A major advancement in Alzheimer’s disease diagnosis is now available to the public, thanks to a decade-long research effort led in part by Indiana University (IU) School of Medicine. A new blood test—the first of its kind to detect Alzheimer’s-related brain changes with high accuracy—received clearance from the U.S. Food and Drug Administration (FDA) in May, offering a more accessible and less invasive alternative to traditional diagnostic methods.
Developed through collaboration between IU and leading research institutions—including the Mayo Clinic, Lund University, the University of San Francisco, and Columbia University—the test measures the ratio of two specific blood biomarkers: phosphorylated tau (pTau217) and beta-amyloid 1-42. These proteins are closely linked to the presence of amyloid plaques in the brain, a hallmark of Alzheimer’s disease. Studies found the test to be over 90% accurate, comparable to PET brain scans or cerebrospinal fluid analysis— the current gold standards in diagnosis.
“Now everybody can benefit from a more definitive diagnosis,” Jeff Dage, PhD, senior research professor of neurology at the IU School of Medicine and one of the lead scientists behind the test, told The Herald-Times. “Early detection means more rapid diagnosis and faster time to treatment.”
Until now, diagnosing Alzheimer’s has required costly and often inaccessible procedures like PET scans or lumbar punctures—tests not readily available to many patients, especially those in rural areas or without specialized insurance coverage.
The new test, now available to adults aged 55 and older who are experiencing cognitive symptoms, can be ordered by physicians. By opening up diagnostic options, it could enable earlier intervention through therapies, participation in clinical trials, or lifestyle changes aimed at slowing cognitive decline.
While the FDA approval is significant, Dage emphasizes that the work is far from over. The current version of the test is intended for use in patients already showing signs of dementia, not for broad screening of asymptomatic individuals. “A false positive could be really traumatic; that’s why the FDA says it’s to be used by people being seen by an expert,” Dage said. “For me, it’s about longitudinal testing and keeping track of how you change over time, because false positives don’t typically repeat.”
Dage’s interest in developing a blood-based biomarker is personal. After experiencing the lengthy and often ambiguous diagnostic process for his mother, who died from complications of dementia in 2019, he committed to making Alzheimer’s testing more accessible.
“While the test is a major milestone, we must continue to refine it, expand its use and ensure it reaches those who need it most,” he said. “Above all, I’m grateful to the patients and families who have participated in our research—they are the true heroes of this story.”
The research is part of a broader effort at the IU School of Medicine to lead Alzheimer’s disease innovation. Dage’s work has supported several major initiatives, including the Indiana Alzheimer’s Disease Research Center and the National Centralized Repository for Alzheimer’s Disease and Related Dementias.
Bruce Lamb, PhD, executive director of the Stark Neurosciences Research Institute at IU, says the test is a prime example of how biomarker research connects basic science and real-world treatment.
“This program has allowed us to identify and validate biomarkers of disease in animal models, identify unique biomarkers linked to therapeutic targets, characterize novel fluid biomarkers in patient populations and clinical trials, and implement biomarkers in the community,” Lamb said in a press release.
Dage’s lab is currently recruiting both cognitively healthy individuals and those with memory concerns to help further research and refine future testing.
With FDA clearance now in hand and broader availability on the horizon, researchers hope the test marks the beginning of a new era in how Alzheimer’s disease is detected and managed.
