Overview
- The Nature Medicine study validated dried blood spot sampling in 337 participants across sites in Spain, Sweden, the United Kingdom, Italy and the United States.
- Finger-prick samples measuring p‑tau217, along with GFAP and NfL, closely matched standard blood assays and identified cerebrospinal‑fluid‑defined Alzheimer’s changes with about 86% accuracy.
- Conventional venous plasma testing remained more accurate, with reported predictive performance near 98% for the same pathology classification.
- One site demonstrated successful participant self‑collection, and the cards can be mailed without refrigeration, supporting inclusion of remote and underserved groups such as people with Down syndrome.
- Study authors and independent neurologists caution the approach is not ready for routine clinical or direct‑to‑consumer use and requires further standardization and larger validation.