| 41. |
- Mattsson, Niklas, et al.
(författare)
-
Prevalence of the apolipoprotein E epsilon 4 allele in amyloid beta positive subjects across the spectrum of Alzheimers disease
- 2018
-
Ingår i: Alzheimer's & Dementia. - : ELSEVIER SCIENCE INC. - 1552-5260 .- 1552-5279. ; 14:7, s. 913-924
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Apolipoprotein E (APOE) epsilon 4 is the major genetic risk factor for Alzheimers disease (AD), but its prevalence is unclear because earlier studies did not require biomarker evidence of amyloid beta(A beta) pathology. Methods: We included 3451 A beta+ subjects (853 AD-type dementia, 1810 mild cognitive impairment, and 788 cognitively normal). Generalized estimating equation models were used to assess APOE epsilon 4 prevalence in relation to age, sex, education, and geographical location. Results: The APOE epsilon 4 prevalence was 66% in AD-type dementia, 64% in mild cognitive impairment, and 51% in cognitively normal, and it decreased with advancing age in A beta+ cognitively normal and A beta+ mild cognitive impairment (P amp;lt;.05) but not in A beta+ AD dementia (P =.66). The prevalence was highest in Northern Europe but did not vary by sex or education. Discussion: The APOE E4 prevalence in AD was higher than that in previous studies, which did not require presence of A beta pathology. Furthermore, our results highlight disease heterogeneity related to age and geographical location. (C) 2018 the Alzheimers Association. Published by Elsevier Inc. All rights reserved.
|
|
| 42. |
- Mattsson, Niklas, et al.
(författare)
-
Prevalence of the apolipoprotein E ε4 allele in amyloid β positive subjects across the spectrum of Alzheimer's disease
- 2018
-
Ingår i: Alzheimer's and Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 14:7, s. 913-924
-
Tidskriftsartikel (refereegranskat)abstract
- 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 β (Aβ) pathology. Methods: We included 3451 Aβ+ 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 Aβ+ cognitively normal and Aβ+ mild cognitive impairment (P <.05) but not in Aβ+ 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 Aβ pathology. Furthermore, our results highlight disease heterogeneity related to age and geographical location.
|
|
| 43. |
- Miller, Anne-Marie, et al.
(författare)
-
Current Approaches and Clinician Attitudes to the Use of Cerebrospinal Fluid Biomarkers in Diagnostic Evaluation of Dementia in Europe.
- 2017
-
Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908. ; 60:1, s. 201-210
-
Tidskriftsartikel (refereegranskat)abstract
- BIOMARKAPD seeks to diminish the barriers associated with the clinical use of cerebrospinal fluid (CSF) biomarker analysis by reducing variation in CSF laboratory methodologies and generating consensus recommendations on their clinical interpretation and application for dementia diagnosis.To examine the disparity in practitioner attitudes and clinical practice relating to the use of CSF biomarkers for dementia diagnosis across Europe.Clinical dementia experts were surveyed on the prevalence of national consensus guidelines and analytical reimbursement across Europe, their biomarker platform preferences, lumbar puncture methodologies and application of reference values and cut-offs for CSF analysis.74% of respondents (total n=51) use CSF biomarkers in clinical practice and 69% perform lumbar punctures on an outpatient basis. Most use CSF biomarkers to diagnose atypical (84%) and early-onset cases of cognitive impairment (71%) and for the differential diagnosis of other dementias (69%). 82% state they are sufficiently informed about CSF biomarkers yet 61% report a lack of national consensus guidelines on their use for dementia diagnosis. 48% of countries represented do not reimburse clinical CSF analysis costs. 43% report using normal reference ranges derived from publications.Variations in attitude and practice relating to CSF biomarkers, widely recognised as barriers to their clinical acceptance, remain evident within and between countries across Europe, even in expert centres. These shortcomings must be addressed by developing consensus guidelines on CSF-related methodologies and their clinical application, to further their use for the diagnostic evaluation of dementia.
|
|
| 44. |
- Neumann, Alexander, et al.
(författare)
-
Multivariate GWAS of Alzheimer's disease CSF biomarker profiles implies GRIN2D in synaptic functioning.
