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INTRODUCTION: We aimed to unravel the underlying pathophysiology of the neurodegeneration (N) markers neurogranin (Ng), neurofilament light (NfL), and hippocampal volume (HCV), in Alzheimer's disease (AD) using cerebrospinal fluid (CSF) proteomics. METHODS: Individuals without dementia were classified as A+ (CSF amyloid beta [Aß]42), T+ (CSF phosphorylated tau181), and N+ or N- based on Ng, NfL, or HCV separately. CSF proteomics were generated and compared between groups using analysis of covariance. RESULTS: Only a few individuals were A+T+Ng-. A+T+Ng+ and A+T+NfL+ showed different proteomic profiles compared to A+T+Ng- and A+T+NfL-, respectively. Both Ng+ and NfL+ were associated with neuroplasticity, though in opposite directions. Compared to A+T+HCV-, A+T+HCV+ showed few proteomic changes, associated with oxidative stress. DISCUSSION: Different N markers are associated with distinct neurodegenerative processes and should not be equated. N markers may differentially complement disease staging beyond amyloid and tau. Our findings suggest that Ng may not be an optimal N marker, given its low incongruency with tau pathophysiology. HIGHLIGHTS: In Alzheimer's disease, neurogranin (Ng)+, neurofilament light (NfL)+, and hippocampal volume (HCV)+ showed differential protein expression in cerebrospinal fluid. Ng+ and NfL+ were associated with neuroplasticity, although in opposite directions. HCV+ showed few proteomic changes, related to oxidative stress. Neurodegeneration (N) markers may differentially refine disease staging beyond amyloid and tau. Ng might not be an optimal N marker, as it relates more closely to tau.
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Alzheimer's disease (AD) biomarkers represent several neurodegenerative processes, such as synaptic dysfunction, neuronal inflammation and injury, as well as amyloid pathology. We performed an exome-wide rare variant analysis of six AD biomarkers (ß-amyloid, total/phosphorylated tau, NfL, YKL-40, and Neurogranin) to discover genes associated with these markers. Genetic and biomarker information was available for 480 participants from two studies: EMIF-AD and ADNI. We applied a principal component (PC) analysis to derive biomarkers combinations, which represent statistically independent biological processes. We then tested whether rare variants in 9576 protein-coding genes associate with these PCs using a Meta-SKAT test. We also tested whether the PCs are intermediary to gene effects on AD symptoms with a SMUT test. One PC loaded on NfL and YKL-40, indicators of neuronal injury and inflammation. Four genes were associated with this PC: IFFO1, DTNB, NLRC3, and SLC22A10. Mediation tests suggest, that these genes also affect dementia symptoms via inflammation/injury. We also observed an association between a PC loading on Neurogranin, a marker for synaptic functioning, with GABBR2 and CASZ1, but no mediation effects. The results suggest that rare variants in IFFO1, DTNB, NLRC3, and SLC22A10 heighten susceptibility to neuronal injury and inflammation, potentially by altering cytoskeleton structure and immune activity disinhibition, resulting in an elevated dementia risk. GABBR2 and CASZ1 were associated with synaptic functioning, but mediation analyses suggest that the effect of these two genes on synaptic functioning is not consequential for AD development.
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Doença de Alzheimer , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/genética , Biomarcadores , Proteína 1 Semelhante à Quitinase-3/genética , Proteínas de Ligação a DNA , Ácido Ditionitrobenzoico , Humanos , Inflamação/genética , Peptídeos e Proteínas de Sinalização Intercelular , Neurogranina/genética , Fatores de Transcrição , Proteínas tauRESUMO
INTRODUCTION: Despite increasing evidence of a role of rare genetic variation in the risk of Alzheimer's disease (AD), limited attention has been paid to its contribution to AD-related biomarker traits indicative of AD-relevant pathophysiological processes. METHODS: We performed whole-exome gene-based rare-variant association studies (RVASs) of 17 AD-related traits on whole-exome sequencing (WES) data generated in the European Medical Information Framework for Alzheimer's Disease Multimodal Biomarker Discovery (EMIF-AD MBD) study (n = 450) and whole-genome sequencing (WGS) data from ADNI (n = 808). RESULTS: Mutation screening revealed a novel probably pathogenic mutation (PSEN1 p.Leu232Phe). Gene-based RVAS revealed the exome-wide significant contribution of rare coding variation in RBKS and OR7A10 to cognitive performance and protection against left hippocampal atrophy, respectively. DISCUSSION: The identification of these novel gene-trait associations offers new perspectives into the role of rare coding variation in the distinct pathophysiological processes culminating in AD, which may lead to identification of novel therapeutic and diagnostic targets.
