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1.
Alzheimers Dement (Amst) ; 14(1): e12286, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35571963

RESUMO

Introduction: It is important to understand which biological processes change with aging, and how such changes are associated with increased Alzheimer's disease (AD) risk. We studied how cerebrospinal fluid (CSF) proteomics changed with age and tested if associations depended on amyloid status, sex, and apolipoprotein E Ɛ4 genotype. Methods: We included 277 cognitively intact individuals aged 46 to 89 years from Alzheimer's Disease Neuroimaging Initiative, European Medical Information Framework for Alzheimer's Disease Multimodal Biomarker Discovery, and Metabolic Syndrome in Men. In total, 1149 proteins were measured with liquid chromatography mass spectrometry with multiple reaction monitoring/Rules-Based Medicine, tandem mass tag mass spectrometry, and SOMAscan. We tested associations between age and protein levels in linear models and tested enrichment for Reactome pathways. Results: Levels of 252 proteins increased with age independently of amyloid status. These proteins were associated with immune and signaling processes. Levels of 21 proteins decreased with older age exclusively in amyloid abnormal participants and these were enriched for extracellular matrix organization. Discussion: We found amyloid-independent and -dependent CSF proteome changes with older age, perhaps representing physiological aging and early AD pathology.

2.
J Alzheimers Dis Rep ; 5(1): 65-77, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33681718

RESUMO

BACKGROUND: How the relationship between obesity and MRI-defined neural properties varies across distinct stages of cognitive impairment due to Alzheimer's disease is unclear. OBJECTIVE: We used multimodal neuroimaging to clarify this relationship. METHODS: Scans were acquired from 47 patients clinically diagnosed with mild Alzheimer's disease dementia, 68 patients with mild cognitive impairment, and 57 cognitively healthy individuals. Voxel-wise associations were run between maps of gray matter volume, white matter integrity, and cerebral blood flow, and global/visceral obesity. RESULTS: Negative associations were found in cognitively healthy individuals between obesity and white matter integrity and cerebral blood flow of temporo-parietal regions. In mild cognitive impairment, negative associations emerged in frontal, temporal, and brainstem regions. In mild dementia, a positive association was found between obesity and gray matter volume around the right temporoparietal junction. CONCLUSION: Obesity might contribute toward neural tissue vulnerability in cognitively healthy individuals and mild cognitive impairment, while a healthy weight in mild Alzheimer's disease dementia could help preserve brain structure in the presence of age and disease-related weight loss.

3.
J Alzheimers Dis ; 79(1): 163-175, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33252070

RESUMO

BACKGROUND: The cerebrospinal fluid (CSF) biomarkers amyloid-ß 1-42 (Aß42), total and phosphorylated tau (t-tau, p-tau) are increasingly used to assist in the clinical diagnosis of Alzheimer's disease (AD). However, CSF biomarker levels can be affected by confounding factors. OBJECTIVE: To investigate the association of white matter hyperintensities (WMHs) present in the brain with AD CSF biomarker levels. METHODS: We included CSF biomarker and magnetic resonance imaging (MRI) data of 172 subjects (52 controls, 72 mild cognitive impairment (MCI), and 48 AD patients) from 9 European Memory Clinics. A computer aided detection system for standardized automated segmentation of WMHs was used on MRI scans to determine WMH volumes. Association of WMH volume with AD CSF biomarkers was determined using linear regression analysis. RESULTS: A small, negative association of CSF Aß42, but not p-tau and t-tau, levels with WMH volume was observed in the AD (r2 = 0.084, p = 0.046), but not the MCI and control groups, which was slightly increased when including the distance of WMHs to the ventricles in the analysis (r2 = 0.105, p = 0.025). Three global patterns of WMH distribution, either with 1) a low, 2) a peak close to the ventricles, or 3) a high, broadly-distributed WMH volume could be observed in brains of subjects in each diagnostic group. CONCLUSION: Despite an association of WMH volume with CSF Aß42 levels in AD patients, the occurrence of WMHs is not accompanied by excess release of cellular proteins in the CSF, suggesting that WMHs are no major confounder for AD CSF biomarker assessment.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Disfunção Cognitiva/líquido cefalorraquidiano , Leucoencefalopatias/líquido cefalorraquidiano , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Idoso , Doença de Alzheimer/diagnóstico , Disfunção Cognitiva/diagnóstico , Fatores de Confusão Epidemiológicos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Leucoencefalopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fosforilação
4.
Alzheimers Dement (Amst) ; 12(1): e12083, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32864411

