What to Know About the First FDA-Cleared Blood Test for Alzheimer’s Disease

Doctors say the test could help individuals who are experiencing symptoms get an earlier diagnosis

Rachel Nania,

AARP

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En español

Published May 19, 2025

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The U.S. Food and Drug Administration (FDA) has green-lit a blood test that can help doctors diagnose Alzheimer’s disease, the most common form of dementia. It is the first blood test to be cleared by the FDA for the disease, which affects more than 7 million older Americans and is marked by a decline in memory and thinking skills.

The test, called Lumipulse, can detect abnormal clumps of protein in the brain, known as amyloid plaques. These plaques disrupt brain cell function and are a hallmark of Alzheimer’s.

PET scans and spinal fluid tests can also detect amyloid plaques and have been used for years to help doctors diagnose Alzheimer’s. But the tests are expensive and, in the case of the lumbar puncture, invasive. They can also be inaccessible for people in rural areas. Lumipulse, on the other hand, requires only a blood draw in patients 55 and older who are showing signs and symptoms of the disease.

“Having a blood test just makes it so much easier in being able to make a diagnosis of Alzheimer's disease,” said Charles Bernick, M.D., a neurologist with the Cleveland Clinic Lou Ruvo Center for Brain Health, based in Las Vegas.

In its news release, the test’s manufacturer, Fujirebio Diagnostics, didn’t specify the cost of the test.

People without symptoms shouldn’t test

The newly approved blood test measures two proteins in the liquid part of the blood, known as plasma, and then calculates the ratio of these proteins, which is “correlated to the presence or absence of amyloid plaques in the patient’s brain, reducing the need for a PET scan,” the FDA said.

The test is only meant for older adults who are experiencing symptoms of Alzheimer’s disease; it is not a screening test. What’s more, the FDA said, the results should be used along with “other clinical evaluations or additional tests” to determine treatment options. In addition to brain imaging and lumbar punctures, doctors often use neurological exams and cognitive tests, for example, to diagnose a patient with Alzheimer’s disease. “It still becomes a diagnosis where you have to really look at the whole picture,” Bernick said.

In recent years, the FDA has approved two medications for the treatment of Alzheimer’s — Kisunla (donanemab) and Leqembi (lecanemab). These drugs, which are given by infusion, don’t cure the disease but can help to slow the rate of decline in people in its early stages. Because they work by clearing amyloid plaques from the brain, the presence of amyloid must be confirmed before they can be prescribed.

“They carry some risk. So if you’re going to use them or utilize them, you’ve got to be pretty sure the person has that protein in the brain,” Bernick said. Risks can include swelling and bleeding in the brain.

New test could ‘revolutionize’ research and clinical care

Some Alzheimer’s specialists have already been using blood tests not cleared by the FDA to help with a diagnosis of the disease. The FDA’s approval is not required for laboratory-developed tests such as these blood tests. Having the agency’s sign-off, however, confirms a test’s accuracy and opens the door for insurance coverage and more widespread use.

Expert groups applauded the FDA’s May 16 announcement. Howard Fillit, M.D., co-founder and chief science officer of the Alzheimer’s Drug Discovery Foundation, said that there’s been a “tremendous need” for blood tests and that having one will “revolutionize clinical care and clinical research” for Alzheimer’s.

“It’s going to reduce the cost of care and diagnosis, and it’s going to give people the opportunity to get a definitive diagnosis and enter into clinical trials,” Fillit told AARP.

“Today marks another important step in Alzheimer’s disease diagnosis,” Maria C. Carrillo, chief science officer and medical affairs lead at the Alzheimer’s Association, said in a statement. “For too long, Americans have struggled to get a simple and accurate diagnosis; with today’s action by the FDA we are hopeful it will be easier for more individuals to receive an accurate diagnosis earlier.”

Fillit predicts that we’ll see more blood tests in the near future, including tests that detect other key features of Alzheimer’s disease, such as inflammation in the brain. Having such tests could help doctors tailor a patient’s treatment as more medications come online.

“It’s kind of going to look like cancer, where patients have a tumor, there’s a biopsy of the tumor, the tumor cells are taken to the lab, they’re characterized according to various biomarkers, and then a treatment plan with various drugs in combination is designed for the patient, and the patient receives multiple drugs affecting multiple pathways in the cancer cell," Fillit said. "We’re going to have that for Alzheimer’s disease in the future. So this is just the beginning of really going into a new age of Alzheimer’s disease diagnosis and care and clinical trials.”

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