Note: Single-source report; awaiting corroboration.
A new blood test detecting specific circular RNAs (circRNAs) may improve prediction of when Alzheimer’s disease symptoms are likely to appear, according to NIH-funded research. Unlike current blood tests that identify amyloid plaques—which accumulate slowly and may appear decades before symptoms—circRNAs are dynamic molecules that reflect recent brain activity.
The study, involving data from over 1,200 people in multiple groups, identified 34 blood circRNAs associated with Alzheimer’s disease. Predictive models using these circRNAs matched the accuracy of those using pTau217 protein, the current leading blood biomarker, in diagnosing existing pathology, and outperformed them in forecasting progression to symptomatic Alzheimer’s. The circRNA levels changed about two to four years before symptoms appeared.
Consistent findings across separate cohorts suggest that measuring circRNAs in blood could form the basis of a clinical test to identify individuals near symptom onset. This may help select appropriate patients for clinical trials and assess treatment effectiveness against cognitive decline.
Richard Hodes, director of NIH’s National Institute on Aging, highlighted the importance of identifying patients approaching symptom onset to optimize treatment choices and trial design.
The research builds on earlier studies linking brain circRNAs to dementia severity and neuropathology. By showing that circulating blood circRNAs have clinical promise, the study points to a potentially more sensitive biomarker for anticipating Alzheimer’s clinical progression.