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Amyloid probability in Alzheimer disease from plasma, cerebrospinal fluid, and amyloid imaging
Khushboo Verma, Satwant Kumar. npj Dementia, 2026-07-01
Topic: Amyloid, tau and blood-test diagnosis
Abstract Blood-based biomarkers are increasingly used to triage patients for amyloid confirmation, yet performance is often reported versus a single comparator despite discordance between amyloid PET and CSF. In a cross-sectional secondary analysis of the Alzheimer’s Disease Neuroimaging Initiative (ADNI), we assembled one PET-anchored PET–CSF–plasma triad per participant ( n = 320). Bayesian latent class models integrating PET, CSF and plasma (Aβ42/40 or %p-tau217) estimated pattern-level posterior probabilities of latent amyloid positivity, with prespecified sensitivity analyses for PET–CSF conditional dependence, timing gaps (≤7, 8–30, >30 days) and CSF cutpoints. Concordant PET + /CSF+ and PET − /CSF− patterns mapped to probabilities near 1 and 0, whereas discordant patterns yielded intermediate probabilities refined by plasma strata and most sensitive to dependence assumptions. PET–CSF discordance occurred even within ≤7 days (12/98; 12%). A CSF Aβ42 coverage analysis showed similar gradients. Pattern-to-probability reporting may aid interpretation without privileging a reference test.
Key findings
- Abstract Blood-based biomarkers are increasingly used to triage patients for amyloid confirmation, yet performance is often reported versus a single comparator despite discordance between amyloid PET and CSF.
Why it matters
This study used statistical modeling to estimate the probability of amyloid positivity from blood, spinal fluid, and PET scan results, finding that discordant results between PET and spinal fluid gave intermediate probabilities. It is a diagnostic interpretation study and does not test any treatment, cure, or prevention.
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Study details
- Study designcross-sectional
- Participants320
- Evidence strengthLow
How this study scored 36/100
Published in a peer-reviewed 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 | 7 / 10 | Tier 3 — peer-reviewed journal (npj Dementia) |
| Journal's citation record | 0 / 4 | Npj Dementia: journal h-index 10 (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 | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 2 / 4 | 320 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 | 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 | 0 / 6 | Cited 0.0× 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 | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 1 / 4 | Last-listed author Satwant Kumar: h-index 10 (OpenAlex, whole career) |
| Institution's track record | 0 / 3 | The University of Texas at Tyler: institution h-index 140 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 2 / 2 | Free to read |
| Total | 36 / 100 | — |
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. Check the citation against the original before you use it.
APA 7th
Verma, K., & Kumar, S. (2026). Amyloid probability in Alzheimer disease from plasma, cerebrospinal fluid, and amyloid imaging. npj Dementia. https://doi.org/10.1038/s44400-026-00109-4
Vancouver
Verma K, Kumar S. Amyloid probability in Alzheimer disease from plasma, cerebrospinal fluid, and amyloid imaging. npj Dementia. 2026. doi:10.1038/s44400-026-00109-4.
BibTeX
@article{verma2026-6f44c1d3,
author = {Verma, Khushboo and Kumar, Satwant},
title = {{Amyloid probability in Alzheimer disease from plasma, cerebrospinal fluid, and amyloid imaging}},
journal = {npj Dementia},
year = {2026},
doi = {10.1038/s44400-026-00109-4},
url = {https://doi.org/10.1038/s44400-026-00109-4}
}
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