RESUMO

INTRODUCTION: Web-based cognitive tests have potential for standardized screening in neurodegenerative disorders. We examined accuracy and consistency of cCOG, a computerized cognitive tool, in detecting mild cognitive impairment (MCI) and dementia. METHODS: Clinical data of 306 cognitively normal, 120 mild cognitive impairment (MCI), and 69 dementia subjects from three European cohorts were analyzed. Global cognitive score was defined from standard neuropsychological tests and compared to the corresponding estimated score from the cCOG tool containing seven subtasks. The consistency of cCOG was assessed comparing measurements administered in clinical settings and in the home environment. RESULTS: cCOG produced accuracies (receiver operating characteristic-area under the curve [ROC-AUC]) between 0.71 and 0.84 in detecting MCI and 0.86 and 0.94 in detecting dementia when administered at the clinic and at home. The accuracy was comparable to the results of standard neuropsychological tests (AUC 0.69-0.77 MCI/0.91-0.92 dementia). DISCUSSION: cCOG provides a promising tool for detecting MCI and dementia with potential for a cost-effective approach including home-based cognitive assessments.

5.
J Alzheimers Dis ; 74(1): 277-286, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32007958

RESUMO

Accurate differentiation between neurodegenerative diseases is developing quickly and has reached an effective level in disease recognition. However, there has been less focus on effectively distinguishing the prodromal state from later dementia stages due to a lack of suitable biomarkers. We utilized the Disease State Index (DSI) machine learning classifier to see how well quantified metabolomics data compares to clinically used cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD). The metabolic profiles were quantified for 498 serum and CSF samples using proton nuclear magnetic resonance spectroscopy. The patient cohorts in this study were dementia (with a clinical AD diagnosis) (N = 359), mild cognitive impairment (MCI) (N = 96), and control patients with subjective memory complaints (N = 43). DSI classification was conducted for MCI (N = 51) and dementia (N = 214) patients with low CSF amyloid-ß levels indicating AD pathology and controls without such amyloid pathology (N = 36). We saw that the conventional CSF markers of AD were better at classifying controls from both dementia and MCI patients. However, quantified metabolic subclasses were more effective in classifying MCI from dementia. Our results show the consistent effectiveness of traditional CSF biomarkers in AD diagnostics. However, these markers are relatively ineffective in differentiating between MCI and the dementia stage, where the quantified metabolomics data provided significant benefit.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/metabolismo , Metabolômica/métodos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/classificação , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/classificação , Estudos de Coortes , Diagnóstico Diferencial , Progressão da Doença , Feminino , Humanos , Aprendizado de Máquina , Espectroscopia de Ressonância Magnética , Masculino , Testes de Estado Mental e Demência , Metaboloma , Pessoa de Meia-Idade , Caracteres Sexuais
6.
J Alzheimers Dis ; 72(1): 127-137, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31561355

