ST. LOUIS — Blood samples may forewarn one’s risk of developing Alzheimer’s years in advance, a new study finds.
Researchers at the Washington University School of Medicine in St. Louis studied 41 elderly individuals, aged 60 or older, by drawing 20 blood samples from each individual over a 24-hour period.
The blood samples were intended to demonstrate whether an individual had high levels of a protein called “amyloid beta” in their bloodstream, which is linked to the development and progression of Alzheimer’s.
Prior to this research, there were only two known methods for testing the prevalence of amyloid beta: spinal taps, which are invasive, and PET scanning, which is expensive and not widely available.
“Our results demonstrate that this amyloid beta blood test can detect if amyloid has begun accumulating in the brain,” says Dr. Randall J. Bateman, the study’s senior author, in a news release. “This is exciting because it could be the basis for a rapid and inexpensive blood screening test to identify people at high risk of developing Alzheimer’s disease.”
While amyloid beta is naturally occurring, it can cause neurological problems when it binds itself to neurons.
Interestingly, previous research had been unable to find a firm correlation between amyloid beta levels in blood and the brain.
In the blood samples collected, the researchers analyzed the composition of three particular subtypes of amyloid beta in the bloodstream, and were finally able to find a formula that predicted the protein’s prevalence in the brain with 89 percent accuracy.
“Our method is very sensitive, and particularly when you have many repeated samples as in this study — more than 500 samples overall — we can be highly confident that the difference is real. Even a single sample can distinguish who has amyloid plaques,” explains Bateman.
The other major predictor of Alzheimer’s is the tangling of tau, which are brain proteins.
“If we had a blood test for tau as well, we could combine them to get an even better idea of who is most at risk of developing Alzheimer’s disease,” says Bateman. “That would be a huge step forward in our ability to predict, and maybe even prevent, Alzheimer’s disease.”
The study’s findings were published in the journal Alzheimer’s and Dementia.