RESUMO
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.
Assuntos
Amiloidose , Disfunção Cognitiva , Humanos , Amiloide , Proteínas Amiloidogênicas , Apolipoproteína E4/genética , Biomarcadores , Encéfalo/metabolismo , Disfunção Cognitiva/genética , Disfunção Cognitiva/psicologia , Tomografia por Emissão de PósitronsRESUMO
OBJECTIVES: Mild cognitive impairment (MCI) is associated with an increased risk of further cognitive decline, partly depending on demographics and biomarker status. The aim of the present study was to survey the clinical practices of physicians in terms of biomarker counseling, management, and follow-up in European expert centers diagnosing patients with MCI. METHODS: An online email survey was distributed to physicians affiliated with European Alzheimer's disease Consortium centers (Northern Europe: 10 centers; Eastern and Central Europe: 9 centers; and Southern Europe: 15 centers) with questions on attitudes toward biomarkers and biomarker counseling in MCI and dementia. This included postbiomarker counseling and the process of diagnostic disclosure of MCI, as well as treatment and follow-up in MCI. RESULTS: The response rate for the survey was 80.9% (34 of 42 centers) across 20 countries. A large majority of physicians had access to biomarkers and found them useful. Pre- and postbiomarker counseling varied across centers, as did practices for referral to support groups and advice on preventive strategies. Less than half reported discussing driving and advance care planning with patients with MCI. CONCLUSIONS: The variability in clinical practices across centers calls for better biomarker counseling and better training to improve communication skills. Future initiatives should address the importance of communicating preventive strategies and advance planning.
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Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/diagnóstico , Biomarcadores , Disfunção Cognitiva/diagnóstico , Aconselhamento , Revelação , Progressão da Doença , Europa (Continente) , Seguimentos , Humanos , Sensibilidade e EspecificidadeRESUMO
This article presents recommendations, based on the Grading of Recommendations, Assessment, Development, and Evaluation method, for the clinical application of cerebrospinal fluid (CSF) amyloid-ß1-42, tau, and phosphorylated tau in the diagnostic evaluation of patients with dementia. The recommendations were developed by a multidisciplinary working group based on the available evidence and consensus from focused discussions for (i) identification of Alzheimer's disease (AD) as the cause of dementia, (ii) prediction of rate of decline, (iii) cost-effectiveness, and (iv) interpretation of results. The working group found sufficient evidence to support a recommendation to use CSF AD biomarkers as a supplement to clinical evaluation, particularly in uncertain and atypical cases, to identify or exclude AD as the cause of dementia. Because of insufficient evidence, it was uncertain whether CSF AD biomarkers outperform imaging biomarkers. Operational recommendations for the interpretation of ambiguous CSF biomarker results were also provided.
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Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico , Biomarcadores/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Bases de Dados Bibliográficas/estatística & dados numéricos , Humanos , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidianoRESUMO
This article presents recommendations, based on the Grading of Recommendations, Assessment, Development, and Evaluation method, for the clinical application of cerebrospinal fluid (CSF) amyloid-ß1-42, tau, and phosphorylated tau in the diagnostic evaluation of patients with mild cognitive impairment (MCI). The recommendations were developed by a multidisciplinary working group and based on the available evidence and consensus from focused group discussions for 1) prediction of clinical progression to Alzheimer's disease (AD) dementia, 2) cost-effectiveness, 3) interpretation of results, and 4) patient counseling. The working group recommended using CSF AD biomarkers in the diagnostic workup of MCI patients, after prebiomarker counseling, as an add-on to clinical evaluation to predict functional decline or conversion to AD dementia and to guide disease management. Because of insufficient evidence, it was uncertain whether CSF AD biomarkers outperform imaging biomarkers. Furthermore, the working group provided recommendations for interpretation of ambiguous CSF biomarker results and for pre- and post-biomarker counseling.
Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/diagnóstico , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Humanos , MEDLINE/estatística & dados numéricos , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidianoRESUMO
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.
