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Routine implementation of α-synuclein Seed Amplification Assays reveals high diagnostic performance and the limited value of Alzheimer disease fluid biomarkers for detecting α-synuclein co-pathology
Jourdan O, Duchiron M, Torrent J, Turpinat C, Mondesert E, Busto G, Morchikh M, Dornadic M et al.. medRxiv, 2026-04-23
Topic: Amyloid, tau and blood-test diagnosis
Background In neurodegenerative diseases, the diagnostic value of α-synuclein seed amplification assay (αSAA) in routine clinical practice and its relationship with cognitive performance and fluid biomarkers remains incompletely characterized. In addition, although Alzheimer disease (AD) CSF and blood biomarkers accurately detect amyloid and tau pathology, their ability to identify concomitant α-synuclein (αSyn) pathology remains unknown. Methods We included 398 patients from the multicenter memory clinic ALZAN cohort.
Key findings
- In addition, although Alzheimer disease (AD) CSF and blood biomarkers accurately detect amyloid and tau pathology, their ability to identify concomitant α-synuclein (αSyn) pathology remains unknown.
- Methods We included 398 patients from the multicenter memory clinic ALZAN cohort.
- All participants underwent CSF and blood sampling with measurement of CSF biomarkers (Aβ42/40, tau, p-tau181) and plasma biomarkers (Aβ42/40, p-tau181, p-tau217, GFAP, NfL).
- Cognitive assessment was performed using the Mini-Mental State Examination (MMSE).
Why it matters
In 398 patients from a multicenter memory clinic cohort, this study found that α-synuclein seed amplification assays performed well in routine practice while Alzheimer's disease fluid biomarkers had limited value for detecting α-synuclein co-pathology. It concerns detecting co-pathology and does not offer a treatment, cure, or prevention.
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Study details
- Participants398
- Effect size95.0%; 15.8%; 93.1%
- Evidence strengthModerate
How this study scored 16/100
Preprint — not yet peer-reviewed. It scored 32 on the same rubric, but non-peer-reviewed sources are capped at 16, so it shows as 16. Scored zero for study design and randomised / blinded because the record does not state it. We have no data on impact for its field and year, so that was left out: it earned 30 of the 94 points we could judge it on, which is 32 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 2 / 10 | Tier 4 — not a peer-reviewed journal (medRxiv) |
| Journal's citation record | 0 / 4 | Not a journal article, so the journal's record does not count |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 4 / 10 | Preprint — not yet peer-reviewed. Hosted on a preprint server. |
| How recent | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 2 / 4 | 398 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| 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 | 0 / 7 | Cited 0 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.0 citations a year over 2 year(s) since 2026 |
| 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 | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Sylvain Lehmann: h-index 75 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Inserm: institution h-index 1,988 (OpenAlex) |
| Multi-centre collaboration | 3 / 3 | OpenAlex lists 10 institution(s) in 2 countries |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 30 / 94 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 30 of the 94 points we could judge it on is 32 out of 100. |
| Total | 32 / 100 | Capped to 16 because this is not a peer-reviewed article. |
What each of these 20 components measures, and what this score is not →
Read the original
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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
Jourdan, O., Duchiron, M., Torrent, J., Turpinat, C., Mondesert, E., Busto, G., et al. (2026). Routine implementation of α-synuclein Seed Amplification Assays reveals high diagnostic performance and the limited value of Alzheimer disease fluid biomarkers for detecting α-synuclein co-pathology. medRxiv. https://doi.org/10.64898/2026.04.21.26351389
Vancouver
Jourdan O, Duchiron M, Torrent J, Turpinat C, Mondesert E, Busto G, et al. Routine implementation of α-synuclein Seed Amplification Assays reveals high diagnostic performance and the limited value of Alzheimer disease fluid biomarkers for detecting α-synuclein co-pathology. medRxiv. 2026. doi:10.64898/2026.04.21.26351389.
BibTeX
@article{jourdan2026-b20dbc37,
author = {Jourdan, O. and Duchiron, M. and Torrent, J. and Turpinat, C. and Mondesert, E. and Busto, G. and Morchikh, M. and Dornadic, M. and others},
title = {{Routine implementation of α-synuclein Seed Amplification Assays reveals high diagnostic performance and the limited value of Alzheimer disease fluid biomarkers for detecting α-synuclein co-pathology}},
journal = {medRxiv},
year = {2026},
doi = {10.64898/2026.04.21.26351389},
url = {https://doi.org/10.64898/2026.04.21.26351389}
}
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