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Plasma pTau217 ratio predicts continuous regional brain tau accumulation in amyloid-positive early Alzheimer's disease
Devanarayan V, Charil A, Horie K, Doherty T, Llano DA, Andreozzi E, Sachdev P, Ye Y et al.. Alzheimer's & dementia : the journal of the Alzheimer's Association, 2024-11-22
Topic: Amyloid, tau and blood-test diagnosis
Background This study examines whether phosphorylated plasma Tau217 ratio (pTau217R) can predict tau accumulation in different brain regions, as measured by positron emission tomography (PET) standardized uptake value ratio (SUVR), for staging Alzheimer's disease (AD). Methods Plasma pTau217R was measured using immunoprecipitation-mass spectrometry. Models for predicting tau PET SUVR, developed with 144 early AD individuals using [ 18 F]MK6240, were validated in two validation sets, VS1 (98 early AD) and VS2 (47 preclinical/early AD with a different tracer, flortaucipir (Tauvid)), all amyloid-beta positive (Aβ+). Results The pTau217R-based model predicted tau levels up to an SUVR of 2 in multiple brain regions, effectively assessing tau status at different tau levels with receiver operating characteristic (ROC) curve areas of 0.84-0.95 in VS1 and 0.71-0.88 in VS2 (using a different tracer). It reduced PET scan needs by 65% while maintaining 95% sensitivity. Discussion PTau217R reliably predicts regional tau accumulation in early AD, reducing reliance on tau PET scans and broadening its clinical application. Clinical trial registration number NCT03887455 (ClarityAD) HIGHLIGHTS: Developed a model using plasma pTau217R to predict tau levels across brain regions. pTau217R model outperformed models based on clinical, MRI, and other blood biomarkers. The model reliably predicted tau levels exceeding tau positivity and higher thresholds. Screening with pTau217R could reduce tau PET scans by 65% at 95% sensitivity. pTau217R model aids in disease staging and monitoring in early AD.
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APA 7th
Devanarayan, V., Charil, A., Horie, K., Doherty, T., Llano, D. A., Andreozzi, E., et al. (2025). Plasma pTau217 ratio predicts continuous regional brain tau accumulation in amyloid-positive early Alzheimer's disease. Alzheimer's & dementia : the journal of the Alzheimer's Association. https://doi.org/10.1002/alz.14411
Vancouver
Devanarayan V, Charil A, Horie K, Doherty T, Llano DA, Andreozzi E, et al. Plasma pTau217 ratio predicts continuous regional brain tau accumulation in amyloid-positive early Alzheimer's disease. Alzheimer's & dementia : the journal of the Alzheimer's Association. 2025. doi:10.1002/alz.14411. PMID: 39575854.
BibTeX
@article{devanarayan2025-39575854,
author = {Devanarayan, V. and Charil, A. and Horie, K. and Doherty, T. and Llano, D. A. and Andreozzi, E. and Sachdev, P. and Ye, Y. and others},
title = {{Plasma pTau217 ratio predicts continuous regional brain tau accumulation in amyloid-positive early Alzheimer's disease}},
journal = {Alzheimer's \& dementia : the journal of the Alzheimer's Association},
year = {2025},
doi = {10.1002/alz.14411},
pmid = {39575854},
url = {https://doi.org/10.1002/alz.14411}
}
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Key findings
- Results The pTau217R-based model predicted tau levels up to an SUVR of 2 in multiple brain regions, effectively assessing tau status at different tau levels with receiver operating characteristic (ROC) curve areas of 0.84-0.95 in VS1 and 0.71-0.88 in VS2 (using a different tracer).
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Study details
- Evidence strengthLow
How this study scored 74/100
Published in a leading specialty journal, and it is a large phase 3 trial. Scored zero for sample size and effect reported because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record and institution's track record, so those were left out: it earned 45 of the 61 points we could judge it on, which is 74 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Alzheimer's & dementia : the journal of the Alzheimer's Association) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 11 / 12 | A large phase 3 trial (from PubMed type “Clinical Trial, Phase III”) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (pubmed indexes it as a clinical or observational study) |
| Randomised / blinded | 1 / 2 | Randomised (as stated in the record) |
| Times cited | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | 2 / 3 | PubMed indexes it as a multicentre study |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 39575854) |
| Free to read | 2 / 2 | Free to read |
| Points | 45 / 61 | Scored on 12 of 20 parts. We have no data for the rest, so they are left out: 45 of the 61 points we could judge it on is 74 out of 100. |
| Total | 74 / 100 | — |
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