A blood test to detect 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 may be as good as lumbar punctures at detecting the signs of Alzheimer’s, and better than a range of other tests being developed, experts say.
The protein is a marker for biological changes that occur in the brain with Alzheimer’s disease.
In a study of 786 people, researchers were able to use the ALZpath p-tau217 test to identify patients as likely, intermediate, or unlikely to have Alzheimer’s disease.
Dr Richard Oakley, an associate director of research and innovation at the Alzheimer’s Society, said: “This study is a very welcome step in the right direction as it shows that blood tests can be just as accurate as more invasive and expensive tests to predict whether someone has features of Alzheimer’s disease in their brain.
“Furthermore, it suggests that the results of these tests may be clear enough not to require further follow-up examinations for some people living with Alzheimer’s disease, which could significantly speed up the diagnosis route in the future. However, we still need to see more research across different communities to understand how effective these blood tests are for everyone living with Alzheimer’s disease.”
Currently, the only way to prove someone has a build-up of the protein in the brain is to have a lumbar puncture or an amyloid PET scan, which are only available in around one in 20 NHS memory clinics. A lumbar puncture involves inserting a needle into the lower back, between the bones in the spine.
Dr Sheona Scales, a director of research at Alzheimer’s Research UK, said: “This study suggests that measuring levels of a protein called p-tau217 in the blood could be as accurate as lumbar punctures currently used to detect the biological hallmarks of Alzheimer’s disease, and better than a range of other tests currently being developed, adding to a growing body of evidence that this particular test has great potential for diagnosing people with suspected Alzheimer’s revolutionize.”
She said a better picture is needed of how these types of blood tests perform in real-world healthcare systems.
Prof David Curtis, an honorary professor at the UCL Genetics Institute, University College London, said: “Everyone over 50 could be screened regularly every few years, in much the same way as they are now screened for high cholesterol.
“It is possible that currently available treatments for Alzheimer’s disease will work better in those diagnosed early in this way. However, I think the real hope is that better treatments can also be developed. The combination of a simple screening test with an effective treatment for Alzheimer’s disease will have a dramatic impact for individuals and for society.”
The study by Dr Nicholas Ashton, from the University of Gothenburg, and colleagues is published in the journal Jama Neurology.