%0 Journal Article %J J Alzheimers Dis %D 2020 %T Dickkopf-1 Overexpression in vitro Nominates Candidate Blood Biomarkers Relating to Alzheimer's Disease Pathology. %A Shi, Liu %A Winchester, Laura M %A Liu, Benjamine Y %A Killick, Richard %A Ribe, Elena M %A Westwood, Sarah %A Baird, Alison L %A Buckley, Noel J %A Hong, Shengjun %A Dobricic, Valerija %A Kilpert, Fabian %A Franke, Andre %A Kiddle, Steven %A Sattlecker, Martina %A Dobson, Richard %A Cuadrado, Antonio %A Hye, Abdul %A Ashton, Nicholas J %A Morgan, Angharad R %A Bos, Isabelle %A Vos, Stephanie J B %A Ten Kate, Mara %A Scheltens, Philip %A Vandenberghe, Rik %A Gabel, Silvy %A Meersmans, Karen %A Engelborghs, Sebastiaan %A De Roeck, Ellen E %A Sleegers, Kristel %A Frisoni, Giovanni B %A Blin, Olivier %A Richardson, Jill C %A Bordet, Régis %A Molinuevo, José L %A Rami, Lorena %A Wallin, Anders %A Kettunen, Petronella %A Tsolaki, Magda %A Verhey, Frans %A Lleo, Alberto %A Alcolea, Daniel %A Popp, Julius %A Peyratout, Gwendoline %A Martínez-Lage, Pablo %A Tainta, Mikel %A Johannsen, Peter %A Teunissen, Charlotte E %A Freund-Levi, Yvonne %A Frölich, Lutz %A Legido-Quigley, Cristina %A Barkhof, Frederik %A Blennow, Kaj %A Rasmussen, Katrine Laura %A Nordestgaard, Børge Grønne %A Frikke-Schmidt, Ruth %A Nielsen, Sune Fallgaard %A Soininen, Hilkka %A Vellas, Bruno %A Kloszewska, Iwona %A Mecocci, Patrizia %A Zetterberg, Henrik %A Morgan, B Paul %A Streffer, Johannes %A Visser, Pieter Jelle %A Bertram, Lars %A Nevado-Holgado, Alejo J %A Lovestone, Simon %X

BACKGROUND: Previous studies suggest that Dickkopf-1 (DKK1), an inhibitor of Wnt signaling, plays a role in amyloid-induced toxicity and hence Alzheimer's disease (AD). However, the effect of DKK1 expression on protein expression, and whether such proteins are altered in disease, is unknown.

OBJECTIVE: We aim to test whether DKK1 induced protein signature obtained in vitro were associated with markers of AD pathology as used in the amyloid/tau/neurodegeneration (ATN) framework as well as with clinical outcomes.

METHODS: We first overexpressed DKK1 in HEK293A cells and quantified 1,128 proteins in cell lysates using aptamer capture arrays (SomaScan) to obtain a protein signature induced by DKK1. We then used the same assay to measure the DKK1-signature proteins in human plasma in two large cohorts, EMIF (n = 785) and ANM (n = 677).

RESULTS: We identified a 100-protein signature induced by DKK1 in vitro. Subsets of proteins, along with age and apolipoprotein E ɛ4 genotype distinguished amyloid pathology (A + T-N-, A+T+N-, A+T-N+, and A+T+N+) from no AD pathology (A-T-N-) with an area under the curve of 0.72, 0.81, 0.88, and 0.85, respectively. Furthermore, we found that some signature proteins (e.g., Complement C3 and albumin) were associated with cognitive score and AD diagnosis in both cohorts.

CONCLUSIONS: Our results add further evidence for a role of DKK regulation of Wnt signaling in AD and suggest that DKK1 induced signature proteins obtained in vitro could reflect theATNframework as well as predict disease severity and progression in vivo.

%B J Alzheimers Dis %V 77 %P 1353-1368 %8 2020 Sep 29 %G eng %N 3 %R 10.3233/JAD-200208 %0 Journal Article %J J Alzheimers Dis %D 2020 %T Validation of Plasma Proteomic Biomarkers Relating to Brain Amyloid Burden in the EMIF-Alzheimer's Disease Multimodal Biomarker Discovery Cohort. %A Westwood, Sarah %A Baird, Alison L %A Anand, Sneha N %A Nevado-Holgado, Alejo J %A Kormilitzin, Andrey %A Shi, Liu %A Hye, Abdul %A Ashton, Nicholas J %A Morgan, Angharad R %A Bos, Isabelle %A Vos, Stephanie J B %A Baker, Susan %A Buckley, Noel J %A Ten Kate, Mara %A Scheltens, Philip %A Teunissen, Charlotte E %A Vandenberghe, Rik %A Gabel, Silvy %A Meersmans, Karen %A Engelborghs, Sebastiaan %A De Roeck, Ellen E %A Sleegers, Kristel %A Frisoni, Giovanni B %A Blin, Olivier %A Richardson, Jill C %A Bordet, Régis %A Molinuevo, José L %A Rami, Lorena %A Wallin, Anders %A Kettunen, Petronella %A Tsolaki, Magda %A Verhey, Frans %A Lleo, Alberto %A Sala, Isabel %A Popp, Julius %A Peyratout, Gwendoline %A Martínez-Lage, Pablo %A Tainta, Mikel %A Johannsen, Peter %A Freund-Levi, Yvonne %A Frölich, Lutz %A Dobricic, Valerija %A Legido-Quigley, Cristina %A Bertram, Lars %A Barkhof, Frederik %A Zetterberg, Henrik %A Morgan, B Paul %A Streffer, Johannes %A Visser, Pieter Jelle %A Lovestone, Simon %X