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Doença de Alzheimer , Humanos , Doença de Alzheimer/genética , Doença de Alzheimer/diagnóstico , Exoma/genética , Estudos de Associação Genética , Fenótipo , BiomarcadoresRESUMO
OBJECTIVE: Degenerative dementia is characterized by progressive cognitive decline and neuropsychiatric symptoms. People with Alzheimer's disease (AD), the most common cause of dementia, show synaptic loss and disruption of functional brain networks along with neuritic plaques and neurofibrillary tangles. Electroencephalography (EEG) directly reflects synaptic activity, and among patients with AD it is associated with slowing of background activity. The purpose of this study was to identify associations between neuropsychiatric symptoms and EEG in patients with dementia and to determine whether EEG parameters could be used for clinical assessment of pharmacological treatment of neuropsychiatric symptoms in dementia (NPSD) with galantamine or risperidone. METHODS: Seventy-two patients with EEG recordings and a score ≥10 on the Neuropsychiatric Inventory (NPI) were included. Clinical assessments included administration of the NPI, the Mini-Mental State Examination (MMSE), and the Cohen-Mansfield Agitation Inventory (CMAI). Patients underwent EEG examinations at baseline and after 12 weeks of treatment with galantamine or risperidone. EEG frequency analysis was performed. Correlations between EEG and assessment scale scores were statistically examined, as were EEG changes from baseline to the week 12 visit and the relationship with NPI, CMAI, and MMSE scores. RESULTS: Significant correlations were found between NPI agitation and delta EEG frequencies at baseline and week 12. No other consistent and significant relationships were observed between NPSD and EEG at baseline, after NPSD treatment, or in the change in EEG from baseline to follow-up. CONCLUSIONS: The limited informative findings in this study suggest that there exists a complex relationship between NPSD and EEG; hence, it is difficult to evaluate and use EEG for clinical assessment of pharmacological NPSD treatment.
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Doença de Alzheimer , Demência , Doença de Alzheimer/complicações , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/tratamento farmacológico , Demência/complicações , Demência/diagnóstico , Demência/tratamento farmacológico , Eletroencefalografia , Galantamina/uso terapêutico , Humanos , Testes Neuropsicológicos , Risperidona/uso terapêuticoRESUMO
BACKGROUND: Suspected non-Alzheimer's disease pathophysiology (SNAP) is a biomarker concept that encompasses individuals with neuronal injury but without amyloidosis. We aim to investigate the pathophysiology of SNAP, defined as abnormal tau without amyloidosis, in individuals with mild cognitive impairment (MCI) by cerebrospinal fluid (CSF) proteomics. METHODS: Individuals were classified based on CSF amyloid beta (Aß)1-42 (A) and phosphorylated tau (T), as cognitively normal A-T- (CN), MCI A-T+ (MCI-SNAP), and MCI A+T+ (MCI-AD). Proteomics analyses, Gene Ontology (GO), brain cell expression, and gene expression analyses in brain regions of interest were performed. RESULTS: A total of 96 proteins were decreased in MCI-SNAP compared to CN and MCI-AD. These proteins were enriched for extracellular matrix (ECM), hemostasis, immune system, protein processing/degradation, lipids, and synapse. Fifty-one percent were enriched for expression in the choroid plexus. CONCLUSION: The pathophysiology of MCI-SNAP (A-T+) is distinct from that of MCI-AD. Our findings highlight the need for a different treatment in MCI-SNAP compared to MCI-AD.
