Browsing by Author "Sabbagh, Marwan Noel"

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    Considerations for widespread implementation of blood-based biomarkers of Alzheimer's disease
    (Wiley, 2024) Mielke, Michelle M.; Anderson, Matthew; Ashford, J. Wesson; Jeromin, Andreas; Lin, Pei-Jung; Rosen, Allyson; Tyrone, Jamie; VandeVrede, Lawren; Willis, Deanna; Hansson, Oskar; Khachaturian, Ara S.; Schindler, Suzanne E.; Weiss, Joan; Batrla, Richard; Bozeat, Sasha; Dwyer, John R.; Holzapfel, Drew; Jones, Daryl Rhys; Murray, James F.; Partrick, Katherine A.; Scholler, Emily; Vradenburg, George; Young, Dylan; Braunstein, Joel B.; Burnham, Samantha C.; de Oliveira, Fabricio Ferreira; Hu, Yan Helen; Mattke, Soeren; Merali, Zul; Monane, Mark; Sabbagh, Marwan Noel; Shobin, Eli; Weiner, Michael W.; Udeh-Momoh , Chinedu T.; Medicine, School of Medicine
    Diagnosing Alzheimer's disease (AD) poses significant challenges to health care, often resulting in delayed or inadequate patient care. The clinical integration of blood-based biomarkers (BBMs) for AD holds promise in enabling early detection of pathology and timely intervention. However, several critical considerations, such as the lack of consistent guidelines for assessing cognition, limited understanding of BBM test characteristics, insufficient evidence on BBM performance across diverse populations, and the ethical management of test results, must be addressed for widespread clinical implementation of BBMs in the United States. The Global CEO Initiative on Alzheimer's Disease BBM Workgroup convened to address these challenges and provide recommendations that underscore the importance of evidence-based guidelines, improved training for health-care professionals, patient empowerment through informed decision making, and the necessity of community-based studies to understand BBM performance in real-world populations. Multi-stakeholder engagement is essential to implement these recommendations and ensure credible guidance and education are accessible to all stakeholders.
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    Potential genetic modifiers of disease risk and age at onset in patients with frontotemporal lobar degeneration and GRN mutations: a genome-wide association study
    (Elsevier, 2018-06) Pottier, Cyril; Zhou, Xiaolai; Perkerson, Ralph B.; Baker, Matt; Jenkins, Gregory D.; Serie, Daniel J.; Ghidoni, Roberta; Benussi, Luisa; Binetti, Giuliano; de Munain, Adolfo López; Zulaica, Miren; Moreno, Fermin; Le Ber, Isabelle; Pasquier, Florence; Hannequin, Didier; Sánchez-Valle, Raquel; Antonell, Anna; Lladó, Albert; Parsons, Tammee M.; Finch, NiCole A.; Finger, Elizabeth C.; Lippa, Carol F.; Huey, Edward D.; Neumann, Manuela; Heutink, Peter; Synofzik, Matthis; Wilke, Carlo; Rissman, Robert A.; Slawek, Jaroslaw; Sitek, Emilia; Johannsen, Peter; Nielsen, Jørgen E.; Ren, Yingxue; van Blitterswijk, Marka; DeJesus-Hernandez, Mariely; Christopher, Elizabeth; Murray, Melissa E.; Bieniek, Kevin F.; Evers, Bret M.; Ferrari, Camilla; Rollinson, Sara; Richardson, Anna; Scarpini, Elio; Fumagalli, Giorgio G.; Padovani, Alessandro; Hardy, John; Momeni, Parastoo; Ferrari, Raffaele; Frangipane, Francesca; Maletta, Raffaele; Anfossi, Maria; Gallo, Maura; Petrucelli, Leonard; Suh, EunRan; Lopez, Oscar L.; Wong, Tsz H.; van Rooij, Jeroen G. J.; Seelaar, Harro; Mead, Simon; Caselli, Richard J.; Reiman, Eric M.; Sabbagh, Marwan Noel; Kjolby, Mads; Nykjaer, Anders; Karydas, Anna M.; Boxer, Adam L.; Grinberg, Lea T.; Grafman, Jordan; Spina, Salvatore; Oblak, Adrian; Mesulam, M-Marsel; Weintraub, Sandra; Geula, Changiz; Hodges, John R.; Piguet, Olivier; Brooks, William S.; Irwin, David J.; Trojanowski, John Q.; Lee, Edward B.; Josephs, Keith A.; Parisi, Joseph E.; Ertekin-Taner, Nilüfer; Knopman, David S.; Nacmias, Benedetta; Piaceri, Irene; Bagnoli, Silvia; Sorbi, Sandro; Gearing, Marla; Glass, Jonathan; Beach, Thomas G.; Black, Sandra E.; Masellis, Mario; Rogaeva, Ekaterina; Vonsattel, Jean-Paul; Honig, Lawrence S.; Kofler, Julia; Bruni, Amalia C.; Snowden, Julie; Mann, David; Pickering-Brown, Stuart; Diehl-Schmid, Janine; Winkelmann, Juliane; Galimberti, Daniela; Graff, Caroline; Öijerstedt, Linn; Troakes, Claire; Al-Sarraj, Safa; Cruchaga, Carlos; Cairns, Nigel J.; Rohrer, Jonathan D.; Halliday, Glenda M.; Kwok, John B.; van Swieten, John C.; White, Charles L.; Ghetti, Bernardino; Murell, Jill R.; Mackenzie, Ian R. A.; Hsiung, Ging-Yuek R.; Borroni, Barbara; Rossi, Giacomina; Tagliavini, Fabrizio; Wszolek, Zbigniew K.; Petersen, Ronald C.; Bigio, Eileen H.; Grossman, Murray; Van Deerlin, Vivianna M.; Seeley, William W.; Miller, Bruce L.; Graff-Radford, Neill R.; Boeve, Bradley F.; Dickson, Dennis W.; Biernacka, Joanna M.; Rademakers, Rosa; Pathology and Laboratory Medicine, School of Medicine
