A blood test that can predict Alzheimer's disease may soon be available as scientists have discovered biomarkers in the blood that can predict the onset of the disease years before the symptoms show up.
In the study "Plasma phospholipids identify antecedent memory impairment in older adults" published in the Nature Medicine, March 9, a team of researchers reported of an experimental blood test that can predict individuals in their 70's who are about to develop Alzheimer's disease, a progressive and degenerative illness that destroys brain cells and is characterized by difficulty in remembering things, performing tasks and making decisions, two or three years before symptoms begin.
In their study, the researchers took blood samples from more than 500 people who were 70 years old and over to find a difference between the blood of those who developed Alzheimer's and those who did not. Analyzing and comparing the blood samples of the subjects who developed mild cognitive impairment or Alzheimer's disease over the next five years and those who remained "cognitively normal", the researchers found that a pattern of 10 blood lipids changes in those who develop Alzheimer's or cognitive problems.
"We discovered and validated a set of ten lipids from peripheral blood that predicted phenoconversion to either amnestic mild cognitive impairment or Alzheimer's disease within a 2-3 year timeframe with over 90% accuracy," the researchers reported. "This biomarker panel, reflecting cell membrane integrity, may be sensitive to early neurodegeneration of preclinical Alzheimer's disease."
Study author Howard Federoff, a professor of neurology at Georgetown University, said the blood test can provide a quick and easy way for seniors to evaluate their risks for Alzheimer's.
"This is the first time a highly sensitive and specific test has been able to predict who will become demented," said Federoff. "We did not find any individual that didn't test positive that became demented."
The blood test, however, raised some concerns. Jason Karlawish, a professor of medicine, medical ethics and health policy at the University of Pennsylvania, said that people who get to know they have the Alzheimer's gene are likely to rate their memories as worse than others'. He also raised concerns about stigma and identity.
"How will other people interact with you if they learn that you have this information?" Karlawish said. "And how will you think about your own brain and your sort of sense of self?"
Still, the researchers hope the blood test can change how people manage Alzheimer's disease. "Our novel blood test offers the potential to identify people at risk for progressive cognitive decline and can change how patients, their families and treating physicians plan for and manage the disorder," Federoff said.
