Publications by authors named "Handen B"

Introduction: Adults with Down syndrome demonstrate striatum-first amyloid accumulation with [C]PiB PET imaging, which has not been replicated with [F]florbetapir (FBP). Early striatal accumulation has not been temporally quantified with respect to global cortical measures.

Methods: Longitudinal PiB (n=175 participants) and FBP (n=92 participants) data from the Alzheimer Biomarkers Consortium-Down Syndrome were used to measure cortical and striatal binding.

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  • This study focused on the risk of Alzheimer's disease in adults with Down syndrome, using amyloid and tau PET imaging to track disease progression.
  • It involved a longitudinal analysis of 167 participants, assessing cognitive functioning and biomarkers over two visits between 2017 and 2022.
  • The research aimed to determine the timeline for symptomatic Alzheimer's based on "amyloid age" and its relation to cognitive decline and tau accumulation.
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  • - Development of Alzheimer's disease (AD) pathology occurs faster in individuals with Down's syndrome (DS) compared to others; this study focuses on comparing specific biomarkers in DS individuals and their siblings.
  • - Researchers found that plasma levels of glial fibrillary acidic protein (GFAP) and pTau-217 were elevated in individuals with DS, indicating increased astrogliosis and tau pathology, and GFAP played a mediating role in the relationship between amyloid and tau levels.
  • - The findings suggest that astrogliosis is crucial in the early stages of Alzheimer's in DS, and targeting neuroinflammation might be beneficial primarily for those with amyloid positivity.
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  • - Individuals with Down syndrome (DS) face a high risk of developing Alzheimer's disease (AD), but about 20% do not show dementia symptoms until later in life, potentially due to the presence of mosaicism, which can reduce gene expression from chromosome 21.
  • - Researchers analyzed data from two major studies (ABC-DS and a legacy study) that included neuropsychological assessments and biomarkers to determine the prevalence and impact of mosaicism, finding it in less than 10% of participants.
  • - Those with mosaicism exhibited lower levels of AD-related biomarkers and a slower decline in cognitive scores compared to individuals with full trisomy, indicating a potential protective effect against dementia, though more research is needed to fully understand these findings.
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  • By age 40, over 90% of adults with Down syndrome develop Alzheimer’s disease, with many progressing to dementia, despite having few typical vascular risk factors.
  • This study analyzed how small vessel cerebrovascular disease impacts Alzheimer's disease progression and neurodegeneration in adults with Down syndrome, using MRI and plasma biomarker data from 185 participants.
  • Results indicated a complex relationship where white matter hyperintensity (WMH) levels influenced phosphorylated tau, linked by glial fibrillary acidic protein, suggesting that cerebrovascular health affects Alzheimer’s pathology in this population.
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  • The study investigates the relationship between amyloid-beta (Aβ) and tau biomarkers and the onset of symptomatic Alzheimer's disease (AD) in adults with Down syndrome (DS), highlighting the concept of "amyloid age."* -
  • It analyzes data from 167 adults with DS over roughly five years, finding that cognitive decline becomes noticeable about 2.7 years after reaching Aβ+ status, with tau levels also increasing subsequently.* -
  • The findings suggest a quicker progression to cognitive impairment and dementia in individuals with DS compared to typical late-onset AD, emphasizing the relevance of amyloid age for clinical practice and research.*
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  • - This study examines the link between Down syndrome (DS) and early-onset Alzheimer's disease (AD), focusing on how amyloid positivity, memory function, and clinical status change with age.
  • - Data from the Alzheimer Biomarker Consortium-Down Syndrome (ABC-DS) was used to analyze amyloid levels and cognitive function in 409 adults with DS, revealing that both amyloid positivity and memory decline increase significantly as individuals age.
  • - The research highlights the need for age-specific considerations in monoclonal antibody trials targeting AD in individuals with DS, as there’s a considerable gap between amyloid detection and visible clinical symptoms.
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Adults with Down syndrome have a genetic form of Alzheimer's disease (AD) and evidence of cerebrovascular disease across the AD continuum, despite few systemic vascular risk factors. The onset and progression of AD in Down syndrome is highly age-dependent, but it is unknown at what age cerebrovascular disease emerges and what factors influence its severity. In the Alzheimer's Biomarker Consortium-Down Syndrome study (ABC-DS; n = 242; age = 25-72), we estimated the age inflection point at which MRI-based white matter hyperintensities (WMH), enlarged perivascular spaces (PVS), microbleeds, and infarcts emerge in relation to demographic data, risk factors, amyloid and tau, and AD diagnosis.

