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Combining Lumipulse p-tau217 and Aβ42/40 as confirmatory tests for Aβ positivity prior to disease-modifying therapy
James D Doecke, Ahmed Chenna, Mintzu Lo, Youssouf Badal, Brandon Yee, Robert Martone, Christos Petropoulos, Christopher J Fowler et al.. Alzheimer's & dementia : the journal of the Alzheimer's Association, 2025-09
Topic: Plasma and spinal-fluid biomarkers
Testing an Alzheimer's disease continuum cohort, the area under the curve (AUC), sensitivity, specificity, and accuracy for the p-tau217/Aβ42 ratio reached 0.961, 93%, 92%, and 93%, respectively. Validation in an intention-to-treat cohort demonstrated similar AUC (0.959), with increased sensitivity (99%), decreased specificity (87%), and increased accuracy (95%). Dual cut-offs generating balanced 95% sensitivity/specificity result in 93% accuracy. Combinations of plasma p-tau217 and Aβ42 demonstrate recommended performance, confirming the presence of Aβ positivity prior to selection for disease-modifying therapies. HIGHLIGHTS: The phosphorylated tau (p-tau)217/amyloid beta (Aβ)42 ratio had high performance to detect Aβ positron emission tomography (PET) status, with > 90% sensitivity, specificity, and accuracy. p-tau217/Aβ42 ratio dual cut-offs set at 95% sensitivity and specificity found 10% to 15% of participants in the intermediate zone. Cut-offs derived for the intention-to-treat cohort meet confirmatory assay criteria for a disease-modifying therapy and can be used in clinical settings.
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APA 7th
Doecke, J. D., Chenna, A., Lo, M., Badal, Y., Yee, B., Martone, R., et al. (2025). Combining Lumipulse p-tau217 and Aβ42/40 as confirmatory tests for Aβ positivity prior to disease-modifying therapy. Alzheimer's & dementia : the journal of the Alzheimer's Association. https://doi.org/10.1002/alz.70707
Vancouver
Doecke JD, Chenna A, Lo M, Badal Y, Yee B, Martone R, et al. Combining Lumipulse p-tau217 and Aβ42/40 as confirmatory tests for Aβ positivity prior to disease-modifying therapy. Alzheimer's & dementia : the journal of the Alzheimer's Association. 2025. doi:10.1002/alz.70707. PMID: 40976838.
BibTeX
@article{doecke2025-40976838,
author = {Doecke, James D and Chenna, Ahmed and Lo, Mintzu and Badal, Youssouf and Yee, Brandon and Martone, Robert and Petropoulos, Christos and Fowler, Christopher J and others},
title = {{Combining Lumipulse p-tau217 and Aβ42/40 as confirmatory tests for Aβ positivity prior to disease-modifying therapy}},
journal = {Alzheimer's \& dementia : the journal of the Alzheimer's Association},
year = {2025},
doi = {10.1002/alz.70707},
pmid = {40976838},
url = {https://doi.org/10.1002/alz.70707}
}
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Key findings
- Testing an Alzheimer's disease continuum cohort, the area under the curve (AUC), sensitivity, specificity, and accuracy for the p-tau217/Aβ42 ratio reached 0.961, 93%, 92%, and 93%, respectively.
- Validation in an intention-to-treat cohort demonstrated similar AUC (0.959), with increased sensitivity (99%), decreased specificity (87%), and increased accuracy (95%).
- Dual cut-offs generating balanced 95% sensitivity/specificity result in 93% accuracy.
- Combinations of plasma p-tau217 and Aβ42 demonstrate recommended performance, confirming the presence of Aβ positivity prior to selection for disease-modifying therapies.
- HIGHLIGHTS: The phosphorylated tau (p-tau)217/amyloid beta (Aβ)42 ratio had high performance to detect Aβ positron emission tomography (PET) status, with > 90% sensitivity, specificity, and accuracy. p-tau217/Aβ42 ratio dual cut-offs set at 95% sensitivity and specificity found 10% to 15% of participants in the intermediate zone.
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Study details
- Evidence strengthModerate
How this study scored 50/100
Published in a leading specialty journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record, multi-centre collaboration and free to read, so those were left out: it earned 28 of the 56 points we could judge it on, which is 50 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Alzheimer's & dementia : the journal of the Alzheimer's Association) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| 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 | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| 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 | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 40976838) |
| Free to read | — / 2 | Access not recorded — left out of this score |
| Points | 28 / 56 | Scored on 10 of 20 parts. We have no data for the rest, so they are left out: 28 of the 56 points we could judge it on is 50 out of 100. |
| Total | 50 / 100 | — |
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