A new wave of blood tests could predict Alzheimer's symptoms years in advance, but experts warn about accuracy and reliability.
A study funded by the National Institutes of Health evaluated a blood test measuring p-tau217, a protein linked to Alzheimer's. In over 600 older adults, repeated tests predicted symptom onset within 3-4 years. Higher p-tau217 levels were tied to earlier symptoms.
Lead investigator Dr. Suzanne Schindler at Washington University says the models will accelerate research and clinical trials, but need validation in broader populations.
Sheena Aurora, MD, of the Alzheimer's Association, says blood tests improve diagnosis speed and accuracy when used alongside other tests. But the Association does not recommend them for people without symptoms due to limited data.
The FDA has cleared two tests: Fujirebio's Lumipulse G pTau217/β-Amyloid 1-42 and Roche's Elecsys pTau181. Still, experts warn of false positives, variable accuracy, and the need for clinical follow-up. The Alzheimer's Screening and Prevention (ASAP) Act aims to expand Medicare coverage for such tests.