A set of 34 specific circular RNAs in the blood can predict the onset of Alzheimer’s disease symptoms, according to a study funded by the National Institutes of Health (NIH). Research indicates these markers can identify the transition to symptomatic Alzheimer’s two to four years before clinical signs appear, potentially improving patient selection for clinical trials.
How Do Circular RNAs Differ from Traditional Biomarkers?
Traditional blood-based biomarkers for Alzheimer’s often reveal pathology decades before a patient experiences cognitive decline. However, these markers provide limited insight into the actual progression of the disease, according to the NIH. In contrast, circular RNAs are dynamic molecules that reflect recent brain activity, offering a more immediate snapshot of neurological health.
Carlos Cruchaga, PhD, a researcher at the Washington University School of Medicine and the study’s corresponding author, previously established a link between these molecules and dementia severity in the brain. By shifting the focus to blood analysis, researchers found that these markers provide a broader perspective on disease biology, particularly for patients undergoing amyloid-removal therapies who may test negative for traditional markers but still exhibit disease progression.
Unlike amyloid plaques that accumulate slowly in the brain, circular RNAs are dynamic and reflect recent brain activity.
Can Blood Tests Predict Future Alzheimer’s Progression?
The study, which analyzed blood data from more than 1,200 individuals across multiple independent cohorts, suggests that circular RNAs are highly effective at forecasting the transition to symptomatic Alzheimer’s. In predictive models, the 34 markers identified individuals with Alzheimer’s pathology with similar accuracy to pTau217, but the circular RNA model outperformed the pTau217 model in predicting future disease progression, according to the NIH.
| Metric | Traditional Biomarkers (pTau217) | Circular RNA Model |
|---|---|---|
| Primary Function | Detects Alzheimer’s pathology | Predicts transition to symptomatic Alzheimer’s |
| Predictive Window | Decades (pathology) | 2–4 years (symptom transition) |
What Is the Future of Clinical Alzheimer’s Screening?
The ability to identify patients on the verge of symptom onset is a priority for clinical researchers. Richard Hodes, MD, director of the National Institute on Aging, stated in an NIH release that this information is “invaluable” for selecting the right participants for clinical trials and assessing the effectiveness of treatments designed to prevent cognitive decline.
Researchers are currently collaborating with commercial partners to develop clinical assays. These tests aim to provide clinicians with a more complete view of a patient’s disease trajectory, allowing for better monitoring of how individuals respond to new medical interventions.
Keep an eye on advancements in blood-based diagnostics.
Frequently Asked Questions
- What are circular RNAs? They are molecules found in the blood that reflect recent brain activity.
- How far in advance can these markers predict symptoms? According to the NIH, these circular RNAs can indicate a transition to symptomatic Alzheimer’s approximately two to four years before symptoms manifest.
- Are these tests available now? Not yet. Researchers are currently working with commercial partners to develop clinical assays based on these findings.
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