RESUMO

Decreased levels of serum high-density lipoprotein (HDL) cholesterol have previously been linked to systemic inflammation and neurodegenerative diseases, such as Alzheimer's disease. Here, we aimed to analyze the lipoprotein profile and inflammatory indicators, the high-sensitivity C-reactive peptide (hs-CRP) and glycoprotein acetyls (GlycA), in sporadic and C9orf72 repeat expansion-associated frontotemporal lobar degeneration (FTLD) patients. The C9orf72 hexanucleotide repeat expansion is the most frequent genetic etiology underlying FTLD. The concentrations of different lipid measures in the sera of 67 FTLD patients (15 C9orf72 repeat expansion carriers), including GlycA, were analyzed by nuclear magnetic resonance spectroscopy. To verify the state of systemic inflammation, hs-CRP was also quantified from patient sera. We found that the total serum HDL concentration was decreased in C9orf72 repeat expansion carriers when compared to non-carriers. Moreover, decreased concentrations of HDL particles of different sizes and subclass were consistently observed. No differences were detected in the very low- and low-density lipoprotein subclasses between the C9orf72 repeat expansion carriers and non-carriers. Furthermore, hs-CRP and GlycA levels did not differ between the C9orf72 repeat expansion carriers and non-carriers. In conclusion, the HDL-related changes were linked with C9orf72 repeat expansion associated FTLD but were not seen to associate with systemic inflammation. The underlying reason for the HDL changes remains unclear.


Assuntos
Proteína C9orf72/genética , HDL-Colesterol/sangue , Expansão das Repetições de DNA/genética , Degeneração Lobar Frontotemporal/sangue , Degeneração Lobar Frontotemporal/genética , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
7.
J Alzheimers Dis ; 62(1): 165-174, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29439329

RESUMO

BACKGROUND: The neuropathology of Alzheimer's disease (AD) has previously been shown to be rather common among the elderly. OBJECTIVE: The aim of this study was to inspect the associations between cerebrospinal fluid (CSF) AD biomarker concentrations, age, the APOEɛ4 allele, cardiovascular diseases, diabetes, and cognitive performance in a cohort of a neurologically healthy population. METHODS: This study included 93 subjects (42 men, mean age 67 years) without previous neurological symptoms or subjective cognitive complaints. Their cognition was assessed, and CSF biomarkers and APOEɛ4 status were analyzed. RESULTS: Of the studied subjects, 8.6% (n = 8) had a pathological CSF AD biomarker profile. An increase in age correlated positively with CSF tau pathology and negatively with global cognitive performance. CONCLUSION: AD-type pathological changes in CSF and subtle cognitive impairment are common within a population with no previous memory complaints. Age was the main risk factor for the changes.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Disfunção Cognitiva/líquido cefalorraquidiano , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Cognição , Disfunção Cognitiva/sangue , Disfunção Cognitiva/genética , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
8.
J Alzheimers Dis ; 60(4): 1387-1395, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29036813

RESUMO

BACKGROUND: Lifestyle factors have been associated with the risk of dementia, but the association with Alzheimer's disease (AD) remains unclear. OBJECTIVE: To examine the association between later life lifestyle factors and AD biomarkers (i.e., amyloid-ß 1-42 (Aß42) and tau in cerebrospinal fluid (CSF), and hippocampal volume) in individuals with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). In addition, to examine the effect of later life lifestyle factors on developing AD-type dementia in individuals with MCI. METHODS: We selected individuals with SCD (n = 111) and MCI (n = 353) from the DESCRIPA and Kuopio Longitudinal MCI studies. CSF Aß42 and tau concentrations were assessed with ELISA assay and hippocampal volume with multi-atlas segmentation. Lifestyle was assessed by clinical interview at baseline for: social activity, physical activity, cognitive activity, smoking, alcohol consumption, and sleep. We performed logistic and Cox regression analyses adjusted for study site, age, gender, education, and diagnosis. Prediction for AD-type dementia was performed in individuals with MCI only. RESULTS: Later life lifestyle factors were not associated with AD biomarkers or with conversion to AD-type dementia. AD biomarkers were strongly associated with conversion to AD-type dementia, but these relations were not modulated by lifestyle factors. Apolipoprotein E (APOE) genotype did not influence the results. CONCLUSIONS: Later life lifestyle factors had no impact on key AD biomarkers in individuals with SCD and MCI or on conversion to AD-type dementia in MCI.


