Health

FDA Approves First-Ever Blood Test to Aid in Alzheimer’s Diagnosis

Published

May 16, 2025

The U.S. Food and Drug Administration has cleared a major breakthrough in Alzheimer’s detection. A new blood test could fundamentally change how the disease is diagnosed in adults showing signs of cognitive decline.

The test, developed by Fujirebio Diagnostics, is called the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio. It works by measuring the ratio of two proteins found in the blood—pTau217 and β-amyloid 1-42. These proteins are linked to amyloid plaque buildup in the brain, a hallmark of Alzheimer’s disease.

Until now, doctors have relied on costly PET scans or invasive spinal taps to confirm the presence of plaques. This new test only requires a simple blood draw. That makes it far easier for patients—especially seniors who may not tolerate more intensive procedures.

A Simpler, More Accessible Path to Diagnosis

Dr. Michelle Tarver of the FDA’s Center for Devices and Radiological Health called the test a significant step forward. “It could make Alzheimer’s diagnosis easier and more accessible for U.S. patients earlier in the disease,” she said.

FDA Commissioner Dr. Marty Makary noted the urgency of the crisis. He said Alzheimer’s affects more Americans than breast and prostate cancer combined. About 10% of people over 65 live with the disease. By 2050, that number could double. “We’re hopeful this tool will help patients,” Makary said.

In clinical trials, the Lumipulse test delivered strong results. Over 91% of people who tested positive had confirmed amyloid plaque buildup. Among those who tested negative, 97% were verified as plaque-free. Fewer than 20% received an indeterminate result.

Still, FDA officials warn the test has limits. A false positive could lead to misdiagnosis and unnecessary treatment. A false negative could delay care. That’s why this is not a screening test. Doctors must use it with other clinical evaluations.

The FDA cleared the device through its 510(k) process. It also gave the test “Breakthrough Device” designation to speed up approval. The agency said the test is substantially similar to a previously approved test that required spinal fluid instead of blood.

This development offers hope to nearly 7 million Americans currently living with Alzheimer’s—and to millions more who could face it in the years ahead.