Alzheimer’s disease diagnosis is sped up by a blood test that detects proteins known to be found in the brains of AD patients.
By Yoonna Bae
Imagine slowly losing the memories that make you who you are—that’s the reality millions face with Alzheimer’s disease. Alzheimer’s disease is the most common cause of dementia, with more than 7 million Americans 65 years and older estimated to have this disease. This number is expected to double by 2060.
Early stages of Alzheimer’s disease present as symptoms of forgetting recent events or conversations. However, as the disease progresses, serious memory loss and brain function can lead to inability to complete everyday tasks, dehydration, poor nutrition, infection, and potential death from complications. Although the exact causes aren’t known, risk factors include older age, family history, genetics, lifestyle factors, and environmental factors.
Currently, diagnosis of Alzheimer’s disease involves mental and neuropsychological tests, review of medical history, lab tests, and brain imaging tests.
Fujirebio Diagnostics, Inc., an R&D driven company that develops new technologies and unique biomarkers, has developed a blood test to help diagnose Alzheimer’s disease. The Lumipulse® pTau-217/Beta Amyloid 42 Ratio is the first blood-based test to be approved by the FDA for this purpose. The FDA approved this test on May 16, 2025, through its Breakthrough Device designation. Labcorp announced on August 18, 2025, the availability of the test at all Labcorp locations in the United States.
How does this test work?
The design behind this test is to use a simple blood draw from patients to detect two proteins, pTau217 and β-amyloid 1-42. This is then used to determine the presence of amyloid plaques, which is a key feature in the brains of people with Alzheimer’s disease. These amyloid plaques are abnormal clumps of proteins that disrupt the normal functioning of brain cells.
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Who can take this test?
The FDA has approved this test for early detection of amyloid plaques in patients aged 50 years and older, in a specialized care setting, presenting with signs and symptoms of Alzheimer’s disease.
The Alzheimer’s Association has also released a guideline supporting the use of this type of blood-based biomarker test. Currently, other existing blood-based biomarker tests that detect the pTau217 protein using immunoassay technologies include the Lilly assay, S-PLEX, Simoa, and Elecsys prototype.
What are the risks of this test compared to other testing?
The risks of the Lumipulse® pTau-217/Beta Amyloid 42 Ratio test are mainly false positive and false negative results, and the resulting unnecessary treatment or delay in treatment. This risk is similar for the other existing blood-based biomarker tests. The Alzheimer’s Association’s guideline also warns that there is significant variability in diagnostic test accuracy between the existing tests.
The researchers behind the Lumipulse® pTau-217/Beta Amyloid 42 Ratio test intend for it to be accurate, minimally invasive, and accessible. This test may reduce the need for PET scans or collection of cerebrospinal fluid, which are other methods that accurately determine the presence of amyloid plaques. Collection of cerebrospinal fluid is via lumbar puncture (spinal tap), which is invasive and can be painful. PET scans are time-consuming, costly, and expose patients to radiation. The Lumipulse® pTau-217/Beta Amyloid 42 Ratio test was found to be comparable to PET scans and cerebrospinal fluid tests in detecting the presence of amyloid plaques.
What does this mean for Alzheimer’s patients?
The diagnosis of Alzheimer’s will still need the evaluation of other patient information in addition to the results of this new test. However, this new test could lead to better accessibility and earlier diagnosis for patients presenting with early symptoms of Alzheimer’s. A prompt and accurate diagnosis is important to get the appropriate treatment and care. Doctors need to rule out other potential health conditions causing symptoms such as past strokes, Parkinson’s disease, depression, and sleep apnea.
Although there is currently no cure for Alzheimer’s disease, most existing medicines that target the disease symptoms have better responses with earlier stages of Alzheimer’s. Early treatment can help to slow down progression of the disease. Early diagnosis can also help people with Alzheimer’s to plan, develop support networks, and look for opportunities to participate in research studies to help test new Alzheimer’s therapies.
References
National Institute on Aging. (2025, March 4). What is Alzheimer’s Disease. U.S. Department of Health and Human Services, National Institutes of Health. https://www.nia.nih.gov/health/alzheimers-and-dementia/what-alzheimers-disease
Mayo Clinic. (2024, March 13). Diagnosing Alzheimer’s: How Alzheimer’s is diagnosed. https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/in-depth/alzheimers/art-20048075
Mayo Clinic. (2024, November 8). Alzheimer’s Disease. https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/symptoms-causes/syc-20350447
Palmqvist, S., Whitson, H. E., Allen, L. A., Suarez‐Calvet, M., Galasko, D., Karikari, T. K., Okrahvi, H. R., et al. (2025). Alzheimer’s Association Clinical Practice Guideline on the use of blood‐based biomarkers in the diagnostic workup of suspected Alzheimer’s disease within specialized care settings. Alzheimer’s & Dementia, 21(7). https://doi.org/10.1002/alz.70535
About the Author
Yoonna Bae is a clinical research associate with an interest in medical writing. She has obtained a Masters of Pharmaceutical Medicine from the University of New South Wales, and she is currently based in Seattle, WA.
