title: Plasma β-amyloid in Alzheimer's disease and vascular disease.
abstract: Implementation of amyloid biomarkers in clinical practice would be accelerated if such biomarkers could be measured in blood. We analyzed plasma levels of Aβ42 and Aβ40 in a cohort of 719 individuals (the Swedish BioFINDER study), including patients with subjective cognitive decline (SCD), mild cognitive impairment (MCI), Alzheimer's disease (AD) dementia and cognitively healthy elderly, using a ultrasensitive immunoassay (Simoa platform). There were weak positive correlations between plasma and cerebrospinal fluid (CSF) levels for both Aβ42 and Aβ40, and negative correlations between plasma Aβ42 and neocortical amyloid deposition (measured with PET). Plasma levels of Aβ42 and Aβ40 were reduced in AD dementia compared with all other diagnostic groups. However, during the preclinical or prodromal AD stages (i.e. in amyloid positive controls, SCD and MCI) plasma concentration of Aβ42 was just moderately decreased whereas Aβ40 levels were unchanged. Higher plasma (but not CSF) levels of Aβ were associated with white matter lesions, cerebral microbleeds, hypertension, diabetes and ischemic heart disease. In summary, plasma Aβ is overtly decreased during the dementia stage of AD indicating that prominent changes in Aβ metabolism occur later in the periphery compared to the brain. Further, increased levels of Aβ in plasma are associated with vascular disease.
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden.
authors.forename: Shorena
authors.initials: S
authors.lastname: Janelidze
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden.|Memory Clinic, Skåne University Hospital, Malmö Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Stomrud
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden.|Department of Neurology, Skåne University Hospital, Lund, Sweden.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Palmqvist
authors.affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.|Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK.
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.affiliation: Department of Clinical Sciences Lund, Diagnostic radiology, Lund University, Lund, Sweden.|Imaging and Function, Skåne University Health Care, Lund, Sweden.
authors.forename: Danielle
authors.initials: D
authors.lastname: van Westen
authors.affiliation: Quanterix Corporation, 113 Hartwell Avenue, Lexington, MA, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jeromin
authors.affiliation: Quanterix Corporation, 113 Hartwell Avenue, Lexington, MA, USA.
authors.forename: Linan
authors.initials: L
authors.lastname: Song
authors.affiliation: Quanterix Corporation, 113 Hartwell Avenue, Lexington, MA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Hanlon
authors.affiliation: Diagnostics and Life Sciences, GE Global Research, Niskayuna, NY, USA.
authors.forename: Cristina A
authors.initials: CA
authors.lastname: Tan Hehir
authors.affiliation: Janssen R&D, Titusville, NJ, USA.
authors.forename: David
authors.initials: D
authors.lastname: Baker
authors.affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden.|Memory Clinic, Skåne University Hospital, Malmö Sweden.
authors.forename: Oskar
authors.initials: O
authors.lastname: Hansson
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood* / Q000134:cerebrospinal fluid / Q000000981:diagnostic imaging / Q000235:genetics; D016229:Amyloid beta-Peptides / Q000097:blood* / Q000134:cerebrospinal fluid; D053327:Apolipoprotein E4 / Q000235:genetics; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D019579:Neocortex / Q000000981:diagnostic imaging / Q000378:metabolism; D049268:Positron-Emission Tomography; D014652:Vascular Diseases / Q000097:blood* / Q000134:cerebrospinal fluid / Q000000981:diagnostic imaging / Q000235:genetics
chemical_list: D016229:Amyloid beta-Peptides; D053327:Apolipoprotein E4; D015415:Biomarkers