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| 2. |
- de Rojas, I., et al.
(författare)
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Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Genetic discoveries of Alzheimer’s disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer’s disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer’s disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer’s disease. © 2021, The Author(s).
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| 3. |
- Hampel, H., et al.
(författare)
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Developing the ATX(N) classification for use across the Alzheimer disease continuum
- 2021
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Ingår i: Nature Reviews Neurology. - : Springer Science and Business Media LLC. - 1759-4758 .- 1759-4766. ; 17, s. 580-589
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Tidskriftsartikel (refereegranskat)abstract
- Breakthroughs in the development of highly accurate fluid and neuroimaging biomarkers have catalysed the conceptual transformation of Alzheimer disease (AD) from the traditional clinical symptom-based definition to a clinical-biological construct along a temporal continuum. The AT(N) system is a symptom-agnostic classification scheme that categorizes individuals using biomarkers that chart core AD pathophysiological features, namely the amyloid-beta (A beta) pathway (A), tau-mediated pathophysiology (T) and neurodegeneration (N). This biomarker matrix is now expanding towards an ATX(N) system, where X represents novel candidate biomarkers for additional pathophysiological mechanisms such as neuroimmune dysregulation, synaptic dysfunction and blood-brain barrier alterations. In this Perspective, we describe the conceptual framework and clinical importance of the existing AT(N) system and the evolving ATX(N) system. We provide a state-of-the-art summary of the potential contexts of use of these systems in AD clinical trials and future clinical practice. We also discuss current challenges related to the validation, standardization and qualification process and provide an outlook on the real-world application of the AT(N) system. The AT(N) system is a classification scheme based on biomarkers that reflect the core pathophysiological features of Alzheimer disease. This Perspective outlines the conceptual framework and clinical importance of the AT(N) system and considers its potential expansion to incorporate biomarkers for additional pathophysiological mechanisms.
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| 4. |
- Hampel, H., et al.
(författare)
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State-of-the-art of lumbar puncture and its place in the journey of patients with Alzheimer's disease
- 2022
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 18:1, s. 159-177
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Tidskriftsartikel (refereegranskat)abstract
- Recent advances in developing disease-modifying therapies (DMT) for Alzheimer's disease (AD), and the recognition that AD pathophysiology emerges decades before clinical symptoms, necessitate a paradigm shift of health-care systems toward biomarker-guided early detection, diagnosis, and therapeutic decision-making. Appropriate incorporation of cerebrospinal fluid biomarker analysis in clinical practice is an essential step toward system readiness for accommodating the demand of AD diagnosis and proper use of DMTs-once they become available. However, the use of lumbar puncture (LP) in individuals with suspected neurodegenerative diseases such as AD is inconsistent, and the perception of its utility and safety differs considerably among medical specialties as well as among regions and countries. This review describes the state-of-the-art evidence concerning the safety profile of LP in older adults, discusses the risk factors for LP-associated adverse events, and provides recommendations and an outlook for optimized use and global implementation of LP in individuals with suspected AD.
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| 5. |
- Hampel, H., et al.
(författare)
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The Amyloid-beta Pathway in Alzheimer's Disease
- 2021
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 26, s. 5481-5503
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Tidskriftsartikel (refereegranskat)abstract
- Breakthroughs in molecular medicine have positioned the amyloid-beta (A beta) pathway at the center of Alzheimer's disease (AD) pathophysiology. While the detailed molecular mechanisms of the pathway and the spatial-temporal dynamics leading to synaptic failure, neurodegeneration, and clinical onset are still under intense investigation, the established biochemical alterations of the A beta cycle remain the core biological hallmark of AD and are promising targets for the development of disease-modifying therapies. Here, we systematically review and update the vast state-of-the-art literature of A beta science with evidence from basic research studies to human genetic and multi-modal biomarker investigations, which supports a crucial role of A beta pathway dyshomeostasis in AD pathophysiological dynamics. We discuss the evidence highlighting a differentiated interaction of distinct A beta species with other AD-related biological mechanisms, such as tau-mediated, neuroimmune and inflammatory changes, as well as a neurochemical imbalance. Through the lens of the latest development of multimodal in vivo biomarkers of AD, this cross-disciplinary review examines the compelling hypothesis- and data-driven rationale for A beta-targeting therapeutic strategies in development for the early treatment of AD.
