Particle.news
Download on the App Store

Blood Test ‘Clock’ Predicts Onset of Alzheimer’s Symptoms Within Three to Four Years

Researchers caution it is not ready for routine screening.

Overview

  • The Nature Medicine study from Washington University analyzed longitudinal plasma p‑tau217 in 603 cognitively unimpaired adults from the Knight ADRC and ADNI cohorts to estimate age of symptom onset.
  • The predictive model performed consistently across multiple commercial p‑tau217 assays, including C2N’s PrecivityAD2 and an FDA‑cleared test, underscoring robustness across platforms.
  • Age at biomarker positivity shaped timelines to symptoms, with elevations at about 60 years preceding onset by roughly 20 years and at about 80 years by about 11 years.
  • The team released model‑development code and a web tool to enable replication and refinement, positioning the approach to speed preventive trial enrollment and timelines.
  • Authors and independent experts emphasize the need for validation in more diverse settings and note confounding medical conditions can affect results; the work was supported by the FNIH Biomarkers Consortium and includes disclosed industry ties.