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INTRODUCTION: The evidence for characteristics of persons with subjective cognitive decline (SCD) associated with amyloid positivity is limited. METHODS: In 1640 persons with SCD from 20 Amyloid Biomarker Study cohort, we investigated the associations of SCD-specific characteristics (informant confirmation, domain-specific complaints, concerns, feelings of worse performance) demographics, setting, apolipoprotein E gene (APOE) ε4 carriership, and neuropsychiatric symptoms with amyloid positivity. RESULTS: Between cohorts, amyloid positivity in 70-year-olds varied from 10% to 76%. Only older age, clinical setting, and APOE ε4 carriership showed univariate associations with increased amyloid positivity. After adjusting for these, lower education was also associated with increased amyloid positivity. Only within a research setting, informant-confirmed complaints, memory complaints, attention/concentration complaints, and no depressive symptoms were associated with increased amyloid positivity. Feelings of worse performance were associated with less amyloid positivity at younger ages and more at older ages. DISCUSSION: Next to age, setting, and APOE ε4 carriership, SCD-specific characteristics may facilitate the identification of amyloid-positive individuals.
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Amiloidose , Disfunção Cognitiva , Humanos , Amiloide , Proteínas Amiloidogênicas , Apolipoproteína E4/genética , Biomarcadores , Encéfalo/metabolismo , Disfunção Cognitiva/genética , Disfunção Cognitiva/psicologia , Tomografia por Emissão de PósitronsRESUMO
INTRODUCTION: This study sought to discover and replicate plasma proteomic biomarkers relating to Alzheimer's disease (AD) including both the "ATN" (amyloid/tau/neurodegeneration) diagnostic framework and clinical diagnosis. METHODS: Plasma proteins from 972 subjects (372 controls, 409 mild cognitive impairment [MCI], and 191 AD) were measured using both SOMAscan and targeted assays, including 4001 and 25 proteins, respectively. RESULTS: Protein co-expression network analysis of SOMAscan data revealed the relation between proteins and "N" varied across different neurodegeneration markers, indicating that the ATN variants are not interchangeable. Using hub proteins, age, and apolipoprotein E ε4 genotype discriminated AD from controls with an area under the curve (AUC) of 0.81 and MCI convertors from non-convertors with an AUC of 0.74. Targeted assays replicated the relation of four proteins with the ATN framework and clinical diagnosis. DISCUSSION: Our study suggests that blood proteins can predict the presence of AD pathology as measured in the ATN framework as well as clinical diagnosis.
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Doença de Alzheimer , Peptídeos beta-Amiloides/sangue , Biomarcadores/sangue , Proteínas Sanguíneas , Proteômica , Proteínas tau/sangue , Idoso , Doença de Alzheimer/sangue , Doença de Alzheimer/patologia , Apolipoproteína E4/sangue , Apolipoproteína E4/genética , Disfunção Cognitiva/sangue , Disfunção Cognitiva/patologia , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
INTRODUCTION: We estimated the age-specific duration of the preclinical, prodromal, and dementia stages of Alzheimer's disease (AD) and the influence of sex, setting, apolipoprotein E (APOE) genotype, and cerebrospinal fluid tau on disease duration. METHODS: We performed multistate modeling in a combined sample of 6 cohorts (n = 3268) with death as the end stage and estimated the preclinical, prodromal, and dementia stage duration. RESULTS: The overall AD duration varied between 24 years (age 60) and 15 years (age 80). For individuals presenting with preclinical AD, age 70, the estimated preclinical AD duration was 10 years, prodromal AD 4 years, and dementia 6 years. Male sex, clinical setting, APOE ε4 allele carriership, and abnormal cerebrospinal fluid tau were associated with a shorter duration, and these effects depended on disease stage. DISCUSSION: Estimates of AD disease duration become more accurate if age, sex, setting, APOE, and cerebrospinal fluid tau are taken into account. This will be relevant for clinical practice and trial design.
