A new blood test accurately identifies many people at risk for Alzheimer's disease, researchers reported Thursday. Photo by PublicDomainPictures
Nov. 11 (UPI) -- A new blood test may be more than 80% accurate at identifying people at risk for developing Alzheimer's disease, a study presented Thursday during the Clinical Trials on Alzheimer's Disease conference in Boston found.
The test, called PrecivityAD and manufactured by St.Louis-based diagnostic company C2N, identifies those with elevated levels of the protein amyloid in the brain, the researchers said.
In people in the early stages of Alzheimer's disease, this protein accumulates in clusters in the brain called plaques, disrupting cognitive function.
These plaques, which form before the signs and symptoms of Alzheimer's disease appear, typically are identified through positron emission tomography, or PET, imaging scans of the brain.
However, study data showed the PrecivityAD test can accurately predict levels of amyloid plaques people will have on PET scans 81% of the time, which researchers say may lead to earlier diagnosis of Alzheimer's disease.
"Blood-based screening is a giant leap forward in detecting changes in the brain among people who do not yet show memory loss symptoms," study co-author Dr. Reisa Sperling said in a press release.
"[It] can help identify those more likely to have Alzheimer's disease changes in their brains, which enables them to enroll in prevention or treatment trials as early as possible," said Sperling, director of the Center for Alzheimer Research and Treatment at Brigham and Women's Hospital in Boston.
About 6 million people in the United States have been diagnosed with Alzheimer's disease, making it the most common form of dementia, the Alzheimer's Association estimates.
In addition to memory loss, the disease, which can strike at a younger age and progress more slowly than other dementias, also can cause problems that include speaking and behavioral changes.
PrecivityAD is one of several blood test-based diagnostic technologies being evaluated for Alzheimer's disease, according to the association.
Others include Simoa, made by Quanterix, and Cassava Sciences' SavaDx, both of which measure blood levels of phospho-tau181, another protein that contributes to the development of Alzheimer's disease, according to the National Institutes of Health.
"There is an urgent need for simple, inexpensive, non-invasive and easily available diagnostic tools for Alzheimer's," Maria C. Carrillo, the Alzheimer's Association chief science officer, told UPI in an email.
"In addition to improving diagnosis, new testing technologies could potentially support Alzheimer's drug development in many ways -- for example, by helping identify the right people for clinical trials and by tracking the impact of therapies being tested," she said.
They also would produce results faster, and be less expensive than PET scans, which are the "gold standard" in Alzheimer's diagnosis, Carrillo said.
Based on the results of the study presented Thursday, PrecivityAD will be used in a National Institutes of Health-funded clinical trial called AHEAD, which seeks to identify ways to prevent Alzheimer's symptoms, the researchers said.
The study, being conducted at 75 research centers across North America, is enrolling 1,165 participants as young as age 55 years, they said.
For the study, PrecivityAD will be used to identify participants at risk for Alzheimer's, based on elevated amyloid levels.
Screening blood tests should greatly speed up clinical trial enrollment, which often is a long, expensive process, the researchers said.
This would potentially lower barriers to participating in clinical trials, especially among communities of color, which historically are underrepresented in Alzheimer's trials, they said.
"This is a remarkable achievement that may lead to detecting and treating Alzheimer's much earlier, and hopefully one day, preventing the memory loss associated with this devastating disease," said Sperling, who also is co-principal investigator for the AHEAD Study.
"We also hope that this new test will make it easier for people from diverse backgrounds, especially people of color, to learn if they might be right for the study by starting with this simple blood test," she said.
Such large, long-term studies of the testing technology in diverse populations are desperately needed, Carrillo said.
"The possibility of early detection and being able to intervene with a treatment before significant damage to the brain from Alzheimer's disease would be game changing for individuals, families and our healthcare system," she said.
"A well-tested and verified blood test, for example, will enable interpretation and understanding of Alzheimer's progression in much larger, more diverse and more robust populations."