International project trialling finger prick blood test for Alzheimer’s

The trial is looking at three proteins in the blood that are associated with Alzheimer's and comparing this with current approached which use brain scans and invasive procedures. The finger prick test uses a simple plasma separation card which makes testing a lot cheaper and easier to carry out. It does not need to be refrigerated and can be stored and shipped to a laboratory for analysis at ambient temperature.

If successful, the test could offer a scalable, accessible and cost-effective way to screen for the disease which could enable earlier intervention, with a better chance of delaying the progress of Alzheimer's or the development of symptoms.

The finger prick test will be run as a part of the Global Alzheimer's Platform Foundation (GAP)'s Bio-Hermes-002 study, which is aimed at advancing Alzheimer's disease diagnosis using blood and digital biomarkers. GAP is working in partnership with the not-for-profit medical research organisation, LifeArc, and UK Dementia Research Institute (UK DRI) with its Biomarker Factory.

To date, GAP has enrolled 883 of the 1000 participants from 25 sites across the UK, USA and Canada. This includes a mix of cognitively normal people, those with mild cognitive impairment and some with mild to moderate Alzheimer's disease. Out of this group, over 360 have completed the test.

Researchers will analyse each sample for proteins in the blood, also known as blood-based biomarkers of the disease – phosphorylated tau 217(pTau217), Glial fibrillary acidic protein (GFAP) and Neurofilament light polypeptide (NfL) – and compare the results with a variety of other tests being developed for Alzheimer's disease based on blood-based and digital biomarkers (such as speech tests, retinal scans, cognitive tests) as well as the gold standard PET scans and MRI scans.

Alzheimer's disease is currently detected using expensive scans and lumbar punctures or spinal taps. This can be invasive, costly, slow, and inaccessible for those living in areas with limited healthcare infrastructure.

Dr Giovanna Lalli, Director of Strategy and Operations at LifeArc explains: "Over the last five years, there has been substantial progress in identifying blood-based biomarkers to identify people at high risk of developing Alzheimer's disease before their symptoms present. Developing cheaper, scalable and more accessible tests is vital in the battle against this devastating condition. We are committed to improving patient lives through the development of new tests and treatments, and we are excited about the prospect of a finger-prick blood test for Alzheimer's disease because it will allow more patients to access new drugs, currently being developed, to slow disease progression in its early stages."

Prof Henrik Zetterberg, Lead of the Biomarker Factory at the UK Dementia Research Institute, adds: "This study is unique in its size and scope, with 30% of volunteers being recruited from under-represented groups. Importantly, the results will be compared against current gold standard diagnostic techniques. If successful, being able to diagnose Alzheimer's with a minimally invasive, cost-effective method will revolutionise diagnostics in this area and pave the way for improved diagnosis of all neurodegenerative conditions."

Further evidence is still needed before a blood test can be introduced into the NHS, but the Bio-Hermes-002 study aims to validate, in a large-scale, internationally diverse population, this new finger prick-based approach.

It's expected that at least 25% of volunteers will come from under-represented ethnic groups, and this is vital for closing the health research gap that exists between people of different ethnicities; for example, even though Black and Hispanic people are twice as likely to develop Alzheimer's disease than white people, they are still hugely underrepresented in clinical trials with participation rates often as low as 2% and rarely higher than 20%.

The trial is expected to complete in 2028.