Assuntos
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
Cognitive manifestations usually are the primary abnormalities in dementia. In most cases cognitive deterioration arise in association with behavioral disturbances, and may accelerate institutionalization of patients. Noncognitive symptoms are distressing for both patients and their caregivers. These symptoms are described as "behavioral and psychological symptoms of dementia--BPSD" or neuropsychiatric symptoms. BPSD occurs in all types of dementia, and often are among the most prominent symptoms in the clinical course of the disease. Some disturbances like agitation and aggression may be disruptive and life-treating for patients and surrounding people. Non-pharmacological interventions should be recommended as a first line treatment unless BPSD symptoms are severe, persistent or recurrent. Drug treatment should have a specific target symptom. Atypical antipsychotics are widely used as the first line pharmacological approach to treat BPSD. Antidepressants, anxiolytics and antiepileptic's are also used. Treatment with cholinesterase inhibitors and/or memantine may delay the onset of BPSD and reduce the severity of some symptoms. Effective and safe treatment of BPSD should significantly improves the quality of life of patients and their caregivers.
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Sintomas Comportamentais/prevenção & controle , Transtornos Cognitivos/tratamento farmacológico , Demência/complicações , Idoso , Idoso de 80 Anos ou mais , Agressão/efeitos dos fármacos , Doença de Alzheimer/complicações , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/psicologia , Ansiolíticos/uso terapêutico , Antidepressivos/uso terapêutico , Antipsicóticos/uso terapêutico , Sintomas Comportamentais/etiologia , Inibidores da Colinesterase/uso terapêutico , Transtornos Cognitivos/etiologia , Demência/tratamento farmacológico , Demência/psicologia , Feminino , Humanos , Masculino , Memantina/uso terapêutico , Pessoa de Meia-Idade , Agitação Psicomotora/tratamento farmacológico , Agitação Psicomotora/etiologia , Qualidade de VidaRESUMO
INTRODUCTION: First reports associated mutations in triggering receptors expressed on myeloid cells 2 (TREM2) with autosomal recessive Nasu-Hakola disease characterized by painful bone cysts and progressive presenile dementia with psychotic symptoms; however, recent TREM2 biallelic rare variants are suggested to be causative also for the behavioral variant of frontotemporal dementia (bvFTD) without bone involvement. MATERIAL AND METHODS: Clinical data of three unrelated bvFTD patients carrying TREM2 biallelic variants were evaluated. All patients underwent neurological, psychiatric, and cognitive evaluation and neuroimaging. A full neuropsychological assessment was performed in two cases. RESULTS: Two patients carried compound heterozygous TREM2 variants, p.R62C and p.T66M, and one carried the homozygous p.D87N variant. Based on all obtained clinical and neuroimaging data, a behavioral variant of frontotemporal dementia was diagnosed in all cases. Their clinical manifestation was typical with neuropsychiatric and cognitive features, without bone abnormalities. CONCLUSIONS: Despite all three subjects partially resembling clinical manifestations of Nasu-Hakola disease with TREM2 mutations, we reveal some distinct features, including age of onset, neuroimaging findings, or disease course.
Assuntos
Demência Frontotemporal , Glicoproteínas de Membrana , Receptores Imunológicos , Humanos , Demência Frontotemporal/genética , Demência Frontotemporal/patologia , Receptores Imunológicos/genética , Glicoproteínas de Membrana/genética , Masculino , Feminino , Pessoa de Meia-Idade , Mutação/genética , Panencefalite Esclerosante Subaguda/genética , Adulto , Osteocondrodisplasias/genética , Lipodistrofia/genéticaRESUMO
Circulating miRNAs have potential as minimally invasive biomarkers for diagnosing various diseases, including ageing-related disorders such as Alzheimer's disease (AD). However, the lack of standardization in the common analysis method, RT-qPCR, and specifically in the normalization step, has resulted in inconsistent data across studies, hindering miRNA clinical implementation as well as basic research. To address this issue, this study proposes an optimized protocol for key steps in miRNA profiling, which incorporates absorbance-based haemolysis detection for assessing sample quality, double spike-in controls for miRNA isolation and reverse transcription, and the use of 7 stable normalizers verified in an aging population, including healthy subjects and individuals at different stages of Alzheimer's disease (140 subjects). The stability of these 7 normalizers was demonstrated using our novel method called BestmiRNorm for identifying optimal normalizers. BestmiRNorm, developed utilizing the Python programming language, enables the assessment of up to 11 potential normalizers. The standardized application of this optimized RT-qPCR protocol and the recommended normalizers are crucial for the development of miRNAs as biomarkers for AD and other ageing-related diseases in clinical diagnostics and basic research.