Assuntos
Transtornos Cognitivos/líquido cefalorraquidiano , Transtornos Cognitivos/diagnóstico por imagem , Hipocampo/diagnóstico por imagem , Estilo de Vida , Fatores Etários , Idoso , Consumo de Bebidas Alcoólicas/líquido cefalorraquidiano , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/patologia , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/patologia , Apolipoproteínas E/genética , Cognição , Transtornos Cognitivos/epidemiologia , Transtornos Cognitivos/patologia , Autoavaliação Diagnóstica , Progressão da Doença , Escolaridade , Exercício Físico , Feminino , Seguimentos , Hipocampo/patologia , Humanos , Estudos Longitudinais , Masculino , Tamanho do Órgão , Fatores Sexuais , Sono , Fumar/líquido cefalorraquidiano , Fumar/epidemiologia , Fumar/patologia , Comportamento Social
9.
Alzheimers Res Ther ; 9(1): 31, 2017 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-28441961

RESUMO

BACKGROUND: Insulin resistance (IR) has previously been associated with an increased risk of developing Alzheimer's disease (AD), although the relationship between IR and AD is not yet clear. Here, we examined the influence of IR on AD using plasma and cerebrospinal fluid (CSF) biomarkers related to IR and AD in cognitively healthy men. We also aimed to characterise the shared protein signatures between IR and AD. METHODS: Fifty-eight cognitively healthy men, 28 IR and 30 non-IR (age and APOE ε4 matched), were drawn from the Metabolic Syndrome in Men study in Kuopio, Finland. CSF AD biomarkers (amyloid ß-peptide (Aß), total tau and tau phosphorylated at the Thr181 epitope) were examined with respect to IR. Targeted proteomics using ELISA and Luminex xMAP assays were performed to assess the influence of IR on previously identified CSF and plasma protein biomarker candidates of AD pathology. Furthermore, CSF and plasma SOMAscan was performed to discover proteins that associate with IR and CSF AD biomarkers. RESULTS: CSF AD biomarkers did not differ between IR and non-IR groups, although plasma insulin correlated with CSF Aß/tau across the whole cohort. In total, 200 CSF and 487 plasma proteins were differentially expressed between IR and non-IR subjects, and significantly enriched pathways, many of which have been previously implicated in AD, were identified. CSF and plasma proteins significantly associated with CSF AD biomarkers were also discovered, and those sensitive to both IR and AD were identified. CONCLUSIONS: These data indicate that IR is not directly related to the level of CSF AD pathology in cognitively healthy men. Proteins that associated with both AD and IR are potential markers indicative of shared pathology.


Assuntos
Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Apolipoproteína E4/sangue , Apolipoproteína E4/líquido cefalorraquidiano , Resistência à Insulina , Animais , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
J Alzheimers Dis ; 56(4): 1241-1251, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28106561

RESUMO

While behavioral symptoms are both early and prevalent features of behavioral variant frontotemporal dementia (bvFTD), they can be present in other types of dementia as well, including Alzheimer's disease (AD) and even mild cognitive impairment (MCI). The Frontal Behavioral Inventory (FBI) was specifically developed to capture the behavioral and personality changes in bvFTD; it has also been modified into a self-administered caregiver questionnaire (FBI-mod). We examined the utility of the FBI-mod in differentiating bvFTD (n = 26), primary progressive aphasia (PPA) (n = 7), AD (n = 53), and MCI (n = 50) patients, and investigated how the FBI-mod may be associated with neuropsychological measures. The bvFTD patients scored significantly higher as compared to all other patient groups on the FBI-mod Total (p < 0.005), Negative (p < 0.005), and Positive (p < 0.01) scores. The cut-off point for the FBI-mod Total score that best discriminated the bvFTD and AD patients in our sample was 16, thus substantially lower than reported for the original FBI. For the bvFTD group, only mild correlations emerged between the FBI-mod and the cognitive measures. However, significant correlations between the FBI-mod and depressive symptoms as measured by the BDI-II were found for bvFTD. This suggests that while behavioral symptoms appear independent from cognitive deficits in bvFTD, they may nevertheless be interrelated with depressive symptoms. We conclude that the FBI-mod is an easily administered behavioral scale that can aid in differential diagnosis of bvFTD and should be used in clinical practice. The FBI-mod may further be considered as an outcome measure in clinical trials.


