Scientific poster - CSF pTau181/Aβ1-42 ratio increases pre-analytical variability over measuring Aβ1-42 alone

Jan 4, 2023

Poster presented at the CTAD 2022

In this CTAD 2022 poster, we examine the utility of core cerebrospinal fluid (CSF) biomarker ratios to correct for pre-analytical variability.

Authors of the poster: 
Esquivel, R., Ho, S., Darrow, J., Calabro, A., Thakker, P., Gannon, S., De Simone, F., Moghekar, A.


CSF biomarker concentrations for β-amyloid1-42 (Aβ1-42), β-amyloid1-40 (Aβ1-40), and pTau181 are valuable in the diagnosis of Alzheimer’s disease. Specifically, when used in a ratio Aβ1-42/Aβ1-40 and pTau181/Aβ1-42 have shown high concordance with amyloid PET. However, questions remain on the robustness of these ratios when used in clinical routine due to the tendency of amyloid to adsorb to surfaces causing amyloid loss that may result in misdiagnosis.

In this study the effect of varying polypropylene tube type within clinical routine on amyloid concentration using Aβ1-42/Aβ1-40 and ptau181/Aβ1-42 ratios was evaluated in freshly collected CSF. The utility of the ratios to correct for pre-analytical variability was examined.

The results show that the pTau181/Aβ1-42 ratio may amplify preanalytical variability even when amyloid loss is minimal. Measuring the Aβ1-42/Aβ1-40 ratio alongside pTau181 as an individual analyte may provide most consistent results in studies relying on biobanked samples.

For a more detailed overview of the results, please click on the link below to download the poster.

Download your copy of the poster here

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