# Plasma phospho-tau217 for Alzheimer's disease diagnosis in primary and secondary care using a fully automated platform

Article · Palmqvist S, Warmenhoven N, Anastasi F, Pilotto A, Janelidze S, Tideman P, Stomrud E, Mattsson-Carlgren N, Smith R, Ossenkoppele R, Tan K, Dittrich A, Skoog I, Zetterberg H, Quaresima V, Tolassi C, Höglund K, Brugnoni D, Puig-Pijoan A, Fernández-Lebrero A, Contador J, Padovani A, Monane M, Verghese PB, Braunstein JB and 5 more

- Archive id: doi:10.1038/s41591-025-03622-w
- Published: 2025-04-09
- Venue: Nature medicine
- DOI: https://doi.org/10.1038/s41591-025-03622-w
- PMID: 40205199
- PMCID: PMC12176611
- Citations: 182
- Source URL: https://doi.org/10.1038/s41591-025-03622-w
- PDF: https://europepmc.org/articles/PMC12176611/pdf
- Provenance: europepmc

## Abstract

Global implementation of blood tests for Alzheimer's disease (AD) would be facilitated by easily scalable, cost-effective and accurate tests. In the present study, we evaluated plasma phospho-tau217 (p-tau217) using predefined biomarker cutoffs. The study included 1,767 participants with cognitive symptoms from 4 independent secondary care cohorts in Malmö (Sweden, n = 337), Gothenburg (Sweden, n = 165), Barcelona (Spain, n = 487) and Brescia (Italy, n = 230), and a primary care cohort in Sweden (n = 548). Plasma p-tau217 was primarily measured using the fully automated, commercially available, Lumipulse immunoassay. The primary outcome was AD pathology defined as abnormal cerebrospinal fluid Aβ42:p-tau181. Plasma p-tau217 detected AD pathology with areas under the receiver operating characteristic curves of 0.93-0.96. In secondary care, the accuracies were 89-91%, the positive predictive values 89-95% and the negative predictive values 77-90%. In primary care, the accuracy was 85%, the positive predictive values 82% and the negative predictive values 88%. Accuracy was lower in participants aged ≥80 years (83%), but was unaffected by chronic kidney disease, diabetes, sex, APOE genotype or cognitive stage. Using a two-cutoff approach, accuracies increased to 92-94% in secondary and primary care, excluding 12-17% with intermediate results. Using the plasma p-tau217:Aβ42 ratio did not improve accuracy but reduced intermediate test results (≤10%). Compared with a high-performing mass-spectrometry-based assay for percentage p-tau217, accuracies were comparable in secondary care. However, percentage p-tau217 had higher accuracy in primary care and was unaffected by age. In conclusion, this fully automated p-tau217 test demonstrates high accuracy for identifying AD pathology. A two-cutoff approach might be necessary to optimize performance across diverse settings and subpopulations.

_Abstract reproduced under CC-BY (article license as recorded by Europe PMC; abstract reproduced unmodified apart from markup removal)._

Topics: [Alzheimer's, Parkinson's & Neurodegeneration](https://space-kitty.com/topics/neurodegeneration)

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