A blood test could detect Alzheimer’s disease years before symptoms like memory loss appear.
Within five years, experts predict this test could be rolled out for Britons over 50 on the NHS.
Director of Research at Alzheimer’s Research UK, Dr Sheona Scales, said: “Before any blood tests can become standard diagnostic tools, they must be independently shown to be at least as sensitive and accurate as gold-standard approved tests, such as lumbar punctures.”
She added that the test has “huge potential to revolutionise diagnosis for people with suspected Alzheimer’s”.
The expert explained that in a study, participants were put into groups: those who were very likely to have Alzheimer’s, those who were very unlikely to have the disease, and an ‘intermediate’ group who would require additional tests using lumbar punctures or PET scans.
The new research could be a breakthrough in dementia diagnosis and consequently, treatment
According to research published in JAMA Neurology, this blood test could detect ‘p-tau217’, a form of the protein tau, a hallmark protein in Alzheimer’s disease.
People with Alzheimer’s have a build-up of proteins known as amyloid and tau in their brains, which is one of the main ways to detect the disease.
Alzheimer’s is generally diagnosed based on an individual’s symptoms, for example, thinking or memory problems. But despite this, only two per cent of people with a dementia diagnosis receive one through what can be described as ‘gold standard’ methods, such as PET scans or lumbar punctures.
The new research is coming at a great time, with Alzheimer’s disease therapies on the horizon.
Associate director of research and innovation at Alzheimer’s Society, Dr Richard Oakley, said: “Coming down the line are potentially ground-breaking new drugs which can slow the progression of early-stage Alzheimer’s disease.
“But for people to be eligible for them if they’re approved in the UK, they will need an early, accurate diagnosis.
“This study is a hugely welcome step in the right direction.”
In the new study, levels of p-tau217 in the blood reflected the levels of amyloid and tau proteins seen in brain scans and lumbar punctures.
The test has ‘huge potential to revolutionise diagnosis for people with suspected Alzheimer’s’
Researchers predicted that using a blood test like this could decrease the demand for follow-up tests by roughly 80 per cent.
But while this new research does seem to be a breakthrough in dementia detection, it still has a long way to go.
Dr Scales said: “We need to gain a better picture of how these types of blood tests perform day-to-day in real-world healthcare systems, including more diverse patient populations.”
The tests will also need regulatory approval before being rolled out.
The expert concluded that a rapid and accurate diagnosis will “ultimately bring us closer towards a cure for dementia”.
She said: “In the past year, we have seen incredible progress in the development of blood-based Alzheimer’s tests. And as we see more and more different types of tests becoming available, studies like this are key to understanding which are most accurate.”