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  • The study investigates early Alzheimer's disease changes in the brains of people with Down syndrome and those with genetic variants linked to Alzheimer's, aiming to better understand disease development and improve prevention strategies.
  • Using cross-sectional data from two cohort studies, researchers analyzed tau protein spread and its relationship with amyloid accumulation in participants aged 25 and older.
  • Findings revealed significant differences in the pattern and timing of tau accumulation in the two groups, suggesting implications for early intervention and clinical trials targeting Alzheimer's pathology.
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Introduction: People with Down syndrome (DS) have a 75% to 90% lifetime risk of Alzheimer's disease (AD). AD pathology begins a decade or more prior to onset of clinical AD dementia in people with DS. It is not clear if plasma biomarkers of AD pathology are correlated with early cognitive and functional impairments in DS, and if these biomarkers could be used to track the early stages of AD in DS or to inform inclusion criteria for clinical AD treatment trials.

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Down syndrome (DS) is the most prevalent genetic cause of intellectual disability, resulting from trisomy 21. Recently, positron emission tomography (PET) imaging has been used to image synapses in vivo. The motivation for this pilot study was to investigate whether synaptic density in low functioning adults with DS can be evaluated using the PET radiotracer [C]UCB-J.

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  • Late-onset Alzheimer's disease (LOAD) has a significant genetic basis, and the Long-Life Family Study (LLFS) provides an opportunity to study genetics through families that experience delayed dementia onset.
  • A whole genome sequence analysis of 3,475 LLFS members, along with association studies involving over 14,000 participants, identified specific genetic variants, particularly within the MTUS2 gene, that are linked to LOAD and are influenced by beta amyloid levels.
  • The MTUS2 gene plays a role in the nervous system's development and function, making it a potential target for further research on the biology of LOAD, as the identified genetic variants were consistent across various studies and populations.
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Neuroinflammatory mechanisms have been implicated in the pathophysiology of autism spectrum disorder (ASD). Minocycline is a matrix metalloproteinase inhibitor 9 (MMP9) inhibitor tetracycline antibiotic with known anti-inflammatory properties. In preclinical animal models of ASD, minocycline has demonstrated potential positive effects on phenotypes that may have relevance to ASD.

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Importance: By age 40 years over 90% of adults with Down syndrome (DS) have Alzheimer's disease (AD) pathology and most progress to dementia. Despite having few systemic vascular risk factors, individuals with DS have elevated cerebrovascular disease (CVD) markers that track with the clinical progression of AD, suggesting a role for CVD that is hypothesized to be mediated by inflammatory factors.

Objective: To examine the pathways through which small vessel CVD contributes to AD-related pathophysiology and neurodegeneration in adults with DS.

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  • Individuals with Down syndrome are almost guaranteed to develop Alzheimer's disease, making it crucial to study biomarkers related to the disease for effective clinical interventions.
  • A study involving 177 adults with Down syndrome used advanced imaging techniques to monitor amyloid-beta and tau proteins, finding that elevated tau levels occurred in all brain regions where NFTs (neurofibrillary tangles) develop after amyloid positivity.
  • The research shows that amyloid accumulates rapidly in Down syndrome, with tau increases appearing soon after—a finding that helps to chart the progression of Alzheimer's specifically in this population, rather than relying on age alone.
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Introduction: Down syndrome (DS) is a genetic cause of early-onset Alzheimer's disease (AD). The National Institute on Aging-Alzheimer's Association AT(N) Research Framework is a staging model for AD biomarkers but has not been assessed in DS.

Method: Data are from the Alzheimer's Biomarker Consortium-Down Syndrome.

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Background: Trisomy 21 causes Down syndrome (DS) and is a recognized cause of early-onset Alzheimer's disease (AD).

