Cerebrospinal fluid biomarkers measured by Elecsys assays compared to amyloid imaging

Alzheimers Dement. 2018 Nov;14(11):1460-1469. doi: 10.1016/j.jalz.2018.01.013. Epub 2018 Mar 2.


Introduction: Levels of amyloid β peptide 42 (Aβ42), total tau, and phosphorylated tau-181 are well-established cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease, but variability in manual plate-based assays has limited their use. We examined the relationship between CSF biomarkers, as measured by a novel automated immunoassay platform, and amyloid positron emission tomography.

Methods: CSF samples from 200 individuals underwent separate analysis for Aβ42, total tau, and phosphorylated tau-181 with automated Roche Elecsys assays. Aβ40 was measured with a commercial plate-based assay. Positron emission tomography with Pittsburgh Compound B was performed less than 1 year from CSF collection.

Results: Ratios of CSF biomarkers (total tau/Aβ42, phosphorylated tau-181/Aβ42, and Aβ42/Aβ40) best discriminated Pittsburgh Compound B-positive from Pittsburgh Compound B-negative individuals.

Discussion: CSF biomarkers and amyloid positron emission tomography reflect different aspects of Alzheimer's disease brain pathology, and therefore, less-than-perfect correspondence is expected. Automated assays are likely to increase the utility of CSF biomarkers.

Keywords: Alzheimer's disease; Amyloid; Biomarker; Cerebrospinal fluid; Cutoff.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / diagnosis*
  • Amyloid / metabolism*
  • Amyloid beta-Peptides / cerebrospinal fluid
  • Aniline Compounds
  • Biomarkers / cerebrospinal fluid
  • Brain / diagnostic imaging*
  • Brain / metabolism*
  • Cohort Studies
  • Female
  • Humans
  • Immunoassay*
  • Male
  • Middle Aged
  • Peptide Fragments / cerebrospinal fluid
  • Positron-Emission Tomography*
  • Radiopharmaceuticals
  • Thiazoles
  • tau Proteins / cerebrospinal fluid


  • 2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole
  • Amyloid
  • Amyloid beta-Peptides
  • Aniline Compounds
  • Biomarkers
  • MAPT protein, human
  • Peptide Fragments
  • Radiopharmaceuticals
  • Thiazoles
  • amyloid beta-protein (1-40)
  • amyloid beta-protein (1-42)
  • tau Proteins