A groundbreaking blood test that can spot the first signs of Alzheimer’s a decade before symptoms strike could be available on the NHS within three years.
Scientists in Sweden found the test was as accurate as the current gold standard for diagnosing the cruel, memory robbing condition.
Experts last night said it would ‘revolutionise’ diagnosis, making Alzheimer’s as easy to test for as high cholesterol. It also opens the door for screening all over-50s once more effective treatments become available.
Although not yet offered to patients suspected of having the disease, charities say it could be ready to use widely by 2027.
Some neurologists have, however, raised concerns about the prospect of using the test to spot Alzheimer’s cases among patients with no symptoms. Many might have markers of the condition in their blood but never suffer cognitive decline, they say.
Researchers in Sweden found that the test – made by US firm ALZpath for £150 – accurately detects traces of a protein linked to developing the memory-robbing condition, which can appear 10 to 15 years before forgetfulness kicks in. Pictured: Graphic showing how Alzheimer’s blood tests could work
From 1906 when clinical psychiatrist Alois Alzheimer first reported a ‘severe disease of the cerebral cortex’ to uncovering the mechanics of the disease in the 1980s-90s to the recent ‘breakthrough’ drug lecanemab, scientists have spent over a century trying to grapple with the brutal disease that robs people of their cognition and independence
Researchers at the University of Gothenburg, led by Dr Nicholas Ashton, examined 786 people, aged 66 on average.
Each had a blood test that checked their levels of p-tau217 — a protein that slowly accumulates in the brain and is thought to drive Alzheimer’s. These proteins start to build up on the brain ten to 15 years before symptoms start showing.
Around a third had signs of memory loss, while the rest did not.
As it stands, the only way to check for a build-up of these proteins in the brain is to have a lumbar puncture — which collects fluid from the spine — or an amyloid PET scan.
However, these tests are available in only about one in 20 NHS memory clinics, with patients waiting up to four years for a formal diagnosis.
Based on p-tau217 levels in blood tests results, the scientists grouped participants into being very likely or very unlikely to develop the condition.
Around a fifth of participants were in the middle and would need a lumbar puncture or PET scan to confirm their Alzheimer’s status, the researchers said.
However, using the blood test in this way could reduce the demand for these follow-up tests by around 80 per cent, the researchers predicted.
The findings, published in the journal Jama Neurology, show that the approach was 97 per cent accurate.
This makes the test as effective at spotting Alzheimer’s as the current gold-standard tests and scans.
‘Blood biomarkers are set to revolutionize clinical care by providing objective biomarker-based information,’ the team wrote.
Dr Andreas Jeromin, chief scientific officer at ALZPath, the firm behind the already commercially-available test, said: ‘This diagnostic capability offers increasingly vital aid in medical management and treatment decisions for Alzheimer’s, especially as new disease-modifying treatments become more accessible.’
While previous blood tests have shown promise, these findings have caused particular excitement given the high accuracy levels, large study size and because the test already exists.
With breakthrough treatments such as donanemab and lecanemab on the horizon, which have been shown to clear the brain of the plaques thought to be responsible for dementia, experts say it is vital to have a quick and reliable diagnosis, when drugs could be most effective.
Dr Susan Kohlhaas, executive director of research and partnerships at Alzheimer’s Research UK, said the findings are ‘really encouraging’.
She told BBC Radio 4’s Today programme that the next step is checking that the results still stand when used in clinics among people with memory problems.
The test would then need to be approved by the Medicines and Healthcare products Regulatory Agency and recommended by the National Institute for Health and Care Excellence before the test could be rolled out on the NHS.
As a result, Dr Kohlhaas said it will likely be three to five years before the test is available to patients.
She said: ‘It’s probably on the closer end of five years.
‘What’s really important is that this is really urgent to sort. We can see the time where treatments are just coming round the corner that, for the first time slow progression of diseases like Alzheimer’s.
‘If people can’t get a diagnosis, they won’t have access to those treatments.’
Dr Kohlhaas added: ‘Eventually it would be great to be able to screen people and make sure that they have access to treatments as quickly as possible.’
The ALZpath test could form part of NHS trials starting this month, with health chiefs looking to roll out an effective blood tests for Alzheimer’s within the next five years.
Private healthcare providers may start offering the test sooner based on the findings, allowing people to pay for tests before they become routine, experts suggest.
Dr Sheona Scales, director of research at Alzheimer’s Research UK, said: ‘With new treatments finally on the horizon, it’s never been more important to transform the way people with potential symptoms of Alzheimer’s are diagnosed.
‘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.’
She noted that the test needs to be subject to further checks and undergo regulatory approval before they can be offered to patients but hopes a blood test for Alzheimer’s will be available within five years.
But they can also be a sign of dementia — the memory-robbing condition plaguing nearly 1million Brits and 7million Americans
Changes in humour and swearing more are all signs of Alzheimer’s and frontotemporal dementia (FTD) a type of dementia that causes problems with behaviour and language. According to experts bad parking, and dressing scruffy are also signs of the memory-robbing disease. Graphic shows: Six signs of Alzheimer’s disease
Professor David Curtis, an honorary professor at the UCL Genetics Institute, said the findings could have ‘huge implications’ for how Alzheimer’s is managed.
‘Everybody over 50 could be routinely screened every few years, in much the same way as they are now screened for high cholesterol,’ he said.
‘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.’
Around 944,000 in the UK are thought to be living with dementia, while the figure is thought to be around 7million in the US.
Alzheimer’s disease affects around six in 10 people with dementia.
It is caused by a build-up of amyloid and tau in the brain, which clump together and from plaques and tangles that make it harder for the brain to work properly.
Eventually, the brain struggles to cope with this damage and dementia symptoms develop.
Memory problems, thinking and reasoning difficulties and language problems are common early symptoms of the condition, which then worsen over time.
Dementia are expected to sky-rocket in the coming years, making a cheap screening tool vital to get to grips with the challenge.
Alzheimer’s Research UK analysis found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier, making it the country’s biggest killer.
Shadow Health Minister Karin Smyth told Sky News that the findings are ‘really good news’. However, she said getting it to patients will be ‘the real test’.
She said: ‘A core part of reforming the health service has to be bringing these drugs quicker and more easily to patients at the frontline.
‘Because ultimately, these diseases, as well as being terrible for patients, do cost the system an awful lot of money.’
However, she warned that the frontline system under the Tory Government is ‘not there in the way that it should be’, which could make it difficult to deliver the test.
She said Labour ‘absolutely want to encourage’ these developments.