We have previously investigated, discovered, and replicated plasma protein biomarkers for use to triage potential trials participants for PET or cerebrospinal fluid measures of Alzheimer's disease (AD) pathology. This study sought to undertake validation of these candidate plasma biomarkers in a large, multi-center sample collection. Targeted plasma analyses of 34 proteins with prior evidence for prediction of in vivo pathology were conducted in up to 1,000 samples from cognitively healthy elderly individuals, people with mild cognitive impairment, and in patients with AD-type dementia, selected from the EMIF-AD catalogue. Proteins were measured using Luminex xMAP, ELISA, and Meso Scale Discovery assays. Seven proteins replicated in their ability to predict in vivo amyloid pathology. These proteins form a biomarker panel that, along with age, could significantly discriminate between individuals with high and low amyloid pathology with an area under the curve of 0.74. The performance of this biomarker panel remained consistent when tested in apolipoprotein E ɛ4 non-carrier individuals only. This blood-based panel is biologically relevant, measurable using practical immunocapture arrays, and could significantly reduce the cost incurred to clinical trials through screen failure.

%B J Alzheimers Dis %V 74 %P 213-225 %8 2020 %G eng %N 1 %1 https://www.ncbi.nlm.nih.gov/pubmed/31985466?dopt=Abstract %R 10.3233/JAD-190434 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Preclinical Alzheimer's Disease: Implications for Refinement of the Concept. %A Vos, Stephanie J B %A Visser, Pieter Jelle %X

Increasing interest in clinical trials and clinical research settings to identify Alzheimer's disease (AD) in the earliest stages of the disease has led to the concept of preclinical AD. Individuals with preclinical AD have AD pathology without clinical symptoms yet. Accumulating evidence has shown that biomarkers can identify preclinical AD and that preclinical AD is associated with a poor clinical outcome. Little is known yet about the role of vascular and lifestyle risk factors in the development of preclinical AD. In order to better understand preclinical AD pathology and clinical progression rates, there is a need to refine the concept of preclinical AD. This will be of great value for advancements in future research, clinical trials, and eventually clinical practice.

%B J Alzheimers Dis %V 64 %P S213-S227 %8 2018 %G eng %N s1 %1 http://www.ncbi.nlm.nih.gov/pubmed/29865060?dopt=Abstract %R 10.3233/JAD-179943 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Association Between Later Life Lifestyle Factors and Alzheimer's Disease Biomarkers in Non-Demented Individuals: A Longitudinal Descriptive Cohort Study. %A Reijs, Babette L R %A Vos, Stephanie J B %A Soininen, Hilkka %A Lötjönen, Jyrki %A Koikkalainen, Juha %A Pikkarainen, Maria %A Hall, Anette %A Vanninen, Ritva %A Liu, Yawu %A Herukka, Sanna-Kaisa %A Freund-Levi, Yvonne %A Frisoni, Giovanni B %A Frölich, Lutz %A Nobili, Flavio %A Rikkert, Marcel Olde %A Spiru, Luiza %A Tsolaki, Magda %A Wallin, Asa K %A Scheltens, Philip %A Verhey, Frans %A Visser, Pieter Jelle %X

BACKGROUND: Lifestyle factors have been associated with the risk of dementia, but the association with Alzheimer's disease (AD) remains unclear.

OBJECTIVE: To examine the association between later life lifestyle factors and AD biomarkers (i.e., amyloid-β 1-42 (Aβ42) and tau in cerebrospinal fluid (CSF), and hippocampal volume) in individuals with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). In addition, to examine the effect of later life lifestyle factors on developing AD-type dementia in individuals with MCI.

METHODS: We selected individuals with SCD (n = 111) and MCI (n = 353) from the DESCRIPA and Kuopio Longitudinal MCI studies. CSF Aβ42 and tau concentrations were assessed with ELISA assay and hippocampal volume with multi-atlas segmentation. Lifestyle was assessed by clinical interview at baseline for: social activity, physical activity, cognitive activity, smoking, alcohol consumption, and sleep. We performed logistic and Cox regression analyses adjusted for study site, age, gender, education, and diagnosis. Prediction for AD-type dementia was performed in individuals with MCI only.

RESULTS: Later life lifestyle factors were not associated with AD biomarkers or with conversion to AD-type dementia. AD biomarkers were strongly associated with conversion to AD-type dementia, but these relations were not modulated by lifestyle factors. Apolipoprotein E (APOE) genotype did not influence the results.

