Proteins Failed to Predict Long COVID Risk
Researchers found that measuring FGF2 and PRDX3 proteins did not reliably help forecast long-term COVID-19 outcomes.
Updated on Oct. 10, 2026 in COVID-19
A new study evaluated whether the proteins FGF2 and PRDX3 could serve as effective markers for predicting Long COVID risk. Analysis of two separate patient groups showed these proteins failed to provide a reliable improvement in predictive modeling.
Why it matters
Identifying accurate biomarkers remains a critical challenge in clinical research for managing post-viral conditions. This finding suggests that these specific proteins are not yet useful tools for clinicians to forecast which patients are at higher risk for persistent symptoms.
Researchers analyzed 122 participants in the Su cohort and 113 in the Zurich cohort, comparing models that included FGF2 and PRDX3 proteins against a reference model using age and sex. The addition of these proteins failed to meaningfully improve the accuracy of predicting Long COVID events.
The details
The research team tested the utility of FGF2 and PRDX3 by comparing a standard prediction model against one supplemented with protein data. They found that predictive accuracy did not significantly improve, suggesting that protein standardization is highly dependent on the target cohort. Because clinical markers for Long COVID have proven elusive, this result highlights the complexity of identifying biological signals that remain consistent across diverse patient populations.
Timeline
October 10, 2026: Findings were published to the scientific record.
Health Landscape
This study contributes to the broader research effort by narrowing the field of potential biomarkers currently under investigation by large-scale initiatives like the NIH RECOVER Initiative. It underscores the ongoing difficulty in finding standardized diagnostic tools for a condition characterized by high patient variability.
This finding confirms that there is currently no simple blood-based protein test to predict your personal risk of developing Long COVID. If you are concerned about persistent symptoms following an infection, continue to document your health changes and discuss them with your physician.
The takeaway
While this specific protein-based approach did not prove predictive, ongoing research continues to explore other potential biological markers for Long COVID. Patients should focus on tracking symptoms and maintaining regular checkups with their healthcare providers to manage lingering post-infection health concerns.
Further reading
For more on the current understanding of persistent symptoms, visit COVID-19.