Assuntos
Doença de Alzheimer/diagnóstico , Afasia Primária Progressiva/diagnóstico , Disfunção Cognitiva/diagnóstico , Degeneração Lobar Frontotemporal/diagnóstico , Idoso , Cognição , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Sensibilidade e Especificidade
11.
J Alzheimers Dis ; 56(2): 543-555, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28059783

RESUMO

Cerebrospinal fluid (CSF) biomarkers may support the diagnosis of Alzheimer's disease (AD). We studied if the diagnostic power of AD CSF biomarker concentrations, i.e., Aß42, total tau (t-tau), and phosphorylated tau (p-tau), is affected by differences in lateral ventricular volume (VV), using CSF biomarker data and magnetic resonance imaging (MRI) scans of 730 subjects, from 13 European Memory Clinics. We developed a Matlab-algorithm for standardized automated segmentation analysis of T1 weighted MRI scans in SPM8 for determining VV, and computed its ratio with total intracranial volume (TIV) as proxy for total CSF volume. The diagnostic power of CSF biomarkers (and their combination), either corrected for VV/TIV ratio or not, was determined by ROC analysis. CSF Aß42 levels inversely correlated to VV/TIV in the whole study population (Aß42: r = -0.28; p < 0.0001). For CSF t-tau and p-tau, this association only reached statistical significance in the combined MCI and AD group (t-tau: r = -0.15; p-tau: r = -0.13; both p < 0.01). Correction for differences in VV/TIV improved the differentiation of AD versus controls based on CSF Aß42 alone (AUC: 0.75 versus 0.81) or in combination with t-tau (AUC: 0.81 versus 0.91). In conclusion, differences in VV may be an important confounder in interpreting CSF Aß42 levels.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico por imagem , Ventrículos Cerebrais/diagnóstico por imagem , Disfunção Cognitiva/líquido cefalorraquidiano , Disfunção Cognitiva/diagnóstico por imagem , Idoso , Algoritmos , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Área Sob a Curva , Atrofia , Biomarcadores/líquido cefalorraquidiano , Feminino , Hipocampo/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Reconhecimento Automatizado de Padrão , Fragmentos de Peptídeos/líquido cefalorraquidiano , Curva ROC , Proteínas tau/líquido cefalorraquidiano
12.
J Neurochem ; 139 Suppl 1: 290-317, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26452984

RESUMO

Cerebrospinal fluid (CSF) has been extensively studied to explore biochemical alterations in subjects with neurodegenerative disorders. In Alzheimer's disease, levels of increased CSF tau protein and decreased levels of ß-amyloid 1-42 (Aß42) have been shown to correlate with brain plaque formation and tangle pathology. Intracellular Lewy inclusions containing aggregated α-synuclein (α-syn) represent a pathological hallmark of Parkinson's disease (PD). In most - but not all - studies published to date total CSF α-syn concentrations have been found to be decreased in disorders related to α-syn pathology, that is, PD, dementia with Lewy bodies and multiple system atrophy. However, these reports show extensive signal overlap among tested individuals, thereby diminishing its potential for routine use in clinical practice. To investigate potential biological (i.e., non-technical) confounders of reported CSF levels for α-syn, Aß42, and tau in PD and related disorders, we carried out a methodical review of known factors that underlie signal variability and speculate on those that have not yet been tested. We discuss several biological factors, such as neuropathology, demographics, clinical phenotype, progression and duration of disease, concomitant illnesses and, last but not least, pharmacotherapy, which in isolation or combination can substantially alter values for CSF proteins of interest. Enhanced implementation of standardized clinical protocols, streamlined operating procedures, and further progress in the development of validated assays for CSF proteins have the potential to (i) inform us as to the pathogenesis of disease, (ii) support the laboratory-based diagnosis for symptomatic subjects in the future, and (iii) facilitate breakthrough therapies to alter the course of neurodegenerative disorders, such as PD and Alzheimer's disease. Cerebrospinal fluid (CSF) has been extensively studied to explore biochemical alterations in subjects with neurodegenerative disorders. To investigate potential biological confounders of reported CSF levels for α-synuclein (α-Syn), amyloid-ß 1-42(Aß42) and tau protein in Parkinson's disease and related disorders, we reviewed the current literature for known factors that underlie signal variability and speculate on those that have not yet been tested. This article is part of a special issue on Parkinson disease.


