Tau proteins while reducing other non-specific adsorptions that could increase the optical densities and could lead to false positives. This goal was obtained thanks to the association of cold plasma and wet chemistries of the inner surface of the titration well. The PP surface was cold plasma-activated, then coated with different amphiphilic molecules bearing either ionic charges and/or long hydrocarbon chains. The support treated and coated with hexatrimethylammonium bromide improves the signal detection of proteins while reducing the background due to non-specific associations of biomolecules such as hyperphosphorylated Tau protein. However, coating with 3-butenylamine hydrochloride could also be suitable.

Study of the adhesion of neurodegenerative proteins on plasma-modified and coated polypropylene surfaces.

The inner polymeric surface of an ELISA titration well is plasma-modified and coated with different surfactant molecules. The titration of neurodegenerative proteins markers (prion, Tau and ß-synuclein), previously demonstrated as more efficient with such modified tubes, is related to the adhesion behaviour of these proteins and their corresponding capture antibodies. The adhesion process is studied in terms of anchoring and specific mechanisms. The proteins and antibodies binding onto such modified surfaces is related to the substrate hydrophilic character calculated from the angle contact measure, to the polymer surface charge measured through the streaming potential determination at different pH and the inner surface roughness determined from AFM images. Furthermore, the influence of the blocking agent used during the ELISA titration is also studied.

Rapid screening and confirmatory methods for biochemical diagnosis of human prion disease.

Transmissible spongiform encephalopathies (TSEs) are characterised by accumulation of an abnormal isoform of prion protein (PrP(sc)), mainly in the brain but also in various peripheral tissues. Home-made assays consisting of non-standardised protocols are used currently for laboratory diagnosis of human TSE. The purpose of the present study was to test the ability of two commercial assays, TeSeE™ CJD ELISA and TeSeE™ Western blot, to detect PrPsc in cerebral and lymphoid tissues of TSE patients. Both tests detected a PrPsc-significant signal in the brains of 54 affected patients and not in 51 controls, yielding 100% specificity and 100% sensitivity. Furthermore, three post-mortem spleens and two pre-mortem tonsils from three patients with variant Creutzfeldt-Jakob disease (vCJD) were detected correctly. The expected PrPsc molecular patterns were found in TSE patient brain tissue and in the tonsils and spleens of the three vCJD patients. In conclusion, these rapid and robust in vitro tools were suitable for routine human TSE diagnosis and characterisation. CJD could also be diagnosed during the patient's lifetime by detection of PrPsc in the tonsil. A diagnostic strategy associating TeSeE™ CJD ELISA screening to biochemical confirmation by TeSeE™ Western blot is proposed.

CSF biomarkers in posterior cortical atrophy.

OBJECTIVE: To describe CSF biomarker profiles in posterior cortical atrophy (PCA), which induces high-order visual deficits often associated with Alzheimer disease (AD) pathology, and relate these findings to clinical and neuropsychological assessment. METHODS: This prospective observational study included 22 patients with PCA who underwent CSF biomarker analysis of total tau (t-tau), phosphorylated tau on amino acid 181 (p-tau181), and amyloid ß (Aß(42)). At group level, the CSF profiles of patients with PCA were compared to those of patients with typical AD and patients with other dementia (OD). Individually, the clinical presentation of patients with PCA was correlated to their CSF profile to assess the predictability of clinical features for diagnosis of underlying AD pathology. RESULTS: At group level, the PCA biomarker profile was not different from that of the AD group, but very different from that of the OD group (p < 0.001). More than 90% of patients with PCA had CSF profiles consistent with AD. All patients with PCA with either isolated higher-order visual deficit (n = 8) or visual deficit associated with memory impairment (n = 11) had CSF profiles consistent with AD. Only one of the 3 patients with PCA with asymmetric motor signs fulfilled biological CSF criteria for AD. CONCLUSIONS: PCA syndrome is usually associated with CSF biomarkers suggestive of AD, as shown by previous neuropathologic studies. This does not apply in case of motor signs suggesting associated corticobasal syndrome. CSF biomarkers help to discriminate AD from non-AD processes associated with this condition.

[Diagnosis contribution of biomarkers in Alzheimer disease: A case of frontotemporal dementia]. / Apport diagnostic des marqueurs biologiques de la maladie d'Alzheimer (MA) dans une observation de dégénérescence lobaire fronto-temporale (DLFT).

INTRODUCTION: Cerebrospinal fluid biomarkers are a fundamental contribution for the diagnosis of Alzheimer disease, in particular for young people. CASE REPORT: We report a case of Alzheimer disease of a 51-years old man whose clinical presentation corresponded to frontotemporal behavioural criteria. The clinical evaluation noticed some troubles in verbal memory. Only the CSF biomarkers confirmed the diagnosis. CONCLUSION: There are different phenotypes of presenile Alzheimer disease and among them we note frontotemporal dementia. It is very important to identify them to introduce a specific treatment.

