PHOTOGRAPHY BY BAILEY SHELTON
Researchers at Washington University say they are one step closer to a blood test that can screen for Alzheimer's disease.
The team has developed a blood test that measures how much of a certain protein, amyloid-beta, is flowing through a patient's bloodstream. Knowing the protein is in the bloodstream can help them predict whether it has begun to accumulate in the brain, which, along with other risk-factors, makes people vulnerable to dementia.
When the researchers considered three risk factors together—age, genes, and the amyloid-beta protein—they could identify people with the brain changes of Alzheimer's disease 94 percent of the time. Because the clumps of protein start wreaking havoc on Alzheimer's patient's brains nearly twenty years before they show symptoms such as confusion and memory loss, this blood test could one day allow doctors that much extra time to fight the disease.
The results from the study were published Thursday in Neurology, a peer-reviewed journal. According to the study's authors, the blood test is likely a few years away from being available in doctors' offices.
There is no cure for Alzheimer's, which affects 5.5 to 6 million Americans. However, a huge advantage of this blood test is that it could identify people who might qualify to participate in clinical trials, speeding up the search for preventive treatment.
"I think this will help us get to a cure or preventative treatment," says Suzanne Schindler, one of the study's authors. "To have a good chance at developing a cure, we need a good test."
Schindler says she does not see this test being used to screen people who might develop Alzheimer's because there currently is not much doctors can do to prevent it. However, it can be used to find participants for the drug trials necessary to find those preventive treatments, and can also be used as a test to help neurologists diagnose patients with memory and thinking problems.
Currently, most drug trials use amyloid PET scans of the brain to find participants, but the scans are expensive (approximately $4,000 versus a few hundred dollars for a blood test) and time-consuming. The study found that the blood test may also pick up the Alzheimer's disease brain changes earlier than the current amyloid PET scan test.
"With a blood test, we could potentially screen thousands of people a month," says Randall Bateman, one of the study's authors. "That means we can more efficiently enroll participants in clinical trials, which will help us find treatments faster, and could have an enormous impact on the cost of the disease as well as the human suffering that goes with it.”
