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Plasma and CSF biomarkers for the diagnosis of Alzheimer's disease in adults with Down syndrome: a cross-sectional study
Fortea J, Carmona-Iragui M, Benejam B, Fernández S, Videla L, Barroeta I, Alcolea D, Pegueroles J et al.. The Lancet. Neurology, 2018-08-29
Topic: Amyloid, tau and blood-test diagnosis
The diagnostic performance of plasma biomarkers was poor (area under the curve [AUC] between 0·53 [95% CI 0·44-0·62] and 0·74 [0·66-0·82]) except for plasma NfL concentrations, which had an AUC of 0·88 (0·82-0·93) for the differentiation of the asymptomatic group versus the prodromal Alzheimer's disease group and 0·95 (0·92-0·98) for the asymptomatic group versus the Alzheimer's disease dementia group. In CSF, except for Aβ 1-40 concentrations (AUC 0·60, 95% CI 0·45-0·75), all biomarkers had a good performance in the asymptomatic versus prodromal Alzheimer's disease comparison: AUC 0·92 (95% CI 0·85-0·99) for Aβ 1-42 , 0·81 (0·69-0·94) for t-tau, 0·80 (0·67-0·93) for p-tau, and 0·88 (0·79-0·96) for NfL. Performance of the CSF biomarkers was optimal in the asymptomatic versus Alzheimer's disease dementia comparison (AUC ≥0·90 for all except Aβ 1-40 [0·59, 0·45-0·72]). Our findings support the utility of plasma NfL for the early detection of Alzheimer's disease in Down syndrome in clinical practice and clinical trials.
Key findings
- The diagnostic performance of plasma biomarkers was poor (area under the curve [AUC] between 0·53 [95% CI 0·44-0·62] and 0·74 [0·66-0·82]) except for plasma NfL concentrations, which had an AUC of 0·88 (0·82-0·93) for the differentiation of the asymptomatic group versus the prodromal Alzheimer's disease group and 0·95 (0·92-0·98) for the asymptomatic group versus the Alzheimer's disease dementia group.
- In CSF, except for Aβ 1-40 concentrations (AUC 0·60, 95% CI 0·45-0·75), all biomarkers had a good performance in the asymptomatic versus prodromal Alzheimer's disease comparison: AUC 0·92 (95% CI 0·85-0·99) for Aβ 1-42 , 0·81 (0·69-0·94) for t-tau, 0·80 (0·67-0·93) for p-tau, and 0·88 (0·79-0·96) for NfL.
- Performance of the CSF biomarkers was optimal in the asymptomatic versus Alzheimer's disease dementia comparison (AUC ≥0·90 for all except Aβ 1-40 [0·59, 0·45-0·72]).
- Our findings support the utility of plasma NfL for the early detection of Alzheimer's disease in Down syndrome in clinical practice and clinical trials.
Why it matters
In adults with Down syndrome, plasma neurofilament light performed well at distinguishing asymptomatic people from those with prodromal or dementia-stage Alzheimer's disease, while most other plasma biomarkers performed poorly. This supports plasma NfL for early detection, not for treating, curing, or preventing Alzheimer's disease.
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Study details
- Study designcross-sectional
- Participants282
- Evidence strengthLow
How this study scored 64/100
Published in a leading specialty journal, and it is a snapshot of people at one point in time. Scored zero for effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (The Lancet. Neurology) |
| Journal's citation record | 3 / 4 | The Lancet Neurology: journal h-index 457 (OpenAlex, 2026-10-29) |
| 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 | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2018 — within 10 year(s) of the newest study here |
| Sample size | 2 / 4 | 282 participants |
| 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 (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 203 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 20.3 citations a year over 10 year(s) since 2018 |
| Impact for its field and year | 4 / 6 | Cited 18.4× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 4 / 6 | Cited by 31 other studies in this library |
| Still being cited | 3 / 4 | Cited 59 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Alberto Lleó: h-index 92 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Inserm: institution h-index 1,988 (OpenAlex) |
| Multi-centre collaboration | 3 / 3 | OpenAlex lists 15 institution(s) in 3 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 30172624) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 64 / 100 | — |
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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
Fortea, J., Carmona-Iragui, M., Benejam, B., Fernández, S., Videla, L., Barroeta, I., et al. (2018). Plasma and CSF biomarkers for the diagnosis of Alzheimer's disease in adults with Down syndrome: a cross-sectional study. The Lancet. Neurology. https://doi.org/10.1016/s1474-4422(18)30285-0
Vancouver
Fortea J, Carmona-Iragui M, Benejam B, Fernández S, Videla L, Barroeta I, et al. Plasma and CSF biomarkers for the diagnosis of Alzheimer's disease in adults with Down syndrome: a cross-sectional study. The Lancet. Neurology. 2018. doi:10.1016/s1474-4422(18)30285-0. PMID: 30172624.
BibTeX
@article{fortea2018-30172624,
author = {Fortea, J. and Carmona-Iragui, M. and Benejam, B. and Fernández, S. and Videla, L. and Barroeta, I. and Alcolea, D. and Pegueroles, J. and others},
title = {{Plasma and CSF biomarkers for the diagnosis of Alzheimer's disease in adults with Down syndrome: a cross-sectional study}},
journal = {The Lancet. Neurology},
year = {2018},
doi = {10.1016/s1474-4422(18)30285-0},
pmid = {30172624},
url = {https://doi.org/10.1016/s1474-4422(18)30285-0}
}
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