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| 6. |
- Hampel, H., et al.
(författare)
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The amyloid-beta pathway in Alzheimer's disease: a plain language summary
- 2023
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Ingår i: Neurodegenerative Disease Management. - : Future Medicine Ltd. - 1758-2024 .- 1758-2032. ; 13:3, s. 141-9
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Tidskriftsartikel (refereegranskat)abstract
- What is this summary about? This plain language summary of an article published in Molecular Psychiatry, reviews the evidence supporting the role of the amyloid-b (Ab) pathway and its dysregulation in Alzheimer's disease (AD), and highlights the rationale for drugs targeting the A beta pathway in the early stages of the disease. Why is this important? A beta is a protein fragment (or peptide) that exists in several forms distinguished by their size, shape/structure, degree of solubility and disease relevance. The accumulation of A beta plaques is a hallmark of AD. However, smaller, soluble aggregates of A beta - including Ab protofibrils - also play a role in the disease. Because A beta-related disease mechanisms are complex, the diagnosis, treatment and management of AD should be reflective of and guided by up-to-date scientific knowledge and research findings in this area. This article describes the A beta protein and its role in AD, summarizing the evidence showing that altered A beta clearance from the brain may lead to the imbalance, toxic buildup and misfolding of the protein - triggering a cascade of cellular, molecular and systematic events that ultimately lead to AD. What are the key takeaways? The physiological balance of brain A beta levels in the context of AD is complex. Despite many unanswered questions, mounting evidence indicates that A beta has a central role in driving AD progression. A better understanding of the A beta pathway biology will help identify the best therapeutic targets for AD and inform treatment approaches.
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| 7. |
- Hampel, H., et al.
(författare)
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The AT(N) system for describing biological changes in Alzheimer's disease: a plain language summary
- 2022
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Ingår i: Neurodegenerative Disease Management. - : Future Medicine Ltd. - 1758-2024 .- 1758-2032. ; 12:5, s. 231-239
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Tidskriftsartikel (refereegranskat)abstract
- What is this summary about?: This is a plain language summary of an article published in Nature Reviews Neurology. It explains how Alzheimer's disease is diagnosed. It also looks at whether a newer way to assess people with Alzheimer's disease could help improve how the condition is diagnosed, monitored, and treated. Why is this important?: Alzheimer's disease is a long-term progressive brain disease that leads to difficulties with thinking and memory. It is a progressive condition, which means it gets worse over time. Biological changes occur in the brain of people with Alzheimer's disease. This includes a build-up of toxic protein clusters called amyloid plaques and tau tangles, gradual damage to the brain cells (neurodegeneration), and brain shrinkage due to loss of neurons. It is often due to multiple factors and doctors usually diagnose Alzheimer's disease by looking at a person's symptoms and ruling out other causes of dementia. However, research shows that people diagnosed in this way do not always have the biological changes in the brain that are related to Alzheimer's disease. This means that some people may be misdiagnosed. Additionally, there may be a delay in the appearance of Alzheimer's symptoms, by which point changes in the brain may be severe. For example, people with Alzheimer's disease show biological changes in the brain, years before symptoms appear. What are the key takeaways?: An assessment of biological changes in the brain, by measuring substances that indicate disease progress (biomarkers), may offer a fuller picture of a person's Alzheimer's disease, how advanced it is, and which treatments are likely to work best. A recently developed classification scheme known as the AT(N) system provides a way to assess and describe the biological changes in amyloid (A), tau (T), and neurodegeneration (N) that occur in people with Alzheimer's disease. The goal is to include biomarker testing in clinical practice to help physicians and practitioners diagnose, monitor, and treat people with Alzheimer's disease more effectively. The AT(N) system is being used for various purposes in clinical studies, and has the potential to assist physicians and practitioners in early detection, accurate diagnosis, staging, and treatment selection for people with Alzheimer's disease
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| 8. |
- Hampel, H., et al.