Assuntos
Doença de Alzheimer , MicroRNA Circulante , MicroRNAs , Humanos , Idoso , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/genética , MicroRNAs/genética , Biomarcadores , Envelhecimento/genética , Perfilação da Expressão Gênica/métodosRESUMO
BACKGROUND: Purpose of study was evaluation of regional metabolic disorders using 1H MRS in patients with MCI, as a predictor of clinical conversion to dementia based on clinical follow-up. MATERIAL/METHODS: The study group consisted of 31 subjects with diagnosis of MCI based on criteria the Mayo Clinic Group. ¹H MRS was performed with a single-voxel method using PRESS sequence. The volume of interest (VOI) was located in the hippocampal formation and posterior part of the cingulated gyrus. RESULTS: Patients had annual clinical control at least twice. At the beginning, 9 had amnestic MCI and the others had multidomain MCI. During follow-up (median 3 yrs) 8 subjects had stable disease (SD), 13 had disease progression (DP) and 10 develop Alzheimer disease (AD). Baseline metabolic ratios (1H MRS) between 3 groups indicated significant difference (P < 0.05) in left frontal lobe in mI/H20 ratio, between patients with SD (0.27) and DP. In comparing the groups with DP and AD, a significant difference in NAA/Cr (1.77 vs. 1.43) was found. A significant difference within left temporal external lobes was found between SD and DP in NAA/H2O ratio (0.55 vs. 0.51). An additional significant difference within medial temporal lobe was found between DP and AD in Glx/H2O ratio (0.44 vs. 0.34) on the right side. CONCLUSIONS: 1H MRS seems to be sensitive method allows prediction of which patients are liable to progress from MCI to AD. Combined with other biomarkers of disease staging, it is an important approach in the preclinical AD diagnosis, as well as the assessment of dementia progression.
Assuntos
Ácido Aspártico/análogos & derivados , Colina/metabolismo , Disfunção Cognitiva/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Inositol/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Idoso , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Ácido Aspártico/metabolismo , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prótons , Lobo Temporal/metabolismo , Lobo Temporal/patologiaRESUMO
BACKGROUND: DYRK1A is implicated in mental retardation and Alzheimer's disease (AD) dementia of Down syndrome (DS) individuals. The protein is associated with cytoskeleton and altered expression has been shown to impair the cytoskeletal network via dosage effect. OBJECTIVE: Our original observations of marked reduction of cytoskeletal proteins associated with DYRK1A in brains and lymphoblastoid cell lines from DS and AD prompted an investigation whether cytoskeleton abnormalities could potentially be used as biomarkers of AD. METHODS: Our assay relied on quantification of co-immunoprecipitated cytoskeletal proteins with DYRK1A (co-IP assay) and analysis of the profile of G- and F-actin fractions obtained by high-speed centrifugations (spin-down assay). RESULTS: In co-IP assay, both DS and AD samples displayed reduced abundance of associated cytoskeletal proteins. In spin-down assay, G-actin fractions of controls displayed two closely spaced bands of actin in SDS-PAGE; while in AD and DS, only the upper band of the doublet was present. In both assays, alterations of actin cytoskeleton were present in DS, sporadic and familial AD cases, and in asymptomatic persons who later progressed to confirmed AD, but not in non-AD donors. In blind testing involving six AD and six controls, the above tests positively identified ten cases. Analysis of blood samples revealed the diversity of mild cognitive impairment (MCI) cases regarding the presence of the AD biomarker allowing distinction between likely prodromal AD and non-AD MCI cases. CONCLUSIONS: Both brain tissue and lymphocytes from DS and AD displayed similar semi-quantitative and qualitative alterations of actin cytoskeleton. Their specificity for AD-type dementia and the presence before clinical onset of the disease make them suitable biomarker candidates for early and definite diagnosis of AD. The presence of alterations in peripheral tissue points to systemic underlying mechanisms and suggests that early dysfunction of cytoskeleton may be a predisposing factor in the development of AD.
