Nikhil Prasad Fact checked by:Thailand Medical News Team Jul 26, 2026 1 hour, 2 minutes ago
Medical News: Scientists are now uncovering a critical piece of the COVID-19 puzzle, and it revolves around a group of immune system molecules known as Interleukin-6 or IL-6 family cytokines. These tiny signaling proteins may be responsible not only for life-threatening cases of COVID-19 but also for the persistent symptoms seen in Long COVID.
Scientists reveal how a key immune molecule may drive both severe COVID-19 and lingering symptoms
Researchers from the Institute of Biomedicine of Seville (IBiS), the Spanish National Research Council (CSIC), the University of Seville, and Virgen del Rocio University Hospital in Spain conducted an extensive review to better understand how these molecules behave during and after infection.
Understanding the Role of IL-6 in the Body
Cytokines like IL-6 act as messengers that help the immune system respond to infections. Under normal conditions, they help the body fight viruses and repair damaged tissues. However, when their activity becomes uncontrolled, they can trigger excessive inflammation.
The IL-6 family includes several related molecules that work together in a complex network. This system can be helpful in moderation, but when overactivated, it can lead to harmful effects throughout the body.
Why Severe COVID-19 Becomes Dangerous
One of the key findings is that patients with severe COVID-19 often have very high levels of IL-6. This increase is strongly linked to worse outcomes, including breathing difficulties and organ damage.
IL-6 operates through two different pathways. One pathway supports healing and normal immune function, while the other drives strong inflammation. In serious COVID-19 cases, the inflammatory pathway becomes dominant, leading to what is commonly known as a cytokine storm.
This overwhelming immune response can damage lung tissue, disrupt blood vessels, and increase the risk of dangerous blood clots. The imbalance between protective and harmful effects of IL-6 is now seen as a major factor in disease severity.
The Connection to Long COVID Symptoms
Even after recovery from the initial infection, some individuals continue to experience symptoms for months. Scientists believe that IL-6 may play a role in keeping the immune system in a prolonged state of activation.
This
Medical News report explains that ongoing low-grade inflammation could be behind symptoms such as fatigue, brain fog, and breathing problems. In some patients, IL-6 levels remain elevated, while in others, inflammation may persist in specific tissues without showing clearly in blood tests.
This variation helps explain why Long COVID presents so differently from person to person.
New Approaches to Treatment
Early treatments focused on blocking IL-6 entirely, but researchers now realize that this approach may not be ideal. Since IL-6 also has beneficial roles, completely shutting
it down can weaken the immune response.
New therapies are being designed to target only the harmful inflammatory signals while preserving the protective ones. Some experimental treatments even combine antiviral action with immune regulation, offering a more balanced approach.
Studies in animal models have shown promising results, including reduced lung damage and improved recovery, but more research is needed before these treatments become widely available.
Timing May Be the Key to Success
Another important discovery is that timing matters greatly when targeting IL-6. Blocking it too early may interfere with the body’s ability to fight the virus, while acting too late may not prevent damage.
This means future treatments will likely rely on careful monitoring of immune signals to determine the best moment for intervention.
Conclusion
The growing evidence shows that IL-6 is not just another immune molecule but a central player in both severe COVID-19 and Long COVID. Its dual nature, being both protective and harmful, makes it a challenging but critical target for treatment. Understanding how to control its activity without disrupting essential immune functions will be vital in reducing both immediate complications and long-term health effects associated with the virus.
The study findings were published in the peer reviewed journal: BBA - Molecular Cell Research.
https://www.sciencedirect.com/science/article/pii/S0167488926000972
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Read Also:
https://www.thailandmedical.news/articles/coronavirus
https://www.thailandmedical.news/articles/long-covid
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