- 2023
-
Ingår i: Genome medicine. - 1756-994X. ; 15:1
-
Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) of Alzheimer's disease (AD) have identified several risk loci, but many remain unknown. Cerebrospinal fluid (CSF) biomarkers may aid in gene discovery and we previously demonstrated that six CSF biomarkers (β-amyloid, total/phosphorylated tau, NfL, YKL-40, and neurogranin) cluster into five principal components (PC), each representing statistically independent biological processes. Here, we aimed to (1) identify common genetic variants associated with these CSF profiles, (2) assess the role of associated variants in AD pathophysiology, and (3) explore potential sex differences.We performed GWAS for each of the five biomarker PCs in two multi-center studies (EMIF-AD and ADNI). In total, 973 participants (n=205 controls, n=546 mild cognitive impairment, n=222 AD) were analyzed for 7,433,949 common SNPs and 19,511 protein-coding genes. Structural equation models tested whether biomarker PCs mediate genetic risk effects on AD, and stratified and interaction models probed for sex-specific effects.Five loci showed genome-wide significant association with CSF profiles, two were novel (rs145791381 [inflammation] and GRIN2D [synaptic functioning]) and three were previously described (APOE, TMEM106B, and CHI3L1). Follow-up analysesof the two novel signals in independent datasets only supported the GRIN2D locus, which contains several functionally interesting candidate genes. Mediation tests indicated that variants in APOE are associated with AD status via processes related to amyloid and tau pathology, while markers in TMEM106B and CHI3L1 are associated with AD only via neuronal injury/inflammation. Additionally, seven loci showed sex-specific associations with AD biomarkers.These results suggest that pathway and sex-specific analyses can improve our understanding of AD genetics and may contribute to precision medicine.
|
|
| 45. |
- Quenon, Lisa, et al.
(författare)
-
Amyloid-PET imaging predicts functional decline in clinically normal individuals
- 2024
-
Ingår i: Alzheimer's Research and Therapy. - 1758-9193. ; 16:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: There is good evidence that elevated amyloid-β (Aβ) positron emission tomography (PET) signal is associated with cognitive decline in clinically normal (CN) individuals. However, it is less well established whether there is an association between the Aβ burden and decline in daily living activities in this population. Moreover, Aβ-PET Centiloids (CL) thresholds that can optimally predict functional decline have not yet been established. Methods: Cross-sectional and longitudinal analyses over a mean three-year timeframe were performed on the European amyloid-PET imaging AMYPAD-PNHS dataset that phenotypes 1260 individuals, including 1032 CN individuals and 228 participants with questionable functional impairment. Amyloid-PET was assessed continuously on the Centiloid (CL) scale and using Aβ groups (CL < 12 = Aβ-, 12 ≤ CL ≤ 50 = Aβ-intermediate/Aβ±, CL > 50 = Aβ+). Functional abilities were longitudinally assessed using the Clinical Dementia Rating (Global-CDR, CDR-SOB) and the Amsterdam Instrumental Activities of Daily Living Questionnaire (A-IADL-Q). The Global-CDR was available for the 1260 participants at baseline, while baseline CDR-SOB and A-IADL-Q scores and longitudinal functional data were available for different subsamples that had similar characteristics to those of the entire sample. Results: Participants included 765 Aβ- (61%, Mdnage = 66.0, IQRage = 61.0–71.0; 59% women), 301 Aβ± (24%; Mdnage = 69.0, IQRage = 64.0–75.0; 53% women) and 194 Aβ+ individuals (15%, Mdnage = 73.0, IQRage = 68.0–78.0; 53% women). Cross-sectionally, CL values were associated with CDR outcomes. Longitudinally, baseline CL values predicted prospective changes in the CDR-SOB (bCL*Time = 0.001/CL/year, 95% CI [0.0005,0.0024], p =.003) and A-IADL-Q (bCL*Time = -0.010/CL/year, 95% CI [-0.016,-0.004], p =.002) scores in initially CN participants. Increased clinical progression (Global-CDR > 0) was mainly observed in Aβ+ CN individuals (HRAβ+ vs Aβ- = 2.55, 95% CI [1.16,5.60], p =.020). Optimal thresholds for predicting decline were found at 41 CL using the CDR-SOB (bAβ+ vs Aβ- = 0.137/year, 95% CI [0.069,0.206], p <.001) and 28 CL using the A-IADL-Q (bAβ+ vs Aβ- = -0.693/year, 95% CI [-1.179,-0.208], p =.005). Conclusions: Amyloid-PET quantification supports the identification of CN individuals at risk of functional decline. Trial registration: The AMYPAD PNHS is registered at www.clinicaltrialsregister.eu with the EudraCT Number: 2018-002277-22.
|
|
| 46. |
- Reijs, Babette L R, et al.