CONCLUSIONS: Later life lifestyle factors had no impact on key AD biomarkers in individuals with SCD and MCI or on conversion to AD-type dementia in MCI.

%B J Alzheimers Dis %V 60 %P 1387-1395 %8 2017 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/29036813?dopt=Abstract %R 10.3233/JAD-170039 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Modifiable Risk Factors for Prevention of Dementia in Midlife, Late Life and the Oldest-Old: Validation of the LIBRA Index. %A Vos, Stephanie J B %A van Boxtel, Martin P J %A Schiepers, Olga J G %A Deckers, Kay %A de Vugt, Marjolein %A Carrière, Isabelle %A Dartigues, Jean-François %A Pérès, Karine %A Artero, Sylvaine %A Ritchie, Karen %A Galluzzo, Lucia %A Scafato, Emanuele %A Frisoni, Giovanni B %A Huisman, Martijn %A Comijs, Hannie C %A Sacuiu, Simona F %A Skoog, Ingmar %A Irving, Kate %A O'Donnell, Catherine A %A Verhey, Frans R J %A Visser, Pieter Jelle %A Köhler, Sebastian %X

BACKGROUND: Recently, the LIfestyle for BRAin health (LIBRA) index was developed to assess an individual's prevention potential for dementia.

OBJECTIVE: We investigated the predictive validity of the LIBRA index for incident dementia in midlife, late life, and the oldest-old.

METHODS: 9,387 non-demented individuals were recruited from the European population-based DESCRIPA study. An individual's LIBRA index was calculated solely based on modifiable risk factors: depression, diabetes, physical activity, hypertension, obesity, smoking, hypercholesterolemia, coronary heart disease, and mild/moderate alcohol use. Cox regression was used to test the predictive validity of LIBRA for dementia at follow-up (mean 7.2 y, range 1-16).

RESULTS: In midlife (55-69 y, n = 3,256) and late life (70-79 y, n = 4,320), the risk for dementia increased with higher LIBRA scores. Individuals in the intermediate- and high-risk groups had a higher risk of dementia than those in the low-risk group. In the oldest-old (80-97 y, n = 1,811), higher LIBRA scores did not increase the risk for dementia.

CONCLUSION: LIBRA might be a useful tool to identify individuals for primary prevention interventions of dementia in midlife, and maybe in late life, but not in the oldest-old.

%B J Alzheimers Dis %V 58 %P 537-547 %8 2017 %G eng %N 2 %1 http://www.ncbi.nlm.nih.gov/pubmed/28453475?dopt=Abstract %R 10.3233/JAD-161208 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Added Prognostic Value of Cerebrospinal Fluid Biomarkers in Predicting Decline in Memory Clinic Patients in a Prospective Cohort. %A Handels, Ron L H %A Joore, Manuela A %A Vos, Stephanie J B %A Aalten, Pauline %A Ramakers, Inez H G B %A Rikkert, Marcel Olde %A Scheltens, Philip %A Jansen, Willemijn J %A Visser, Pieter-Jelle %A van Berckel, Bart M N %A van Domburg, Peter %A Smid, Machiel %A Hoff, Erik %A Hoogmoed, Jan %A Bouwman, Femke %A Claassen, Jurgen %A Leentjens, Albert F G %A Wolfs, Claire A G %A Severens, Johan L %A Verhey, Frans R J %X

BACKGROUND: Limited information is available on short-term prognosis of Alzheimer's disease (AD) biomarkers in cerebrospinal fluid (CSF) in addition to routine diagnostic workup.

OBJECTIVE: This study aims to investigate the added prognostic value of AD CSF biomarkers.

METHODS: In a prospective cohort study, clinical experts predicted cognitive and functional symptoms in 114 memory clinic patients by assessing comprehensive routine diagnostic test information (patient history, and physical, neurological, psychiatric, neuropsychological, and MRI examinations), without and with CSF biomarkers. The reference standard was the 'observed clinically relevant decline' using baseline and 1- and 2-year follow-up information.

RESULTS: Decline over a 2-year period was observed in 51% of all participants (3% in SMC, 48% in MCI, 90% in mild dementia). In the total sample, the accuracy of predicted decline did not differ significantly between routine assessment without (79% correctly predicted) and with (74% correctly predicted) CSF biomarkers. Subgroup analyses revealed 25 (83%) correct predictions in SMC, 30 (68%) in MCI, and 35 (88%) in dementia without the use of CSF; and 21 (70%), 27 (61%), and 36 (90%), respectively, with the use of CSF in addition to the routine assessment.

CONCLUSION: AD CSF biomarkers did not increase accuracy of 2-year prognosis of cognitive and functional decline when added to routine diagnostic workup. This suggests that the standard diagnostic workup without CSF biomarkers allows fairly accurate predictions for the short-term course of symptoms. Routine AD biomarkers in CSF have limited prognostic value over 2 years in persons with a suspected cognitive disorder.

%B J Alzheimers Dis %V 52 %P 875-85 %8 2016 Mar 31 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/27031483?dopt=Abstract %R 10.3233/JAD-151120