# Disclosure of plasma p‐tau217 measure improves diagnostic confidence in patients with Alzheimer's disease versus syndromes associated with frontotemporal lobar degeneration

## TL;DR

Adding plasma p-tau217 measurements to routine assessments improves confidence in diagnosing Alzheimer's disease compared to traditional methods.

## Contribution

Plasma p-tau217 significantly enhances diagnostic confidence for Alzheimer's disease comparable to established amyloid markers.

## Key findings

- Diagnostic confidence accuracy increased from 0.93 to 0.97 with plasma p-tau217 addition.
- Plasma p-tau217 performance was comparable to conventional amyloid markers.
- Routine assessments combined with plasma p-tau217 improved Alzheimer's diagnosis confidence.

## Abstract

Further research is needed to understand the performance of plasma phosphorylated tau (p‐tau)217 in the diagnostic thinking at the individual patient level. We evaluated the incremental diagnostic value of plasma p‐tau217, expressed in terms of diagnostic confidence of Alzheimer's disease (DCAD; range 0—100).

Two hundred thirty‐two patients with dementia were included and scored in terms of DCAD in a three‐step consecutive assessment: (1) clinical work‐up, (2) clinical work‐up plus plasma p‐tau217, and (3) clinical work‐up, plasma p‐tau217, plus conventional amyloid markers. Two blinded neurologists were asked to review DCAD at each step.

DCAD accuracy, expressed as area under the curve, significantly increased from 0.93 with clinical work‐up alone, to 0.97 with clinical work‐up plus plasma p‐tau217 (P = 0.01), with no further increase with the addition of conventional amyloid markers (0.99, P = 0.13).

Plasma p‐tau217 in addition to routine assessment significantly enhances diagnostic confidence that is comparable to well‐established amyloidosis biomarkers.

Plasma phosphorylated tau (p‐tau)217 measurements increase diagnostic confidence of Alzheimer's disease.Plasma p‐tau217 increases diagnostic confidence comparable to traditional markers.Plasma p‐tau217 dosage may be helpful in addition to routine assessment.

Plasma phosphorylated tau (p‐tau)217 measurements increase diagnostic confidence of Alzheimer's disease.

Plasma p‐tau217 increases diagnostic confidence comparable to traditional markers.

Plasma p‐tau217 dosage may be helpful in addition to routine assessment.