(författare)
-
Association Between Later Life Lifestyle Factors and Alzheimer's Disease Biomarkers in Non-Demented Individuals : A Longitudinal Descriptive Cohort Study
- 2017
-
Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 60:4, s. 1387-1395
-
Tidskriftsartikel (refereegranskat)abstract
- 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-β 1-42 (Aβ42) 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 Aβ42 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.
|
|
| 47. |
- Reijs, Babette L R, et al.
(författare)
-
The Central Biobank and Virtual Biobank of BIOMARKAPD: A Resource for Studies on Neurodegenerative Diseases.
- 2015
-
Ingår i: Frontiers in neurology. - : Frontiers Media SA. - 1664-2295. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Biobanks are important resources for biomarker discovery and assay development. Biomarkers for Alzheimer's and Parkinson's disease (BIOMARKAPD) is a European multicenter study, funded by the EU Joint Programme-Neurodegenerative Disease Research, which aims to improve the clinical use of body fluid markers for the diagnosis and prognosis of Alzheimer's disease (AD) and Parkinson's disease (PD). The objective was to standardize the assessment of existing assays and to validate novel fluid biomarkers for AD and PD. To support the validation of novel biomarkers and assays, a central and a virtual biobank for body fluids and associated data from subjects with neurodegenerative diseases have been established. In the central biobank, cerebrospinal fluid (CSF) and blood samples were collected according to the BIOMARKAPD standardized pre-analytical procedures and stored at Integrated BioBank of Luxembourg. The virtual biobank provides an overview of available CSF, plasma, serum, and DNA samples at each site. Currently, at the central biobank of BIOMARKAPD samples are available from over 400 subjects with normal cognition, mild cognitive impairment (MCI), AD, frontotemporal dementia (FTD), vascular dementia, multiple system atrophy, progressive supranuclear palsy, PD, PD with dementia, and dementia with Lewy bodies. The virtual biobank contains information on over 8,600 subjects with varying diagnoses from 21 local biobanks. A website has been launched to enable sample requests from the central biobank and virtual biobank.
|
|
| 48. |
- Remnestål, Julia
(författare)
-
Dementia Proteomics
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The term dementia encompass a number of conditions arising as a consequence of tissue degeneration in the brain. This degeneration is caused by molecular events occurring on a cellular level including inflammation, defective waste disposal and accumulation of insoluble proteins and peptides. Many of these molecular events are in turn also reflected in the composition of the cerebrospinal fluid (CSF) which circulates within and around the brain. This thesis summarise five studies conducted with the aim to explore and profile CSF proteins in the context of dementia and other neurodegenerative disorders. Protein profiles were obtained by so-called suspension bead arrays (SBAs), created by coupling antibodies to color-coded microspheres, allowing detection of more than 350 CSF proteins simultaneously. The majority of the explored proteins are referred to as brain-enriched, entailing that the corresponding genes are highly expressed in brain tissue in comparison to other tissues. In Paper I, the SBA technology was utilised to profile about 280 proteins in CSF from several neurodegenerative disorders, i.e. Alzheimer’s disease (AD), dementia with Lewy Bodies and Parkinson’s disease. Distinct differences in the CSF proteome were identified depending on site of collection (ventricular or lumbar) and time point (post mortem or ante mortem). Disease-associated profiles for the two synaptic proteins neuromodulin (GAP43) and neurogranin (NRGN) could be confirmed, in which both proteins displayed higher levels in AD compared to controls. High levels of the two proteins were furthermore observed in patients at preclinical stages of AD in two independent cohorts. To verify the identified protein profiles, parallel reaction monitoring (PRM) assays were developed for 17 proteins in Paper II, including GAP43. Eight proteins displayed concordance to data generated with SBAs and among these were GAP43, cholecystokinin, neurofilament medium chain (NF-M), leucine-rich alpha-2-glycoprotein and vascular cell adhesion protein 1. In Paper III, the SBA technology was again applied to characterise early dementia-related changes in the CSF proteome by comparing samples from individuals with mild cognitive impairment (MCI), controls and AD patients in two independent cohorts. The MCI individuals were moreover stratified based on CSF concentration of the core AD biomarkers Aβ42 and tau. The six proteins amphiphysin, aquaporin 4, cAMP regulated phosphoprotein 21, β-synuclein, GAP43 and NF-M did all show significant differences between sample groups in both cohorts. Further exploration of