New blood tests could enable NHS to diagnose dementia

University researchers are investigating the potential of blood tests to offer an early diagnosis of dementia

10th April 2024 about a 4 minute read
"New drugs targeting early-stage Alzheimer's disease are just around the corner, but without a diagnosis, people simply won't be able to access them if they are approved." Fiona Carragher, research and influencing director, Alzheimer’s Society

Research teams at University College London (UCL), the University of Cambridge and the University of Oxford are planning to lead clinical trials to see if blood tests could be used to diagnose dementia.

The hope is that they can gather enough evidence to enable blood tests for dementia to be validated for use in the NHS in the next five years. Together they form a programme known as the Blood Biomarker Challenge

Two teams are involved in the research. The READ-OUT team will be led by Dr Vanessa Raymont and Dr Ivan Koychev of the University of Oxford, and Professor James Rowe from the University of Cambridge. This team will evaluate both existing and new blood tests for various different types of dementia, including Alzheimer’s disease, vascular dementia, frontotemporal dementia, and dementia with Lewy bodies. They will also establish whether the blood tests can detect the diseases at different stages.

The ADAPT team will be led by Jonathan Schott, a professor of neurology, and Dr Ashvini Keshavan, both of UCL. They will focus on the most promising biomarker for Alzheimer’s disease – p-tau217.

The researchers will analyse whether measuring this biomarker in the blood increases the rate at which Alzheimer’s disease is diagnosed. This will be on both people with early dementia and memory problems.

A blood test would not be able definitely show every time whether a patient has Alzheimer’s, but it could be an easy way to help doctors identify which patients have hidden physical signs of the disease, years before symptoms appear. Current blood tests under development look for traces of brain proteins such as tau or amyloid that have leaked into the bloodstream. Amyloids start to build up in the brain a decade or more before people develop memory loss and confusion.

Dr Susan Kohlhaas, from Alzheimer’s Research UK, said: “We need to move these tests out of the lab and assess their effectiveness in real-world settings like the NHS.”

Nearly 4 in 10 are undiagnosed

Approximately 1,000 participants for both research trials will be recruited from across the country, and findings will be applicable to the entire UK population.

“Dementia is the UK’s biggest killer, yet a third of people living with dementia don’t have a diagnosis, which means they’re not able to access care and support,” said Fiona Carragher, research and influencing director of the Alzheimer’s Society. “Nearly four in 10 people in the UK who have dementia have not received a diagnosis. We also know that those who do have a diagnosis have often waited many months, sometimes years, to receive it.

“This means thousands of families are stuck in limbo, trying to manage symptoms and plan for the future without access to the vital care and support that a diagnosis can bring.

“New drugs targeting early-stage Alzheimer’s disease are just around the corner, but without a diagnosis, people simply won’t be able to access them if they are approved.”

Potential to transform dementia diagnosis

A diagnostic blood test would transform the diagnosis of dementia in the UK. Currently, a firm diagnosis can take several years. UK regulators would still need to approve a blood test, however, and research would need to show it is cost-effective for the NHS to use.

Having a measurable biomarker for the disease would also provide a way to monitor how well new treatments work.

The Blood Biomarker Challenge has received financial support from several sources:

  • Alzheimer’s Society
  • Alzheimer’s Research UK
  • The National Institute for Health and Care Research
  • Gates Ventures
  • People’s Postcode Lottery

Schott, who is also chief medical officer at Alzheimer’s Research UK, said: “If, as we hope, new treatments that can slow down Alzheimer’s disease become available soon, then this will be vital. “This would pave the way for fair and equitable access to new and potentially life-changing treatments to all who might benefit.”

FCC Insight

Nearly one million people in the UK are affected by dementia. Currently, however, diagnosis is difficult and time-consuming, and more than a third of people with this debilitating disease remain undiagnosed. This means that they are not benefiting from new drugs such as Lecanemab, which can slow the advance of Alzheimer’s. A diagnostic blood test could be transformative, because it would be a more reliable, and less resource-intensive way of diagnosing the disease, and would enable people to be treated at an earlier stage, before the disease has advanced. As the population ages, more and more people are at risk of developing dementia, so research efforts to improve diagnosis should be welcomed, particularly as effective treatments are finally starting to emerge.