Publications by authors named "Tarraga L"

Background: Alzheimer's disease (AD) stands as the leading cause of dementia worldwide, and projections estimate over 150 million patients by 2050. AD prevalence is notably higher in women, nearly twice that of men, with discernible sex differences in certain risk factors. To enhance our understanding of how sex influences the characteristics of AD patients and its potential impact on the disease trajectory, we conducted a comprehensive analysis of demographic, clinical, cognitive, and genetic data from a sizable and well-characterized cohort of AD dementia patients at a memory clinic in Barcelona, Spain.

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High-throughput proteomic platforms are crucial to identify novel Alzheimer's disease (AD) biomarkers and pathways. In this study, we evaluated the reproducibility and reliability of aptamer-based (SomaScan 7k) and antibody-based (Olink Explore 3k) proteomic platforms in cerebrospinal fluid (CSF) samples from the Ace Alzheimer Center Barcelona real-world cohort. Intra- and inter-platform reproducibility were evaluated through correlations between two independent SomaScan assays analyzing the same samples, and between SomaScan and Olink results.

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Background: Second-generation tau tracers for positron emission tomography (PET) show high affinity for paired helical filaments tau deposits characteristic of Alzheimer´s disease and low off-target binding. Differences in their chemical structure though may lead to variations in their regional tau uptake and off-target signal. In this work, we aimed to compare the in-vivo uptake of tau tracers [F]PI-2620 and [F]RO948 in the early stages of the AD continuum.

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Background: Optical coherence tomography (OCT) enables high-resolution imaging of ocular structures in health and disease. Choroid thickness (CT) is a key vascular retinal parameter that can be assessed by OCT and might be relevant in the evaluation of the vascular component of cognitive decline. We aimed to investigate CT changes in a large cohort of individuals cognitive unimpaired (CU), with mild cognitive impairment due to Alzheimer's (MCI-AD), mild cognitive impairment due to cerebrovascular disease (MCI-Va), Alzheimer's disease dementia (ADD), and vascular dementia (VaD).

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Objective: Pathological amyloid-β (Aβ) accumulation and hyperphosphorylated tau proteins have been described in resected temporal lobe specimens of epilepsy patients. We aimed to determine cerebrospinal fluid (CSF) Aβ1-42 and p181-tau levels and cerebral Aβ deposits on positron emission tomography (Aβ PET) and correlate these findings with cognitive performance in adults with drug-resistant temporal lobe epilepsy (TLE).

Methods: In this cross-sectional study, we enrolled individuals with drug-resistant TLE who were 25-55 years old.

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Background: The identification of patients with an elevated risk of developing Alzheimer's disease (AD) dementia and eligible for the disease-modifying treatments (DMTs) in the earliest stages is one of the greatest challenges in the clinical practice. Plasma biomarkers has the potential to predict these issues, but further research is still needed to translate them to clinical practice. Here we evaluated the clinical applicability of plasma pTau181 as a predictive marker of AD pathology in a large real-world cohort of a memory clinic.

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Background: Alzheimer's disease (AD) has a high heritable component characteristic of complex diseases, yet many of the genetic risk factors remain unknown. We combined genome-wide association studies (GWAS) on amyloid endophenotypes measured in cerebrospinal fluid (CSF) and positron emission tomography (PET) as surrogates of amyloid pathology, which may be helpful to understand the underlying biology of the disease.

Methods: We performed a meta-analysis of GWAS of CSF Aβ42 and PET measures combining six independent cohorts (n=2,076).

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Article Synopsis
  • - Microglial dysfunction is linked to Alzheimer's disease (AD), with a focus on a variant affecting the SIRPβ1 receptor that regulates the clearance of amyloid-β (Aβ).
  • - The study found that a specific insertion in the SIRPβ1 gene alters protein function, increasing the risk of AD and affecting cognitive decline rates in patients with mild cognitive impairment.
  • - Results suggest that this SIRPβ1 variant could influence microglial responses to Aβ and may serve as a potential target for treatment strategies that involve the TREM2-TYROBP pathway.
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Introduction: Optical coherence tomography angiography (OCT-A) is a novel tool that allows the detection of retinal vascular changes. We investigated the association of macular vessel density (VD) in the superficial plexus assessed by OCT-A with measures of cerebrovascular pathology and atrophy quantified by brain magnetic resonance imaging (MRI) in non-demented individuals.