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Doença de Alzheimer , Amiloide , Apolipoproteína E4/genética , Disfunção Cognitiva/patologia , Progressão da Doença , Sintomas Prodrômicos , Idoso , Alelos , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Biomarcadores/líquido cefalorraquidiano , Feminino , Genótipo , Humanos , Estudos Longitudinais , Masculino , Tomografia por Emissão de Pósitrons , Fatores Sexuais , Fatores de Tempo , Proteínas tau/líquido cefalorraquidianoRESUMO
INTRODUCTION: Within-person trajectories of cerebrospinal fluid (CSF) biomarkers in Alzheimer's disease (AD) are not well defined. METHODS: We included 467 subjects from the BIOMARKAPD study with at least two serial CSF samples. Diagnoses were subjective cognitive decline (n = 75), mild cognitive impairment (n = 128), and AD dementia (n = 110), and a group of cognitively unimpaired subjects (n = 154) were also included. We measured baseline and follow-up CSF levels of total tau (t-tau), phosphorylated tau (p-tau), YKL-40, and neurofilament light (NfL). Median CSF sampling interval was 2.1 years. RESULTS: CSF levels of t-tau, p-tau, NfL, and YKL-40 were 2% higher per each year of baseline age in controls (P <.001). In AD, t-tau levels were 1% lower (P <.001) and p-tau levels did not change per each year of baseline age. Longitudinally, only NfL (P <.001) and YKL-40 (P <.02) increased during the study period. DISCUSSION: All four CSF biomarkers increase with age, but this effect deviates in AD for t-tau and p-tau.
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Doença de Alzheimer , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva , Proteínas tau/líquido cefalorraquidiano , Idoso , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico , Apolipoproteínas E/genética , Proteína 1 Semelhante à Quitinase-3 , Disfunção Cognitiva/líquido cefalorraquidiano , Disfunção Cognitiva/diagnóstico , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Proteínas de Neurofilamentos/líquido cefalorraquidiano , Fragmentos de Peptídeos , FosforilaçãoRESUMO
INTRODUCTION: We investigated relations between amyloid-ß (Aß) status, apolipoprotein E (APOE) ε4, and cognition, with cerebrospinal fluid markers of neurogranin (Ng), neurofilament light (NFL), YKL-40, and total tau (T-tau). METHODS: We included 770 individuals with normal cognition, mild cognitive impairment, and Alzheimer's disease (AD)-type dementia from the EMIF-AD Multimodal Biomarker Discovery study. We tested the association of Ng, NFL, YKL-40, and T-tau with Aß status (Aß- vs. Aß+), clinical diagnosis APOE ε4 carriership, baseline cognition, and change in cognition. RESULTS: Ng and T-tau distinguished between Aß+ from Aß- individuals in each clinical group, whereas NFL and YKL-40 were associated with Aß+ in nondemented individuals only. APOE ε4 carriership did not influence NFL, Ng, and YKL-40 in Aß+ individuals. NFL was the best predictor of cognitive decline in Aß+ individuals across the cognitive spectrum. DISCUSSION: Axonal degeneration, synaptic dysfunction, astroglial activation, and altered tau metabolism are involved already in preclinical AD. NFL may be a useful prognostic marker.
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Doença de Alzheimer/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/líquido cefalorraquidiano , Proteínas de Neurofilamentos/líquido cefalorraquidiano , Neurogranina/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides , Apolipoproteína E4/genética , Disfunção Cognitiva/fisiopatologia , Feminino , HumanosRESUMO
INTRODUCTION: Plasma proteins have been widely studied as candidate biomarkers to predict brain amyloid deposition to increase recruitment efficiency in secondary prevention clinical trials for Alzheimer's disease. Most such biomarker studies are targeted to specific proteins or are biased toward high abundant proteins. METHODS: 4001 plasma proteins were measured in two groups of participants (discovery group = 516, replication group = 365) selected from the European Medical Information Framework for Alzheimer's disease Multimodal Biomarker Discovery study, all of whom had measures of amyloid. RESULTS: A panel of proteins (n = 44), along with age and apolipoprotein E (APOE) ε4, predicted brain amyloid deposition with good performance in both the discovery group (area under the curve = 0.78) and the replication group (area under the curve = 0.68). Furthermore, a causal relationship between amyloid and tau was confirmed by Mendelian randomization. DISCUSSION: The results suggest that high-dimensional plasma protein testing could be a useful and reproducible approach for measuring brain amyloid deposition.
