A BREAKTHROUGH new blood test could predict whether you’re likely to develop Alzheimer’s disease with ‘high accuracy’ even before symptoms appear, researchers say.
It works by testing for levels of p-tau217 in the blood, a protein that’s a key marker for biological changes that happen in the brain during Alzheimer’s.
AlamyThe ALZpath p-tau217 test measures Alzheimer’s markers in the blood[/caption]
The disease is characterised by a buildup of two substances in the brain called beta amyloid and tau, which clump up and form tiny structures called plaques and tangles.
But research published in the journal JAMA Neurology pointed to p-tau217, whose levels increase in the blood at the same time in people with the condition.
Scientists say it could be key to catching Alzheimer’s early, with the potential to “revolutionise” diagnosis for people suspected of having it.
Lead by Dr Nicholas Ashton , researchers at the University of Gothenburg were able to categorise 786 people as ‘likely’, ‘intermediate’ and ‘unlikely’ to have Alzheimer’s disease using the ALZpath p-tau217 test.
They found that evels of p-tau217 in the blood reflected the levels of amyloid and tau proteins seen in brain scans and lumbar punctures.
Dr Richard Oakley, associate 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 at predicting if someone has features of Alzheimer’s disease in their brain.
“Furthermore, it suggests results from these tests could be clear enough to not require further follow-up investigations for some people living with Alzheimer’s disease, which could speed up the diagnosis pathway significantly in future.
“However, we still need to see more research across different communities to understand how effective these blood tests are across everyone who lives with Alzheimer’s disease.”
Currently the only way to prove that someone has a build-up of the proteins in the brain is to have a lumbar puncture or an amyloid PET scan, which are available in only about one in 20 NHS memory clinics.
A lumbar puncture involves a needle being inserted into the lower back, between the bones in the spine.
Dr Sheona Scales, 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 currently used lumbar punctures for detecting the biological hallmarks of Alzheimer’s disease, and superior to a range of other tests currently under development.
“This adds to a growing body of evidence that this particular test has huge potential to revolutionise diagnosis for people with suspected Alzheimer’s.”
However, she added that a better picture is needed of how these types of blood tests perform day-to-day in real-world healthcare systems.
Prof David Curtis, honorary professor, UCL Genetics Institute, University College London, said: “Everybody over 50 could be routinely screened 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 would 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 would have a dramatic impact for individuals and for society.”
It’s estimated that more than 900,000 people in the UK have dementia – most of these cases are caused by Alzheimer’s disease or vascular dementia.
This number is estimated to rise to 1.6 million by 2040, according to Alzheimer’s Society.