A blood test for detecting Alzheimer’s disease could be as accurate as painful and invasive lumbar punctures and could revolutionize the diagnosis of the condition, research suggests.
Measuring levels of a protein called p-tau217 in the blood could be as good as lumbar punctures at detecting the signs of Alzheimer’s disease, and better than a range of other tests in development, experts say.
The protein is a marker for biological changes that take place in the brain in Alzheimer’s disease.
In a study of 786 people, researchers were able to use the ALZpath p-tau217 test to identify patients who had probable, intermediate, or unlikely Alzheimer’s disease.
Dr. Richard Oakley, deputy director of research and innovation at the Alzheimer’s Society, said: “This study is a hugely welcome step in the right direction as it shows that blood tests can be just as accurate as more invasive and expensive tests in predicting whether someone has features of Alzheimer’s disease in his brain.
“Additionally, it suggests that the results of these tests could be clear enough not to require further follow-up testing for some people with Alzheimer’s disease, which could significantly speed up the diagnosis path in the future. However, we still need more research in different communities to understand how effective these blood tests are in everyone living with Alzheimer’s disease.”
Currently, the only way to prove that someone has a build-up of proteins in the brain is to undergo a lumbar puncture or an amyloid PET scan, which are only available in around one in twenty NHS memory clinics. During a lumbar puncture, a needle is inserted into the lower back, between the bones in the spine.
Dr. Sheona Scales, research director at Alzheimer’s Research UK, said: “This study suggests that measuring the levels of a protein called p-tau217 in the blood could be as accurate as the currently used lumbar punctures for detecting the biological features of Alzheimer’s disease. and superior to a range of other tests currently in development. This adds to a growing body of evidence that this specific test has enormous potential to revolutionize diagnosis for people with suspected Alzheimer’s.”
She said a better picture was needed of how these types of blood tests performed in real health care systems.
Prof David Curtis, honorary professor at the UCL Genetics Institute, University College London, said: “Everyone over 50 could be routinely screened every few years, in much the same way they are now screened for high cholesterol.
“It is possible that currently available treatments for Alzheimer’s disease would work better in people diagnosed early in this way. However, I think the real hope is that better treatments can also be developed. Combining a simple screening test with an effective treatment for Alzheimer’s disease would have a dramatic impact for individuals and for society.”
The study of Dr. Nicholas Ashton, from the University of Gothenburg, and colleagues is published in the journal Jama Neurology.