- 2,002studies in the library match, of 29,380
- 764name it in the title
- 1996–2026years published
- 1,891peer-reviewed articles
The query: title or abstract mentions "blood test", "blood-based biomarker/test/assay", "plasma p-tau/biomarker/Aβ/amyloid/NfL/GFAP", "p-tau217/181/231" or "serum p-tau/biomarker/NfL/GFAP", matched case-insensitively against each record's title and abstract (its summary field) in alzhub's library of 29,380 study records, as of 2026-11-08. Every count on this page comes from that match. The matched list as JSON.
The tests measure proteins that leak from the brain into the blood: forms of tau phosphorylated at particular sites (p-tau217, p-tau181, p-tau231), the ratio of two amyloid-beta fragments (Aβ42/40), and markers of brain cell injury and inflammation (NfL, GFAP). Their accuracy is usually reported against an amyloid PET scan or a spinal fluid test as the reference.
Accuracy depends on the marker, the assay, the setting and who was tested, and some conditions such as kidney disease change the levels. The quoted sentences below give the figures each paper reported; alzhub's sourced evidence page on blood tests walks through them.
This page describes what published research in alzhub's library reports. It is not medical advice and does not apply to any one person: a doctor who knows the person's history is the only one who can say what a result or a treatment means for them.
What the studies report, in their own words
Whole sentences copied from the abstract or key findings of the highest-scoring matched studies, chosen because they mention the subject and give a figure. 8 of the 2,002 matched records are quoted; each links to its study page and from there to the paper.
“Plasma p-tau217-eligible participants were enrolled (N = 2196), with Clinical Dementia Rating (CDR) scale-Global score (CDR-GS) of 0 (n = 1202) and 0.5 (n = 664).”
“Lower baseline amyloid beta (Aβ)42/40 ratio and higher phosphorylated tau 181 (p-tau181), glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) were associated with an increased risk of MCI and dementia; GFAP was most strongly associated.”
“In meta-analysis of unadjusted correlation coefficients, kidney function (primarily eGFR) was inversely associated with concentrations of blood NfL, GFAP, Aβ40, β-amyloid 1-40 (A β 40), β-amyloid 1-42, and phosphorylated tau (p-tau181).”
“Mean percentage change in plasma p-tau217 in the SAMe group was an increase of 53.22 (standard deviation [SD] 159.19) compared to 25.34 (SD 94.83) in the placebo group (standardized mean difference 37.58, 95% confidence interval -32.61, 107.76; p = 0.288).”
“Conclusions and relevance This study found that a commercially available plasma p-tau217 immunoassay accurately identified biological AD, comparable with results using CSF biomarkers, with reproducible cut-offs across cohorts.”
“Plasma Aβ42/40-ratio increased significantly with blarcamesine group vs. placebo, (P = 0.048) and whole brain volume loss was significantly decreased (P = 0.002).”
“Consistent with the overall data set, a robust dose-dependent decrease in amyloid beta levels as assessed with amyloid-PET and plasma p-tau181 was observed.”
“Notably, the p-tau217/Aβ 42 ratio on automated platforms provided a significant incremental AUC gain of 0.025 (95% CI: 0.005 to 0.045; I2 = 0%) compared to single-analyte assays, effectively bridging the performance gap with MS.”
What kind of evidence it is
By study design
| Design (as recorded) | Studies |
|---|---|
| Systematic review or meta-analysis | 52 |
| Randomised controlled trial | 5 |
| Other clinical trial | 35 |
| Cohort or longitudinal study | 384 |
| Case-control study | 18 |
| Cross-sectional study | 225 |
| Other recorded design | 13 |
| No design recorded | 1,270 |
The design is the one named in alzhub's record for the study; a record with none is counted as "no design recorded".
By year
| Year | Studies | Share |
|---|---|---|
| 2026 | 301 | |
| 2025 | 430 | |
| 2024 | 252 | |
| 2023 | 233 | |
| 2022 | 194 | |
| 2021 | 113 | |
| 2020 | 81 | |
| 2019 | 78 | |
| 2018 | 48 | |
| 2017 | 45 | |
| 2016 and earlier | 227 |
Other counts within the matched set
| Peer-reviewed articles | 1,891 |
| Marked open access in the record | 906 |
| Rated "high" evidence strength in alzhub's summary | 128 |
| Rated "moderate" evidence strength in alzhub's summary | 780 |
| Rated "low" evidence strength in alzhub's summary | 1,082 |
| No evidence-strength rating | 12 |
| Records stating a participant count | 1,185 |
| Median participants (those records) | 208 |
| Largest participant count | 274,160 |
Within the 2,002 matched studies
| Studies… | Count | Rule |
|---|---|---|
| …that name p-tau217 | 549 | the abstract also contains "p-tau217" |
| …that report an AUC (area under the curve) | 341 | the abstract also contains "AUC" or "area under" |
| …set in primary care | 45 | the abstract also contains "primary care" |
The 10 highest-scoring matched studies
Title matches first, then by alzhub's usefulness score, which rates a study's design, journal, evidence and recency, not whether its result is good news.
