Comparison of analytical platforms for cerebrospinal fluid measures of β-amyloid 1-42, total tau, and p-tau181 for identifying Alzheimer disease amyloid plaque pathology

Arch Neurol. 2011 Sep;68(9):1137-44. doi: 10.1001/archneurol.2011.105. Epub 2011 May 9.


Background: Cerebrospinal fluid (CSF) biomarkers of Alzheimer disease (AD) are currently being considered for inclusion in revised diagnostic criteria for research and/or clinical purposes to increase the certainty of antemortem diagnosis.

Objective: To test whether CSF biomarker assays differ in their ability to identify true markers of underlying AD pathology (eg, amyloid plaques and/or neurofibrillary tangles) in living individuals.

Design: We compared the performances of the 2 most commonly used platforms, INNOTEST enzyme-linked immunosorbent assay and INNO-BIA AlzBio3, for measurement of CSF β-amyloid (Aβ) and tau proteins to identify the presence of amyloid plaques in a research cohort (n=103). Values obtained for CSF Aβ1-42, total tau, and phosphorylated tau 181 (p-tau(181)) using the 2 assay platforms were compared with brain amyloid load as assessed by positron emission tomography using the amyloid imaging agent Pittsburgh compound B.

Setting: The Knight Alzheimer's Disease Research Center at Washington University in St Louis, Missouri.

Subjects: Research volunteers who were cognitively normal or had mild to moderate AD dementia.

Results: The 2 assay platforms yielded different (approximately 2- to 6-fold) absolute values for the various analytes, but relative values were highly correlated. The CSF Aβ1-42 correlated inversely and tau and p-tau(181) correlated positively with the amount of cortical Pittsburgh compound B binding, albeit to differing degrees. Both assays yielded similar patterns of CSF biomarker correlations with amyloid load. The ratios of total tau to Aβ1-42 and p-tau(181) to Aβ1-42 outperformed any single analyte, including Aβ1-42, in discriminating individuals with vs without cortical amyloid.

Conclusions: The INNOTEST and INNO-BIA CSF platforms perform equally well in identifying individuals with underlying amyloid plaque pathology. Differences in absolute values, however, point to the need for assay-specific diagnostic cutoff values.

Publication types

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

MeSH terms

  • Aged
  • Alzheimer Disease / cerebrospinal fluid*
  • Alzheimer Disease / metabolism
  • Alzheimer Disease / pathology*
  • Amyloid beta-Peptides / cerebrospinal fluid*
  • Biomarkers / cerebrospinal fluid
  • Cohort Studies
  • Enzyme-Linked Immunosorbent Assay / methods
  • Enzyme-Linked Immunosorbent Assay / standards
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Peptide Fragments / cerebrospinal fluid*
  • Phosphorylation / physiology
  • Plaque, Amyloid / cerebrospinal fluid*
  • Plaque, Amyloid / pathology*
  • tau Proteins / cerebrospinal fluid*
  • tau Proteins / metabolism


  • Amyloid beta-Peptides
  • Biomarkers
  • Peptide Fragments
  • amyloid beta-protein (1-42)
  • tau Proteins