FDA Approves Blood Test for Early Alzheimer’s Risk Detection Using Neutrophil Inflammation Marker

The U.S. Food and Drug Administration on May 16, 2025, approved the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio blood test for diagnosing Alzheimer’s disease in adults 55 and older showing cognitive decline. According to FDA officials, the test measures specific protein ratios in blood to detect amyloid plaques, providing a noninvasive tool to aid early identification of Alzheimer’s pathology in specialized care settings.

The Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test, developed by Fujirebio Diagnostics with contributions from Johns Hopkins University and Lund University researchers, is the first blood test cleared by the FDA to assist in diagnosing Alzheimer’s disease. The agency announced its clearance on May 16, 2025, authorizing the test for marketing as an in vitro diagnostic device. It is intended for use in adults aged 55 and older who exhibit symptoms of cognitive decline, such as memory loss, confusion, or impaired thinking, according to FDA officials.

According to published data, 91.7% of patients with positive blood test results were confirmed to have amyloid plaques through positron emission tomography (PET) scans or cerebrospinal fluid (CSF) analysis, while 97.3% of those with negative results showed no plaques on follow-up testing.

This blood test measures the plasma ratio of phosphorylated tau 217 (pTau217) to ß-Amyloid 1-42 proteins, biomarkers associated with amyloid plaque formation in the brain, a hallmark of Alzheimer’s disease. The test provides an amyloid range score indicating the likelihood of amyloid pathology but does not offer a definitive diagnosis. Results are to be interpreted alongside other clinical information in specialized care settings, including primary care and specialist clinics, as stated by the FDA. The test uses a routine blood draw, which is then processed in commercial diagnostic laboratories with electronic medical record integration, facilitating broader clinical use, Johns Hopkins’ Abhay Moghekar noted.

Clinical studies reviewed by the FDA demonstrated the test’s high specificity and accuracy. Patients with test results above the high-end cutoff have over a 90% likelihood of having Alzheimer’s amyloid pathology, officials said. This accuracy supports the test’s role as a noninvasive alternative to more costly and less accessible diagnostic tools like PET scans or spinal fluid tests.

The FDA’s Michelle Tarver, M.D., Ph.D., described the clearance as an important step toward making Alzheimer’s diagnosis easier and potentially more accessible. Ken Zaentz, president and CEO of Alzheimer’s New Jersey, called the approval a “giant step forward” in early diagnosis. The Alzheimer’s Association also welcomed the decision on the day of the announcement, highlighting the reduced invasiveness of amyloid detection with the blood test. Yale Medicine’s Sayed Azizi, M.D., Ph.D., characterized the development as a “game changer” for the field.

Nearly 7 million Americans currently live with Alzheimer’s disease, a number expected to rise to 13 million in the coming decades, according to epidemiological data cited by the FDA and Alzheimer’s organizations. The disease affects about 11% of people aged 65 and older. Early detection is considered critical as newly approved drugs such as Leqembi and Kisunla have shown the ability to slow disease progression in early stages. However, existing diagnostic methods like PET scans remain costly and are available only in select centers, limiting access for many patients.

The Lumipulse test is not recommended for general screening of asymptomatic individuals but is aimed at patients already showing signs of cognitive impairment. It is intended to help clinicians determine the need for further confirmatory tests like PET or CSF analysis. Roche’s Elecsys pTau181 plasma test, cleared in October 2025, serves a complementary role by helping primary care providers rule out amyloid pathology. Additionally, Labcorp offers an APOE-4 genetic test to assess late-onset Alzheimer’s risk in individuals over 60 to 65 years old.

The rollout of the Lumipulse test is underway, with diagnostic laboratories acquiring kits to begin processing patient samples. Mayo Clinic specialists note that while the test detects amyloid changes associated with Alzheimer’s, it should be used alongside other diagnostic tools for a comprehensive evaluation. The test’s integration with electronic medical records aims to facilitate its adoption in clinical practice, expanding access to early Alzheimer’s disease detection in symptomatic adults.