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Doença de Alzheimer , Amiloide/metabolismo , Biomarcadores/sangue , Encéfalo/metabolismo , Proteômica , Fatores Etários , Idoso , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
INTRODUCTION: A critical and as-yet unmet need in Alzheimer's disease (AD) is the discovery of peripheral small molecule biomarkers. Given that brain pathology precedes clinical symptom onset, we set out to test whether metabolites in blood associated with pathology as indexed by cerebrospinal fluid (CSF) AD biomarkers. METHODS: This study analyzed 593 plasma samples selected from the European Medical Information Framework for Alzheimer's Disease Multimodal Biomarker Discovery study, of individuals who were cognitively healthy (n = 242), had mild cognitive impairment (n = 236), or had AD-type dementia (n = 115). Logistic regressions were carried out between plasma metabolites (n = 883) and CSF markers, magnetic resonance imaging, cognition, and clinical diagnosis. RESULTS: Eight metabolites were associated with amyloid ß and one with t-tau in CSF, these were primary fatty acid amides (PFAMs), lipokines, and amino acids. From these, PFAMs, glutamate, and aspartate also associated with hippocampal volume and memory. DISCUSSION: PFAMs have been found increased and associated with amyloid ß burden in CSF and clinical measures.
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Peptídeos beta-Amiloides , Amiloidose/sangue , Biomarcadores , Hipocampo , Memória/fisiologia , Metabolômica , Idoso , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Amiloidose/líquido cefalorraquidiano , Amiloidose/metabolismo , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Encéfalo/patologia , Disfunção Cognitiva/diagnóstico , Estudos de Coortes , Feminino , Hipocampo/metabolismo , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Proteínas tau/sangue , Proteínas tau/líquido cefalorraquidianoRESUMO
INTRODUCTION: Apolipoprotein E (APOE) ε4 is the major genetic risk factor for Alzheimer's disease (AD), but its prevalence is unclear because earlier studies did not require biomarker evidence of amyloid ß (Aß) pathology. METHODS: We included 3451 Aß+ subjects (853 AD-type dementia, 1810 mild cognitive impairment, and 788 cognitively normal). Generalized estimating equation models were used to assess APOE ε4 prevalence in relation to age, sex, education, and geographical location. RESULTS: The APOE ε4 prevalence was 66% in AD-type dementia, 64% in mild cognitive impairment, and 51% in cognitively normal, and it decreased with advancing age in Aß+ cognitively normal and Aß+ mild cognitive impairment (P < .05) but not in Aß+ AD dementia (P = .66). The prevalence was highest in Northern Europe but did not vary by sex or education. DISCUSSION: The APOE ε4 prevalence in AD was higher than that in previous studies, which did not require presence of Aß pathology. Furthermore, our results highlight disease heterogeneity related to age and geographical location.
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Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Apolipoproteína E4/genética , Disfunção Cognitiva/metabolismo , Idoso , Alelos , Biomarcadores/líquido cefalorraquidiano , Europa (Continente) , Feminino , Humanos , Masculino , Tomografia por Emissão de Pósitrons , PrevalênciaRESUMO
INTRODUCTION: We aimed to determine the added value of cerebrospinal fluid (CSF) to clinical and imaging tests to predict progression from mild cognitive impairment (MCI) to any type of dementia. METHODS: The risk of progression to dementia was estimated using two logistic regression models based on 250 MCI participants: the first included standard clinical measures (demographic, clinical, and imaging test information) without CSF biomarkers, and the second included standard clinical measures with CSF biomarkers. RESULTS: Adding CSF improved predictive accuracy with 0.11 (scale from 0-1). Of all participants, 136 (54%) had a change in risk score of 0.10 or higher (which was considered clinically relevant), of whom in 101, it was in agreement with their dementia status at follow-up. DISCUSSION: An individual person's risk of progression from MCI to dementia can be improved by relying on CSF biomarkers in addition to recommended clinical and imaging tests for usual care.
