Blood test could predict dementia 15 years before diagnosis

New research suggests profiles of proteins in the blood, known as biomarkers, can accurately predict dementia up to 15 years prior to clinical diagnosis.

Lead author of the study, Professor Jianfeng Feng from the University of Warwick, says the predictive model, which combines AI and protein analysis, could be “seamlessly integrated into the NHS and used as a screening tool by GPs.”

A ‘breakthrough’

The research, published in the journal Nature Aging, used the largest cohort of blood proteomics and dementia to date, including blood samples from 52,645 participants recruited from UK Biobank.

The blood samples, collected between 2006 and 2010, were frozen and then analysed 10-15 years later by research teams at the University of Warwick and Fudan University, Shanghai.

Of the participants, a total of 1,417 went on to develop dementia. Upon analysing their blood samples, the researchers found that these people’s blood showed dysregulation of protein biomarkers.

In total, 11 proteins were shown to be ‘highly accurate’ at predicting future dementia, the researchers say. This includes proteins such as Gfap, Nefl, Gdf15 and Ltbp2, which were present in high levels among those who developed all-cause dementia, Alzheimer’s disease or vascular dementia.

The researchers say when combined with more conventional risk factors such as age, sex, education and genetic susceptibility, the predictive model is over 90% accurate, indicating its potential future use in community-based dementia screening programmes.

Professor Wei Cheng, a co-corresponding author from Fudan University, described the newly developed protein-based model as a “breakthrough”.

Early diagnosis critical for dementia patients

Dementia is the UK’s biggest killer, accounting for over 74,000 deaths (11.3%) in 2022. However, many people with dementia receive a delayed diagnosis, or never receive a diagnosis at all.

One study found that three quarters of people with dementia did not receive a dementia or Alzheimer’s diagnosis until at least one year after their symptoms began, while roughly a third waited more than three years.

An early diagnosis is critical for those with dementia, as it ensures they receive the help and support they need. Furthermore, new drugs, such as donanemab and lecanemab, may be able to slow the progression of Alzheimer’ disease, but only if the disease is detected early enough.

Dr Richard Oakley, Associate Director of Research and Innovation at Alzheimer’s Society, said the model could help clinicians to predict those at risk of dementia and Alzheimer’s disease.

“It’s very early days and lots more work is needed but this could lay the groundwork for the early prediction of dementia and teach us more about how to provide an early and accurate diagnosis,” he said.