Researchers at Georgetown University announced the discovery of a blood test that can predict whether a person will develop Alzheimer’s disease or a related condition within three years.
Their study, described Sunday in the journal Nature Medicine, identifies 10 lipids in the blood that predict onset of the disease. Researchers tested the blood of 525 people age 70 and older over five years, 74 of whom either began the study meeting the criteria or later developed the criteria for mild Alzheimer’s disease or a memory loss condition known as amnestic mild cognitive impairment that is often a precursor to Alzheimer’s. Among those who developed the disease, the researchers discovered the presence of 10 lipids that were abnormal and that predicted with more than 90 percent accuracy the onset of the disease.
They plan to expand the study by looking at larger longitudinal studies to see whether these lipids were present in the blood of patients in those studies who later developed the disease, said Howard J. Federoff, professor of neurology and executive vice president for health sciences at Georgetown University Medical Center, who led the study. If so, he said, they would move on to clinical trials.
“We want to look back on when they were asymptomatic and see if these lipids were present,” he said, adding that a larger study would offer greater range in terms of patients’ age and racial diversity.
There is no cure or effective treatment for Alzheimer’s disease, which afflicts more than 5 million Americans and 35.6 million people worldwide. The Centers for Disease Control and Prevention lists Alzheimer’s as the sixth-leading cause of death, but recent research ranks it as the third-biggest killer in the United States. The numbers of those affected are expected to nearly triple by 2050 if there are no significant medical breakthroughs.
A large field of research is currently looking at indicators for Alzheimer’s in blood and cerebral spinal fluid. It would probably be several years before a test for the lipids identified in this study could be ordered by a physician.
“Developing tests that ultimately become ones that your doctor can order is not a straightforward process,” Federoff said, noting that some patients may ultimately prefer not to know they are likely to develop the disease because there is no treatment.
But the presence of such a test could help researchers identify people at high risk and design a clinical trial to determine whether a drug could delay or prevent the onset of symptoms, he said.
Heather Snyder, director of medical and scientific operations for the Alzheimer’s Association, called the Georgetown test intriguing, but cautioned that it was preliminary.
“It would need to be further developed,” she said. Snyder added that even without available treatments, such a test could allow patients to “plan their care future, their financial future, to communicate with caregivers and friends, and to participate in a clinical trial as a chance to change the future for others with Alzheimer’s disease.”
Research on indicators in cerebral spinal fluid, while further along in development than blood tests, are also still not ready for widespread diagnosis or prediction of the disease, Snyder said.