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Disfunção Cognitiva/líquido cefalorraquidiano , Demência/líquido cefalorraquidiano , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/diagnóstico por imagem , Demência/diagnóstico por imagem , Progressão da Doença , Escolaridade , Feminino , Seguimentos , Humanos , Modelos Logísticos , Imageamento por Ressonância Magnética , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Prognóstico , Medição de Risco , Lobo Temporal/diagnóstico por imagemRESUMO
Three sets of research criteria are available for diagnosis of Alzheimer's disease in subjects with mild cognitive impairment: the International Working Group-1, International Working Group-2, and National Institute of Aging-Alzheimer Association criteria. We compared the prevalence and prognosis of Alzheimer's disease at the mild cognitive impairment stage according to these criteria. Subjects with mild cognitive impairment (n = 1607), 766 of whom had both amyloid and neuronal injury markers, were recruited from 13 cohorts. We used cognitive test performance and available biomarkers to classify subjects as prodromal Alzheimer's disease according to International Working Group-1 and International Working Group-2 criteria and in the high Alzheimer's disease likelihood group, conflicting biomarker groups (isolated amyloid pathology or suspected non-Alzheimer pathophysiology), and low Alzheimer's disease likelihood group according to the National Institute of Ageing-Alzheimer Association criteria. Outcome measures were the proportion of subjects with Alzheimer's disease at the mild cognitive impairment stage and progression to Alzheimer's disease-type dementia. We performed survival analyses using Cox proportional hazards models. According to the International Working Group-1 criteria, 850 (53%) subjects had prodromal Alzheimer's disease. Their 3-year progression rate to Alzheimer's disease-type dementia was 50% compared to 21% for subjects without prodromal Alzheimer's disease. According to the International Working Group-2 criteria, 308 (40%) subjects had prodromal Alzheimer's disease. Their 3-year progression rate to Alzheimer's disease-type dementia was 61% compared to 22% for subjects without prodromal Alzheimer's disease. According to the National Institute of Ageing-Alzheimer Association criteria, 353 (46%) subjects were in the high Alzheimer's disease likelihood group, 49 (6%) in the isolated amyloid pathology group, 220 (29%) in the suspected non-Alzheimer pathophysiology group, and 144 (19%) in the low Alzheimer's disease likelihood group. The 3-year progression rate to Alzheimer's disease-type dementia was 59% in the high Alzheimer's disease likelihood group, 22% in the isolated amyloid pathology group, 24% in the suspected non-Alzheimer pathophysiology group, and 5% in the low Alzheimer's disease likelihood group. Our findings support the use of the proposed research criteria to identify Alzheimer's disease at the mild cognitive impairment stage. In clinical settings, the use of both amyloid and neuronal injury markers as proposed by the National Institute of Ageing-Alzheimer Association criteria offers the most accurate prognosis. For clinical trials, selection of subjects in the National Institute of Ageing-Alzheimer Association high Alzheimer's disease likelihood group or the International Working Group-2 prodromal Alzheimer's disease group could be considered.
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Doença de Alzheimer/epidemiologia , Disfunção Cognitiva/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Biomarcadores/metabolismo , Disfunção Cognitiva/etiologia , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prevalência , Prognóstico , Análise de SobrevidaRESUMO
Specialized proresolving mediators (SPMs) induce resolution of inflammation. SPMs are derivatives of n-3 and n-6 PUFAs and may mediate their beneficial effects. It is unknown whether supplementation with PUFAs influences the production of SPMs. Alzheimer's disease (AD) is associated with brain inflammation and reduced levels of SPMs. The OmegAD study is a randomized, double-blind, and placebo-controlled clinical trial on AD patients, in which placebo or a supplement of 1.7 g DHA and 0.6 g EPA was taken daily for 6 months. Plasma levels of arachidonic acid decreased, and DHA and EPA levels increased after 6 months of n-3 FA treatment. Peripheral blood mononuclear cells (PBMCs) were obtained before and after the trial. Analysis of the culture medium of PBMCs incubated with amyloid-ß 1-40 showed unchanged levels of the SPMs lipoxin A4 and resolvin D1 in the group supplemented with n-3 FAs, whereas a decrease was seen in the placebo group. The changes in SPMs showed correspondence to cognitive changes. Changes in the levels of SPMs were positively correlated to changes in transthyretin. We conclude that supplementation with n-3 PUFAs for 6 months prevented a reduction in SPMs released from PBMCs of AD patients, which was associated with changes in cognitive function.
