Simple Dual-Tau Blood Test Detects and Stages Alzheimer’s Disease

Alzheimer’s disease is typically confirmed and staged with positron emission tomography scans and cerebrospinal fluid testing, procedures that are costly and invasive. Broader access to minimally invasive biomarkers could speed evaluation and follow-up while reducing patient burden. Blood-based measures that mirror brain pathology are therefore a priority for clinical adoption. A new study shows a two-tau protein blood model may detect Alzheimer’s disease and estimate stage with accuracy comparable to imaging.

In the study published in JAMA Neurology, researchers detail a simple blood-based model that measures two forms of tau protein to detect and stage Alzheimer’s disease. The approach is intended to track disease progression using circulating biomarkers rather than neuroimaging or cerebrospinal fluid sampling. By focusing on tau species associated with neurodegeneration, the model seeks to align blood-based signals with established biological staging frameworks.

The investigators tested the model in more than 1,000 individuals spanning the Alzheimer’s disease spectrum. Participants included cognitively unimpaired people, patients with mild cognitive impairment, those with Alzheimer’s dementia, and individuals with other neurodegenerative diseases. This design was used to evaluate both case detection and staging performance across clinically relevant cohorts.

Staging derived from the blood model closely matched the accuracy of positron emission tomography (PET) brain scans. According to the article, the findings suggest potential utility for assigning disease stage in routine settings when imaging or lumbar puncture is impractical. The study was published on May 26, 2026 in JAMA Neurology. The authors note that larger and more diverse populations will be important to confirm performance. An external clinical reviewer at Northwell Lenox Hill Hospital in New York City commented on potential downstream clinical benefits but emphasized the need for additional validation. 

“If the data hold up in bigger studies, … I think it can really dramatically expand access to biological Alzheimer’s testing, which is a big deal,” said Dr. Randy D’Amico, director of the Brain and Spine Metastasis Program of Neurosurgery at Northwell Lenox Hill Hospital in New York City. “And with better staging, that means you can better select targets for therapies … and you might actually be able to prevent irreversible brain damage or at least expect better outcomes.”