    BACKGROUND: Loss-of-function mutations in GRN cause frontotemporal lobar degeneration (FTLD). Patients with GRN mutations present with a uniform subtype of TAR DNA-binding protein 43 (TDP-43) pathology at autopsy (FTLD-TDP type A); however, age at onset and clinical presentation are variable, even within families. We aimed to identify potential genetic modifiers of disease onset and disease risk in GRN mutation carriers. METHODS: The study was done in three stages: a discovery stage, a replication stage, and a meta-analysis of the discovery and replication data. In the discovery stage, genome-wide logistic and linear regression analyses were done to test the association of genetic variants with disease risk (case or control status) and age at onset in patients with a GRN mutation and controls free of neurodegenerative disorders. Suggestive loci (p<1 × 10-5) were genotyped in a replication cohort of patients and controls, followed by a meta-analysis. The effect of genome-wide significant variants at the GFRA2 locus on expression of GFRA2 was assessed using mRNA expression studies in cerebellar tissue samples from the Mayo Clinic brain bank. The effect of the GFRA2 locus on progranulin concentrations was studied using previously generated ELISA-based expression data. Co-immunoprecipitation experiments in HEK293T cells were done to test for a direct interaction between GFRA2 and progranulin. FINDINGS: Individuals were enrolled in the current study between Sept 16, 2014, and Oct 5, 2017. After quality control measures, statistical analyses in the discovery stage included 382 unrelated symptomatic GRN mutation carriers and 1146 controls free of neurodegenerative disorders collected from 34 research centres located in the USA, Canada, Australia, and Europe. In the replication stage, 210 patients (67 symptomatic GRN mutation carriers and 143 patients with FTLD without GRN mutations pathologically confirmed as FTLD-TDP type A) and 1798 controls free of neurodegenerative diseases were recruited from 26 sites, 20 of which overlapped with the discovery stage. No genome-wide significant association with age at onset was identified in the discovery or replication stages, or in the meta-analysis. However, in the case-control analysis, we replicated the previously reported TMEM106B association (rs1990622 meta-analysis odds ratio [OR] 0·54, 95% CI 0·46-0·63; p=3·54 × 10-16), and identified a novel genome-wide significant locus at GFRA2 on chromosome 8p21.3 associated with disease risk (rs36196656 meta-analysis OR 1·49, 95% CI 1·30-1·71; p=1·58 × 10-8). Expression analyses showed that the risk-associated allele at rs36196656 decreased GFRA2 mRNA concentrations in cerebellar tissue (p=0·04). No effect of rs36196656 on plasma and CSF progranulin concentrations was detected by ELISA; however, co-immunoprecipitation experiments in HEK293T cells did suggest a direct binding of progranulin and GFRA2. INTERPRETATION: TMEM106B-related and GFRA2-related pathways might be future targets for treatments for FTLD, but the biological interaction between progranulin and these potential disease modifiers requires further study. TMEM106B and GFRA2 might also provide opportunities to select and stratify patients for future clinical trials and, when more is known about their potential effects, to inform genetic counselling, especially for asymptomatic individuals. FUNDING: National Institute on Aging, National Institute of Neurological Disorders and Stroke, Canadian Institutes of Health Research, Italian Ministry of Health, UK National Institute for Health Research, National Health and Medical Research Council of Australia, and the French National Research Agency.
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    Recommendations for clinical implementation of blood-based biomarkers for Alzheimer's disease
    (Wiley, 2024) Mielke, Michelle M.; Anderson, Matthew; Ashford, J. Wesson; Jeromin, Andreas; Lin, Pei-Jung; Rosen, Allyson; Tyrone, Jamie; Vandevrede, Lawren; Willis, Deanna R.; Hansson, Oskar; Khachaturian, Ara S.; Schindler, Suzanne E.; Weiss, Joan; Batrla, Richard; Bozeat, Sasha; Dwyer, John R.; Holzapfel, Drew; Jones, Daryl Rhys; Murray, James F.; Partrick, Katherine A.; Scholler, Emily; Vradenburg, George; Young, Dylan; Braunstein, Joel B.; Burnham, Samantha C.; de Oliveira, Fabricio Ferreira; Hu, Yan Helen; Mattke, Soeren; Merali, Zul; Monane, Mark; Sabbagh, Marwan Noel; Shobin, Eli; Weiner, Michael; Udeh-Momoh, Chinedu T.; Medicine, School of Medicine
    Blood-based biomarkers (BBM) for Alzheimer's disease (AD) are being increasingly used in clinical practice to support an AD diagnosis. In contrast to traditional diagnostic modalities, such as amyloid positron emission tomography and cerebrospinal fluid biomarkers, BBMs offer a more accessible and lower cost alternative for AD biomarker testing. Their unique scalability addresses the anticipated surge in demand for biomarker testing with the emergence of disease-modifying treatments (DMTs) that require confirmation of amyloid pathology. To facilitate the uptake of BBMs in clinical practice, The Global CEO Initiative on Alzheimer's Disease convened a BBM Workgroup to provide recommendations for two clinical implementational pathways for BBMs: one for current use for triaging and another for future use to confirm amyloid pathology. These pathways provide a standardized diagnostic approach with guidance on interpreting BBM test results. Integrating BBMs into clinical practice will simplify the diagnostic process and facilitate timely access to DMTs for eligible patients.