Impact of CSF storage volume on the analysis of Alzheimer's disease biomarkers on an automated platform

Clin Chim Acta. 2019 Mar;490:98-101. doi: 10.1016/j.cca.2018.12.021. Epub 2018 Dec 20.

Abstract

Objectives: To assess the potential influence of the ratio between the storage tube surface area and the volume of cerebrospinal fluid (CSF) (surface/volume) on the quantifications of four Alzheimer's disease (AD) biomarkers on the Lumipulse G600II automated platform.

Methods: CSF samples of 10 consecutive patients were stored in 2 ml polypropylene tubes containing four different CSF volumes: 1.5 ml, 1 ml, 0.5 ml and 0.25 ml. Concentration of CSF Aβ1-42, Aβ1-40, t-Tau and p-Tau were measured in all aliquots using the LUMIPULSE G600II automated platform from Fujirebio.

Results: Levels of CSF Aβ1-42 and Aβ1-40 were lower in samples stored with lower volumes (higher surface/volume ratios). This decrease was partly compensated by using the ratio Aβ1-42/Aβ1-40. Quantification of t-Tau and p-Tau were not influenced by this pre-analytical condition.

Conclusion: The surface/volume ratio can potentially influence the results of amyloid AD biomarkers. It appears essential to take into account the surface/volume ratio of the storage tubes when quantifying CSF biomarkers in clinical routine.

Keywords: Alzheimer's disease; Amyloid; Biomarkers; Cerebrospinal fluid; Lumipulse; Tau.

MeSH terms

  • Alzheimer Disease / cerebrospinal fluid*
  • Amyloid beta-Peptides / cerebrospinal fluid
  • Automation
  • Female
  • Humans
  • Male
  • Peptide Fragments / cerebrospinal fluid
  • Phosphorylation
  • Specimen Handling / methods*
  • tau Proteins / cerebrospinal fluid
  • tau Proteins / metabolism

Substances

  • Amyloid beta-Peptides
  • Peptide Fragments
  • amyloid beta-protein (1-40)
  • amyloid beta-protein (1-42)
  • tau Proteins