Major Alzheimer's blood test trial seeks 1,100 patients

A blood test to accelerate the diagnosis of Alzheimer's disease will be trialled in a major study recruiting 1,100 patients from across the UK. The test measures levels of a protein called p-tau217, which has been linked to the presence of toxic proteins amyloid and tau in the brain. Researchers will evaluate whether using the blood test when patients are near the start of an assessment for memory or thinking problems can improve diagnosis and guide decisions on further tests or treatment.

The landmark ADAPT study is part of the Blood Biomarker Challenge, a multi-million pound programme aiming to find a reliable blood test to transform diagnosis of dementia. Trial leader Professor Jonathan Schott, an expert in neurology at University College London and chief medical officer at Alzheimer's Research UK, said it was hoped the work would "take us a step forward in revolutionising the way we diagnose dementia".

He added: "After decades of research, we now have a blood test for Alzheimer's disease that is backed by strong scientific evidence and provides comparable information to other gold-standard diagnostic tests such as PET scans and lumbar punctures yet is far more accessible, and cheaper.

"Currently only about 2% of people diagnosed with Alzheimer's have access to one of these gold-standard diagnostic tests.

"While identifying Alzheimer's disease early and accurately is already important for enabling access to current therapies and planning care, it will become even more critical as a new generation of treatments emerge that can slow down the decline of memory and thinking."

Experts believe blood tests such as plasma p-tau217 can detect these proteins as accurately as more invasive methods such as PET scans and lumbar punctures.

The study is now recruiting participants through NHS memory services. Half will receive their blood test results within three months of their first assessment, while the rest receive theirs after one year.

The researchers will assess whether providing results earlier helps speed up diagnosis and guides clinical decisions, as well as the impact on patients' quality of life.

A second study also launched under the Blood Biomarker Challenge - which is supported by Alzheimer's Society, Alzheimer's Research UK and the People's Postcode Lottery - is evaluating a range of blood tests for various types of dementia including Alzheimer's, vascular and frontotemporal dementia.

A recent Alzheimer's Society survey found only a third of people with dementia felt their experience of the diagnostic process was positive.

Professor Fiona Carragher, the charity's chief policy and research officer, said: "Too often, dementia is diagnosed late, limiting access to support, treatment, and opportunities to plan ahead.

"For many across the UK, getting that diagnosis remains a major challenge - one that it will take society, researchers and governments working together to fix.

"Blood tests could offer a faster and more accessible route to diagnosis. The Blood Biomarker Challenge is committed to building the evidence needed to bring these innovative tests into NHS care, delivering real benefits for people living with dementia and their families."

Dr Sheona Scales, director of research at Alzheimer's Research UK, added: "Today, one in three people with dementia do not have a diagnosis.

"The ADAPT trial is an important opportunity to change this and transform the way dementia is diagnosed across the UK. It shows how sustained investment in research is leading to breakthroughs in dementia."