NATURE COMMUNICATIONS | APRIL 03, 2020

Janelidze S, Stomrud E, Smith R, Palmqvist S, Mattsson N, Airey DC, Proctor NK, Chai X, Shcherbinin S, Sims JR, Triana-Baltzer G, Theunis C, Slemmon R, Mercken M, Kolb H, Dage JL and Hansson O.

Nat Commun 11, 1683 (2020).

DOI: https://doi.org/10.1038/s41467-020-15436-0

This study was peformed using a Simoa® Homebrew assay.

Abstract

Cerebrospinal fluid (CSF) p-tau181 (tau phosphorylated at threonine 181) is an established biomarker of Alzheimer’s disease (AD), reflecting abnormal tau metabolism in the brain. Here we investigate the performance of CSF p-tau217 as a biomarker of AD in comparison to p-tau181. In the Swedish BioFINDER cohort (n = 194), p-tau217 shows stronger correlations with the tau positron emission tomography (PET) tracer [18F]flortaucipir, and more accurately identifies individuals with abnormally increased [18F]flortaucipir retention. Furthermore, longitudinal increases in p-tau217 are higher compared to p-tau181 and better correlate with [18F]flortaucipir uptake. P-tau217 correlates better than p-tau181 with CSF and PET measures of neocortical amyloid-β burden and more accurately distinguishes AD dementia from non-AD neurodegenerative disorders. Higher correlations between p-tau217 and [18F]flortaucipir are corroborated in an independent EXPEDITION3 trial cohort (n = 32). The main results are validated using a different p-tau217 immunoassay. These findings suggest that p-tau217 might be more useful than p-tau181 in the diagnostic work up of AD.