Methods: Clinical, demographical, OCT-A, and brain MRI data from non-demented research participants were included.

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Background: Several studies have reported a relationship between retinal thickness and dementia. Therefore, optical coherence tomography (OCT) has been proposed as an early diagnosis method for Alzheimer's disease (AD). In this study, we performed a genome-wide association study (GWAS) aimed at identifying genes associated with retinal nerve fiber layer (RNFL) and ganglion cell inner plexiform layer (GCIPL) thickness assessed by OCT and exploring the relationships between the spectrum of cognitive decline (including AD and non-AD cases) and retinal thickness.

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Background: Advancement in screening tools accessible to the general population for the early detection of Alzheimer's disease (AD) and prediction of its progression is essential for achieving timely therapeutic interventions and conducting decentralized clinical trials. This study delves into the application of Machine Learning (ML) techniques by leveraging paralinguistic features extracted directly from a brief spontaneous speech (SS) protocol. We aimed to explore the capability of ML techniques to discriminate between different degrees of cognitive impairment based on SS.

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Article Synopsis
  • The study conducted the first genome-wide association study (GWAS) on sporadic Alzheimer's disease (AD) using a sample from Argentina and Chile, involving 539 patients and 854 controls.
  • Combining their findings with data from the European Alzheimer and Dementia Biobank (EADB), researchers identified apolipoprotein E ε4 as a significant genetic risk factor and discovered four new loci linked to AD.
  • The research highlights the shared genetic factors affecting AD risk across different populations, while also noting that a genetic risk score (GRS) showed diminishing effectiveness with increasing Native American ancestry.
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Alzheimer's disease (AD) is a neurodegenerative condition characterized by a gradual decline in cognitive functions. Currently, there are no effective treatments for AD, underscoring the importance of identifying individuals in the preclinical stages of mild cognitive impairment (MCI) to enable early interventions. Among the neuropathological events associated with the onset of the disease is the accumulation of amyloid protein in the brain, which correlates with decreased levels of A42 peptide in the cerebrospinal fluid (CSF).

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Although beta-amyloid (Aβ) and phosphorylated tau remain the preferred targets for disease-modifying treatments (DMT) against Alzheimer's disease (AD), part of the pathophysiological mechanisms of cognitive impairment are related to neuroinflammation and oxidative stress. In mild cognitive impairment (MCI), a prodromal stage of AD and other neurodegenerative conditions, the joint appearance of inflammation, oxidative stress, and metabolic alterations are the common pathways of neurotoxicity and neurodegeneration. The standardized extract of Ginkgo biloba EGb 761 interferes with the pathogenic mechanisms involved in both the development of cognitive impairment due to AD and that of vascular origin.

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Background: Optical coherence tomography angiography (OCT-A) is a novel method in the dementia field that allows the detection of retinal vascular changes. The comparison of OCT-A measures with established Alzheimer's disease (AD)-related biomarkers is essential to validate the former as a marker of cerebrovascular impairment in the AD continuum. We aimed to investigate the association of macular vessel density (VD) in the superficial plexus quantified by OCT-A with the AT(N) classification based on cerebrospinal fluid (CSF) Aβ1-42, p181-tau and t-tau measurements in individuals with mild cognitive impairment (MCI).

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Article Synopsis
  • The development of Alzheimer's disease (AD) typically has a prodromal phase characterized by high levels of Aβ and p-tau, alongside mild cognitive impairment (MCI), leading to challenges in early diagnosis.
  • Blood biomarkers are being explored as early screening tools, with plasma extracellular vesicles (pEVs) showing potential as new biomarkers for the initial stages of AD.
  • A study of early-onset MCI patients found that proteins in pEVs correlated with indicators of AD, suggesting pEVs could help identify amyloid-related changes in the brain before more widespread neuronal damage occurs.
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Few studies have addressed the impact of the association between Alzheimer's disease (AD) biomarkers and NPSs in the conversion to dementia in patients with mild cognitive impairment (MCI), and no studies have been conducted on the interaction effect of these two risk factors. AT(N) profiles were created using AD-core biomarkers quantified in cerebrospinal fluid (CSF) (normal, brain amyloidosis, suspected non-Alzheimer pathology (SNAP) and prodromal AD). NPSs were assessed using the Neuropsychiatric Inventory Questionnaire (NPI-Q).

