A recent study that was funded by the National Institutes of Health (NIH) has found that a blood test could reveal Alzheimer’s symptom risk, according to a news release.

The clues lie in certain circular RNAs (circRNAs), which reveal recent brain activity. Previous research from the Washington University School of Medicine, St. Louis showed a connection between circRNAs in the brain and dementia and neuropathological severity. The researchers wanted to see if these findings extended to blood.

Upon reviewing more than 1,200 participants’ blood data, the researchers were able to connect 34 circRNAs with Alzheimer’s. They then used predictive models to test the associations. The models effectively recognized patients with Alzheimer's pathology, similar to pTau217.

The circRNAs proved more effective than pTau217 for predicting symptom onset, with levels changing two-four years before they start. Additionally, “circRNAs in the blood nearly tripled patients’ risk of developing symptoms.” These findings could aid personalized treatment strategies and monitoring.