Assuntos
Proteínas do Líquido Cefalorraquidiano/líquido cefalorraquidiano , Transtornos Cognitivos/líquido cefalorraquidiano , Doença de Parkinson/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Biomarcadores/líquido cefalorraquidiano , Ensaios Clínicos como Assunto/métodos , Transtornos Cognitivos/diagnóstico , Humanos , Doença de Parkinson/diagnóstico , Fragmentos de Peptídeos/líquido cefalorraquidiano , alfa-Sinucleína/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano
13.
Neurodegener Dis Manag ; 5(5): 379-82, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26477468

RESUMO

The 7th Kuopio Alzheimer symposium was held on 11-13 June, 2015, in Kuopio, Finland and attracted ~250 attendees from 14 different countries around the world. The theme for the symposium in its seventh year was 'From mechanisms to prevention and intervention of Alzheimer's disease'. The 3-day international scientific symposium composed of seven oral sessions and a poster session. The program, spanning from molecular mechanisms to prevention, prediction, diagnosis and treatment of Alzheimer's disease, provided a forum for the attendees to share their research, network and to obtain a comprehensive overview of the current status and future directions of research into Alzheimer's disease.


Assuntos
Doença de Alzheimer , Congressos como Assunto , Doença de Alzheimer/complicações , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/terapia , Europa (Continente) , Humanos
14.
Front Neurol ; 6: 153, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26217300

RESUMO

INTRODUCTION: Core cerebrospinal fluid (CSF) biomarkers - Aß42, Tau, and phosphorylated Tau (pTau) - have been recently incorporated in the revised criteria for Alzheimer's disease (AD). However, their widespread clinical application lacks standardization. Pre-analytical sample handling and storage play an important role in the reliable measurement of these biomarkers across laboratories. AIM: In this study, we aim to surpass the efforts from previous studies, by employing a multicenter approach to assess the impact of less studied CSF pre-analytical confounders in AD-biomarkers quantification. METHODS: Four different centers participated in this study and followed the same established protocol. CSF samples were analyzed for three biomarkers (Aß42, Tau, and pTau) and tested for different spinning conditions [temperature: room temperature (RT) vs. 4°C; speed: 500 vs. 2000 vs. 3000 g], storage volume variations (25, 50, and 75% of tube total volume), as well as freezing-thaw cycles (up to five cycles). The influence of sample routine parameters, inter-center variability, and relative value of each biomarker (reported as normal/abnormal) was analyzed. RESULTS: Centrifugation conditions did not influence biomarkers levels, except for samples with a high CSF total protein content, where either non-centrifugation or centrifugation at RT, compared to 4°C, led to higher Aß42 levels. Reducing CSF storage volume from 75 to 50% of total tube capacity decreased Aß42 concentration (within analytical CV of the assay), whereas no change in Tau or pTau was observed. Moreover, the concentration of Tau and pTau appears to be stable up to five freeze-thaw cycles, whereas Aß42 levels decrease if CSF is freeze-thawed more than three times. CONCLUSION: This systematic study reinforces the need for CSF centrifugation at 4°C prior to storage and highlights the influence of storage conditions in Aß42 levels. This study contributes to the establishment of harmonized standard operating procedures that will help reducing inter-lab variability of CSF-AD biomarkers evaluation.

