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Population-based reference equations and Z-scores for blood biomarkers of neurodegenerative diseases
Lehmann S, Andriambelosoa T, Morchikh M, Mortamais M, Duchiron M, Ayrignac X, Busto G, Gabelle A et al.. medRxiv, 2026-08-11
Topic: Brain proteins, microglia and lab models
Background Blood biomarkers are increasingly used to support the diagnosis and monitoring of neurodegenerative diseases. However, their interpretation is complicated by physiological determinants, including age, sex, body-mass index, and renal function, and by differences in absolute concentrations between analytical methods. We aimed to develop population-based reference equations allowing individualized interpretation of the main blood biomarkers used in neurology.
Key findings
- However, their interpretation is complicated by physiological determinants, including age, sex, body-mass index, and renal function, and by differences in absolute concentrations between analytical methods.
- We aimed to develop population-based reference equations allowing individualized interpretation of the main blood biomarkers used in neurology.
- Methods In this cross-sectional study, we analysed plasma samples from cognitively unimpaired participants selected from the French CONSTANCES and Three-City population-based cohorts.
- Generalized additive models for location, scale, and shape were used to model neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), phosphorylated tau 181 (p-tau181), amyloid-β40, amyloid-β42, and their ratios according to age, sex, body-mass index, and renal function.
Why it matters
This cross-sectional study developed population-based reference equations and Z-scores to help interpret blood biomarkers of neurodegenerative diseases, accounting for factors such as age, sex, body-mass index, and renal function. It is about how to read biomarker results and does not test treatment, cure, or prevention.
New to this subject? Start with our plain-English guide: Blood tests & biomarkers →
Study details
- Study designcross-sectional
- Participants5,123
- Effect size2.6%; 2.2%
- Evidence strengthLow
How this study scored 16/100
Preprint — not yet peer-reviewed. It scored 34 on the same rubric, but non-peer-reviewed sources are capped at 16, so it shows as 16. Scored zero for 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 32 of the 94 points we could judge it on, which is 34 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 | 4 / 12 | A snapshot of people at one point in time |
| Strength of evidence | 1 / 5 | Rated “low” 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 | 3 / 4 | 5,123 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 | 2 / 4 | Last-listed author Thibault Mura: h-index 39 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Inserm: institution h-index 1,988 (OpenAlex) |
| Multi-centre collaboration | 3 / 3 | OpenAlex lists 16 institution(s) in 1 country |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 32 / 94 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 32 of the 94 points we could judge it on is 34 out of 100. |
| Total | 34 / 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
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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
Lehmann, S., Andriambelosoa, T., Morchikh, M., Mortamais, M., Duchiron, M., Ayrignac, X., et al. (2026). Population-based reference equations and Z-scores for blood biomarkers of neurodegenerative diseases. medRxiv. https://doi.org/10.64898/2026.08.09.26360027
Vancouver
Lehmann S, Andriambelosoa T, Morchikh M, Mortamais M, Duchiron M, Ayrignac X, et al. Population-based reference equations and Z-scores for blood biomarkers of neurodegenerative diseases. medRxiv. 2026. doi:10.64898/2026.08.09.26360027.
BibTeX
@article{lehmann2026-77405502,
author = {Lehmann, S. and Andriambelosoa, T. and Morchikh, M. and Mortamais, M. and Duchiron, M. and Ayrignac, X. and Busto, G. and Gabelle, A. and others},
title = {{Population-based reference equations and Z-scores for blood biomarkers of neurodegenerative diseases}},
journal = {medRxiv},
year = {2026},
doi = {10.64898/2026.08.09.26360027},
url = {https://doi.org/10.64898/2026.08.09.26360027}
}
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