# Plasma p‐tau217 for Alzheimer's disease diagnosis: a memory clinic implementation approach

## TL;DR

This study shows that plasma p-tau217 can accurately detect Alzheimer's disease in memory clinics and could reduce the need for spinal taps.

## Contribution

The paper introduces a practical workflow for integrating plasma p-tau217 into memory clinic diagnostics and validates its clinical utility.

## Key findings

- Plasma p-tau217 distinguished amyloid-positive from amyloid-negative individuals with high accuracy.
- A dual cut-off strategy could reduce lumbar punctures by 65% in clinical practice.
- Neurofilament light chain (NfL) levels were elevated in non-AD neurodegenerative disorders.

## Abstract

Plasma phosphorylated tau at threonine 217 (p‐tau217) has shown excellent diagnostic performance for Alzheimer's disease (AD), yet real‐world validation and implementation pathways remain limited. This study assessed its clinical applicability and proposed a practical workflow for memory clinics.

Plasma p‐tau217, p‐tau181, and neurofilament light chain (NfL) were quantified in consecutive patients referred for cognitive assessment. Cerebrospinal fluid (CSF) amyloid beta (Aβ) 42/40 defined amyloid (A) status, and final etiological diagnoses were reached through multidisciplinary consensus integrating clinical, neuropsychological, and metabolic imaging data.

Among 163 patients (mean age 69.3 ± 7.4 years, 52% female), plasma p‐tau217 distinguished A+ from A− individuals (area under the curve [AUC] 0.90, 81% sensitivity, 91% specificity). AD patients showed the highest p‐tau217 levels, while non‐AD neurodegenerative disorders exhibited elevated NfL (p < 0.001). A dual cut‐off strategy with 95% sensitivity and specificity could have avoided 65% of lumbar punctures.

Plasma p‐tau217 demonstrated robust clinical validity and supports structured integration into routine diagnostic pathways.

Plasma p‐tau217 was evaluated in a real‐world unselected memory‐clinic population.Plasma p‐tau217 accurately identified CSF amyloid pathology.A dual 95% sensitivity/specificity cut‐off strategy could have reduced lumbar punctures by 65%.P‐tau217 supported AD diagnosis, while NfL indicated non‐AD neurodegeneration.A biomarker‐driven workflow was defined for clinical implementation in memory clinics.

Plasma p‐tau217 was evaluated in a real‐world unselected memory‐clinic population.

Plasma p‐tau217 accurately identified CSF amyloid pathology.

A dual 95% sensitivity/specificity cut‐off strategy could have reduced lumbar punctures by 65%.

P‐tau217 supported AD diagnosis, while NfL indicated non‐AD neurodegeneration.

A biomarker‐driven workflow was defined for clinical implementation in memory clinics.