- Alzheimer's blood-based biomarkers, incident dementia, and interactions with age, APOE status, and hormone therapy
- Diagnostic performance of plasma p-Tau217, p-Tau181, and p-Tau231 across the Alzheimer's disease continuum: a network meta-analysis
- Association of Donanemab Treatment With Exploratory Plasma Biomarkers in Early Symptomatic Alzheimer Disease: A Secondary Analysis of the TRAILBLAZER-ALZ Randomized Clinical Trial
- Assessment of Plasma Amyloid-β42/40 and Cognitive Decline Among Community-Dwelling Older Adults
- Plasma Aβ as a biomarker for predicting Aβ-PET status in Alzheimer's disease：a systematic review with meta-analysis
- Plasma p-tau217 and tau-PET predict future cognitive decline among cognitively unimpaired individuals: implications for clinical trials
- Prediction of Longitudinal Cognitive Decline in Preclinical Alzheimer Disease Using Plasma Biomarkers
- Prognostic value of plasma %p-tau217 in cognitively unimpaired older adults
- Associations between trajectories of plasma biomarkers for Alzheimer's disease, brain structures, and cognitive function: a prospective cohort study in the UK Biobank
- Plasma GFAP is an early marker of amyloid-β but not tau pathology in Alzheimer's disease
Systematic reviews and meta-analyses in the set
52 of the matched records are recorded as a systematic review, meta-analysis or umbrella review; the highest-scoring not already listed above:
- Rates of Screening for Breast, Colorectal, and Cervical Cancers in Older People With Cognitive Impairment or Dementia: A Meta-Analysis
- Kidney Function and Blood and Cerebrospinal Fluid Biomarkers in Alzheimer's Disease and Related Dementias: Systematic Review and Meta-Analysis
- Cerebrospinal Fluid Biomarkers in Cerebral Amyloid Angiopathy: New Data and Quantitative Meta-Analysis
- CSF and blood biomarkers for the diagnosis of Alzheimer's disease: a systematic review and meta-analysis
- The FDA-approved anti-amyloid-β monoclonal antibodies for the treatment of Alzheimer's disease: a systematic review and meta-analysis of randomized controlled trials
Newest matched studies
- Longitudinal plasma biomarkers and multimodal PET across APOE ε4 genotypes: a prospective cohort study
- Concurrent cognitive, behavioral and systemic physiological features mark preclinical Alzheimer's disease
- Blood-based biomarkers across the Alzheimer's disease continuum in older Korean population
- Cognition in healthy aging, ages 36 to 108: Associations with dementia risk factors and neurodegenerative disease biomarkers
- Detection of tau spatial extent using MK6240 and flortaucipir PET
Journals with the most matched studies
| Journal | Studies |
|---|---|
| Alzheimer's & dementia : the journal of the Alzheimer's Association | 233 |
| Alzheimer's research & therapy | 125 |
| Journal of Alzheimer's disease : JAD | 120 |
| Neurology | 91 |
| Alzheimer's & dementia (Amsterdam, Netherlands) | 64 |
Questions
- Can a blood test diagnose Alzheimer's?
- The tests measure brain proteins in blood and, in the studies below, agree closely with PET scans and spinal-fluid tests in many settings. A diagnosis still rests on a clinical assessment of symptoms; the test is one piece of evidence a clinician weighs.
- What does p-tau mean?
- Tau is a brain protein; in Alzheimer's it becomes abnormally phosphorylated (p-tau) and forms tangles. The number after p-tau (217, 181, 231) is the position on the protein where the phosphate is attached, and different positions behave differently as blood markers.
- How many studies on blood tests for alzheimer's does alzhub hold?
- 2,002 of the 29,380 study records in alzhub's library match the query "title or abstract mentions "blood test", "blood-based biomarker/test/assay", "plasma p-tau/biomarker/Aβ/amyloid/NfL/GFAP", "p-tau217/181/231" or "serum p-tau/biomarker/NfL/GFAP""; 764 of them name it in the title. Counted from the records when this page was built.
- What kinds of study are they?
- 52 systematic review or meta-analysis, 5 randomised controlled trials, 35 other clinical trials, 384 cohort or longitudinal studys, 18 case-control studys, 225 cross-sectional studys; 1,270 record no design.
- What is the most recent study in the set?
- "Longitudinal plasma biomarkers and multimodal PET across APOE ε4 genotypes: a prospective cohort study" (Research Square, 2026), the newest by publication date among the matched records.
- Which journals publish most on it?
- Alzheimer's & dementia : the journal of the Alzheimer's Association (233); Alzheimer's research & therapy (125); Journal of Alzheimer's disease : JAD (120), counted across the matched records.
Read on
- Blood tests for Alzheimer's: what they measure and how accurate they arealzhub's sourced evidence page, every figure tied to a paper or an FDA document.
- Biomarker accuracy tableSensitivity and specificity by test.
- p-tau217The single marker most of the newest papers focus on.