Amyloid-beta 42 adsorption following serial tube transfer.

ABSTRACT:

Introduction

Cerebrospinal fluid (CSF) amyloid-beta 38 (A?38), 40 (A?40), 42 (A?42) and total tau (T-tau) are finding increasing utility as biomarkers of Alzheimer's disease (AD). The purpose of this study was to determine whether measured CSF biomarker concentrations were affected by transfer of CSF between tubes, and whether addition of a non-ionic surfactant mitigates any observed effects.

Methods

AD and control CSF was transferred consecutively between polypropylene tubes. A? peptides and T-tau were measured with and without addition of Tween 20 (0.05%).

Results

Measured concentrations of A?42 decreased by approximately 25% with each consecutive transfer. Measured concentrations of A?38 and A?40 were also observed to decrease significantly with each consecutive transfer (approximately 16% loss per transfer). Measured concentrations of T-tau also decreased significantly, but at much smaller magnitude than the A? peptides (approximately 4% loss per transfer). The addition of Tween 20 mitigated this effect in all samples.

Conclusions

Consecutive CSF transfer between tubes has a significant impact on the measured concentration of all A? peptides, and significant effect of lesser magnitude on T-tau. This would be sufficient to alter biomarker ratios enough to mislead diagnosis. The introduction of Tween 20 at the initial aliquoting stage was observed to significantly mitigate this effect.

SUBMITTER: Toombs J 

PROVIDER: S-EPMC4059346 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature