Groundbreaking Alzheimer's blood test can spot cruel disease 15 YEARS before symptoms emerge: Scientists believe breakthrough might lead to a national screening programme for all over-50s

 Discovery could form the foundations for a new national screening programmeREAD MORE: Experts say there could be 5 types of Alzheimer's in breakthrough 

A blood test is set to ‘revolutionise’ the diagnosis of Alzheimer’s, laying the foundations for a national screening programme.

The commercially available test is more accurate than a lumbar puncture – and could be used to track disease progression, according to the results of an eight-year trial.

It works by measuring levels of p-tau217 in the blood, a protein found in patients with Alzheimer’s disease.

For the first time, a test could categorise as person’s chances of having the disease as ‘likely’, ‘intermediate’ or ‘unlikely’ – ruling out the need for further invasive tests.

Experts said the test is so simple, patients could expect results within ‘days’, rather than the years it currently takes to get a diagnosis.

A new blood test for Alzheimer’s  is so simple experts say patients could expect results within ‘days’, rather than the years it currently takes to get a diagnosis (stock image)

It could also open the door to treatment breakthroughs by making trials much faster, potentially removing barriers such as painful spinal taps or brain scans, which can take months.

Made by diagnostics company ALZpath, the trial involving 786 people found the levels of p-tau217 in the blood reflected the levels of amyloid and tau proteins seen in brain scans and lumbar punctures.

Scientists said it had ‘huge implications’ for the disease, which is now this country’s biggest killer.

Professor David Curtis, of the UCL Genetics Institute, University College London (UCL), said this was effectively ‘one half of the solution,’ as we await effective treatments.

He said: ‘This could potentially have huge implications. 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.’

Around 900,000 people in the UK live with dementia – with Alzheimer’s the most common form.

The growing ageing population means that numbers are expected to rise to 1.6 million by 2040, 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.

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

Alzheimer’s Research UK analysis found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier.

University of Gothenburg researchers found that the higher the levels of p-tau217 in the blood, the more signs of Alzheimer’s Disease there were in the brain.

It means doctors could use the tests to monitor how quickly the disease is progressing in patients, tailoring treatment in the future.

Doctors are hopeful the tests will become the gold standard for identifying the biggest killer in the UK, boosting and speeding up detection rates.

At present, the only ways to definitively diagnose Alzheimer’s are through expensive brain scans or lumbar punctures, which involve taking a fluid sample from the patient’s spinal cord.

But a lack of diagnostic capacity and long waiting lists mean only 2 per cent of cases are diagnosed this way.

Patients often face waits of between two and four years for a diagnosis, with around one in four dying before any formal diagnosis is made.

The performance of the test was consistent in identifying levels of amyloid and tau in the brain across three international study groups, according to the results published in JAMA.

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

With breakthrough treatments such as donanemab and lecanemab on the horizon, experts say it is vital to have a quick and reliable diagnosis, when drugs could be most effective.

The study from Dr Nicholas Ashton at the University of Gothenburg, and colleagues, is published in the Jama Neurology journal.

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.’