Diagnostic performance of Plasma p-tau217 and Aβ42/40 Biomarkers in an Outpatient Memory Clinic - Poster Presentation

Q: What biomarker types were evaluated in the outpatient memory clinic study?

The study evaluated plasma p-tau217 and plasma Aβ42/40, including the combined ratio p-tau217/Aβ42.

Q: What were the main findings about diagnostic accuracy?

After excluding patients with intermediate plasma p-tau217, plasma p-tau217 distinguished symptomatic AD with 95% sensitivity and 82% specificity. Adding Aβ42 integration incrementally improved specificity to 86%, and plasma performance aligned closely with CSF AD biomarkers while outperforming Aβ42/40 alone.

Sep 30, 2026

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Plasma p-tau217 offers a practical alternative to PET- and CSF-based Alzheimer’s disease biomarkers, but its diagnostic value in outpatient memory clinics with multiple causes of cognitive impairment had been unclear. Plasma Aβ42/40 and p-tau217 were measured with Fujirebio Lumipulse in patients evaluated at Mayo Clinic, using consensus syndromic and etiologic diagnoses supported by MRI, FDG-PET, and CSF AD biomarkers. Cutpoints categorized patients by amyloid-PET pathology, and p-tau217 distinguished symptomatic AD with high sensitivity and specificity; Aβ42 integration modestly improved specificity, while performance matched established CSF measures and was affected by kidney function when interpreting p-tau217.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages2

Reading Time5 min

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Abstract

Background

Method

Result

Conclusion

DOI: 10. 1002/alz70856_104860 BIOMARKERS POSTER PRESENTATION BIOMARKERS (NON-NEUROIMAGING) Diagnostic performance of Plasma p-tau217 andAβ42/40 Biomarkers in an Outpatient Memory Clinic Yoav D Piura1 Daniel Figdore2 Alicia Algeciras-Schimnich2 Joshua A Bornhorst2 Christian Lachner 1 Neill R. Graff-Radford 1 Gregory S Day 1 1 Mayo Clinic in Florida, Jacksonville, FL, USA 2 Mayo Clinic, Rochester, MN, USA Correspondence Yoav D Piura, Mayo Clinic in Florida, Jacksonville, FL, USA. [Email:](Email: piura.yoav@mayo.edu)[ piura.yoav@mayo.edu](Email: piura.yoav@mayo.edu) Abstract Background: Plasma p-tau217 represents a promising alternative to PET- and CSF-based biomarkers of AD in well-characterized research cohorts. However, the performance of this accessible biomarker in outpatient clinics comprised of patients with multiple causes of cognitive impairment has yet to be established. Method: PlasmaAβ42/40andp-tau217concentrations were measured using Fujirebio Lumipulse assays in patients evaluated within a subspecialty memory clinic at Mayo Clinic in Florida. Syndromic and etiologic diagnoses were established by consensus, integrating clinical data and findings from MRI (n = 484), FDG-PET (n = 117), and CSF AD biomarkers (n = 440). Plasma biomarker performance was evaluated using established diagnostic cutpoints to identify patients with “positive/elevated”,“intermediate”, or “negligible” levels of cerebral amyloid pathology on amyloid-PET. Result: Plasma AD biomarkers were measured in 509 patients (mean 68.6±9. 3 years; 47% female; 91.3% non-Hispanic White), including patients with typical amnestic AD (n = 237, 46.6%), non-amnestic presentations of AD (n = 48, 9.4%), and non-AD causes of cognitive concerns (n = 224, 44.0%).“Intermediate” plasma p-tau217 and p-tau217/Aβ42 concentrations were reported in < 15% of patients (43% of patients with Aβ42/40), implying the need for further testing to inform the likelihood of AD neuropathologic change in these patients. After excluding these patients, plasma ptau217 reliably distinguished patients with symptomatic AD with 95% sensitivity and 82% specificity. Integration of Aβ42 measures (ptau217/Aβ42) incrementally improved specificity (86%). Diagnostic performance was unaffected by age (> vs < 65-years). Plasma p-tau217 (AUC: 0.94; 95%CI: 0.91-0.96) and p-tau217/Aβ42 performance (AUC: 0.96; 95%CI: 0.94-0.98) were closely aligned with results of established CSFAD biomarkers (p-tau181/Aβ42), outperforming Aβ42/40 (AUC: 0.78; 95%CI: 0.74-0.83). Reduced kidney function was associated with elevated plasma p- This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2025 The Alzheimer’s Association. Alzheimer’s & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer’s Association. Alzheimer’s Dement. 2025;21(Suppl. 2):e104860. [https://doi.org/10.1002/alz70856_104860](https://doi.org/10.1002/alz70856_104860) wi[leyonlinelibrary.com/journal/alz](leyonlinelibrary.com/journal/alz) 1of2 BIOMARKERS tau217 and p-tau217/Aβ42 concentrations in patients without AD (referencing CSFAD biomarkers). Conclusion: Concentrations of plasma p-tau217, but not Aβ42/40, strongly associated with clinical diagnoses of symptomatic AD and CSF AD biomarker results. Integration of Aβ42 measures yielded marginal improvements in performance, with increased complexity and cost. These findings support the use of plasma p-tau217 in heterogeneous clinical cohorts, including patients with multiple causes of cognitive impairment. Caution is advised when interpreting p-tau217 concentrations in patients with decreased kidney function, due to potential elevations in plasma biomarker concentrations.

FAQs

What biomarker types were evaluated in the outpatient memory clinic study?

The study evaluated plasma p-tau217 and plasma Aβ42/40, including the combined ratio p-tau217/Aβ42.

How were diagnoses and biomarker cutpoints determined?

Syndromic and etiologic diagnoses were established by consensus using clinical data supported by MRI, FDG-PET, and CSF AD biomarkers. Diagnostic performance was assessed using established cutpoints based on amyloid-PET pathology levels.

What were the main findings about diagnostic accuracy?

After excluding patients with intermediate plasma p-tau217, plasma p-tau217 distinguished symptomatic AD with 95% sensitivity and 82% specificity. Adding Aβ42 integration incrementally improved specificity to 86%, and plasma performance aligned closely with CSF AD biomarkers while outperforming Aβ42/40 alone.

Sep 30, 2026

Upload by Jasmine