WASHINGTON (Reuters) - US researchers have identified a new way to identify people at risk of developing Alzheimer's disease before symptoms appear by measuring levels of the blood protein to predict its accumulation in the brain, the hallmark of Alzheimer's disease.
Experts said the results were promising, a reliable step in treating Alzheimer's disease and accelerating the search for a cure for dementia, but further studies were needed.
Alzheimer's is one of the leading causes of dementia, affecting more than 520,000 people in the United Kingdom, mostly over 65, and millions more around the world.
Researchers at the University of Washington School of Medicine measured levels of a protein known as amyloid beta in the blood of 158 people over the age of 50 to see if they matched the levels of CT scans on their brains.
It turned out to be so, but only 88 percent this time - a percentage that is not accurate enough for a diagnostic test.
When researchers combined this information with two other causes of the disease - over the age of 65, and a genetic variable known as APOE4, which doubles the risk of the disease three times - the accuracy of the blood test was 94 percent.
Randall J. Pitman, a senior neuroscientist, says the test is now helping to examine more people than expensive brain CT scans.
"It can be used to get faster access to treatments, to reduce the cost of these treatments, and to reduce the suffering of patients," says Pittman.
Participants in clinical trials should have experienced the early changes caused by Alzheimer's disease in the brain - like amyloid buildup - but have not yet reached the stage of cognitive problems.