(författare)
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The use of lumbar puncture and safety recommendations in Alzheimer's disease: a plain language summary
- 2022
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Ingår i: Neurodegenerative Disease Management. - : Future Medicine Ltd. - 1758-2024 .- 1758-2032. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- What is this summary about? This is a plain language summary of an article published in Alzheimer's & Dementia. It looks at a type of test called a lumbar puncture (also known as spinal tap) used in people suspected of having Alzheimer's disease or some other form of dementia. This summary focuses on how to do a lumbar puncture safely. Why is this important? Alzheimer's disease is a progressive condition, which means it gets worse over time. This leads to difficulties with thinking and memory. People with Alzheimer's disease show a build up of proteins called amyloid-beta and tau in the brain. This is followed by a gradual loss of brain cells and brain function. The changes in the brain are thought to occur years before symptoms appear. Lumbar puncture is a medical procedure during which samples of cerebrospinal fluid are collected. In Alzheimer's disease, it is used to examine cerebrospinal fluid biomarkers that can help diagnose disease. Lumbar puncture is traditionally considered as a painful and invasive procedure with frequent side effects. However, multiple studies indicate that a lumbar puncture can be performed safely. Side effects are typically mild and do not require specialist intervention. What are the key takeaways? Despite the low risk of serious complications associated with a lumbar puncture, physicians and their patients may be reluctant to recommend or undergo this procedure. Patient education, specialist training, as well as new methods concerning patient safety are important factors to support the widespread use of lumbar puncture in Alzheimer's disease.
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| 9. |
- Lemercier, P., et al.
(författare)
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Association of plasma A beta 40/A beta 42 ratio and brain A beta accumulation: testing a whole-brain PLS-VIP approach in individuals at risk of Alzheimer's disease
- 2021
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580. ; 107, s. 57-69
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Tidskriftsartikel (refereegranskat)abstract
- Molecular and brain regional/network-wise pathophysiological changes at preclinical stages of Alzheimer's disease (AD) have primarily been found through knowledge-based studies conducted in late-stage mild cognitive impairment/dementia populations. However, such an approach may compromise the objective of identifying the earliest spatial-temporal pathophysiological processes. We investigated 261 individuals with subjective memory complaints, a condition at increased risk of AD, to test a whole-brain, non-a-priori method based on partial least squares in unraveling the association between plasma A beta 42/A beta 40 ratio and an extensive set of brain regions characterized through molecular imaging of A beta accumulation and cortical metabolism. Significant associations were mapped onto large-scale networks, identified through an atlas and by knowledge, to elaborate on the reliability of the results. Plasma A beta 42/beta 40 ratio was associated with A beta-PET uptake (but not FDG-PET) in regions generally investigated in preclinical AD such as those belonging to the default mode network, but also in regions/networks normally not accounted including the central executive and salience networks which likely have a selective vulnerability to incipient A beta accumulation. The present whole-brain approach is promising to investigate early pathophysiological changes of AD to fully capture the complexity of the disease, which is essential to develop timely screening, detection, diagnostic, and therapeutic interventions. (C) 2021 Elsevier Inc. All rights reserved.
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| 10. |
- Vergallo, A., et al.
(författare)
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Association of plasma YKL-40 with brain amyloid-β levels, memory performance, and sex in subjective memory complainers
- 2020
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580. ; 96, s. 22-32
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Tidskriftsartikel (refereegranskat)abstract
- Neuroinflammation, a key early pathomechanistic alteration of Alzheimer's disease, may represent either a detrimental or a compensatory mechanism or both (according to the disease stage). YKL-40, a glycoprotein highly expressed in differentiated glial cells, is a candidate biomarker for in vivo tracking neuroinflammation in humans. We performed a longitudinal study in a monocentric cohort of cognitively healthy individuals at risk for Alzheimer's disease exploring whether age, sex, and the apolipoprotein E ε4 allele affect plasma YKL-40 concentrations. We investigated whether YKL-40 is associated with brain amyloid-β (Aβ) deposition, neuronal activity, and neurodegeneration as assessed via neuroimaging biomarkers. Finally, we investigated whether YKL-40 may predict cognitive performance. We found an age-associated increase of YKL-40 and observed that men display higher concentrations than women, indicating a potential sexual dimorphism. Moreover, YKL-40 was positively associated with memory performance and negatively associated with brain Aβ deposition (but not with metabolic signal). Consistent with translational studies, our results suggest a potentially protective effect of glia on incipient brain Aβ accumulation and neuronal homeostasis. © 2020 Elsevier Inc.
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