how the pathological processes preceding dementia affect the CSF proteome, was done by analysis of 104 brain-enriched proteins in CSF from asymptomatic 70 year-olds in Paper IV. Protein profiles were correlated to Aβ42, t-tau and p-tau CSF concentration, revealing a large number of proteins displaying significant correlations to tau levels. Upon dividing the asymptomatic individuals based on Aβ42 CSF pathology, some proteins showed significantly different associations in the two groups. Most of these proteins yielding interesting profiles, were plasma membrane proteins or proteins connected to synaptic vesicle transport. While AD is the most common form of dementia, accounting for more than 60 % of all cases worldwide, frontotemporal dementia (FTD) is the most frequently occurring form of young-onset dementia. In Paper V, CSF protein profiles were explored in the context of FTD. Patients with behavioural variant FTD and primary progressive aphasia, were compared to unaffected individuals with a high risk of developing FTD. Proteomic differences between patients with FTD and the unaffected individuals were observed already at a global level, and particularly for the six proteins NF-M, neurosecretory protein VGF, neuronal pentraxin receptor, prodynorphin, transmembrane protein 132D and tenascin-R. The disease-associated profiles identified in the presented studies provide a basis for future research within dementia proteomics. Whether the proteins identified will have the possibility to aid in clinical diagnosis, prognosis or characterisation of dementia, remains to be evaluated. Given the fortunate situation, especially in Sweden, with access to large and well characterised CSF collections, there are ample opportunities for future proteomic studies to elucidate the true potential of these proteins.
|
|
| 49. |
- Sannemann, Lena, et al.
(författare)
-
General practitioners’ attitude toward early and pre-dementia diagnosis of ad in five European countries—a mopead project survey
- 2021
-
Ingår i: Alzheimer's and Dementia: Diagnosis, Assessment and Disease Monitoring. - : Wiley. - 2352-8729. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: General practitioners (GPs) play a key role in early identification of dementia, yet diagnosis is often missed or delayed in primary care. As part of the multinational Models of Patient Engagement for Alzheimer’s Disease project, we assess GPs’ attitude toward early and pre-dementia diagnosis of AD and explore barriers to early diagnosis. Methods: Our survey covered general attitude toward early diagnosis, diagnostic procedures, resources, and opinion on present and future treatment options across five European countries. Results: In total 343 GPs completed the survey; 74% of GPs indicated that an early diagnosis is valuable. There were country-specific differences in GPs’ perceptions of reimbursement and time available for the patient. If a drug were available to slow down the progression of AD, 59% of the GPs would change their implementation of early diagnosis. Discussion: Our findings provide insight into GPs’ attitudes by exploring differences in perception and management of early diagnosis.
|
|
| 50. |
- Shi, Liu, et al.
(författare)
-
Dickkopf-1 Overexpression in vitro Nominates Candidate Blood Biomarkers Relating to Alzheimer's Disease Pathology.
- 2020
-
Ingår i: Journal of Alzheimer's disease : JAD. - : IOS Press. - 1875-8908 .- 1387-2877. ; 77:3, s. 1353-1368
-
Tidskriftsartikel (refereegranskat)abstract
- Previous studies suggest that Dickkopf-1 (DKK1), an inhibitor of Wnt signaling, plays a role in amyloid-induced toxicity and hence Alzheimer's disease (AD). However, the effect of DKK1 expression on protein expression, and whether such proteins are altered in disease, is unknown.We aim to test whether DKK1 induced protein signature obtained in vitro were associated with markers of AD pathology as used in the amyloid/tau/neurodegeneration (ATN) framework as well as with clinical outcomes.We first overexpressed DKK1 in HEK293A cells and quantified 1,128 proteins in cell lysates using aptamer capture arrays (SomaScan) to obtain a protein signature induced by DKK1. We then used the same assay to measure the DKK1-signature proteins in human plasma in two large cohorts, EMIF (n = 785) and ANM (n = 677).We identified a 100-protein signature induced by DKK1 in vitro. Subsets of proteins, along with age and apolipoprotein E ɛ4 genotype distinguished amyloid pathology (A + T-N-, A+T+N-, A+T-N+, and A+T+N+) from no AD pathology (A-T-N-) with an area under the curve of 0.72, 0.81, 0.88, and 0.85, respectively. Furthermore, we found that some signature proteins (e.g., Complement C3 and albumin) were associated with cognitive score and AD diagnosis in both cohorts.Our results add further evidence for a role of DKK regulation of Wnt signaling in AD and suggest that DKK1 induced signature proteins obtained in vitro could reflect theATNframework as well as predict disease severity and progression in vivo.
|
|
