Scientists have hailed a potentially “revolutionary” breakthrough in Alzheimer’s research as a blood test was found to be accurate at detecting early signs of the disease.
The ALZpath ptau217 test works by identifying a protein called p-tau217 in the blood that is a biological marker of the disease.
A team of researchers at the University of Gothenburg used the test to categorise people as “likely, “intermediate” and “unlikely” to have Alzheimer’s.
For the study, scientists tested more than 700 people from three international groups over an eight-year period.
The blood test was found to identify levels of amyloid and tau consistently and accurately in the brain.
It is hoped that the test could eventually be used to screen individuals experiencing memory issues or early cognitive symptoms associated with Alzheimer’s.
Alzheimer's disease is characterised by abnormal clumps amyloid and tau in the brain.
Currently, the only way to prove that someone has a built-up of these proteins is to have a lumbar puncture or an amyloid PET scan, which are only available in about 1 in 20 NHS memory clinics.
The researchers predict that the test could reduce demand for these follow-up tests by around 80 per cent.
Dr Sheona Scales, Director of Research at Alzheimer’s Research UK, said: “This adds to a growing body of evidence that this particular test has huge potential to revolutionise diagnosis for people with suspected Alzheimer’s.
“What’s particularly promising about the new study is that the researchers used a cut-off threshold to group people into those who were very likely to have Alzheimer’s, those who were very unlikely to have the disease, and an ‘intermediate’ group who would need further tests using conventional methods like lumbar punctures or PET scans.”
She said that researchers would 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”.
“Even when tests show promise in studies like this, they still need to go through regulatory approval before they can be used in a health care setting,” she added.
Charles Marshall, Professor of Clinical Neurology at Queen Mary University of London, said of the study: “The hope is that blood tests like this will improve access to a diagnosis in those seeking help for memory problems, and ultimately ensure that people can benefit from emerging treatments that can slow the progression of Alzheimer’s disease.
“Before these tests become widely used in the NHS, we will need further evidence to show that the blood test can accurately diagnose who is in the process of developing dementia, and that it can identify who is likely to benefit from treatments to slow down the disease.”
