Blood test could speed up Alzheimer's diagnosis

Test would be much cheaper than current alternatives and could be available within three years

A blood test to help diagnose Alzheimer's disease is being trialled.

A major new blood test for Alzheimer’s is being trialled in the UK that could revolutionise diagnosis of the deadly condition.

People with suspected dementia are being recruited via NHS memory clinics to check how well the test works. Experts hope to have answers within three years.

The trial forms part of the Blood Biomarker Challenge, a multimillion-pound programme supported by Alzheimer’s Society, Alzheimer’s Research UK and the People’s Postcode Lottery.

A team led by University College London (UCL) is investigating whether the test, which measures the protein p-tau217, can improve the early and accurate diagnosis of Alzheimer’s disease.

The test has already been shown to be effective in looking for the protein but researchers want to know whether giving it to patients near the start of an assessment for memory and thinking problems helps guide diagnosis and treatment.

The study will recruit 1,100 people from diverse geographic, ethnic and economic backgrounds, alongside those living with other health conditions, to ensure the findings are relevant in a wide population.

Analysis suggests the test can tell around 80 per cent of people with cognitive decline whether they are likely to have Alzheimer’s.

Alzheimer’s disease is the most common cause of dementia and linked to the build-up of two key proteins in the brain called amyloid and tau.

P-tau217 is regarded as a promising biomarker that shows both amyloid and tau are present in the brain.

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

If shown to work in NHS practice, blood tests could be used as part of a wider assessment to confirm the diagnosis of Alzheimer’s disease for people who already have memory or thinking problems.

The Alzheimer’s Disease Diagnosis and Plasma pTau217 (Adapt) team behind the study is led by Professor Jonathan Schott and Dr Ashvini Keshavan.

Dr Keshavan said on Wednesday it was vital new research helped identify the type of dementia a patient is suffering from.

Comparing dementia diagnosis to cancer, she told the BBC: “We wouldn’t accept not knowing what type of cancer a person has and appropriate treatment.

“Right now that’s the situation in the UK, where most people don’t know what type of dementia they have.”

Professor Schott, from UCL and chief medical officer at Alzheimer’s Research UK, said:

“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 yet is far more accessible, and cheaper.

“Currently only about 2 per cent 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.

“Timely diagnosis will be key to ensuring these advances reach the people who need them most.”

In January, a research team from the University of Oxford and University of Cambridge – also part of the Blood Biomarker Challenge – announced they had begun using a different suite of tests on dementia patients.

This team is assessing multiple new and existing blood tests, looking at a range of dementia types including Alzheimer’s disease, vascular dementia, frontotemporal dementia, and dementia with Lewy bodies.