Dried Blood Spot Testing Shows Early Promise for Alzheimer’s Biomarkers

Dried blood samples collected from a finger prick can be used to measure key signs of Alzheimer’s disease, according to a Nature Medicine paper. 

This approach could make detecting Alzheimer’s disease easier and less invasive, and could help expand testing in places where traditional methods are difficult to access. 

Alzheimer’s disease is usually confirmed through brain scans or spinal fluid tests, which are invasive and expensive. Blood tests that measure biomarkers, such as p-tau217, are emerging as accurate and accessible tools for detecting Alzheimer’s disease. 

Although drawing blood is much simpler than procedures such as spinal taps or brain scans, practical hurdles remain, including how samples are handled and stored and whether people have access to trained staff to collect them. 

Nicholas Ashton, PhD, and colleagues tested a new method for detecting Alzheimer’s disease using a few drops of blood obtained from the fingertip and then dried on a card. This process was used to find proteins linked to Alzheimer’s disease and other brain changes in 337 people. 

The authors found that levels of p-tau217 in finger-prick samples closely matched results from standard blood tests and were able to identify Alzheimer’s disease-related changes in spinal fluid with an accuracy of 86 percent. 

Two other markers, GFAP and NfL, were also successfully measured and showed strong agreement with traditional tests. 

The authors also found that participants were able to successfully obtain the blood samples themselves, without the guidance of study personnel. 

The researchers caution that the method is not ready for clinical use yet and further work is needed. 

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.