A simple fingerprick blood test can accurately detect Alzheimer's disease biomarkers, potentially transforming how the condition is diagnosed beyond specialized medical centers, according to new research published in Nature Medicine.
The DROP-AD project involved 337 participants across seven European centers. It demonstrated that dried blood spot samples collected from fingerpricks can be used to measure key Alzheimer's disease (AD) biomarkers – including phosphorylated tau-217 (p-tau217), glial fibrillary acidic protein, and neurofilament light. These capillary samples showed strong correlations with standard venous blood draws and accurately predicted abnormal cerebrospinal fluid biomarkers indicating AD pathology.
The breakthrough addresses an important logistical barrier in AD diagnostics. While blood biomarkers have emerged as accurate alternatives to brain imaging and spinal fluid analysis, standard blood tests still require venipuncture, immediate processing, and temperature-controlled storage. Such requirements can limit widespread implementation, particularly in underserved communities and remote areas.
Dried blood spots eliminate these constraints. Samples can be collected via fingerprick, stored at room temperature, and shipped without refrigeration to laboratories for analysis.
Preliminary data from 30 participants who collected their own samples unsupervised showed high concordance with professionally collected specimens, suggesting potential for home-based testing. However, researchers encountered unsuccessful collections in 15 to 25 percent of cases due to insufficient blood flow or technical issues.
The study found that capillary p-tau217 levels increased progressively with disease severity and showed good accuracy in detecting cerebrospinal fluid biomarker positivity.
Researchers also successfully tested the method in individuals with Down syndrome, a population at high genetic risk for AD where standard blood draws may be more challenging. The technique revealed elevated biomarkers in those with dementia compared to asymptomatic individuals.
Despite promising results, the researchers emphasize the method requires further refinement before clinical use. Capillary samples showed somewhat lower diagnostic accuracy compared to venous blood, and standardized collection protocols need development. Currently, the technique shows most promise for research settings, population screening, and therapeutic trial recruitment rather than immediate patient care decisions.
“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,” said study author Anne Corbett, Professor in Dementia Research at the University of Exeter.
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