[Atypical Lewy body disease revealed by burning mouth syndrome and a pseudo-psychiatric syndrome]. / Démence à corps de Lewy atypique révélée par une glossodynie et des troubles pseudo-psychiatriques.

INTRODUCTION: Among the degenerative diseases of the nervous system, Lewy body disease has the most psychiatric symptoms especially hallucinations, delusion and identification disorders. CASE REPORT: We report a case of Lewy body disease that started with a burning mouth syndrome for three year as the only symptom before the development of a pseudo-psychiatric syndrome (melancholy and Capgras). None of the usual cardinal criteria were present. MRI, cerebrospinal fluid, and DAT scan findings enabled the diagnosis. CONCLUSION: The dopaminergic hypothesis put forward in some cases of burning mouth syndrome might explain this symptom in Lewy body disease.

New hospital disinfection processes for both conventional and prion infectious agents compatible with thermosensitive medical equipment.

With the detection of prions in specific tissues in variant and sporadic Creutzfeldt-Jakob diseases, efficient decontamination for human transmissible spongiform encephalopathy (TSE) agents, that is compatible with medical equipment, has become a major issue. We previously described the cleavage of prions on exposure to copper (Cu) and hydrogen peroxide (H(2)O(2)) and have used this property to develop efficient prion decontamination processes. To validate this approach, in-vitro assays on genuine human and animal prions using both brain homogenates and steel wires to mimic contamination of medical equipment were conducted. In-vivo experiments using steel wire in the hamster 263 K model were then used to evaluate the effect on prion infectivity. Assays on classical pathogens following international norms completed these prion experiments. In-vitro data confirmed the full decontamination efficacy of H(2)O(2)/Cu on different TSE strains. Combination of Cu with peracetic acid, used for endoscope disinfection, also revealed improved prion decontamination. Animal assay demonstrated efficacy on TSE infectivity of H(2)O(2)/Cu alone or in combination with detergents (reduction factor > or =5.25 log(10)). Assays on classical pathogens confirmed the disinfection properties of the different processes. Taken together, these new disinfection processes are efficient for both conventional and prion infectious agents and are, compatible with thermosensitive medical equipment. They can be adapted to hospitals' and practitioners' routine use, and they present reduced risks for the environment and for healthcare professionals.

[Near a biological diagnosis of Alzheimer's disease and related disorders]. / Vers un diagnostic biologique de la maladie d'Alzheimer et des syndromes apparentés.

PURPOSE: To review the current concepts in the biological diagnosis of Alzheimer's disease (AD) and related disorders. CURRENT KNOWLEDGE AND KEY POINTS: As new therapeutics specific of AD may be available soon, early diagnosis of AD in the context of mild cognitive impairment (MCI) or dementia appears to be challenging. The high amount of atypical clinical forms of AD leads to develop new tools allowing in vivo diagnosis. New CerebroSpinal Fluid (CSF) biomarkers seem to reflect specific aspects of deep neuropathological changes observed in AD, i.e. amyloid deposits and neurofibrillary tangles. Amyloid beta-peptide 1-42 (Abeta(1-42)) and hyperphosphorylated tubulin associated unit (tau) isoforms appear to be the most sensitive and specific CSF biomarkers, the combination of these biomarkers depicting the best diagnosis value for AD. These molecules are also efficient in the prediction of the conversion from the MCI state to the dementia state of AD. Combined to clinical and neuro-imaging information, CSF biomarkers appear thus to be highly relevant in improving the early etiological diagnosis of dementia. FUTURE PROSPECTS AND PROJECTS: The current research focalises on the development of new molecules coming from Abeta and tau protein families, in the CSF and in the serum, as well as molecules reflecting other pathological metabolism changes, as alpha-synuclein in Lewy Body Disease. The diagnosis value of CSF biological markers is so promising that they have been recently included in the research diagnosis criteria of AD.

Urinary neopterin is a valuable tool in monitoring Crohn's disease activity.

