Basal forebrain atrophy along the Alzheimer's disease continuum in adults with Down syndrome

[Background] Basal forebrain (BF) degeneration occurs in Down syndrome (DS)-associated Alzheimer's disease (AD). However, the dynamics of BF atrophy with age and disease progression, its impact on cognition, and its relationship with AD biomarkers have not been studied in DS.[Methods] We included 234 adults with DS (150 asymptomatic, 38 prodromal AD, and 46 AD dementia) and 147 euploid controls. BF volumes were extracted from T-weighted magnetic resonance images using a stereotactic atlas in SPM12. We assessed BF volume changes with age and along the clinical AD continuum and their relationship to cognitive performance, cerebrospinal fluid (CSF) and plasma amyloid/tau/neurodegeneration biomarkers, and hippocampal volume.[Results] In DS, BF volumes decreased with age and along the clinical AD continuum and significantly correlated with amyloid, tau, and neurofilament light chain changes in CSF and plasma, hippocampal volume, and cognitive performance.[Discussion] BF atrophy is a potentially valuable neuroimaging biomarker of AD-related cholinergic neurodegeneration in DS.This study was supported by the Fondo de Investigaciones Sanitario, Carlos III Health Institute (PI20/01473 to JF, PI13/01532, PI16/01825 to RB, PI18/00335 to MCI, PI18/00435 to DA, PI14/1561, PI20/01330 to AL, PI20/00613 to MJG) and the CIBERNED Program 1. This work was also supported by the National Institutes of Health (NIH) grants (1R01AG056850-01A1; 3RF1AG056850-01S1; AG056850, R21AG056974, and R01AG061566 to JF; P30AG066512 and P01AG060882 to TW), Departament de Salut de la Generalitat de Catalunya, Fundación Tatiana Pérez de Guzmán el Bueno (IIBSP-DOW-2020-151 to JF), and the European Union's Horizon 2020, ‘MES-CoBraD’ (H2020-SC1-BHC-2018-2020 / GA 965422 to JF). MRA acknowledges support from the Alzheimer's Association Research Fellowship to Promote Diversity (AARF-D) Program (AARFD-21-852492). MFI acknowledges support from the Jérôme Lejeune postdoctoral award and pilot grant (#1941). AB acknowledges support from a Miguel Servet grant (CP20/00038) from the Carlos III Health Institute. MJG acknowledges support from a Miguel Servet grant (CP19/00031) from the Carlos III Health Institute. MCI acknowledges support from the Alzheimer's Association and Global Brain Health Institute (GBHI_ALZ-18-543740), the Jérôme Lejeune Foundation (#1913 Cycle 2019B), and the Societat Catalana de Neurologia (Premi Beca Fundació SCN 2020). LVA was supported by Margarita Salas junior postdoctoral fellowship (UNI/551/2021, NextGenerationUE). VM and NVT acknowledge support from predoctoral grants from the Carlos III Health Institute (FI18/00275 to VM and FI22/00077 to NVT). MA and JA were supported by the Río Hortega Fellowship from Carlos III Health Institute (CM19/00066 to MA and CM21/00243 to JA). CP acknowledges support from a Sara Borrell Fellowship (CP20/00133) from the Carlos III Health Institute. HZ is a Wallenberg Scholar supported by grants from the Swedish Research Council (#2018-02532), the European Research Council (#681712 and #101053962), Swedish State Support for Clinical Research (#ALFGBG-71320), the Alzheimer Drug Discovery Foundation (ADDF), USA (#201809-2016862), the AD Strategic Fund and the Alzheimer's Association (#ADSF-21-831376-C, #ADSF-21-831381-C and #ADSF-21-831377-C), the Bluefield Project, the Olav Thon Foundation, the Erling-Persson Family Foundation, Stiftelsen för Gamla Tjänarinnor, Hjärnfonden, Sweden (#FO2022-0270), the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 860197 (MIRIADE), the European Union Joint Programme – Neurodegenerative Disease Research (JPND2021-00694), and the UK Dementia Research Institute at UCL (UKDRI-1003). KB is supported by the Swedish Research Council (#2017-00915), the Swedish Alzheimer Foundation (#AF-930351, #AF-939721 and #AF-968270), Hjärnfonden, Sweden (#FO2017-0243 and #ALZ2022-0006), the Swedish state under the agreement between the Swedish government and the County Councils, the ALF-agreement (#ALFGBG-715986 and #ALFGBG-965240), and the Alzheimer's Association 2021 Zenith Award (ZEN-21-848495).Peer reviewe

Evaluation of biochemical and hematological parameters in adults with Down syndrome