Assuntos
Actinas/metabolismo , Doença de Alzheimer/diagnóstico , Citoesqueleto/metabolismo , Leucócitos Mononucleares/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Biomarcadores/sangue , Linhagem Celular , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/metabolismo , Feminino , Humanos , Imunoprecipitação , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Quinases DyrkRESUMO
The only well confirmed genetic risk factor for sporadic Alzheimer's disease (AD) is the possession of apolipoprotein E (APOE) epsilon4 allele. As it contributes to 40-70% of AD cases, a large proportion of genetic variance may be determined by additional loci. Our aim was to estimate how reported genetic factors (APOE, NOS3, MTHFR) interact to increase the risk for AD and combine them with environmental factors (homocysteine, vitamin B12, cholesterol). Genotyping was performed in 154 AD patients and 176 healthy controls. Levels of homocysteine, vitamin B12 and cholesterol were assessed in subgroups of 100 AD patients and 100 controls. We found a difference in APOE epsilon4 and NOS3 G/G distribution between groups (p<0.005). Plasma total homocysteine was increased and vitamin B12 decreased in AD patients (p<0.001). The influence of APOE epsilon4 and NOS3 G alleles on the risk of AD was independent of homocysteine, vitamin B12 levels and MTHFR status.
Assuntos
Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Predisposição Genética para Doença , Apolipoproteínas E/genética , Frequência do Gene , Homocisteína/sangue , Humanos , Hipercolesterolemia , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Óxido Nítrico Sintase Tipo III/genética , Fatores de Risco , Vitamina B 12/sangueRESUMO
The evaluation of cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease (AD) (ß-amyloid, t-tau, p-tau) can be used to estimate the risk of developing dementia in patients at the pre-clinical stages of AD, i.e. subjective cognitive decline (SCD) and mild cognitive impairment (MCI). Erlangen Score Algorithm allows interpretation of CSF biomarker concentrations and is cut-off value independent. The aim of this study was to establish if this algorithm can be applied for routine diagnostic testing in clinical and preclinical subjects and has prognostic value. We analysed 217 patients from the memory clinic with the diagnosis of SCD (n = 31), MCI (n = 104), and AD (n = 82) with clinical follow-up amounting to 14.33 months (SD = 6.82). It was found that the highest Erlangen Score dominated in the AD group and was the rarest in the SCD group. In the group of patients with progression of symptoms during our period of observation, the AD pathology was confirmed in 93.75% of cases. Among the non-progressing subjects (n = 119) the algorithm indicated the risk of developing AD as possible in 40.34% and probable in 15.97% of cases. To conclude, the Erlangen Score Algorithm is a useful tool to determinate the risk of developing AD before the onset of dementia or to confirm the AD diagnosis. It is extremely valuable in preclinical stages of AD for planning purposes and early intervention as well as for future clinical trials.
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Algoritmos , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/líquido cefalorraquidiano , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Importance: Cerebral amyloid-ß aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials. Objective: To investigate whether amyloid-ß aggregation is associated with cognitive functioning in persons without dementia. Design, Setting, and Participants: This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017. Main Outcomes and Measures: Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype. Results: Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P = .16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P < .001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P < .001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years. Conclusions and Relevance: Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.
