Blood Test For Alzheimer’s Detects Signs 20 years Before Falter
A new blood test detected Alzheimer’s disease as accurately as expensive brain scans or spinal taps, raising the possibility for a new, inexpensive option to diagnose the most common form of dementia, researchers said. Researchers at the Alzheimer’s Association International Conference presented the results of multiple studies of whether a blood test could distinguish Alzheimer’s disease from other forms of dementia.
In one study published in JAMA, researchers said the blood test could could identify Alzheimer’s disease and even detected signs of disease 20 years before cognitive problems were expected in a group of people who carry a rare genetic mutation. A blood test to detect Alzheimer’s disease early could be more precise than memory and thinking tests now used to diagnose the disease. Invasive and expensive brain scans and spinal taps that measure spinal fluid are used, but insurance does not always cover those tests. Researchers reported the blood test measuring the protein tau accurately distinguished Alzheimer’s from other forms of dementia in 89% to 98% of cases.
“It is a promising blood test that seems to be highly accurate and seems to detect (Alzheimer’s) relatively early,” said Dr. Eric Reiman, a researcher in one of the studies and executive director of Banner Alzheimer’s Institute in Phoenix
But experts warned it could take a few years to validate a blood test as a reliable option for both doctors and researchers. And would patients want to know they are destined to develop memory and thinking problems if there are no reliable medications to slow the deadly disease?
Randall J. Bateman, a Washington University neurology professor and Alzheimer’s researcher, said blood tests could be useful both for patients and doctors as well scientists studying new drugs to slow the mind-robbing disease. Doctors might use the test to accurately diagnose Alzheimer’s earlier and begin treatments with existing Food and Drug Administration-approved drugs that ease symptoms, if not mental decline. But perhaps the bigger payoff would come for accelerating research for new drugs that seek to slow or halt a disease that afflicts 5.8 million older Americans. Drug companies for decades have developed therapies targeting amyloid proteins on the theory it is responsible for scuttling memory and thinking in Alzheimer’s patients. Some recent studies have sought to administer drugs targeting these proteins before memory and thinking problems emerge.