| 1. |
- Ashton, Nicholas J., et al.
(författare)
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A plasma protein classifier for predicting amyloid burden for preclinical Alzheimer's disease.
- 2019
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Ingår i: Science advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- A blood-based assessment of preclinical disease would have huge potential in the enrichment of participants for Alzheimer's disease (AD) therapeutic trials. In this study, cognitively unimpaired individuals from the AIBL and KARVIAH cohorts were defined as Aβ negative or Aβ positive by positron emission tomography. Nontargeted proteomic analysis that incorporated peptide fractionation and high-resolution mass spectrometry quantified relative protein abundances in plasma samples from all participants. A protein classifier model was trained to predict Aβ-positive participants using feature selection and machine learning in AIBL and independently assessed in KARVIAH. A 12-feature model for predicting Aβ-positive participants was established and demonstrated high accuracy (testing area under the receiver operator characteristic curve = 0.891, sensitivity = 0.78, and specificity = 0.77). This extensive plasma proteomic study has unbiasedly highlighted putative and novel candidates for AD pathology that should be further validated with automated methodologies.
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| 2. |
- Ashton, Nicholas J., et al.
(författare)
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Increased plasma neurofilament light chain concentration correlates with severity of post-mortem neurofibrillary tangle pathology and neurodegeneration
- 2019
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Ingår i: Acta Neuropathologica Communications. - : Springer Science and Business Media LLC. - 2051-5960. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is pathologically characterized by the accumulation of amyloid-β (Aβ) plaques, neurofibrillary tangles and widespread neuronal loss in the brain. In recent years, blood biomarkers have emerged as a realistic prospect to highlight accumulating pathology for secondary prevention trials. Neurofilament light chain (NfL), a marker of axonal degeneration, is robustly elevated in the blood of many neurological and neurodegenerative conditions, including AD. A strong relationship with cerebrospinal fluid (CSF) NfL suggests that these biomarker modalities reflect the same pathological process. Yet, the connection between blood NfL and brain tissue pathology has not been directly compared. In this study, longitudinal plasma NfL from cognitively healthy controls (n = 12) and AD participants (n = 57) were quantified by the Simoa platform. On reaching post-mortem, neuropathological assessment was performed on all participants, with additional frozen and paraffin-embedded tissue acquired from 26 participants for further biochemical (Aβ1-42, Aβ1-40, tau) and histological (NfL) evaluation. Plasma NfL concentrations were significantly increased in AD and correlated with cognitive decline, independent of age. Retrospective stratification based on Braak staging revealed that baseline plasma NfL concentrations were associated with higher neurofibrillary tangle pathology at post-mortem. Longitudinal increases in plasma NfL were observed in all Braak groupings; a significant negative association, however, was found between plasma NfL at time point 1 and both its rate of change and annual percentage increase. Immunohistochemical evaluation of NfL in the medial temporal gyrus (MTG) demonstrated an inverse relationship between Braak stages and NfL staining. Importantly, a significant negative correlation was found between the plasma NfL measurement closest to death and the level of NfL staining in the MTG at post-mortem. For the first time, we demonstrate that plasma NfL associates with the severity of neurofibrillary tangle pathology and neurodegeneration in the post-mortem brain.
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| 3. |
- Bloniecki, Victor, et al.
(författare)
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Effects of Risperidone and Galantamine Treatment on Alzheimer's Disease Biomarker Levels in Cerebrospinal Fluid
- 2017
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 57:2, s. 387-393
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Treatment for neuropsychiatric symptoms (NPS) in dementia is insufficient. Antipsychotics and acetylcholinesterase inhibitors are used generating symptomatic improvements in behavior and cognition, but few studies have investigated their effect on Alzheimer's disease (AD) biomarkers in cerebrospinal fluid (CSF).OBJECTIVE: This is a secondary analysis based on an earlier clinical trial comparing the treatment effects on NPS. The aim of this study was to examine whether treatment with risperidone and galantamine affect levels of the biomarkers T-Tau, P-Tau, Aβ1-42, and Aβ42/40-ratio in CSF. The secondary aim was to test if baseline levels of these biomarkers are associated with the clinical course of NPS.METHODS: 83 patients (mean + SD 77.9.6±7.7 years) with dementia and NPS were randomized to galantamine (n = 44) or risperidone (n = 39) treatment. CSF samples were collected at baseline and after 12 weeks.RESULTS: Changes in levels of biomarkers between the two treatment groups did not differ significantly. Low baseline levels of Aβ1 - 42 was significantly associated with reduction of irritability at follow up. Low baseline levels of Aβ1-42, Aβ42/40, and P-Tau were significant correlates of reduction in appetite and eating disorders. CSF Aβ1-42 levels in patients treated with risperidone were significantly decreased at follow up, showing an 8% (40 pg/mL) reduction as compared with baseline (p = 0.03).CONCLUSIONS: Our results suggest that risperidone may affect the CSF profile of AD biomarkers indicating more amyloid pathology. Treatment with galantamine did not affect the CSF biomarkers in any direction. The AD CSF biomarkers displayed correlations with specific NPS suggesting potential research questions to be pursued.
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| 4. |
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| 5. |
- Enache, Daniela, et al.