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Doença de Alzheimer , Cognição/efeitos dos fármacos , Ácidos Graxos Ômega-3/administração & dosagem , Mediadores da Inflamação/sangue , Leucócitos Mononucleares/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/farmacologia , Células Cultivadas , Método Duplo-Cego , Ácidos Graxos Ômega-6/administração & dosagem , Feminino , Humanos , Leucócitos Mononucleares/patologia , Masculino , Fragmentos de Peptídeos/farmacologiaRESUMO
IMPORTANCE: Cerebral amyloid-ß aggregation is an early pathological event in Alzheimer disease (AD), starting decades before dementia onset. Estimates of the prevalence of amyloid pathology in persons without dementia are needed to understand the development of AD and to design prevention studies. OBJECTIVE: To use individual participant data meta-analysis to estimate the prevalence of amyloid pathology as measured with biomarkers in participants with normal cognition, subjective cognitive impairment (SCI), or mild cognitive impairment (MCI). DATA SOURCES: Relevant biomarker studies identified by searching studies published before April 2015 using the MEDLINE and Web of Science databases and through personal communication with investigators. STUDY SELECTION: Studies were included if they provided individual participant data for participants without dementia and used an a priori defined cutoff for amyloid positivity. DATA EXTRACTION AND SYNTHESIS: Individual records were provided for 2914 participants with normal cognition, 697 with SCI, and 3972 with MCI aged 18 to 100 years from 55 studies. MAIN OUTCOMES AND MEASURES: Prevalence of amyloid pathology on positron emission tomography or in cerebrospinal fluid according to AD risk factors (age, apolipoprotein E [APOE] genotype, sex, and education) estimated by generalized estimating equations. RESULTS: The prevalence of amyloid pathology increased from age 50 to 90 years from 10% (95% CI, 8%-13%) to 44% (95% CI, 37%-51%) among participants with normal cognition; from 12% (95% CI, 8%-18%) to 43% (95% CI, 32%-55%) among patients with SCI; and from 27% (95% CI, 23%-32%) to 71% (95% CI, 66%-76%) among patients with MCI. APOE-ε4 carriers had 2 to 3 times higher prevalence estimates than noncarriers. The age at which 15% of the participants with normal cognition were amyloid positive was approximately 40 years for APOE ε4ε4 carriers, 50 years for ε2ε4 carriers, 55 years for ε3ε4 carriers, 65 years for ε3ε3 carriers, and 95 years for ε2ε3 carriers. Amyloid positivity was more common in highly educated participants but not associated with sex or biomarker modality. CONCLUSIONS AND RELEVANCE: Among persons without dementia, the prevalence of cerebral amyloid pathology as determined by positron emission tomography or cerebrospinal fluid findings was associated with age, APOE genotype, and presence of cognitive impairment. These findings suggest a 20- to 30-year interval between first development of amyloid positivity and onset of dementia.
