Alzheimer’s Early Diagnosis Blood Tests
Detecting Alzheimer’s early involves extensive testing, including brain imaging and spinal fluid tests, which can be invasive, expensive, and not readily available for the millions of people who need testing. Thankfully, new ways of testing for the disease are being developed, including a simple blood test. Med-testing giant Quest Diagnostics has recently launched one of these diagnosis blood tests, allowing patients at risk to be screened for Alzheimer’s years before symptoms appear. The test, called QUEST AD-Detect Amyloid Beta 42/40 Ratio, works by identifying specific biomarkers in blood and measuring the ratio between the two peptides of amyloid-beta. The comparison shows whether the amyloid-beta is leaving the blood and likely starting to form plaques in the brain, which is an early indication of Alzheimer’s.
Due to the comparison required for the test, patients will most likely need to take multiple tests, and research scientists are currently seeking to identify the best intervals for these tests and how the test performs with other conditions, such as diabetes and hypertension. The time between these positive blood tests and the first onset of Alzheimer’s symptoms is also being researched. Dr. Michael K. Racke, a neurology medical director for Quest, says “more research could help persuade clinical trial sponsors that blood tests alone are enough to screen patients,” as many therapies for the disease require costly tests for patients, such as PET scans. “No one yet will say that the blood test by itself is good enough. They want to see more data,” Racke states.
Having the ability to test for Alzheimer’s before symptoms onset gives patients a better chance of being a candidate for testing new therapies, as most enrolled patients in earlier trials were already symptomatic, making them less likely to benefit from any treatment. Past treatments have sucked the amyloids from the brain, Racke explains, but the damage is already done to patients with symptoms, resulting in failed trials. The blood test will also assist with more research projects. As Racke recalled, “The Alzheimer’s Clinical Trial Consortium was looking at approximately 40,000 people who were interested in being evaluated, but only about 300 were able and willing to come into an Alzheimer’s disease research center.” With the new blood tests, patients can go to one of the 2,000 Quest Patient Service Centers in the U.S. and have the test performed there, making it simple due to close proximity. “Then, if they are found to be at risk, they are more likely to make the trip to a major medical center.”
More companies, other than Quest Diagnostics, are also exploring the use of blood tests for early diagnosing of Alzheimer’s, such as C2N Diagnostics, a St. Louis-based Company. This company has a test called PrecivityAD, which also analyzes peptides in amyloid-beta. Other companies, like Merck and digital health startup Evidation, are using digital tools for research to test if smartphone data can assist in Alzheimer’s drug development. Regardless of competition in this market, patients will be happy to welcome these new, less invasive tests. A poll sent out by Quest Diagnostics showed that 86% of adults have some fear of learning they may develop Alzheimer’s, and 83% say they would take a blood test if the results helped researchers develop an effective treatment.
June is Alzheimer’s and Brain Awareness Month, which is an opportunity to learn more about the disease, show support for the millions worldwide living with it, and learn about the long road to finding a successful cure.
