Highly accurate blood test for Alzheimer's disease is similar or superior to clinical cerebrospinal fluid tests

This study evaluated a precise blood test using plasma %p-tau217 (ratio of phosphorylated-tau217 to non-phosphorylated tau) against established cerebrospinal fluid (CSF) tests in detecting Alzheimer's disease (AD) pathology. In two cohorts (BioFINDER-2, n = 1,422; Knight ADRC, n = 337), plasma %p-tau217 showed clinically equivalent or superior performance to FDA-approved CSF tests in classifying amyloid-β (Aβ) and tau pathology using PET imaging as the reference standard, particularly in cognitively impaired individuals. The blood test demonstrated high accuracy (89–90% for Aβ PET, 87–88% for tau PET), improving to 95% with a two-cutoff approach. This suggests a potential for replacing CSF tests and enhancing AD diagnosis and treatment access.

Nicolas R. Barthélemy, Gemma Salvadó, Suzanne E. Schindler, Yingxin He, Shorena Janelidze, Lyduine E. Collij, Benjamin Saef, Rachel L. Henson, Charles D. Chen, Brian A. Gordon, Yan Li, Renaud La Joie, Tammie L. S. Benzinger, John C. Morris, Niklas Mattsson-Carlgren, Sebastian Palmqvist, Rik Ossenkoppele, Gil D. Rabinovici, Erik Stomrud, Randall J. Bateman, Oskar Hansson