What to Know About New FDA-Approved Blood Tests for Diagnosing Alzheimer’s

Until recently, diagnosing Alzheimer’s in someone who is showing signs of memory loss or thinking difficulties often meant undergoing a brain scan (a PET scan) or a lumbar puncture (spinal tap) to look for signs of amyloid or tau changes in the brain. These procedures can be expensive, invasive, or not easy to access. Now, the U.S. Food & Drug Administration (FDA) has cleared the first blood-test for Alzheimer’s disease — the Lumipulse G pTau217/β‑Amyloid 1‑42 Plasma Ratio developed by Fujirebio Diagnostics, Inc..  

What this means: for adults age 55 or older who are already showing signs of cognitive decline, a simple blood draw can now help the doctor determine whether Alzheimer’s pathology (specifically amyloid plaques) is likely present — as part of the overall evaluation.  

It’s important to know: this test is not designed for general screening of healthy people, and a “positive” result still needs to be considered alongside symptoms, other exams, and possibly further testing. 

The Lumipulse blood test measures two specific proteins in the plasma (the liquid part of blood): a form of tau (pTau217) and a form of amyloid-beta (β-amyloid 1-42). It calculates a ratio of these two proteins, and that ratio correlates with whether amyloid plaques are present in the brain.  

For residents, family members, and care-teams, this kind of blood test has several practical advantages:

• It is less invasive: just a blood draw, instead of lumbar puncture or complex PET scan.  
• It may be more accessible and timely, so issues can be identified earlier.  
• Earlier detection may help doctors and families plan interventions or support services sooner — even though there is no cure yet, some treatments may work better earlier, and non-drug strategies (like lifestyle changes, supportive care) can start sooner.

At the same time, it’s vital to keep realistic expectations: this test does not diagnose Alzheimer’s definitively by itself; it’s one piece of a larger diagnostic process. Also, currently it’s meant for people already showing signs of cognitive decline, not for routine screening of healthy older adults. 

To learn more about the new FDA-approved blood tests for diagnosing Alzheimer’s, from the Mayo Clinic, CLICK HERE.