☝️Finger-Prick Blood Test Could Revolutionize Early Alzheimer’s Detection

Why Early Detection Matters

Alzheimer’s disease begins silently, often 15–20 years before memory loss becomes noticeable. During this time, changes in brain proteins—amyloid and tau—progress unnoticed. Detecting these changes early is critical because new treatments work best in the earliest stages. Early diagnosis gives patients and families time to plan, adopt protective lifestyle changes, and access medical support.

How Finger-Prick Testing Differs

Traditional Alzheimer’s diagnostics often involve a complex and costly process: patients undergo venous blood draws for multiple biomarkers, cognitive assessments with specialists, and advanced imaging such as MRI or PET scans. These steps require clinic visits, specialized equipment, and significant financial resources—barriers that can delay or prevent early detection for many people.

Finger-prick testing introduces a paradigm shift. With just a single drop of blood collected at home, individuals can access preliminary insights without traveling to a clinic. This simplicity makes screening more inclusive, particularly for rural populations or those with mobility challenges. Moreover, finger-prick sampling is inexpensive and easy to repeat, enabling continuous monitoring over time. This opens the door to proactive health management, where people can track changes in Alzheimer’s risk before symptoms emerge, rather than waiting for advanced disease stages. This type of testing is of growing interest: a survey of adults recently conducted in the U.S. revealed 22% have pursued a self-test to appease their curiosity¹.

The Role of p-Tau217

At the heart of this innovation is p-Tau217, a phosphorylated tau protein fragment that rises in the blood as Alzheimer’s pathology begins. Unlike older biomarkers, p-Tau217 offers exceptional accuracy in detecting early pathological changes—even before cognitive decline becomes apparent. Its predictive power has been validated in multiple studies, showing strong correlation with brain imaging or cerebrospinal fluid markers^2,3,4.

What makes p-Tau217 particularly exciting is its sensitivity even in tiny blood samples. Recent research demonstrates that finger-prick collections can reliably measure this biomarker, making it feasible for at-home testing⁵. Detecting elevated p-Tau217 could help identify individuals at higher risk of Alzheimer’s progression, enabling earlier interventions such as lifestyle adjustments or enrollment in clinical trials. In short, p-Tau217 is not just another marker—it represents a breakthrough in making Alzheimer’s detection simpler, faster, and more accessible.

Is It Ready for Clinical Use?

Not yet. Finger-prick Alzheimer’s tests are still experimental and require full validation and regulatory approval. PREDICTOM aims to bridge this gap by comparing finger-prick results with traditional blood, cerebrospinal fluid, imaging, and cognitive data from hundreds of participants. The goal: determine accuracy and feasibility for future clinical practice.

What’s Next?

The study runs until 2027, with interim findings expected earlier. If successful, finger-prick testing could transform Alzheimer’s detection—making it faster, cheaper, and more inclusive.

Siemens Healthineers is leading the Finger-Prick Blood Test in PREDICTOM clinical Study. Learn more about Alzheimer’s and Siemens Healthineers’ solutions .

References:

1. https://www.siemens-healthineers.com/en-us/patient-testing-survey-social-media-healthcare

2. Malek-Ahmadi M et al. Plasma Phosphorylated Tau 217 and Amyloid Burden in Older Adults Without Cognitive Impairment: A Meta-Analysis. JAMA Neurol. 2025 Dec 1. doi: 10.1001/jamaneurol.2025.4721. Epub ahead of print. PMID: 41324928.

3. Dag Aarsland et al. Prevalence of Alzheimer’s disease pathology in the community. 2025 Dec 17. doi: https://doi.org/10.1038/d41586-025-04133-x

4. Huber H, et al. A minimally invasive dried blood spot biomarker test for the detection of Alzheimer’s disease pathology. 2026 Jan 05. https://www.nature.com/articles/s41591-025-04080-0

5. Huber H, et al. Biomarkers of Alzheimer's disease and neurodegeneration in dried blood spots-A new collection method for remote settings. Alzheimers Dement. 2024 Apr;20(4):2340-2352. https://doi.org/10.1002/alz.13697. Epub 2024 Jan 29. PMID: 38284555; PMCID: PMC11032540.