16.
J Neural Transm (Vienna) ; 122(7): 957-72, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25239189

RESUMO

The BrainNet Europe consortium assessed the reproducibility in the assignment of the type of frontotemporal lobar degeneration (FTLD) with TAR DNA-binding protein (TDP) 43 following current recommendations. The agreement rates were influenced by the immunohistochemical (IHC) method and by the classification strategy followed. p62-IHC staining yielded good uniform quality of stains, but the most reliable results were obtained implementing specific Abs directed against the hallmark protein TDP43. Both assessment of the type and the extent of lesions were influenced by the Abs and by the quality of stain. Assessment of the extent of the lesions yielded poor results repeatedly; thus, the extent of pathology should not be used in diagnostic consensus criteria. Whilst 31 neuropathologists typed 30 FTLD-TDP cases, inter-rater agreement ranged from 19 to 100 per cent, being highest when applying phosphorylated TDP43/IHC. The agreement was highest when designating Type C or Type A/B. In contrast, there was a poor agreement when attempting to separate Type A or Type B FTLD-TDP. In conclusion, we can expect that neuropathologist, independent of his/her familiarity with FTLD-TDP pathology, can identify a TDP43-positive FTLD case. The goal should be to state a Type (A, B, C, D) or a mixture of Types (A/B, A/C or B/C). Neuropathologists, other clinicians and researchers should be aware of the pitfalls whilst doing so. Agreement can be reached in an inter-laboratory setting regarding Type C cases with thick and long neurites, whereas the differentiation between Types A and B may be more troublesome.


Assuntos
Encéfalo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Degeneração Lobar Frontotemporal/patologia , Corpos de Inclusão/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Encéfalo/patologia , Europa (Continente) , Feminino , Degeneração Lobar Frontotemporal/metabolismo , Humanos , Masculino , Neuritos/patologia , Neurônios/metabolismo , Neurônios/patologia , Fosforilação , Estudos Retrospectivos , Proteína Sequestossoma-1 , Análise Serial de Tecidos , Ubiquitina/metabolismo
17.
J Neuropathol Exp Neurol ; 72(6): 452-61, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23656988

RESUMO

There is no consensus on the pathologic conditions or severity implied by the term "hippocampal sclerosis" (HS). In this study, a panel of experienced neuropathologists evaluated inter-rater agreement for pathologic diagnoses in the hippocampus and proposes consensus recommendations on the use of the term "HS." In a group of 251 cases of HS selected from a large autopsy cohort (1,388; 18%), a coordinating group identified 5 patterns of degenerative or vascular pathology. Four independent neuropathologists assessed a single set of hematoxylin and eosin-stained sections following descriptive definitions to classify the appearances and assign the diagnosis of HS, if appropriate. Diagnostic agreement (range, 36%-70%) was highest for vascular lesions. Subsequent joint review of all cases highlighted the need to identify neurodegenerative lesions using immunohistochemistry. Initial agreement in assigning the diagnosis of HS varied from 0% to 86%. After a joint review, the group recommended that the term "HS" should be applied to all cases with complete/near-complete neuronal loss and gliosis in the subfields of the cornu Ammonis but not to hippocampal microinfarction. Therefore, the etiology of HS must be defined in association with a neurodegenerative process or as "lacking neurodegenerative markers," a pathologic condition presumed to arise from hypoxic/ischemic mechanisms.


Assuntos
Consenso , Hipocampo/patologia , Guias de Prática Clínica como Assunto/normas , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Esclerose/patologia , Método Simples-Cego
18.
J Alzheimers Dis ; 33(1): 23-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22890097

RESUMO

Genetic variants in the granulin (GRN) gene have been shown to increase the risk of Alzheimer's disease (AD). Here, we report that the A allele of rs5848 in GRN reduces plasma granulin levels in a dose-dependent manner in a clinically-defined AD sample cohort. Similarly, the mRNA levels of granulin were decreased with respect to A allele of rs5848 in the inferior temporal cortex of neuropathologically confirmed AD patients. Our findings suggest that the A allele of rs5848 is functionally relevant by reducing the expression of granulin.


