In the UK, while dementia already affects hundreds of thousands of people, most early memory problems are never assessed by a specialist. A study published in the journal Nature Communications is testing an unexpected solution: a kit made entirely at home to identify adults most at risk of developing Alzheimer’s disease. At the heart of this device is a home blood testcombined with short online brain tests.
How this at-home Alzheimer’s blood test works
The University of Exeter Medical School and the PROTECT program asked 174 volunteers aged over 40 to take a drop of blood from their finger and then complete memory, attention and decision-making exercises on a computer.
- The kit relies on a capillary sample: the drop of blood is placed on a dried blood card, dried at room temperature and then mailed to researchers funded by the National Institute for Health and Care Research. In the laboratory, the team measures two proteins: the tau 217 protein, associated with Alzheimer’s disease, and the Gfap protein, linked to general cognitive decline;
- The same people took a battery of memory, attention and executive function tests online.
Levels of p-tau217 and GFAP were found to be closely linked to cognitive performance, distinguishing between low, intermediate and high risk profiles. Professor Anne Corbett from the University of Exeter Medical School, who is leading the study, explains: “Our previous research has shown that a finger prick blood test can be effectively done at home and mailed to laboratories, and that we can identify biomarkers in the blood linked to dementia. This new study builds on this to show that we can link these performance biomarkers to brain tests, giving us a potential way to predict dementia risk“.
Remote triage, not a ready-made Alzheimer’s diagnosis
Can this work pave the way for risk screening without consultation or complex clinical examination? Today, we can hope that they will make it possible to prioritize the monitoring and diagnosis of people most at risk, and thus guarantee them support and treatment adapted to their needs.
As a first step in the diagnostic process, this self-test could reassure some people and offer others faster access to additional tests and support. Easy to use and carried out remotely, this test could facilitate access to assessments for those who encounter practical obstacles in going to specialized centers.
Another striking result is that the GFAP often identifies another type of risk: people positive for this biomarker reported almost five times more heart disease. In a context where only one person in a thousand with early decline consults a specialist, this large-scale filtering is a game-changer for care pathways.
A promising Alzheimer’s blood test, to be carefully supervised
As several specialists point out, for the moment, it is not a diagnostic tool, but early detection to be confirmed in the clinic. So other experts are tempering this enthusiasm a little.
In Science Media Centre, Professor Tara Spires-Jones, professor of neurodegeneration at the University of Edinburgh and former president of the British Neuroscience Association, specifies that: “Numerous studies have already demonstrated that blood biomarkers for Alzheimer’s disease, in particular the pTau217 marker, one of the two used in this study, are extremely reliable in detecting the brain changes observed in people with the disease. However, it is important to note that these brain changes, alone, do not guarantee the onset of Alzheimer’s disease symptoms; their use for large-scale screening or in routine clinical practice is therefore not yet recommended“.
Although this at-home blood test does not yet allow a diagnosis of Alzheimer’s disease to be made, it nevertheless marks a possible turning point in the management of cognitive disorders. More accessible, faster and potentially capable of directing patients towards appropriate care earlier, this type of screening could profoundly transform memory pathways in the years to come. Provided, specialists warn, that its use is strictly regulated to avoid false hope, unnecessary anxiety or premature diagnoses.