First FDA-Approved Blood Test for Alzheimer’s Diagnosis
On May 16, 2025, the U.S. Food and Drug Administration (FDA) approved a new test that may change how Alzheimer's disease is diagnosed — the Lumipulse G pTau217/β-Amyloid 1-42 Plasma Ratio test. It’s the first blood-based test approved to aid in detecting Alzheimer’s in people showing symptoms.
What Does the Test Do?
This new blood test looks at two proteins in your blood—pTau217 and β-amyloid 1-42 — which are linked to the changes in the brain seen in Alzheimer’s disease. The test calculates the ratio between them. If the ratio is high, it may indicate the presence of amyloid plaques, one of the hallmarks of Alzheimer’s.
Why Is This a Big Deal?
Until now, confirming amyloid plaques required expensive PET scans or an invasive spinal tap to test cerebrospinal fluid — procedures that aren’t always accessible, especially in rural or smaller clinics. This new test only requires a blood draw, making it:
- Less invasive
- More accessible
- Potentially more affordable
Studies show that this test demonstrates high accuracy, with sensitivity and specificity >90%, making it comparable to established PET imaging and cerebrospinal fluid (spinal tap) methods for detecting Alzheimer’s-related amyloid pathology.
Who Is This Test For?
The test is approved for adults aged 55 and older who are showing signs of cognitive decline. It’s not meant for screening people who don’t have symptoms and doesn’t provide a diagnosis on its own. Instead, it’s used alongside other tools — like memory testing, brain scans, and medical history—to help guide next steps.
What Are the Benefits?
- Earlier Detection: It may detect brain changes years before symptoms become severe.
- Fewer Invasive Tests: Could reduce the need for spinal taps and exposure to radiation.
- Faster Answers: May help people get clarity and support sooner.
- Better Planning: Enables healthcare providers and families to make more informed decisions about care and treatment options.
Are There Any Limitations?
Yes — here are a few important things to keep in mind:
- The test is not for people under 55, even if they’re showing symptoms.
- It’s not a replacement for a full medical work-up.
- False positives or negatives are possible (like with any medical test).
- Amyloid plaques can be present in other conditions, not just Alzheimer’s.
- Smaller or less specialized clinics may lack the necessary instrumentation and would need to invest in additional equipment to offer it.
- More research is needed to confirm how well the test performs in people of different backgrounds and health conditions.
What About Insurance Coverage?
Now that there’s FDA approval for the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test, insurance coverage is expected to follow—but it hasn’t happened just yet. As of May 2025, there is no official confirmation that Medicare or private insurers have begun covering the test. Until formal coverage policies are announced, patients may still face out-of-pocket costs, but broader access is likely on the horizon.
If you or someone you care about is noticing memory changes, talk to your healthcare provider. The Lumipulse blood test may be a helpful option to consider as part of a full evaluation.
While it’s not a cure, it is progress. And for many caregivers and families, progress — especially when it comes to early detection and planning — can make a meaningful difference.
Note: This article is for informational purposes only and should not replace medical advice from a qualified healthcare provider.
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