The presence of amyloid plaques and neurofibrillary tangles in the brain has long been considered the biological sign or biomarkers of Alzheimer’s disease. Plaques form as a result of amyloid-beta protein clumping and depositing outside of the neurons in the brain while neurofibrillary tangles are twisted fibers of tau protein that accumulate inside neurons.
Up until now, these proteins could be detected and measured using an expensive and not readily accessible imaging technique called Positron Emission Tomography (PET) Scan or by an invasive lumbar puncture to analyze cerebrospinal fluid.
In a significant step forward, last week, the US Food and Drug Administration (FDA) approved the first blood test to help in the diagnosis of Alzheimer’s disease. The test is called the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test as it measures the presence of these two proteins in the bloodstream. A numerical ratio from the results can then determine the presence or absence of plaques in the brain. While there are other blood tests on the market, Lumipulse is the only one that now has FDA approval.
The Lumipulse blood test offers the first noninvasive method to evaluate individuals showing signs of cognitive decline. It is approved for the early detection of amyloid plaques associated with Alzheimer’s disease in individuals 55 and older who are exhibiting signs and symptoms of cognitive decline. The accuracy of the approved blood test was demonstrated in a clinical study, where 91.7% of individuals with a positive result had the presence of amyloid plaque confirmed by a follow up PET scan or spinal fluid test. At the same time, 97.3% of those who had negative results via the blood test were also cleared through further investigation.
“The FDA approval of a noninvasive blood test that can be more readily available and cost effective is a giant step forward in the ability to help diagnose Alzheimer’s disease earlier,” said Ken Zaentz, President and CEO of Alzheimer’s New Jersey®. “This is especially significant when we now have disease modifying treatments like Leqembi® and Kisunla™ that that have been shown to improve cognition in those with MCI and early-stage Alzheimer’s disease. The blood test can help determine who is most likely to benefit from these drugs. At the same time, it is important that the blood test be used appropriately as one tool in a physician’s complete diagnostic process. The blood test is not meant to be a standalone test and it is not approved for use unless the individual has symptoms of cognitive impairment,” said Zaentz.
While this blood test represents a hopeful step forward in Alzheimer’s diagnosis, the blood test is new. There will be continued research, monitoring, and data collection to determine its long-term impact and appropriate use.
If you are concerned about changes in memory and thinking, or changes in behavior, mood or movement that do not seem normal, talk to your doctor.
Questions? Call the Alzheimer’s New Jersey® Helpline at 888 280-6055.