Down syndrome (DS) is the most common worldwide cause of intellectual disability of genetic origin and the most common chromosomal disorder affecting live-born infants. In addition to intellectual disability, individuals with DS have other comorbidities and complex medical conditions. The increase in the life expectancy of patients with DS requires expanding the knowledge about their clinical characteristics and related laboratory parameters. Several studies exploring laboratory tests in DS patients exist, but their focus is limited to specific areas of metabolism. Therefore, our main goal was to describe the biochemical and hematological findings in a DS cohort and to compare the values to those of a control population. A total of 248 DS individuals and 84 control subjects were enrolled. DS individuals had a higher frequency of several clinical conditions compared to control individuals and presented with significant differences with respect to the controls in both biochemical and hematological parameters. We found age- and sex-related differences in several of the parameters. A good understanding of the differences in our cohort might be of aid in the clinical follow-up of adults with DS, especially considering that the lifespan of DS individuals may reach 60 years of age in developed countries.This study was supported by the Fondo de Investigaciones Sanitario (FIS), Instituto de Salud Carlos III (PI18/00164 to FB-V and MT, PI14/01126 and PI17/01019 to JF, PI13/01532 and PI16/01825 to RB, PI18/00335 to MCI and PI14/1561, PI17/01896 to AL), the CIBERNED program (Program 1, Alzheimer’s Disease to Alberto Lleó and SIGNAL study, www.signalstudy.es), and CIBERDEM, partly jointly funded by the Fondo Europeo de Desarrollo Regional, Unión Europea, Una manera de hacer Europa. This work was also supported by the National Institutes of Health (NIA grants 1R01AG056850-01A1; R21AG056974 and R01AG061566 to JF), Departament de Salut de la Generalitat de Catalunya, Pla Estratègic de Recerca i Innovació en Salut (SLT002/16/00408 to AL), Fundació La Marató de TV3 (20141210 to JF and 044412 to RB). The Fundació Catalana Síndrome de Down and Fundació Víctor Grífols i Lucas partially supported this work. This work was also supported by the Generalitat de Catalunya (SLT006/17/00119 to JF) and a grant from the Fundació Bancaria La Caixa to RB. DdG-C was a recipient of a Juan de la Cierva-Incorporación grant from the Ministry of Science Innovation and Universities (IJCI-2016-29393).Peer reviewe

Basal forebrain atrophy along the Alzheimer's disease continuum in adults with Down syndrome

Altres ajuts: acords transformatius de la UABBackground: Basal forebrain (BF) degeneration occurs in Down syndrome (DS)-associated Alzheimer's disease (AD). However, the dynamics of BF atrophy with age and disease progression, its impact on cognition, and its relationship with AD biomarkers have not been studied in DS. Methods: We included 234 adults with DS (150 asymptomatic, 38 prodromal AD, and 46 AD dementia) and 147 euploid controls. BF volumes were extracted from T-weighted magnetic resonance images using a stereotactic atlas in SPM12. We assessed BF volume changes with age and along the clinical AD continuum and their relationship to cognitive performance, cerebrospinal fluid (CSF) and plasma amyloid/tau/neurodegeneration biomarkers, and hippocampal volume. Results: In DS, BF volumes decreased with age and along the clinical AD continuum and significantly correlated with amyloid, tau, and neurofilament light chain changes in CSF and plasma, hippocampal volume, and cognitive performance. Discussion: BF atrophy is a potentially valuable neuroimaging biomarker of AD-related cholinergic neurodegeneration in DS

Use of plasma biomarkers for AT(N) classification of neurodegenerative dementias

International audienceObjectives All categories included in the AT(N) classification can now be measured in plasma. However, their agreement with cerebrospinal fluid (CSF) markers is not fully established. A blood signature to generate the AT(N) classification would facilitate early diagnosis of patients with Alzheimer’s disease (AD) through an easy and minimally invasive approach. Methods We measured Aβ, pTau181 and neurofilament light (NfL) in 150 plasma samples of the Sant Pau Initiative on Neurodegeneration cohort including patients with mild cognitive impairment, AD dementia, frontotemporal dementia, dementia with Lewy bodies and cognitively normal participants. We classified participants in the AT(N) categories according to CSF biomarkers and studied the diagnostic value of plasma biomarkers within each category individually and in combination. Results The plasma Aβ composite, pTau181 and NfL yielded areas under the curve (AUC) of 0.75, 0.78 and 0.88 to discriminate positive and negative participants in their respective A, T and N categories. The combination of all three markers did not outperform pTau181 alone (AUC=0.81) to discriminate A+T+ from A–T– participants. There was a moderate correlation between plasma Aβ composite and CSF Aβ1–42/Aβ1–40 (Rho=−0.5, p<0.001) and between plasma pTau181 and CSF pTau181 in the entire cohort (Rho=0.51, p<0.001). NfL levels in plasma showed high correlation with those in CSF (Rho=0.78, p<0.001). Conclusions Plasma biomarkers are useful to detect the AT(N) categories, and their use can differentiate patients with pathophysiological evidence of AD. A blood AT(N) signature may facilitate early diagnosis and follow-up of patients with AD through an easy and minimally invasive approach

The Sant Pau Initiative on Neurodegeneration (SPIN) cohort : A data set for biomarker discovery and validation in neurodegenerative disorders

Altres ajuts: The SPIN cohort has received funding from CIBERNED; Instituto de Salud Carlos III; jointly funded by Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea, "Una manera de hacer Europa"; Generalitat de Catalunya; Fundació "La Marató TV3" Fundació Bancària Obra Social La Caixa; Fundación BBVA; Fundación Española para el Fomento de la Investigación de la Esclerosis Lateral Amiotrófica (FUNDELA); Global Brain Health Institute; Fundació Catalana Síndrome de Down; and Fundació Víctor Grífols i Lucas. These funding sources had no role in study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the article for publication.The SPIN (Sant Pau Initiative on Neurodegeneration) cohort is a multimodal biomarker platform designed for neurodegenerative disease research following an integrative approach. Participants of the SPIN cohort provide informed consent to donate blood and cerebrospinal fluid samples, receive detailed neurological and neuropsychological evaluations, and undergo a structural 3T brain MRI scan. A subset also undergoes other functional or imaging studies (video-polysomnogram, 18 F-fluorodeoxyglucose PET, amyloid PET, Tau PET). Participants are followed annually for a minimum of 4 years, with repeated cerebrospinal fluid collection and imaging studies performed every other year, and brain donation is encouraged. The integration of clinical, neuropsychological, genetic, biochemical, imaging, and neuropathological information and the harmonization of protocols under the same umbrella allows the discovery and validation of key biomarkers across several neurodegenerative diseases. We describe our particular 10-year experience and how different research projects were unified under an umbrella biomarker program, which might be of help to other research teams pursuing similar approaches