FDA Approves First Blood Test To Help Diagnose Alzheimer's
- Lidi Garcia
- Jun 5
- 3 min read
The FDA has approved the first blood test to help identify early signs of Alzheimer's. The test measures two proteins in the blood that indicate the presence of plaques in the brain, one of the main signs of the disease. It is a simpler, faster and less invasive alternative to current tests, such as CT scans or spinal taps. Although it is not definitive, the test can facilitate early diagnosis and the start of treatment.
The agency that regulates drugs and medical devices in the United States, the FDA (Food and Drug Administration), has approved for the first time a blood test that can help diagnose Alzheimer's disease.
Being approved by the FDA means that the product has undergone rigorous scientific and clinical evaluation in the United States and has been deemed safe and effective for its indicated use.
This innovative test, called Lumipulse G pTau217/ß-Amyloid 1-42, can identify early signs of the disease in people aged 55 or older who are already showing symptoms of memory loss or mental confusion.
Alzheimer's is a disease that affects the brain and gradually causes a person to lose their ability to remember, think and perform daily tasks. It is more common in the elderly, and is estimated to affect around 10% of people aged 65 or over.
Since it is a disease that worsens over time, the earlier it is detected, the better the chance of planning treatment and care.
Until now, the most reliable method for detecting early signs of the disease involved expensive tests, such as positron emission tomography (PET) or the collection of spinal fluid (cerebrospinal fluid), an invasive procedure called a lumbar puncture.
These methods, although effective, are difficult to perform on a large scale, as they involve high costs, discomfort and risks to patients. The new blood test offers a much simpler and more accessible alternative, with a common blood collection done in a laboratory.
This test works by measuring the amount of two proteins in the blood: pTau217 and beta-amyloid 1-42. Alzheimer's is strongly associated with the accumulation of beta-amyloid plaques in the brain, which appear years before symptoms.
The proportion of these two proteins in the blood can indicate whether or not there are these plaques in the person's brain. In other words, the test can “predict” what is happening in the brain without needing to see it directly.
Clinical tests carried out with almost 500 people showed that the test has good accuracy. More than 91% of the people who tested positive on the test actually had Alzheimer's plaques confirmed by more advanced tests, such as PET. And almost 97% of those who tested negative were also free of plaques. Less than 20% of the participants had an indeterminate result, that is, inconclusive.
Despite being a major breakthrough, the test does not completely replace other diagnostic methods. It is a tool that helps doctors better assess patients' symptoms, but the results must be analyzed together with other clinical data, such as memory tests and medical history.
However, this does not mean that it is already available in pharmacies or for immediate use by the general public. After approval, the company responsible still needs to organize production, distribution and, often, negotiate with laboratories, clinics or health systems so that the test can be offered.
In addition, in other countries such as Brazil or the European Union, the test would also need to be evaluated by Anvisa or EMA before being marketed. In addition, like all medical tests, there is a small risk of errors.
A false-positive result (saying that Alzheimer's is present when there is not) can lead to unnecessary treatments and anxiety. A false-negative result can delay the correct diagnosis and the start of treatment.
The FDA evaluated this test through a special process that accelerates the release of devices considered innovative and promising in the treatment of serious diseases. The company responsible for the test is Fujirebio Diagnostics, Inc., which had already developed another similar test, but which required the collection of fluid from the spinal cord.
With this approval, the diagnosis of Alzheimer's could become simpler, less invasive and more accessible, especially for those in the early stages of the disease. This change represents an important step towards earlier and more effective detection, which can significantly improve the quality of life of patients and their families.
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FDA NEWS RELEASE
May 16, 2025
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