Blood Test Using p‑tau217 Biomarker Predicts Alzheimer’s Risk Up to a Decade

A multinational study of about 2,684 cognitively normal older adults from North America, Japan and Australia measured plasma p‑tau217, a protein linked to Alzheimer’s disease. Participants with the highest p‑tau217 levels had a 38% chance of developing cognitive impairment within five years and a 78% chance over ten years, compared with much lower risks for those with low levels. The findings were presented at the Alzheimer’s Association International Conference in London and published in JAMA. Researchers say the test could help identify individuals at elevated risk for use in preventive‑treatment trials and early‑intervention planning, but it is not yet recommended for routine clinical screening of asymptomatic people. Experts caution that a high‑risk result does not constitute a diagnosis and could cause anxiety without proven preventive therapies.