Related Experiment Video
Updated: Jun 1, 2025

In Vitro Aggregation Assays Using Hyperphosphorylated Tau Protein
Published on: January 2, 2015
Clinical decision points for two plasma p-tau217 laboratory developed tests in neuropathology confirmed samples
Anna E Mammel1, Ging-Yuek Robin Hsiung2, Ali Mousavi2,3
1Neurochemistry Neurocode USA Inc Bellingham USA.
Introduction:
We evaluated the diagnostic performance of two commercial plasma p-tau217 immunoassays compared to cerebrospinal fluid (CSF) testing and neuropathology.
Methods:
One hundred and seventy plasma samples from the University of British Columbia Hospital Clinic for Alzheimer's (AD) and Related Disorders were analyzed for p-tau217 using Fujirebio and ALZpath assays. Decision points were determined using CSF testing and autopsy findings as the standard.
Results:
Fujirebio and ALZpath p-tau217 had similar overall analytical and clinical performance, with distinct decision points for each assay. Based on autopsy findings, both p-tau217 assays identified individuals with AD from other neurodegenerative diseases (ALZpath area under the curve [AUC] = 0.94, Fujirebio AUC = 0.90). The ALZpath assay detected AD pathology at milder disease stages compared to the Fujirebio assay.
Discussion:
Our study reinforces the clinical utility of plasma p-tau217 as an AD biomarker. Differences in test performance and clinical decision points suggest an assay-specific diagnostic approach is required for plasma p-tau217 in clinical practice.
Highlights:
Two commercially available p-tau217 immunoassays (ALZpath and Fujirebio) showed equal performance based on CSF testing.ALZpath p-tau217 showed higher performance compared to Fujirebio p-tau217 based on AD diagnosis by neuropathology confirmation.Specific plasma p-tau217 assays may require distinct decision points for AD screening, diagnosis, and disease progression monitoring.

