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ApoE4 lowers the ptau217 threshold for tau aggregation and spread in an allele dose-dependent manner
Steward A, Dewenter A, Hirsch F, Roemer-Cassiano SN, Zhu Z, Dehsarvi A, Biel D, Klonowski M, Frontzkowski L, Palleis C, Gnörich J, Dichgans M, et al.. Brain, 2026-06-03
Topic: Brain proteins, microglia and lab models
We found that ApoE4 did not facilitate amyloid-PET-associated ptau increases, suggesting that amyloid-related ptau secretion is not altered by ApoE4 carriage. Contrastingly, we found that plasma ptau217 elevations were linked to faster tau-PET spread from local epicentres across connected brain regions in an ApoE4 allele dose-dependent manner, independent of amyloid [ADNI/A4-LEARN: mean standardized beta (β) = 0.44/0.56, P < 0.001/P < 0.001]. Lastly, we found that a higher ApoE4 allele count was linked to lower ptau217 thresholds marking transition to tauopathy, i.e. early abnormal tau-PET increases, consistently across both samples (ADNI: 0/1/2 ApoE4 alleles = 0.62/0.34/0.15 pg/ml, representing ∼45% and ∼76% reductions from non-carriers; Fujirebio ptau217 assay; A4-LEARN: 0/1/2 ApoE4 alleles = 0.31/0.23/0.18 pg/ml, representing ∼26% and ∼42% reductions; Eli Lilly ptau217 assay). These findings suggest that ApoE4, i.e. the key genetic risk factor for sporadic Alzheimer's disease, facilitates amyloid-dependent tau aggregation in an allele dose-dependent manner by enhancing the ptau-driven spread of fibrillar tau, leading to an earlier transition from amyloidosis to tauopathy at lower ptau217 levels.
Key findings
- We found that ApoE4 did not facilitate amyloid-PET-associated ptau increases, suggesting that amyloid-related ptau secretion is not altered by ApoE4 carriage.
- Contrastingly, we found that plasma ptau217 elevations were linked to faster tau-PET spread from local epicentres across connected brain regions in an ApoE4 allele dose-dependent manner, independent of amyloid [ADNI/A4-LEARN: mean standardized beta (β) = 0.44/0.56, P < 0.001/P < 0.001].
- Lastly, we found that a higher ApoE4 allele count was linked to lower ptau217 thresholds marking transition to tauopathy, i.e. early abnormal tau-PET increases, consistently across both samples (ADNI: 0/1/2 ApoE4 alleles = 0.62/0.34/0.15 pg/ml, representing ∼45% and ∼76% reductions from non-carriers; Fujirebio ptau217 assay; A4-LEARN: 0/1/2 ApoE4 alleles = 0.31/0.23/0.18 pg/ml, representing ∼26% and ∼42% reductions; Eli Lilly ptau217 assay).
- These findings suggest that ApoE4, i.e. the key genetic risk factor for sporadic Alzheimer's disease, facilitates amyloid-dependent tau aggregation in an allele dose-dependent manner by enhancing the ptau-driven spread of fibrillar tau, leading to an earlier transition from amyloidosis to tauopathy at lower ptau217 levels.
Why it matters
This study found that plasma ptau217 elevations were linked to faster tau-PET spread in an ApoE4 allele dose-dependent manner, and that a higher ApoE4 allele count was linked to lower ptau217 thresholds marking transition to tauopathy. It clarifies how the key genetic risk factor for sporadic Alzheimer's disease relates to tau aggregation and spread, but offers no treatment, cure or prevention.
Study details
- Study designcohort
- Participants401
- Effect sizeTau spread vs p-tau217 by e4 dose: standardised beta 0.44 (ADNI) and 0.56 (A4-LEARN); p-tau217 threshold reduced ~45% and ~76% (ADNI) for 1 and 2 e4 alleles
- Evidence strengthModerate
How this study scored 60/100
Published in a leading specialty journal, and it is a cohort study following people over time. Scored zero for randomised / blinded because the record does not state it. We have no data on free to read, so that was left out: it earned 59 of the 98 points we could judge it on, which is 60 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Brain) |
| Journal's citation record | 4 / 4 | Brain: journal h-index 503 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A cohort study following people over time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 2 / 4 | 401 participants |
| Effect reported | 3 / 3 | Effect reported with a statistic (interval, p-value, ratio or similar) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 2 / 7 | Cited 5 times (OpenAlex, 2026-10-10) |
| Citations per year | 1 / 5 | 2.5 citations a year over 2 year(s) since 2026 |
| Impact for its field and year | 2 / 6 | Cited 2.7× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 1 / 4 | Cited 5 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Nicolai Franzmeier: h-index 49 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Ludwig-Maximilians-Universität München: institution h-index 1,224 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 7 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 41410687) |
| Free to read | — / 2 | Access not recorded — left out of this score |
| Points | 59 / 98 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 59 of the 98 points we could judge it on is 60 out of 100. |
| Total | 60 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
May need a subscription Unpaywall, Europe PMC and OpenAlex found no free copy of the full text (checked 10 Oct 2026), so the publisher may charge for it. The PubMed abstract is free.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Steward, A., Dewenter, A., Hirsch, F., Roemer-Cassiano, S. N., Zhu, Z., Dehsarvi, A., et al. (2026). ApoE4 lowers the ptau217 threshold for tau aggregation and spread in an allele dose-dependent manner. Brain. https://doi.org/10.1093/brain/awaf463
Vancouver
Steward A, Dewenter A, Hirsch F, Roemer-Cassiano SN, Zhu Z, Dehsarvi A, et al. ApoE4 lowers the ptau217 threshold for tau aggregation and spread in an allele dose-dependent manner. Brain. 2026. doi:10.1093/brain/awaf463. PMID: 41410687.
BibTeX
@article{steward2026-41410687,
author = {Steward, A. and Dewenter, A. and Hirsch, F. and Roemer-Cassiano, S. N. and Zhu, Z. and Dehsarvi, A. and Biel, D. and Klonowski, M. and Frontzkowski, L. and Palleis, C. and Gnörich, J. and Dichgans, M. and others},
title = {{ApoE4 lowers the ptau217 threshold for tau aggregation and spread in an allele dose-dependent manner}},
journal = {Brain},
year = {2026},
doi = {10.1093/brain/awaf463},
pmid = {41410687},
url = {https://doi.org/10.1093/brain/awaf463}
}
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