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Peptídeos beta-Amiloides/análise , Apolipoproteína E4/genética , Encéfalo/patologia , Disfunção Cognitiva/patologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/análise , Líquido Cefalorraquidiano/química , Demência/patologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Prevalência , Fatores de RiscoRESUMO
OBJECTIVE: To examine the effects of galantamine and risperidone on neuropsychiatric symptoms in dementia (NPSD) and global function. METHODS: Using a randomized, controlled and open-blind, one-center trial at an in- and outpatient clinic at a university hospital, we studied 100 adults with probable dementia and NPSD. Participants received galantamine (N = 50, target dose 24 mg) or risperidone (N = 50, target dose 1.5 mg) for 12 weeks. The primary outcome was effects on NPSD assessed by the Neuropsychiatric Inventory (NPI). Secondary measures included the Mini-Mental State Examination (MMSE), Clinical Dementia Rating, Clinical Global Impression, and Simpson Angus scales. All tests were performed before and after treatment. RESULTS: Outcome measures were analyzed using analysis of covariance. Ninety-one patients (67% women, mean age 79 ± 7.5 years) with initial NPI score of 51.0 (± 25.8) and MMSE of 20.1 (± 4.6) completed the trial. Both galantamine and risperidone treatments resulted in improved NPSD symptoms and were equally effective in treating several NPI domains. However, risperidone showed a significant treatment advantage in the NPI domains irritation and agitation, F(1, 97) = 5.2, p = 0.02. Galantamine treatment also ameliorated cognitive functions where MMSE scores increased 2.8 points compared with baseline (95% confidence interval: 1.96-3.52). No treatment-related severe side effects occurred. CONCLUSIONS: These results support that galantamine, with its benign safety profile, can be used as first-line treatment of NPSD symptoms, unless symptoms of irritation and agitation are prominent, where risperidone is more efficient.
Assuntos
Antipsicóticos/uso terapêutico , Inibidores da Colinesterase/uso terapêutico , Demência/tratamento farmacológico , Galantamina/uso terapêutico , Humor Irritável , Agitação Psicomotora/tratamento farmacológico , Risperidona/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Demência/psicologia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Agitação Psicomotora/psicologia , Resultado do TratamentoRESUMO
AIMS: To examine the effects of galantamine and risperidone on agitation in patients with dementia. METHODS: A total of 100 patients with dementia and neuropsychiatric symptoms (mean age ± SD: 78.6 ± 7.5 years; 67% female) were included in this 12-week, randomized, parallel-group, controlled, single-center trial. The participants received galantamine (n = 50; target dose: 24 mg) or risperidone (n = 50; target dose: 1.5 mg) for 12 weeks. RESULTS: Both galantamine and risperidone treatment resulted in reduced agitation. However, risperidone showed a significant advantage over galantamine both at week 3 (mean difference in total Cohen-Mansfield Agitation Inventory score: 3.7 points; p = 0.03) and at week 12 (4.3 points; p = 0.01). CONCLUSIONS: Agitation improved in both groups, even if the treatment effects were more pronounced in the risperidone group; however, the effects on cognition and other aspects of tolerability were stronger with galantamine.
Assuntos
Antipsicóticos/uso terapêutico , Demência/tratamento farmacológico , Galantamina/uso terapêutico , Nootrópicos/uso terapêutico , Agitação Psicomotora/tratamento farmacológico , Risperidona/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/psicologia , Demência/psicologia , Demência Vascular/tratamento farmacológico , Demência Vascular/psicologia , Feminino , Humanos , Masculino , Agitação Psicomotora/psicologia , Resultado do TratamentoRESUMO
Background: Deposits of amyloid-ß (Aß) appear early in Alzheimer's disease (AD). Objective: The aim of the present study was to compare the presence of cortical and subcortical Aß in early AD using positron emission tomography (PET). Methods: Eight cognitively unimpaired (CU) subjects, 8 with mild cognitive impairment (MCI) and 8 with mild AD were examined with PET and [11C]AZD2184. A data driven cut-point for Aß positivity was defined by Gaussian mixture model of isocortex binding potential (BPND) values. Results: Sixteen subjects (3 CU, 5 MCI and 8 AD) were Aß-positive. BPND was lower in subcortical and allocortical regions compared to isocortex. Fifteen of the 16 Aß-positive subjects displayed Aß binding in striatum, 14 in thalamus and 10 in allocortical regions. Conclusions: Aß deposits appear to be widespread in early AD. It cannot be excluded that deposits appear simultaneously throughout the whole brain which has implications for improved diagnostics and disease monitoring.