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Article Synopsis
  • mLOY (mosaic loss of chromosome Y) is linked to aging and has associations with Alzheimer's disease (AD), but its influence can be misinterpreted due to age factors in studies.
  • Using Mendelian randomization, researchers created a polygenic risk score (mloy-PRS) that accounts for age, revealing a significant increase in mLOY risk that is independent of age.
  • Results indicate that higher genetic risk for mLOY correlates with quicker AD progression in men with mild cognitive impairment, while showing no impact on women, and suggesting mLOY plays a role in the development of AD.
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Background: Accessible and cost-effective diagnostic tools are urgently needed to accurately quantify blood biomarkers to support early diagnosis of Alzheimer's disease (AD). In this study, we investigated the ability of plasma amyloid-beta (Aβ)42/Aβ40 ratio measured by an antibody-free mass-spectrometric (MS) method, ABtest-MS, to detect early pathological changes of AD.

Methods: This cohort study included data from the baseline and 2-year follow-up visits from the Fundació ACE Healthy Brain Initiative (FACEHBI) study.

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Optical coherence tomography angiography (OCT-A) allows the detection of retinal vessel density (VD) loss, which is a reflection of brain vascular pathology. We aimed to investigate differences in macular VD in the superficial plexus in a large cohort of individuals cognitively unimpaired (CU), with mild cognitive impairment due to Alzheimer´s disease (MCI-AD), MCI due to cerebrovascular pathology (MCI-Va), probable Alzheimer´s disease dementia (ADD) and Vascular Dementia (VaD). Clinical, demographical, ophthalmological and OCT-A data from the Neuro-ophthalmology Research at Fundació ACE (NORFACE) project were analyzed.

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Article Synopsis
  • Amyloid-beta 42 (Aβ42) and phosphorylated tau (pTau) levels in cerebrospinal fluid (CSF) offer better insight into Alzheimer's disease (AD) than just clinical diagnosis.
  • The European Alzheimer & Dementia Biobank (EADB) analyzed data from 31 cohorts with over 13,000 individuals, identifying new genetic associations such as CR1 for Aβ42 and BIN1 for pTau, alongside novel associations with GMNC and C16orf95.
  • Analysis of all AD risk loci revealed four biological categories linked to Aβ42 and pTau, suggesting multiple pathways in AD's development, with further studies indicating GMNC and C16orf95 also relate to brain ventricular volume.
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Background: Neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) can be disruptive for patients and their families.

Objective: We aimed to classify patients based on NPS and to explore the relationship of these classes with sex and with caregiver burden.

Methods: The study cohort comprised individuals with AD dementia diagnosed at Ace Alzheimer Center in Barcelona, Spain, between 2011-2020.

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Background: There are currently no drug therapies modifying the natural history of patients suffering Alzheimer's disease (AD). Most recent clinical trials in the field include only subjects in early stage of the disease, while patients with advanced AD are usually not represented.

Objectives: To evaluate the feasibility, safety and efficacy of systemic infusions of adenosine triphosphate (ATP) in patients with moderate to severe AD, and to select the minimum effective dose of infusion.

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Background: Clinical diagnosis of Alzheimer's disease (AD) increasingly incorporates CSF biomarkers. However, due to the intrinsic variability of the immunodetection techniques used to measure these biomarkers, establishing in-house cutoffs defining the positivity/negativity of CSF biomarkers is recommended. However, the cutoffs currently published are usually reported by using cross-sectional datasets, not providing evidence about its intrinsic prognostic value when applied to real-world memory clinic cases.

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