Study Shows Dual Biomarkers Improve Accuracy of Alzheimer’s Detection

Alzheimer’s disease develops slowly, and biological changes can appear in blood many years before symptoms. While plasma assays for phosphorylated tau offer earlier detection, discerning whether these changes explain a patient’s cognitive complaints remains a challenge. Overcalling disease in symptomatic populations risks false-positive results. Researchers now report that combining two plasma tau markers can improve identification of established Alzheimer’s disease in individuals evaluated for cognitive impairment.

Lund University (Lund, Sweden), in collaboration with Washington University (St. Louis, MO, USA), assessed the integration of plasma eMTBR-tau243 with phosphorylated tau 217 (p-tau217) to refine diagnosis. The approach targets a tau marker linked to a later stage of disease and pairs it with an established early-change indicator. The new marker currently requires analysis using advanced techniques such as mass spectrometry.

Image: New findings show that combining blood markers ehances both detection and staging of Alzheimer’s Disease (photo courtesy of Adobe Stock)

In the prospective BioFinder2 cohort, 572 individuals sought medical care for cognitive impairment. Among 350 participants with high p-tau217 measured using advanced techniques, 341 (97%) also had amyloid in the brain, yet only 199 had already developed Alzheimer’s disease. Within this group, 43% of those with high p-tau217 represented false-positive results relative to diagnostic criteria.

Adding eMTBR-tau243 clarified disease status. Of participants positive for p-tau217, 194 (55%) also had elevated eMTBR-tau243; combining both markers identified individuals with established Alzheimer’s disease with approximately 80% accuracy and reduced the false-positive rate from 43% to 16%. The findings were validated in a second cohort of American participants with similar cognitive difficulties.

Participants positive for both biomarkers experienced faster cognitive decline over time and showed increasing tau accumulation in the brain. The study was published on March 18, 2026, in The Lancet Neurology and involved researchers at Lund University with collaborators at Washington University. The team indicated that next steps include evaluating whether the test can be simplified for wider use.

“By combining blood markers, we can better identify which people have Alzheimer’s disease and which of them have such an advanced stage of the disease that it leads to symptoms,” said Niklas Mattsson-Carlgren, associate professor at Lund University and consultant at Skåne University Hospital. “The new marker still requires analysis using advanced techniques such as mass spectrometry. The next step is to investigate whether the test can be simplified, and whether it can be used more widely, in primary care, for example.”

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