Breakthrough for Alzheimer’s test that uses finger-prick blood samples
A groundbreaking NIHR-supported international study has shown that Alzheimer's disease biomarkers can be accurately detected using simple finger-prick blood samples. These samples can be collected at home and posted to laboratories without refrigeration or prior processing.
The research, led by US institute Banner Health working with the University of Exeter Medical School and supported by the NIHR, has been published in Nature Medicine.
It represents the first large-scale validation of a testing approach that could take place anywhere in the world without requiring specialised healthcare infrastructure.
The DROP-AD project
The DROP-AD project was conducted at 7 European medical centres, including the University of Exeter. It successfully tested 337 participants and proved that finger-prick blood collection can accurately measure key markers of Alzheimer's pathology and brain damage.
Alzheimer's disease is usually confirmed through brain scans or spinal fluid tests. These are invasive and expensive. Blood tests that measure biomarkers, such as p-tau217, are emerging as accurate and accessible tools for detecting it.
Drawing blood through venipuncture (inserting a needle into a vein) is much simpler than spinal taps or brain scans. However, practical hurdles remain, including how samples are handled and stored, and whether people have access to trained staff to collect them.
Professor Nicholas Ashton, senior director of Banner's Fluid Biomarker Program and lead investigator of the study, said:
"This breakthrough could fundamentally change how we conduct Alzheimer's research by proving that the same biomarkers doctors use to detect Alzheimer's pathology can be measured from a simple finger prick collected at home or in more remote community settings.
“While we're still years away from clinical use, we're opening doors to research that was previously impossible – studying diverse populations, conducting large-scale screening studies, and including communities that have been historically underrepresented in Alzheimer's studies.
“Ultimately, we are moving toward a pathway of treating people for Alzheimer’s disease before symptoms emerge. If this trajectory continues, we will need innovative ways to identify eligible individuals who are not routinely presenting in clinical settings. This work represents one such approach in that direction and further validation remains.”
“This type of research – with the potential to transform diagnosis and care for people with Alzheimer’s disease – showcases the importance of NIHR infrastructure funding and the expertise of its researchers supporting internationally collaborative commercial research.”
How the study worked
The researchers tested a new method using a few drops of blood obtained from the fingertip and then dried on a card. They used the samples to look for proteins linked to Alzheimer's disease and other brain changes in the 337 participants.
Levels of p-tau217 in the finger-prick samples closely matched results from standard blood tests. They could identify Alzheimer's disease-related changes in spinal fluid with an accuracy of 86%. Two other markers, Glial Fibrillary Acidic Protein (GFAP) and neurofilament light (NfL), were also successfully measured and showed strong agreement with traditional tests.
The University of Exeter Medical School played a pivotal role, recruiting participants from the PROTECT-UK study and serving as the only site to test self-collection capabilities. Participants successfully collected their own finger-prick samples without the guidance of study personnel after watching trained staff and receiving written instructions.
Professor Anne Corbett, Professor in Dementia Research at the University of Exeter, said:
"What excites me most is that this work makes this type of research far more accessible. We're moving toward a future where anyone, anywhere, can contribute to advancing our understanding of brain diseases. This isn't just a technical advancement – it's a paradigm shift in how we conduct neuroscience research.”
Co-author Professor Clive Ballard, Professor of Age-Related Diseases at
the University of Exeter Medical School, added:
“Our ongoing work will determine whether this could also be a valuable way of identifying people in the community who would benefit from more detailed diagnostic tests for Alzheimer’s disease.”
Professor Marian Knight, Scientific Director for NIHR Infrastructure, said:
“This type of research – with the potential to transform diagnosis and care for people with Alzheimer’s disease – showcases the importance of NIHR infrastructure funding and the expertise of its researchers supporting internationally collaborative commercial research. The future potential to enable testing in different settings outside of hospital clinics is hugely exciting.”
Application beyond Alzheimer’s
The method also shows promise for research applications beyond Alzheimer's, including studies of Parkinson's disease, multiple sclerosis, ALS and brain injuries by the detection and accurate measurement of NfL, a key biomarker of neurodegeneration.
The findings suggest that this simple technique could make large-scale studies and remote testing possible, including for people with Down syndrome, who face a higher risk of Alzheimer's disease and for other underserved populations.
The researchers emphasize that significant additional research and validation is required before any clinical application and caution that the method is not ready for clinical use yet.
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A minimally invasive dried blood spot biomarker test for the detection of 28 Alzheimer’s disease pathology is published in Nature Medicine.