Assuntos
Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Encéfalo/metabolismo , Encéfalo/patologia , Regulação para Baixo/genética , Variação Genética/genética , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Peptídeos e Proteínas de Sinalização Intercelular/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Biomarcadores/sangue , Biomarcadores/metabolismo , Encéfalo/irrigação sanguínea , Estudos de Coortes , Feminino , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/biossíntese , Masculino , Pessoa de Meia-Idade , Oxirredução , Progranulinas
19.
Acta Neuropathol ; 124(1): 37-50, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22370907

RESUMO

α-Synuclein is the major protein associated with Lewy body dementia, Parkinson's disease and multiple system atrophy. Since α-synuclein is present in the brain in physiological conditions as a presynaptic protein, it is crucial to characterize disease-associated modifications to develop an in vivo biomarker. With the aim to develop antibodies showing high specificity and sensitivity for disease-associated α-synuclein, synthetic peptides containing different amino acid sequences were used for immunization of mice. After generation of α-synuclein aggregates, ELISA and immunoblotting were used to test the specificity of antibodies. Tissue microarray sections originating from different human α-synucleinopathies were used to compare immunostaining with other, commercially available antibodies. Immunization of mice with the peptide TKEGVVHGVATVAE (amino acid 44-57 of α-synuclein) resulted in the generation of a monoclonal antibody (5G4), which was able to bind aggregated α-synuclein preparation in sandwich ELISA or coated on magnetic beads. 5G4 proved to be superior to other antibodies in comparative immunohistochemical studies by revealing more widespread and distinct α-synuclein pathology. Immunoblotting of human brain tissue revealed an additional band seen in dementia with Lewy bodies, whereas the band representing monomeric α-synuclein was very weak or lacking. In summary, the 5G4 antibody is most promising for re-evaluation of archival material and may offer new perspective for the development of in vivo diagnostic assays for detecting disease-associated α-synuclein in body fluids.


Assuntos
Anticorpos/metabolismo , Encefalopatias/patologia , Encéfalo/metabolismo , Encéfalo/patologia , alfa-Sinucleína/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Degeneração Lobar Frontotemporal/patologia , Humanos , Imuno-Histoquímica , Atrofia de Múltiplos Sistemas/patologia , Neurônios/metabolismo , Neurônios/patologia , Doença de Parkinson/patologia , alfa-Sinucleína/metabolismo
20.
Neuropathology ; 32(1): 60-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21518013

RESUMO

We report two unusual autopsy cases with frontotemporal lobar degeneration (FTLD) that were hyperphosphorylated-tau- and TAR DNA binding protein 43 (TDP-43)- negative. The behavioral symptoms in both cases were compatible with frontotemporal dementia, but they exhibited more prominent speech and language related symptoms than previously reported. Moreover, they displayed a short duration of the disease; the male case had a disease onset age of 45 years, and duration of 5 years, and the female case suffered even shorter disease duration and a later onset of the symptoms, at the age of 67 years. Moreover, the motor functions had deteriorated in different ways in these cases. The male patient showed progressive motor symptoms, weakness of extremities and bulbar muscles suggesting motor neuron disease with a muscle biopsy supporting neurogenic deficits, whereas the female patient exhibited dyskinesias and tremor with progressive swallowing disorders. The father of the male case displayed dementia of similar type at the age of 68 years. In both cases, neuropathological examination showed fused-in sarcoma (FUS)-positive pathology. The male patient had intensely FUS-positive cytoplasmic and intranuclear inclusions that resembled the characteristics previously reported in FTLD FUS, whereas the female patient did not exhibit any cytoplasmic inclusions but had roundish, dense FUS-positive intranuclear inclusions. She also displayed a plethora of other pathologies including α-synuclein, hyperphosphorylated-tau, ß-amyloid aggregation and some neuronal polyglutamine aggregation (1C2) but no well-demarcated inclusions were observed. We conclude that clinical phenotypes of FUS pathologies also include elderly patients and are more variable with motor and speech disorders than previously reported.


Assuntos
Progressão da Doença , Degeneração Lobar Frontotemporal/complicações , Degeneração Lobar Frontotemporal/patologia , Corpos de Inclusão/metabolismo , Corpos de Inclusão/patologia , Proteína FUS de Ligação a RNA/metabolismo , Idade de Início , Idoso , Autopsia , Feminino , Degeneração Lobar Frontotemporal/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
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