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- Lautner, Ronald, et al.
(author)
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Preclinical effects of APOE epsilon 4 on cerebrospinal fluid A beta 42 concentrations
- 2017
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In: Alzheimers Research & Therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 9
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Journal article (peer-reviewed)abstract
- Background: From earlier studies it is known that the APOE epsilon 2/epsilon 3/epsilon 4 polymorphism modulates the concentrations of cerebrospinal fluid (CSF) beta-amyloid(1-42) (A beta 42) in patients with cognitive decline due to Alzheimer's disease (AD), as well as in cognitively healthy controls. Here, in a large cohort consisting solely of cognitively healthy individuals, we aimed to evaluate how the effect of APOE on CSF A beta 42 varies by age, to understand the association between APOE and the onset of preclinical AD. Methods: APOE genotype and CSF A beta 42 concentration were determined in a cohort comprising 716 cognitively healthy individuals aged 17-99 from nine different clinical research centers. Results: CSF concentrations of A beta 42 were lower in APOE epsilon 4 carriers than in noncarriers in a gene dose-dependent manner. The effect of APOE epsilon 4 on CSF A beta 42 was age dependent. The age at which CSF A beta 42 concentrations started to decrease was estimated at 50 years in APOE epsilon 4-negative individuals and 43 years in heterozygous APOE epsilon 4 carriers. Homozygous APOE epsilon 4 carriers showed a steady decline in CSF A beta 42 concentrations with increasing age throughout the examined age span. Conclusions: People possessing the APOE epsilon 4 allele start to show a decrease in CSF A beta 42 concentration almost a decade before APOE epsilon 4 noncarriers already in early middle age. Homozygous APOE epsilon 4 carriers might deposit A beta 42 throughout the examined age span. These results suggest that there is an APOE epsilon 4-dependent period of early alterations in amyloid homeostasis, when amyloid slowly accumulates, that several years later, together with other downstream pathological events such as tau pathology, translates into cognitive decline.
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- Lista, S., et al.
(author)
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Biomarkers in Sporadic and Familial Alzheimer's Disease
- 2015
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In: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 47:2, s. 291-317
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Journal article (peer-reviewed)abstract
- Most forms of Alzheimer's disease (AD) are sporadic (sAD) or inherited in a non-Mendelian fashion, and less than 1% of cases are autosomal-dominant. Forms of sAD do not exhibit familial aggregation and are characterized by complex genetic and environmental interactions. Recently, the expansion of genomic methodologies, in association with substantially larger combined cohorts, has resulted in various genome-wide association studies that have identified several novel genetic associations of AD. Currently, the most effective methods for establishing the diagnosis of AD are defined by multi-modal pathways, starting with clinical and neuropsychological assessment, cerebrospinal fluid (CSF) analysis, and brain-imaging procedures, all of which have significant cost- and access-to-care barriers. Consequently, research efforts have focused on the development and validation of non-invasive and generalizable blood-based biomarkers. Among the modalities conceptualized by the systems biology paradigm and utilized in the "exploratory biomarker discovery arena", proteome analysis has received the most attention. However, metabolomics, lipidomics, transcriptomics, and epigenomics have recently become key modalities in the search for AD biomarkers. Interestingly, biomarker changes for familial AD (fAD), in many but not all cases, seem similar to those for sAD. The integration of neurogenetics with systems biology/physiology-based strategies and high-throughput technologies for molecular profiling is expected to help identify the causes, mechanisms, and biomarkers associated with the various forms of AD. Moreover, in order to hypothesize the dynamic trajectories of biomarkers through disease stages and elucidate the mechanisms of biomarker alterations, updated and more sophisticated theoretical models have been proposed for both sAD and fAD.
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- Lista, S, et al.
