Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring (Jan 2016)

Comparing biological markers of Alzheimer's disease across blood fraction and platforms: Comparing apples to oranges

  • Sid E. O'Bryant,
  • Simone Lista,
  • Robert A. Rissman,
  • Melissa Edwards,
  • Fan Zhang,
  • James Hall,
  • Henrik Zetterberg,
  • Simon Lovestone,
  • Veer Gupta,
  • Neill Graff‐Radford,
  • Ralph Martins,
  • Andreas Jeromin,
  • Stephen Waring,
  • Esther Oh,
  • Mitchel Kling,
  • Laura D. Baker,
  • Harald Hampel,
  • ISTAART Blood Based Biomarker Professional Interest Area

DOI
https://doi.org/10.1016/j.dadm.2015.12.003
Journal volume & issue
Vol. 3, no. 1
pp. 27 – 34

Abstract

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Abstract Introduction This study investigated the comparability of potential Alzheimer's disease (AD) biomarkers across blood fractions and assay platforms. Methods Nonfasting serum and plasma samples from 300 participants (150 AD patients and 150 controls) were analyzed. Proteomic markers were obtained via electrochemiluminescence or Luminex technology. Comparisons were conducted via Pearson correlations. The relative importance of proteins within an AD diagnostic profile was examined using random forest importance plots. Results On the Meso Scale Discovery multiplex platform, 10 of the 21 markers shared >50% of the variance across blood fractions (serum amyloid A R2 = 0.99, interleukin (IL)10 R2 = 0.95, fatty acid‐binding protein (FABP) R2 = 0.94, I309 R2 = 0.94, IL‐5 R2 = 0.94, IL‐6 R2 = 0.94, eotaxin3 R2 = 0.91, IL‐18 R2 = 0.87, soluble tumor necrosis factor receptor 1 R2 = 0.85, and pancreatic polypeptide R2 = 0.81). When examining protein concentrations across platforms, only five markers shared >50% of the variance (beta 2 microglobulin R2 = 0.92, IL‐18 R2 = 0.80, factor VII R2 = 0.78, CRP R2 = 0.74, and FABP R2 = 0.70). Discussion The current findings highlight the importance of considering blood fractions and assay platforms when searching for AD relevant biomarkers.

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