European scientists have developed a preliminary method to identify Alzheimer's using a drop of dried blood from a finger, achieving 86% accuracy in detecting amyloid pathology. The study, validated in 337 patients from several countries, is published in Nature Medicine and aims to simplify early diagnosis of this disease affecting over 50 million people worldwide.
A team of scientists from Europe and North America has refined a test that detects Alzheimer's from dried capillary blood obtained via a simple finger prick. Validated in 337 patients with and without dementia symptoms at centers in Barcelona, Sweden, the UK, and Italy, it quantifies proteins such as p-tau217, GFAP, and NfL. The test identifies amyloid pathology, a key indicator of the disease, with 86% accuracy.
Unlike current methods requiring invasive lumbar punctures or costly PET scans, this approach uses just a drop of blood dried on filter paper, needing no refrigeration or complex equipment. Existing blood tests detect p-tau217 with over 90% accuracy, but this system eases collection in remote areas or even at home.
Xavier Morató, neuroscientist at the Alzheimer's Center Ace in Barcelona and co-author of the study, states: “This method could accelerate the identification of people at risk of Alzheimer's, streamlining their referral to specialized memory units.” He emphasizes the goal of “democratizing access to early diagnosis.”
Alzheimer's, incurable and progressing silently for decades, affects over 50 million people worldwide. Spain's Neurological Society estimates over 50% of mild cases go undiagnosed, with a two-to-three-year delay between symptoms and confirmation. New drugs delay progression by about 18 months if applied early.
Independent experts provide balanced views. Raquel Sánchez Valle from Barcelona's Hospital Clínic sees it as simplifying large-scale research but advises against current clinical use or population screening without medical oversight, warning of risks from direct-to-consumer commercialization. David Pérez, neurologist at Madrid's Hospital 12 de Octubre, calls it “interesting” for quickly ruling out healthy individuals, though he notes its lower sensitivity compared to venous blood and the need for technical refinements before widespread clinical application.