Assuntos
Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Encéfalo/fisiopatologia , Transtornos Cognitivos/fisiopatologia , Idoso , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/psicologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/psicologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Estudos Transversais , Feminino , Humanos , Masculino , Memória Episódica , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Valores de ReferênciaRESUMO
BACKGROUND: Mild cognitive impairment (MCI) is a condition referring to persons with significant memory impairment, often accompanied by functional deficits in the attention, language, visuospatial, and psychomotor domains, who do not fulfill the criteria for dementia. Individuals with MCI are at an increased risk of developing dementia. The objective of this study was to examine baseline differences between MCI subjects who did or did not deteriorate at follow-up on measures of cognition and neuroimaging. MATERIAL/METHODS: MCI individuals (n=105) enrolled in a longitudinal study at the Alzheimer's Day Clinic in Warsaw received annual clinical and psychometric examinations for up to a mean of three years. At baseline, all patients received temporal lobe-oriented CT and 99mTc HMPAO SPECT. The diagnosis of MCI according to Mayo Clinic Petersen's Criteria was conducted by a panel of specialists and neuropsychological testing was completed on all subjects. RESULTS: After three years of follow-up, 42 subjects remained stable or had improved (8) and 63 had progressive cognitive disturbances, including 23 who converted to dementia. Compared with stable MCI patients, decliners have significantly higher radial width of the temporal horn bilaterally and width of the lateral part of the transverse fissure on the right, dilated third ventricle, and smaller oblique thickness of the anterior part of the hippocampal formation bilaterally at the baseline. No significant differences in SPECT perfusion were found between the two groups. CONCLUSIONS: The proposed linear measurements of atrophy in CT may constitute a predictor for those MCI patients who are more likely to deteriorate.
Assuntos
Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/patologia , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Idoso , Transtornos Cognitivos/fisiopatologia , Demência/patologia , Demência/fisiopatologia , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Testes Neuropsicológicos , Valor Preditivo dos Testes , Prognóstico , Fatores de RiscoRESUMO
Alzheimer's disease (AD) is the most common age-related dementia. Among its major challenges is identifying molecular signatures characteristic for the early AD stage in patients with Mild Cognitive Impairment (MCI-AD), which could serve for deciphering the AD pathomechanism and also as non-invasive, easy-to-access biomarkers. Using qRT-PCR we compared the microRNA (miRNA) profiles in blood plasma of 15 MCI-AD patients, whose diagnoses were confirmed by cerebrospinal fluid (CSF) biomarkers, with 20 AD patients and 15 non-demented, age-matched individuals (CTR).To minimize methodological variability, we adhered to standardization of blood and CSF assays recommended by the international Joint Programming for Neurodegenerative Diseases (JPND) BIOMARKAPD consortium, and we employed commercially available Exiqon qRT-PCR-assays. In the first screening, we assessed 179 miRNAs of plasma. We confirmed 23 miRNAs reported earlier as AD biomarker candidates in blood and found 26 novel differential miRNAs between AD and control subjects. For representative 15 differential miRNAs, the TargetScan, MirTarBase and KEGG database analysis indicated putative protein targets among such AD hallmarks as MAPT (Tau), proteins involved in amyloidogenic proteolysis, and in apoptosis. These 15 miRNAs were verified in separate, subsequent subject groups. Finally, 6 miRNAs (3 not yet reported in AD context and 3 reported in AD blood) were selected as the most promising biomarker candidates differentiating early AD from controls with the highest fold changes (from 1.32 to 14.72), consistent significance, specificities from 0.78 to 1 and sensitivities from 0.75 to 1. (patent pending, PCT/IB2016/052440).
