scholarly journals Longitudinal amyloid and tau accumulation in autosomal dominant Alzheimer’s disease: findings from the Colombia-Boston (COLBOS) biomarker study

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Justin S. Sanchez ◽  
Bernard J. Hanseeuw ◽  
Francisco Lopera ◽  
Reisa A. Sperling ◽  
Ana Baena ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Decline ◽  
Symptom Onset ◽  
Autosomal Dominant ◽  
Amyloid Β ◽  
Cognitive Changes ◽  
Cross Sectional ◽  
Rates Of Change ◽  
Autosomal Dominant Alzheimer’S Disease

Abstract Background Neuroimaging studies of autosomal dominant Alzheimer’s disease (ADAD) enable characterization of the trajectories of cerebral amyloid-β (Aβ) and tau accumulation in the decades prior to clinical symptom onset. Longitudinal rates of regional tau accumulation measured with positron emission tomography (PET) and their relationship with other biomarker and cognitive changes remain to be fully characterized in ADAD. Methods Fourteen ADAD mutation carriers (Presenilin-1 E280A) and 15 age-matched non-carriers from the Colombian kindred underwent 2–3 sessions of Aβ (11C-Pittsburgh compound B) and tau (18F-flortaucipir) PET, structural magnetic resonance imaging, and neuropsychological evaluation over a 2–4-year follow-up period. Annualized rates of change for imaging and cognitive variables were compared between carriers and non-carriers, and relationships among baseline measurements and rates of change were assessed within carriers. Results Longitudinal measurements were consistent with a sequence of ADAD-related changes beginning with Aβ accumulation (16 years prior to expected symptom onset, EYO), followed by entorhinal cortex (EC) tau (9 EYO), neocortical tau (6 EYO), hippocampal atrophy (6 EYO), and cognitive decline (4 EYO). Rates of tau accumulation among carriers were most rapid in parietal neocortex (~ 9%/year). EC tau PET signal at baseline was a significant predictor of subsequent neocortical tau accumulation and cognitive decline within carriers. Conclusions Our results are consistent with the sequence of biological changes in ADAD implied by cross-sectional studies and highlight the importance of EC tau as an early biomarker and a potential link between Aβ burden and neocortical tau accumulation in ADAD.

scholarly journals Single-subject grey matter network trajectories over the disease course of autosomal dominant Alzheimer’s disease

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Lisa Vermunt ◽  
Ellen Dicks ◽  
Guoqiao Wang ◽  
Aylin Dincer ◽  
Shaney Flores ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Symptom Onset ◽  
Grey Matter ◽  
Autosomal Dominant ◽  
Single Subject ◽  
Mutation Carriers ◽  
Autosomal Dominant Alzheimer’S Disease ◽  
Network Properties ◽  
Over Time

Abstract Structural grey matter covariance networks provide an individual quantification of morphological patterns in the brain. The network integrity is disrupted in sporadic Alzheimer’s disease, and network properties show associations with the level of amyloid pathology and cognitive decline. Therefore, these network properties might be disease progression markers. However, it remains unclear when and how grey matter network integrity changes with disease progression. We investigated these questions in autosomal dominant Alzheimer’s disease mutation carriers, whose conserved age at dementia onset allows individual staging based upon their estimated years to symptom onset. From the Dominantly Inherited Alzheimer Network observational cohort, we selected T1-weighted MRI scans from 269 mutation carriers and 170 non-carriers (mean age 38 ± 15 years, mean estimated years to symptom onset −9 ± 11), of whom 237 had longitudinal scans with a mean follow-up of 3.0 years. Single-subject grey matter networks were extracted, and we calculated for each individual the network properties which describe the network topology, including the size, clustering, path length and small worldness. We determined at which time point mutation carriers and non-carriers diverged for global and regional grey matter network metrics, both cross-sectionally and for rate of change over time. Based on cross-sectional data, the earliest difference was observed in normalized path length, which was decreased for mutation carriers in the precuneus area at 13 years and on a global level 12 years before estimated symptom onset. Based on longitudinal data, we found the earliest difference between groups on a global level 6 years before symptom onset, with a greater rate of decline of network size for mutation carriers. We further compared grey matter network small worldness with established biomarkers for Alzheimer disease (i.e. amyloid accumulation, cortical thickness, brain metabolism and cognitive function). We found that greater amyloid accumulation at baseline was associated with faster decline of small worldness over time, and decline in grey matter network measures over time was accompanied by decline in brain metabolism, cortical thinning and cognitive decline. In summary, network measures decline in autosomal dominant Alzheimer’s disease, which is alike sporadic Alzheimer’s disease, and the properties show decline over time prior to estimated symptom onset. These data suggest that single-subject networks properties obtained from structural MRI scans form an additional non-invasive tool for understanding the substrate of cognitive decline and measuring progression from preclinical to severe clinical stages of Alzheimer’s disease.

scholarly journals White matter diffusion alterations precede symptom onset in autosomal dominant Alzheimer’s disease

Brain ◽  
2018 ◽  
Vol 141 (10) ◽  
pp. 3065-3080 ◽  
Author(s):  
Miguel Ángel Araque Caballero ◽  
Marc Suárez-Calvet ◽  
Marco Duering ◽  
Nicolai Franzmeier ◽  
Tammie Benzinger ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
White Matter ◽  
Symptom Onset ◽  
Autosomal Dominant ◽  
Autosomal Dominant Alzheimer’S Disease

scholarly journals Plasma Aβ ratios in autosomal dominant Alzheimer’s disease: the influence of genotype