BACKGROUND: The aim was to investigate the relation between urinary neopterin and the Crohn's Disease Activity Index (CDAI) and to compare its ability to discriminate active versus inactive CD with serum C-reactive protein (CRP). METHODS: In all, 217 urinary samples for neopterin measurement were obtained in a cohort of 93 consecutive patients with CD and 66 samples in 33 healthy volunteers. Clinical parameters were recorded and blood samples for CRP were collected as well. RESULTS: Whereas patients with inactive CD showed similar levels of urinary neopterin excretion than healthy volunteers (163 +/- 8 versus 142 +/- 7 nmol/mol of creatinine, respectively; P = 0.1), urinary neopterin excretion from mild to severe active CD was significantly higher (302 +/- 15 nmol/mol of creatinine; P < 0.001). Serum CRP levels were higher in active CD (14.8 +/- 2.1 mg/L) compared with inactive CD (5.6 +/- 0.8 mg/L; P < 0.001). Urinary neopterin excretion, and to a lesser degree CRP, were positively and significantly correlated with CDAI (r = 0.64 and 0.43, respectively, P < 0.001). Based on the cutoff of 183 nmol/mol of creatinine for urinary neopterin, the sensitivity and specificity of urinary neopterin to discriminate between active and inactive CD were 73% and 82%, respectively, and the positive and negative predictive values were 80% and 78%, respectively. CONCLUSIONS: Urinary neopterin excretion is an objective, valuable, simple, and noninvasive biomarker to detect and follow fluctuations of CD activity. Further work is warranted to study its clinical value and relation to mucosal healing.

CJD PrPsc removal by nanofiltration process: application to a therapeutic immunoglobulin solution (Lymphoglobuline).

The characteristic of transmissible spongiform encephalopathies (TSE) is an accumulation of partially protease resistant (PrP(res)) abnormal prion protein (PrP(sc)). This pathological prion protein is very resistant to conventional inactivation methods. The risk of transmission of TSE, such as Creutzfeldt-Jakob disease (CJD), by biopharmaceutical products prepared from human cells must be taken into account. The nanofiltration process has been proved to be effective in removing viruses and scrapie agent. The major advantages of this technique are flexibility and efficacy in removing infectious particles without altering biopharmaceutical characteristics and properties. This study focused on the removal of human PrP(sc) by means of a nanofiltration method after spiking a Lymphoglobuline solution with a CJD brain homogenate. Lymphoglobuline equine anti-human thymocyte immunoglobulin is a selective immunosuppressive agent acting mainly on human T lymphocytes. The therapeutic indications are: immunosuppression for transplantation: prevention and treatment of graft rejection; treatment of aplastic anemia. In our study, CJD homogenate was spiked at three different dilutions (low, moderate and high) in the Lymphoglobuline product. The nanofiltration process was performed on each sample. Using the western blot technique, the PrP(res) signal detected in nanofiltrates was compared to that obtained with a reference scale (dilution series of CJD brain homogenate in Lymphoglobuline detected by western blot and elaborated on 3.3 log). After nanofiltration, the PrP(res) western blot signal was detected with a significant reduction in the less dilute sample, whereas the signal was undetectable in the two other samples. These are the first data in CJD demonstrating a clearance between 1.6 and 3.3 log with a Lymphoglobuline recovery of over 93%. The nanofiltration process confirms its relative efficacy in removing human CJD PrP(sc).

[Heidenhain's variant of Creutzfeldt-Jakob's disease]. / Forme de Heidenhain de la maladie de Creutzfeldt-Jacob.

INTRODUCTION: Creutzfeldt-Jakob's disease has various anatomoclinical presentations including a rare form with preponderant visual signs described by Heidenhain. In this form, the visual symptoms may be isolated for a few weeks, leading to multiple ophthalmological examinations. OBSERVATION: We report the case of a 75-year-old woman who developed isolated visual disorders which rapidly increased over a period of two months. Addition of neurological symptoms, abnormalities of EEG and positivity of 14-3-3 protein led to the diagnosis of Creutzfeldt-Jakob's disease. The patient died 14 months after the first neuroophthalmologic signs. The diagnosis was established by post-mortem examination and immuno-electrophoretic demonstration of type 1 prion protein. CONCLUSION: Heidenhain's form of Creutzfeldt-Jakob's disease highlights the importance of general rules for prevention of iatrogenic hazard during ophthalmological examinations.

[Improving the interlaboratory variation for creatinine serum assay]. / Dosage de la créatininémie en 20003: état des lieux analytique et essai de standardisation de l'étalonnage.