Assuntos
Doença de Alzheimer/genética , Demência/genética , Perfilação da Expressão Gênica/métodos , MicroRNAs/genética , Idoso , Doença de Alzheimer/sangue , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Demência/sangue , Demência/diagnóstico , Diagnóstico Diferencial , Diagnóstico Precoce , Feminino , Humanos , Masculino , MicroRNAs/sangue , Pessoa de Meia-Idade , Fragmentos de Peptídeos/líquido cefalorraquidiano , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas tau/líquido cefalorraquidianoRESUMO
In the course of Alzheimer's disease (AD), early pathological changes in the brain start decades before any clinical manifestation. The concentration levels of AD cerebrospinal fluid (CSF) biomarkers, such as amyloid-ß1-42 (Aß1-42), total tau (T-tau), and phosphorylated tau (P-tau), may reflect a cerebral pathology facilitating an early diagnosis of the disease and predicting a cognitive deterioration. The aim of this study was to estimate the prevalence of AD CSF biomarkers in those individuals with a subjective cognitive decline (SCD), a mild cognitive impairment (MCI), and Alzheimer's dementia (AD-D), together with the relationships between the biomarkers, an APOE É4 presence, and a verbal episodic memory performance. We included 252 patients from the memory clinic with a diagnosis of SCD (nâ=â85), MCI (nâ=â87), and AD-D (nâ=â80). A verbal episodic memory performance level was assessed and was based on a delayed recall trial from the 10-word list of an auditory verbal learning task (AVLT). We found that the patients with more severe cognitive impairments had significantly lower levels of Aß1-42 and higher levels of T-tau and P-tau. This pattern was also typical for the APOE É4 carriers, who had lower levels of Aß1-42 than the noncarriers in the AD-D and MCI groups. The levels of T-tau and P-tau were significantly higher in the APOE É4 carriers than in the noncarriers, but only in the MCI patients. The AVLT performance in the whole study samples was predicted by age, Aß1-42, and the T-tau CSF biomarkers, but not by the APOE genotyping.
Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Disfunção Cognitiva/líquido cefalorraquidiano , Disfunção Cognitiva/genética , Aprendizagem , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/psicologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/psicologia , Escolaridade , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/líquido cefalorraquidiano , Percepção , Fatores de Risco , Método Simples-Cego , Percepção da Fala , Proteínas tau/líquido cefalorraquidianoRESUMO
BACKGROUND: Assay-vendor independent quality control (QC) samples for neurochemical dementia diagnostics (NDD) biomarkers are so far commercially unavailable. This requires that NDD laboratories prepare their own QC samples, for example by pooling leftover cerebrospinal fluid (CSF) samples. OBJECTIVE: To prepare and test alternative matrices for QC samples that could facilitate intra- and inter-laboratory QC of the NDD biomarkers. METHODS: Three matrices were validated in this study: (A) human pooled CSF, (B) Aß peptides spiked into human prediluted plasma, and (C) Aß peptides spiked into solution of bovine serum albumin in phosphate-buffered saline. All matrices were tested also after supplementation with an antibacterial agent (sodium azide). We analyzed short- and long-term stability of the biomarkers with ELISA and chemiluminescence (Fujirebio Europe, MSD, IBL International), and performed an inter-laboratory variability study. RESULTS: NDD biomarkers turned out to be stable in almost all samples stored at the tested conditions for up to 14 days as well as in samples stored deep-frozen (at - 80°C) for up to one year. Sodium azide did not influence biomarker stability. Inter-center variability of the samples sent at room temperature (pooled CSF, freeze-dried CSF, and four artificial matrices) was comparable to the results obtained on deep-frozen samples in other large-scale projects. CONCLUSION: Our results suggest that it is possible to replace self-made, CSF-based QC samples with large-scale volumes of QC materials prepared with artificial peptides and matrices. This would greatly facilitate intra- and inter-laboratory QC schedules for NDD measurements.