2021 ◽  
Author(s):  
Antoinette O’Connor ◽  
Josef Pannee ◽  
Teresa Poole ◽  
Charles Arber ◽  
Erik Portelius ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Autosomal Dominant ◽  
Age At Onset ◽  
Cross Sectional ◽  
Autosomal Dominant Alzheimer’S Disease ◽  
Liquid Chromatography Tandem Mass ◽  
The Relationship

AbstractIn-vitro studies of autosomal dominant Alzheimer’s disease (ADAD) implicate longer Aβ peptides in pathogenesis, however less is known about the behaviour of ADAD mutations in-vivo. In this cross-sectional cohort study, we used liquid chromatography-tandem mass spectrometry to analyse 66 plasma samples from ADAD family members who were at-risk of inheriting a mutation or were already symptomatic. We tested for differences in plasma Aβ42:38, 38:40 and 42:40 ratios between Presenilin1 (PSEN1) and Amyloid Precursor Protein (APP) carriers. We examined the relationship between plasma and in-vitro models of Aβ processing and, among PSEN1 carriers, tested for associations with parental age at onset (AAO). 39 participants were mutation carriers (28 PSEN1 and 11 APP). Age- and sex-adjusted models showed marked differences in plasma Aβ between APP and PSEN1: higher Aβ42:38 in PSEN1 versus APP (p<0.001) and non-carriers (p<0.001); higher Aβ38:40 in APP versus PSEN1 (p<0.001) and non-carriers (p<0.001), while Aβ42:40 was higher in APP and PSEN1 compared to non-carriers (both p<0.001). Aβ profiles were reasonably consistent in plasma and cell lines. Within PSEN1, sex-adjusted models demonstrated negative associations between (i)Aβ42:40 (ii)Aβ42:38 and parental AAO. In-vivo differences in Aβ processing between APP and PSEN1 provide insights into ADAD pathophysiology which can inform therapy development.

GENOTYPE-DEPENDENT LONGITUDINAL TRAJECTORIES OF COGNITIVE DECLINE IN AUTOSOMAL DOMINANT ALZHEIMER’S DISEASE

2017 ◽  
Vol 13 (7) ◽  
pp. P1554
Author(s):  
Ove Almkvist ◽  
Elena Rodriguez-Vieitez ◽  
Steinunn Thordardottir ◽  
Anne Kinhult Ståhlbom ◽  
Matti Viitanen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Decline ◽  
Autosomal Dominant ◽  
Longitudinal Trajectories ◽  
Autosomal Dominant Alzheimer’S Disease

scholarly journals Staging biomarkers in preclinical autosomal dominant Alzheimer's disease by estimated years to symptom onset

2019 ◽  
Vol 15 (4) ◽  
pp. 506-514 ◽  
Author(s):  
Guoqiao Wang ◽  
Dean Coble ◽  
Eric M. McDade ◽  
Jason Hassenstab ◽  
Anne M. Fagan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Symptom Onset ◽  
Autosomal Dominant ◽  
Autosomal Dominant Alzheimer’S Disease

scholarly journals Associations of AT(N) biomarkers with neuropsychiatric symptoms in preclinical Alzheimer’s disease and cognitively unimpaired individuals

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Kok Pin Ng ◽  
Hui Chiew ◽  
Pedro Rosa-Neto ◽  
Nagaendran Kandiah ◽  
Zahinoor Ismail ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Decline ◽  
Longitudinal Studies ◽  
Neuropsychiatric Symptoms ◽  
Amyloid Β ◽  
Cross Sectional ◽  
Preclinical Ad ◽  
Cross Sectional Studies

AbstractThe development of in vivo biomarkers of Alzheimer’s disease (AD) has advanced the diagnosis of AD from a clinical syndrome to a biological construct. The preclinical stage of AD continuum is defined by the identification of AD biomarkers crossing the pathological threshold in cognitively unimpaired individuals. While neuropsychiatric symptoms (NPS) are non-cognitive symptoms that are increasingly recognized as early manifestations of AD, the associations of NPS with AD pathophysiology in preclinical AD remain unclear. Here, we review the associations between NPS and AD biomarkers amyloid-β (Aβ), tau and neurodegeneration in preclinical AD and cognitively-unimpaired individuals in 19 eligible English-language publications (8 cross-sectional studies, 10 longitudinal, 1 both cross-sectional and longitudinal). The cross-sectional studies have consistently shown that NPS, particularly depressive and anxiety symptoms, are associated with higher Aβ. The longitudinal studies have suggested that greater NPS are associated with higher Aβ and cognitive decline in cognitively unimpaired subjects over time. However, most of the studies have either cross-sectionally or longitudinally shown no association between NPS and tau pathology. For the association of NPS and neurodegeneration, two studies have shown that the cerebrospinal fluid total-tau is linked to longitudinal increase in NPS and that the NPS may predict longitudinal metabolic decline in preclinical AD, respectively. However, evidence for the association between atrophy and NPS in preclinical AD is less consistent. Therefore, future longitudinal studies with well-designed methodologies and NPS measurements are required not only to determine the relationship among AT(N) biomarkers, NPS and cognitive decline, but also to elucidate the contribution of comorbid pathology to preclinical AD.

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