PURPOSE: To assess inter-assay variation and accuracy of blood creatinine measurements as well as the effect of the standardization of the calibration procedures on inter-assay variation. METHODS: Inter-assay variation and accuracy were assessed using 30 frozen human sera and 3 certified reference materials, which were analysed by 17 creatinine assays (colorimetric: 12, enzymatic: 4, HPLC: 1). Usual calibration procedure was compared with two common calibration procedures using either a reference material (404.1 micromol/L), or secondary sera calibrators (69, 115 et 180 micromol/L). RESULTS: Most of the commercially available methods display inaccuracy, > 10% for creatininemia < 150 micromol/L in most cases. For this concentration range, the mean creatininemia was statistically significantly different as a function of the assay used (p < 0.001). Enzymatic assays produced lower results than colorimetric ones for low creatinine levels but higher results for high creatinine levels. Assays being calibrated according to the manufacturer's recommendations, the median dispersion factor was 14% for the 20 samples between 45 and 150 micromol/L, and 8% for the 10 samples between 250 and 350 micromol/L. The calibration procedure modified inter-assay variation significantly (p < 0.001) but we gained little advantage from both common calibration procedures. A significant decrease of inter-assay variation occurred within each technical group (colorimetric or enzymatic) when a common calibration was performed using calibrators which concentration(s) was(were) close to the concentrations to be measured. CONCLUSIONS: Inter-assay variation is too high to allow prediction of glomerular filtration rate (GFR) or creatinine clearance from serum creatinine level. Our results highlight the interest of a calibration procedure using several concentrations with at least one between 90 and 150 micromol/L. The marketing of such a calibrator should be considered in order to decrease inter-assay variation in the range of creatinine levels which defines a mild chronic renal failure. Such an approach will certainly reduce inter-assay variation only within each technical group but could allow to include technical group as a co-variable in the algorithms developed for predicting GFR or creatinine clearance. A global transferability will certainly need the correlation of all types of creatinine assays versus a definitive method, whom definition remains uncertain.

[Hashimoto's encephalopathy: an anatomicoclinical observation]. / Encéphalopathie d'Hashimoto: une observation anatomo-clinique.

Hashimoto's encephalopathy (HE) is a rare neurological complication of chronic lymphocytic thyroiditis. As its clinical presentation is aspecific, other etiologies of acute encephalopathy have to be ruled out. We report the case of a 29-year old woman with neuropsychiatric signs preceding coma, myoclonus and epileptic seizures. Clinical and electroencephalographic features were consistent with the diagnosis of new variant of Creutzfeldt-Jakob disease. However, high titres of antithyroid antibodies in serum directed towards the diagnosis of HE. Despite oral steroids, the patient died five months later. Neuropathological findings ruled out spongiform encephalopathy and disclosed aspecific activated microglia. Our observation suggests that this process could be involved in the pathogenesis of HE. Even in the absence of clinical dysthyroidism, HE diagnosis has to be suspected in the settings of acute encephalopathy associated with seric antithyroid antibodies.

Microdialysis study of amino acid neurotransmitters in the spinal dorsal horn of patients undergoing microsurgical dorsal root entry zone lesioning. Technical note.

The aim of this study was to develop, for the first time in the human spinal dorsal horn (DH), an in vivo method for the study of amino acids (AAs). A microdialysis technique was used to sample AAs in the extracellular fluid of the DH apex in eight patients in whom surgery in the dorsal root entry zone (DREZ) was performed. Before making microsurgical lesions, specific concentric-type microdialysis probes were implanted over a 60-minute period in the DREZ and directed to the DH apex (10 implantations). The AA concentrations in the dialysates were determined using high-performance liquid chromatography with fluorescence detection. The concentrations of excitatory AAs (glutamate and aspartate) and inhibitory AAs (gamma-aminobutyric acid and glycine) decreased and were stabilized by 45 minutes after probe implantation, whereas the levels of nonneurotransmitter AAs (alanine and threonine) were not stabilized at 60 minutes. The ability of the probe to track the changes of extracellular AAs was demonstrated. Neither intra- nor postoperative microdialysis-related complications were observed (with a follow up of 18 months). The present study demonstrates that microdialysis can be performed safely in the human DH during DREZ lesioning. Despite technical and analytical limitations related to the intraoperative conditions, this technique offers new possibilities for clinical research on neurotransmitters involved in some relevant pathological states, especially in chronic pain and spasticity.

[Non-familial Creutzfeldt-Jakob disease: a study of 53 cases]. / Maladie de Creutzfeldt-Jakob non familiale certaine: étude de 53 observations.

Creutzfeldt-Jakob disease (CJD) is the most frequent human spongiform encephalopathy. We have analyzed 53 cases of definite non familial CJD over a study period of 28 years. All were autopsied in the same neuropathological unit. Clinical and epidemiological data were in accordance with previous studies: low incidence of CJD under the age of 40, high incidence around the sixty years of age (26%) a sex ratio at 0.65 and high frequency of myoclonus, dementia and cerebellar ataxia during evolution (78%). This study highlights the rapidity at the onset of the disease (within 24 hours) in 16% of the cases. EEG disclosed typical pseudoperiodic activity in only 53% of cases and cerebral MRI showed high T2 signal intensity in basal nuclei in 15%. This regional study is the second of its nature to be carried out in France, the first one covering the area of Paris.