(author)
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Blood and cerebrospinal fluid biomarkers for Alzheimer’s disease
- 2017
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In: Dementia. David Ames, John T. O'Brien, Alistair Burns (red.). - Boca Raton : CRC Press. - 9781498703116 ; , s. 528-538
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Book chapter (other academic/artistic)abstract
- In general, a biomarker denes a biological process or disease characteristic that is objectively measured (Biomarkers Denitions Working Group, 2001). Such measurements may be used for diagnostic purposes, but also to study physiological or pathophysiological mechanisms and to evaluate desired pharmacodynamic eects or side eects of pharmacological treatments. According to Biomarkers Denitions Working Group: ‘Molecular and Biochemical Markers of Alzheimer’s Disease’, the ideal biomarker for Alzheimer’s disease (AD) should detect a fundamental feature of neuropathology and be validated in neuropathologically con-rmed cases as well as have a diagnostic accuracy of at least 80% (e Ronald and Nancy Reagan Research Institute of the Alzheimer’s Association and National Institute on Aging Working Group, 1998). With respect to clinically relevant questions, such as detection, diagnosis, prediction and treatment of a given disease, biomarkers may serve certain distinct functions
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- Lista, S., et al.
(author)
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Evolving Evidence for the Value of Neuroimaging Methods and Biological Markers in Subjects Categorized with Subjective Cognitive Decline
- 2015
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In: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 48
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Journal article (peer-reviewed)abstract
- There is evolving evidence that individuals categorized with subjective cognitive decline (SCD) are potentially at higher risk for developing objective and progressive cognitive impairment compared to cognitively healthy individuals without apparent subjective complaints. Interestingly, SCD, during advancing preclinical Alzheimer's disease (AD), may denote very early, subtle cognitive decline that cannot be identified using established standardized tests of cognitive performance. The substantial heterogeneity of existing SCD-related research data has led the Subjective Cognitive Decline Initiative (SCD-I) to accomplish an international consensus on the definition of a conceptual research framework on SCD in preclinical AD. In the area of biological markers, the cerebrospinal fluid signature of AD has been reported to be more prevalent in subjects with SCD compared to healthy controls; moreover, there is a pronounced atrophy, as demonstrated by magnetic resonance imaging, and an increased hypometabolism, as revealed by positron emission tomography, in characteristic brain regions affected by AD. In addition, SCD individuals carrying an apolipoprotein epsilon 4 allele are more likely to display AD-phenotypic alterations. The urgent requirement to detect and diagnose AD as early as possible has led to the critical examination of the diagnostic power of biological markers, neurophysiology, and neuroimaging methods for AD-related risk and clinical progression in individuals defined with SCD. Observational studies on the predictive value of SCD for developing AD may potentially be of practical value, and an evidence-based, validated, qualified, and fully operationalized concept may inform clinical diagnostic practice and guide earlier designs in future therapy trials.
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- Molinuevo, J. L., et al.
(author)
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Current state of Alzheimer's fluid biomarkers
- 2018
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In: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 136:6, s. 821-853
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Research review (peer-reviewed)abstract
- Alzheimer's disease (AD) is a progressive neurodegenerative disease with a complex and heterogeneous pathophysiology. The number of people living with AD is predicted to increase; however, there are no disease-modifying therapies currently available and none have been successful in late-stage clinical trials. Fluid biomarkers measured in cerebrospinal fluid (CSF) or blood hold promise for enabling more effective drug development and establishing a more personalized medicine approach for AD diagnosis and treatment. Biomarkers used in drug development programmes should be qualified for a specific context of use (COU). These COUs include, but are not limited to, subject/patient selection, assessment of disease state and/or prognosis, assessment of mechanism of action, dose optimization, drug response monitoring, efficacy maximization, and toxicity/adverse reactions identification and minimization. The core AD CSF biomarkers A42, t-tau, and p-tau are recognized by research guidelines for their diagnostic utility and are being considered for qualification for subject selection in clinical trials. However, there is a need to better understand their potential for other COUs, as well as identify additional fluid biomarkers reflecting other aspects of AD pathophysiology. Several novel fluid biomarkers have been proposed, but their role in AD pathology and their use as AD biomarkers have yet to be validated. In this review, we summarize some of the pathological mechanisms implicated in the sporadic AD and highlight the data for several established and novel fluid biomarkers (including BACE1, TREM2, YKL-40, IP-10, neurogranin, SNAP-25, synaptotagmin, -synuclein, TDP-43, ferritin, VILIP-1, and NF-L) associated with each mechanism. We discuss the potential COUs for each biomarker.