(författare)
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CAIDE Dementia Risk Score and biomarkers of neurodegeneration in memory clinic patients without dementia
- 2016
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 42, s. 124-131
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to explore cross-sectional associations between Cardiovascular Risk Factors, Aging and Dementia Study (CAIDE) Dementia Risk Score and dementia-related cerebrospinal fluid and neuroimaging biomarkers in 724 patients without dementia from the Memory Clinic at Karolinska University Hospital, Huddinge, Sweden. We additionally evaluated the score's capacity to predict dementia. Two risk score versions were calculated: one including age, gender, obesity, hyperlipidemia, and hypertension; and one additionally including apolipoprotein E (APOE) ε4 carrier status. Cerebrospinal fluid was analyzed for amyloid β (Aβ), total tau, and phosphorylated tau. Visual assessments of medial temporal lobe atrophy (MTA), global cortical atrophy-frontal subscale, and Fazekas scale for white matter changes (WMC) were performed. Higher CAIDE Dementia Risk Score (version without APOE) was significantly associated with higher total tau, more severe MTA, WMC, and global cortical atrophy-frontal subscale. Higher CAIDE Dementia Risk Score (version with APOE) was associated with reduced Aβ, more severe MTA, and WMC. CAIDE Dementia Risk Score version with APOE seemed to predict dementia better in this memory clinic population with short follow-up than the version without APOE.
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| 6. |
- Jansen, Willemijn J, et al.
(författare)
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Association of Cerebral Amyloid-β Aggregation With Cognitive Functioning in Persons Without Dementia.
- 2018
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Ingår i: JAMA psychiatry. - : American Medical Association (AMA). - 2168-6238 .- 2168-622X. ; 75:1, s. 84-95
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral amyloid-β 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.To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia.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.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.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.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.
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| 7. |
- Jansen, Willemijn J, et al.
(författare)
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Prevalence of cerebral amyloid pathology in persons without dementia: a meta-analysis.
- 2015
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Ingår i: JAMA. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 313:19, s. 1924-38
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral amyloid-β 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.
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| 8. |
- Kramberger, Milica G., et al.
(författare)
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Long-Term Cognitive Decline in Dementia with Lewy Bodies in a Large Multicenter, International Cohort
- 2017
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 57:3, s. 787-795
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Tidskriftsartikel (refereegranskat)abstract
- Background/Objective: The aim of this study was to describe the rate and clinical predictors of cognitive decline in dementia with Lewy bodies (DLB), and compare the findings with Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) patients. Methods: Longitudinal scores for the Mini-Mental State Examination (MMSE) in 1,290 patients (835 DLB, 198 PDD, and 257 AD) were available from 18 centers with up to three years longitudinal data. Linear mixed effects analyses with appropriate covariates were used to model MMSE decline over time. Several subgroup analyses were performed, defined by anti-dementia medication use, baseline MMSE score, and DLB core features. Results: The mean annual decline in MMSE score was 2.1 points in DLB, compared to 1.6 in AD (p=0.07 compared to DLB) and 1.8 in PDD (p=0.19). Rates of decline were significantly higher in DLB compared to AD and PDD when baseline MMSE score was included as a covariate, and when only those DLB patients with an abnormal dopamine transporter SPECT scan were included. Decline was not predicted by sex, baseline MMSE score, or presence of specific DLB core features. Conclusions: The average annual decline in MMSE score in DLB is approximately two points. Although in the overall analyses there were no differences in the rate of decline between the three neurodegenerative disorders, there were indications of a more rapid decline in DLB than in AD and PDD. Further studies are needed to understand the predictors and mechanisms of cognitive decline in DLB.
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| 9. |
- Lleó, Alberto, et al.
(författare)
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Cerebrospinal fluid biomarkers in trials for Alzheimer and Parkinson diseases.
- 2015
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Ingår i: Nature reviews. Neurology. - : Springer Science and Business Media LLC. - 1759-4766 .- 1759-4758. ; 11, s. 41-55
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Forskningsöversikt (refereegranskat)abstract
- Alzheimer disease (AD) and Parkinson disease (PD) are the most common neurodegenerative disorders. For both diseases, early intervention is thought to be essential to the success of disease-modifying treatments. Cerebrospinal fluid (CSF) can reflect some of the pathophysiological changes that occur in the brain, and the number of CSF biomarkers under investigation in neurodegenerative conditions has grown rapidly in the past 20 years. In AD, CSF biomarkers are increasingly being used in clinical practice, and have been incorporated into the majority of clinical trials to demonstrate target engagement, to enrich or stratify patient groups, and to find evidence of disease modification. In PD, CSF biomarkers have not yet reached the clinic, but are being studied in patients with parkinsonism, and are being used in clinical trials either to monitor progression or to demonstrate target engagement and downstream effects of drugs. CSF biomarkers might also serve as surrogate markers of clinical benefit after a specific therapeutic intervention, although additional data are required. It is anticipated that CSF biomarkers will have an important role in trials aimed at disease modification in the near future. In this Review, we provide an overview of CSF biomarkers in AD and PD, and discuss their role in clinical trials.
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| 10. |
- Mattsson, Niklas, et al.
(författare)
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Prevalence of the apolipoprotein E epsilon 4 allele in amyloid beta positive subjects across the spectrum of Alzheimers disease
- 2018
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Ingår i: Alzheimer's & Dementia. - : ELSEVIER SCIENCE INC. - 1552-5260 .- 1552-5279. ; 14:7, s. 913-924
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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.
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