Objective: The current study sought to determine if premorbid intellectual disability level (ID) was associated with variability in age-trajectories of AD biomarkers and cognitive impairments. General linear mixed models compared the age-trajectory of the AD biomarkers PET Aβ and tau and cognitive decline across premorbid ID levels (mild, moderate, and severe/profound), in models controlling trisomy type, APOE status, biological sex, and site.

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Introduction: People with Down syndrome (DS) often develop Alzheimer's disease (AD). Here, we asked whether ultrasensitive plasma immunoassays for a tau N-terminal fragment (NT1-tau) and Aβ isoforms predict cognitive impairment.

Methods: Plasma NT1-tau, Aβ , Aβ , and Aβ levels were measured in a longitudinal discovery cohort (N = 85 participants, 220 samples) and a cross-sectional validation cohort (N = 239).

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  • - Research on Down syndrome, particularly focusing on trisomy 21 (T21), has made significant progress in recent years, enhancing our understanding of the related molecular and cellular processes.
  • - The Trisomy 21 Research Society (T21RS) hosted its first virtual conference during the COVID pandemic, uniting 342 researchers, families, and industry representatives from over 25 countries to discuss recent findings.
  • - The conference showcased 91 abstracts covering diverse topics such as neuroscience, behavioral changes, and potential therapies, emphasizing the ongoing interest in developing new biomarkers and treatment methods for health issues linked to T21.
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Adults with Down syndrome (DS) experience high risk for Alzheimer's disease (AD), but there is variability in the timing of transition from a cognitively stable state to prodromal AD and dementia. The present study examined the association between a modifiable lifestyle factor, employment complexity, and cognitive decline across two time points in adults with DS. Employment complexity, defined as the degree of problem-solving or critical thinking required for employment activities, was operationalized using the Dictionary of Occupational Titles, a system which classifies occupations based on three categories: .

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Introduction: People with Down syndrome (DS) often develop Alzheimer disease (AD). Here we asked whether ultrasensitive plasma immunoassays for a tau N-terminal fragment (NT1-tau) and Aβ isoforms predict cognitive impairment.

Methods: Plasma NT1-tau, Aβ , Aβ , and Aβ levels were measured in a longitudinal discovery cohort (N = 85 participants, 220 samples) and a cross-sectional validation cohort (N = 239).

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Purpose Of Review: Down syndrome regression disorder (DSRD) is a symptom cluster consisting of neuropsychiatric regression without cause. Although knowledge of this condition has accelerated over the last decade, prior studies have been limited by heterogenous nomenclature, diagnostic approaches and therapeutic interventions. This review highlights recent advances in the diagnosis and clinical approach to DSRD and reviews the most up-to-date literature on therapeutic interventions for this condition.

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Background: Adults with Down syndrome have an increased risk of aging-related physical and mental health conditions and experience them at an earlier age than the general population. There is a need to investigate modifiable lifestyle factors that may reduce risk for these conditions.

Method: The present study investigated the associations between physical activity (i.

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Background: Virtually all adults with Down syndrome (DS) develop Alzheimer's disease (AD) pathology, but research gaps remain in understanding early signs of AD in DS.

Objective: The goal of the present study was to determine if unintentional weight loss is part of AD in DS. The specific aims were to: 1) examine relation between chronological age, weight, AD pathology, and AD-related cognitive decline were assessed in a large cohort of adults with DS, and 2) determine if baseline PET amyloid-β (Aβ) and tau PET status (-versus+) and/or decline in memory and mental status were associated with weight loss prior to AD progression.

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Article Synopsis
  • The study aims to compare amyloid accumulation and its timing in two groups: individuals with autosomal dominant Alzheimer's disease and those with Down syndrome, both significant for understanding Alzheimer's pathogenesis.
  • Participants included adults aged 25 and older who underwent MRI and amyloid PET scans, allowing researchers to analyze differences in amyloid burden based on genetic factors and cognitive status.
  • The study found that patterns of amyloid accumulation may vary between the two groups, with a focus on factors like mutation type, age, and APOE genotype, enhancing our understanding of Alzheimer's disease risk and progression.
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