Alzheimer’s disease, which is one of the most common forms of dementia, affects millions worldwide, and early detection has long been a challenge. Early detection and intervention are key to managing symptoms and improving quality of life. What if a blood test could help you detect the disease in its earlier stages? Yes, that’s right. A recent advancement is set to change the landscape of Alzheimer’s diagnosis. Recently, the US Food and Drug Administration (FDA) approved the first blood test designed to assist doctors in diagnosing Alzheimer’s disease.
A significant breakthrough in the detection and management of the debilitating brain disorder, this is the first in vitro diagnostic device that tests blood to aid in diagnosing Alzheimer’s disease. Cleared for marketing on Wednesday, the Lumipulse G pTau217/ß-Amyloid 1-42 plasma ratio test identifies amyloid plaques, one of the key hallmarks of Alzheimer’s, in adults aged 55 and older who are experiencing signs and symptoms of cognitive decline.
“Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer combined. Knowing that 10% of people aged 65 and older have Alzheimer's, and that by 2050 that number is expected to double, I am hopeful that new medical products such as this one will help patients,” FDA Commissioner Martin A. Makary, M.D., M.P.H. said in a release.
Alzheimer’s disease is a brain disorder that slowly destroys a person’s memory and thinking skills. It is a progressive neurological disorder that causes the brain to shrink (atrophy) and brain cells to die. This disease leads to a loss of cognitive functioning, such as thinking, remembering, and reasoning, along with behavioural abilities, to the point where it disrupts a person's daily life and routines. Over time, Alzheimer’s patients lose their ability to perform simple daily tasks, such as eating or walking. Alzheimer’s disease is the most common form of dementia.
In most people with Alzheimer’s disease, the clinical symptoms appear later in life. A key sign of the disease is the buildup of amyloid plaques in the brain. These can be detected using amyloid PET scans, often years before symptoms begin. However, PET scans are expensive, time-consuming, and involve radiation exposure. That’s where the new blood test comes in.
The Lumipulse G pTau217/β-Amyloid 1-42 Plasma ratio test measures two proteins, pTau217 and β-amyloid 1-42, found in human plasma, a component of blood. It calculates a ratio linked to the presence of amyloid plaques in the brain, and slashes the need for PET scans. Unlike earlier tests that require a spinal tap to collect cerebrospinal fluid, this new test only needs a simple blood draw, making it less invasive and easier for patients.
“Nearly 7 million Americans are living with Alzheimer's disease, and this number is projected to rise to nearly 13 million. Today’s clearance is an important step for Alzheimer’s disease diagnosis, making it easier and potentially more accessible for U.S. patients earlier in the disease,” Center for Devices and Radiological Health Director Michelle Tarver, M.D., Ph.D, said.
The FDA’s decision is based on data from a multicenter clinical study involving 499 cognitively impaired adults. The results from the blood test were compared against either PET scans or CSF-based tests. According to the findings, 91.7% of participants with positive Lumipulse test results were confirmed to have amyloid plaques through PET scans or CSF tests. Meanwhile, 97.3% of those with negative results had no plaques. Fewer than 20% of participants received an indeterminate result. These results point at the reliability of the test. However, the FDA emphasized that the test is not a stand-alone diagnostic tool and should be used in conjunction with other clinical evaluations.