Assuntos
Testes de Química Clínica/normas , Demência/sangue , Demência/líquido cefalorraquidiano , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Antibacterianos/farmacologia , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Bovinos , Humanos , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/líquido cefalorraquidiano , Controle de Qualidade , Padrões de Referência , Soroalbumina Bovina/análise , Azida Sódica/farmacologia , Fatores de Tempo , Preservação de Tecido/métodos , Proteínas tau/sangue , Proteínas tau/líquido cefalorraquidianoRESUMO
Excess cholesterol is removed from the brain via hydroxylation mediated by cholesterol 24S-hydroxylase (CYP46). Although serum and cerebrospinal fluid (CSF) concentrations of 24S-hydroxycholesterol are altered during the progress of Alzheimer's disease, studies carried out to date in different populations on the association of CYP46 gene polymorphisms and risk of AD have been inconclusive. In this report, we analyzed CYP46 polymorphisms in 215 Polish AD cases and 173 healthy individuals. A fragment of CYP46 intron 2 was amplified by PCR reaction and sequenced. We discovered a new single nucleotide substitution in CYP46 intron 2, but found no difference in particular genotype or allele frequencies between AD patients and controls. However, the GG genotype of the known rs754203 polymorphic site might be a risk factor for AD, especially in APOE varepsilon4 carriers. Interestingly, in AD patients the rs754203 G allele was more frequent in males than in females. However, considering the extreme divergence of results obtained by different authors, a clear connection between the CYP46 gene and AD is questionable.
Assuntos
Doença de Alzheimer/genética , Polimorfismo Genético , Esteroide Hidroxilases/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/epidemiologia , Apolipoproteína E4 , Apolipoproteínas E/genética , Estudos de Casos e Controles , Colesterol 24-Hidroxilase , Análise Mutacional de DNA/métodos , Feminino , Frequência do Gene , Genótipo , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Fatores de Risco , Fatores SexuaisRESUMO
UNLABELLED: Alzheimer's disease (AD), a progressive degenerative disorder of the brain, affects a significant proportion of elderly population. The pharmacotherapy of AD is evolving rapidly. However, many doctors suggest the treatment which does not provide benefits in patients with the disease. The primary aim of this article was to review available data on the pathophysiologic background of AD and thus the most commonly used therapeutic agents, specifically cholinesterase-inhibitors (rivastigmine), Ginkgo biloba, piracetam and selegiline. Relevant double-blind, randomized, placebo-controlled studies were identified through a comprehensive search of Medline, NICE, Embase and CENTRAL databases. CONCLUSIONS: Only inhibitors of acetylcholinesterase are approved in mild and moderate stages of AD treatment. There is no evidence that Ginkgo biloba, selegiline, piracetam provide cognitive or behavioural improvement.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Nootrópicos/uso terapêutico , Padrões de Prática Médica , Ginkgo biloba , Humanos , Fitoterapia , Piracetam/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Selegilina/uso terapêuticoRESUMO
INTRODUCTION: Prior to registration, no clinical trial evaluating safety and tolerability of Zolafren® (Adamed Sp. z o.o., Czosnów, Poland), a generic olanzapine formulation, had been performed. Therefore, the aim of this post-authorization safety study (PASS) was to evaluate the safety and tolerability of Zolafren in patients with bipolar disorder (BD). METHODS: Adverse events (AEs) associated with the use of Zolafren were recorded in a PASS, in an open-label, non-randomized, multicenter observational study involving 20,698 outpatients with BD. RESULTS: Zolafren was used in both monotherapy (82.8%) and polytherapy (17.2%) at a mean dose of 12.1±4.2 mg. The most commonly used formulation was coated tablets (70.9%). Orally dissolving tablets (19.7%) and hard capsules (9.4%) were less commonly used. During a period of 171±47 days of exposure to Zolafren, 5883 AEs were reported in 2138 patients (10.3% of the study population). None of the reported AEs were severe. Zolafren-associated AEs were the reason for discontinuation in 43 patients and the reason for dose reduction in a further 762 patients. The most common AE was weight gain (by 1.6±3.3 kg) which was considered unrelated to the dose of Zolafren. During follow-up, the percentage of patients with very good tolerance with Zolafren increased from 44.4% to 59.8%. The percentage of patients who had confidence in Zolafren also increased. CONCLUSION: The results of this PASS support the safety of Zolafren use and indicate a high tolerance in patients treated for BD. FUNDING: Adamed Sp. z o.o., Czosnów, Poland.