New research shows that certain blood tests can match expensive brain scans in identifying Alzheimer’s disease pathology. 🩸🧪
Published In: Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring
Date: January 2026
Authors: Wang, et al.
Link to Study: https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/dad2.70196
Summary
This study examined whether blood-based biomarkers can reliably identify Alzheimer’s disease (AD) pathology compared to amyloid PET brain scans, which are currently a standard diagnostic tool. Researchers analyzed over 500 adults with mild cognitive impairment or mild dementia and compared two blood tests (PrecivityAD® and plasma p-Tau217) with PET imaging results. Both blood tests showed strong agreement with PET scans and were statistically “non-inferior,” meaning they performed similarly in identifying people with amyloid buildup in the brain. These findings suggest that blood tests could serve as a simpler, more accessible alternative to brain scans for identifying patients who may benefit from new amyloid-targeting treatments.
Key Takeaways
✅ Two blood tests showed high agreement (81–90%) with amyloid PET brain scans.
✅ The p-Tau217 blood test correctly identified Alzheimer’s-related brain changes in about 88% of positive cases.
âś… Both blood tests performed nearly as well as PET scans used in clinical trials.
✅ Blood testing could help “rule in” Alzheimer’s pathology without requiring expensive imaging.
✅ Some results were labeled “intermediate” or “indeterminate,” meaning follow-up testing may still be needed in certain cases.
Why It Matters for You
Brain scans for Alzheimer’s are expensive, not always covered by insurance, and not widely available. Reliable blood tests could make it easier, faster, and more affordable to detect Alzheimer’s pathology—especially for people in the early stages of memory decline.
Citation
Wang, J., et al. (2026). Interchangeability of blood-based biomarkers and PET to identify Alzheimer’s disease pathology. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, 18, e70196. https://doi.org/10.1002/dad2.7019