Zurich, Switzerland – Scientists have made a significant breakthrough in the understanding of long Covid, identifying a key change in blood proteins that suggests the immune system remains hyperactive long after initial infection. This finding, published in the journal Science, may provide insights into the persistent symptoms experienced by long Covid patients and potentially pave the way for diagnostic tests and treatments.
The study followed 113 Covid patients for up to one year post-infection, comparing them to 39 healthy individuals. At the six-month mark, 40 patients developed long Covid symptoms. Analysis of their blood samples revealed persistent activation of the complement system, a part of the immune system responsible for eliminating viruses and bacteria. In long Covid patients, the complement system remained active even after the pathogens were cleared, leading to damage in healthy cells, blood clot formation, and tissue damage in organs.
Dr. Onur Boyman, an immunology professor at the University of Zurich, explained that the inflamed endothelial cells in long Covid patients are more vulnerable to exercise due to impaired function. Microclots formed by the activated complement system can disrupt the delivery of oxygen and nutrients to various organs, leading to symptoms like fatigue, brain fog, and memory issues.
This new study delves into the molecular mechanisms underlying the tissue damage and blood clotting observed in long Covid patients. Previous research has also highlighted potential mechanisms, such as viral remnants in the gut triggering reductions in serotonin levels and lower cortisol levels in long Covid patients compared to other Covid patients and healthy individuals.
Experts believe that these findings open up possibilities for developing diagnostic tests and treatments by targeting the complement system proteins. However, the methods used in this study are not suitable for routine diagnostic labs, and the researchers emphasize the need for collaboration with diagnostic companies and further replication of the study’s results. If a simplified test can be developed, pharmaceutical companies can begin clinical trials of potential treatments, including drugs that modulate and inhibit the complement system.
Dr. Monica Verduzco-Gutierrez, chair of rehabilitation medicine at the University of Texas Health Science Center, expressed optimism about the study’s implications for future research and treatment options for long Covid. She underscored the importance of longer-term studies to understand the condition’s impact on patients over time.
While there is still much to learn, this new research represents a crucial step forward in unraveling the mysteries of long Covid and offers hope for improved diagnosis and treatment methods.