Predictive Ability of Plasma p-tau217 for β-Amyloid Status: A Prospective Multicenter Study

Area of Science:

• Neurology
• Biomarker Research
• Alzheimer's Disease Diagnostics

Background:

• Plasma tau phosphorylated at threonine 217 (p-tau217) shows promise for Alzheimer's disease (AD) diagnosis.
• Real-world multicenter data on p-tau217 automated platforms are limited.

Purpose of the Study:

• To validate the diagnostic performance of plasma p-tau217 for identifying AD pathology.
• To assess p-tau217 accuracy in a real-world, multicenter cohort across memory clinics.

Main Methods:

• Prospective multicenter study including patients with cognitive impairment.
• Centralized analysis of plasma samples using the Lumipulse G p-tau217 assay.
• Assessment of diagnostic accuracy for Aβ status overall and across participating sites.

Main Results:

• Plasma p-tau217 demonstrated excellent accuracy (AUC 0.916) for CSF-defined Aβ status, with consistent performance across centers.
• A dual-threshold strategy improved classification into low, intermediate, and high probability categories of Aβ positivity.
• A strict model achieved 95.3% accuracy in confidently classifying over half of participants.

Conclusions:

• Plasma p-tau217 on an automated platform accurately discriminates CSF Aβ status in a real-world multicenter setting.
• The assay enables reliable rule-in/rule-out classification for Alzheimer's disease in over 50% of patients.
• Findings support the broader clinical adoption of plasma p-tau217 as an initial diagnostic tool for AD.