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- Shahim, Pashtun, 1984, et al.
(author)
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Cerebrospinal Fluid Stanniocalcin-1 as a Biomarker for Alzheimer’s Disease and Other Neurodegenerative Disorders
- 2017
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In: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 19:1, s. 154-160
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Journal article (peer-reviewed)abstract
- © 2016 Springer Science+Business Media New YorkStanniocalcin-1 (STC-1) is a nerve cell-enriched protein involved in intracellular calcium homeostasis regulation. Changes in calcium regulation are hypothesized to play a role in the pathophysiology of Alzheimer’s disease (AD). The expression of STC-1 increases in response to ischemic stroke, but whether it is altered in neurodegenerative disorder, particularly Alzheimer’s disease (AD), has not been investigated before. We measured STC-1 in cerebrospinal fluid (CSF) samples from a total of 163 individuals including AD, prodromal AD (pAD), mixed AD, stable mild cognitive impairment (sMCI), and diagnoses of other dementia than AD, as well as cognitively normal controls (CNC) enrolled at academic centers in France and Sweden. STC-1 concentration was reliably measureable in all CSF samples and was significantly increased in the initial exploratory cohort of neurochemically enriched AD patients versus AD biomarker-negative controls. In the second cohort, STC-1 was increased in AD versus pAD, and other dementia disorders, but the difference was not statistically significant. In the third cohort, there was no significant difference in STC-1 concentration between AD and CNC; however, STC-1 concentration was significantly decreased in patients with other dementia disorders compared with AD and CNC. Taken together, CSF STC-1 showed an increasing trend in AD, but the findings were not consistent across the three study cohorts. In contrast, CSF STC-1 concentrations were reduced in patients with dementia diagnoses other than AD, as compared with both AD patients and CNC. The findings from these studies suggest CSF STC-1 as a potential biomarker in differential diagnosis of dementias.
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| 9. |
- van Doorn, Ljcv, et al.
(author)
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Improved Cerebrospinal Fluid-Based Discrimination between Alzheimer's Disease Patients and Controls after Correction for Ventricular Volumes
- 2017
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In: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 56:2, s. 543-555
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Journal article (peer-reviewed)abstract
- 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., A beta(42), 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 A beta(42) levels inversely correlated to VV/TIV in the whole study population (A beta(42): 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 A beta(42) 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 A beta(42) levels.
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| 10. |
- Vergallo, A., et al.
(author)
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Plasma amyloid beta 40/42 ratio predicts cerebral amyloidosis in cognitively normal individuals at risk for Alzheimer's disease
- 2019
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In: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 15:6, s. 764-775
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Journal article (peer-reviewed)abstract
- Introduction: Blood-based biomarkers of pathophysiological brain amyloid beta (A beta) accumulation, particularly for preclinical target and large-scale interventions, are warranted to effectively enrich Alzheimer's disease clinical trials and management. Methods: We investigated whether plasma concentrations of the A beta(1-40)/A beta(1-42) ratio, assessed using the single-molecule array (Simoa) immunoassay, may predict brain A beta positron emission tomography status in a large-scale longitudinal monocentric cohort (N = 276) of older individuals with subjective memory complaints. We performed a hypothesis-driven investigation followed by a no-apriori hypothesis study using machine learning. Results: The receiver operating characteristic curve and machine learning showed a balanced accuracy of 76.5% and 81%, respectively, for the plasma A beta(1-40)/A beta(1-42) ratio. The accuracy is not affected by the apolipoprotein E (APOE) epsilon 4 allele, sex, or age. Discussion: Our results encourage an independent validation cohort study to confirm the indication that the plasma A beta(1-40)/A beta(1-42) ratio, assessed via Simoa, may improve future standard of care and clinical trial design. (C) 2019 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
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