COVID-19: Men vs. Women – Cytokine & Severity
Men with severe COVID-19 present higher levels of proinflammatory cytokines, a key finding from a new study. This research, published in the European Journal of Immunology, reveals that elevated IL-18 levels in men may contribute to a less effective immune response, impacting the severity of their illness. The primarykeyword, cytokine, plays a significant role in the body’s reaction, while the secondarykeyword, COVID-19, remains at the forefront of health concerns. The study,conducted by Umeå University,sheds light on why men are more frequently admitted to intensive care units. Researchers analyzed 206 participants focusing on sex-based differences in NETs and proinflammatory cytokines, with significant implications for future treatment strategies. Find this and more news at NewsDirectory3. Discover what’s next …
Men’s COVID-19 Severity Linked to Cytokine Levels
Updated June 19, 2025
Men who develop severe COVID-19 exhibit higher levels of proinflammatory cytokines compared to women, according to a study from Umeå University in Sweden. The research, published in the European Journal of Immunology, suggests that the presence of IL-18, a cytokine affecting neutrophil activation, may contribute to a less effective immune response against the virus.
While most COVID-19 infections are mild, some patients experience severe disease characterized by hyperinflammation in the lungs and dysregulated immune responses. Neutrophil extracellular traps (NETs) can exacerbate this,promoting immunothrombosis and tissue damage.
Identifying those at higher risk for severe COVID-19 is crucial. Interestingly, men are more likely to require intensive care, despite similar overall case numbers between sexes. The study aimed to understand this disparity.
Johan Mormark, an infectious disease physician at Umeå University, noted that men are three times more likely to need intensive care. ”our study contributes to understanding how this sex-related difference in severe COVID-19 arises,” Mormark said.
Researchers analyzed plasma from 206 participants, including 86 women, focusing on sex-based differences in NETs and proinflammatory cytokines. They confirmed that COVID-19 plasma triggered NET release, increasing with disease severity. They then examined cytokine levels within the first 30 days of infection.
The study found that several proinflammatory cytokines, including IL-10, IL-6, CCL7, and IL-18, were elevated in severe COVID-19 cases, with higher levels in men. Further analysis focused on IL-10 and IL-18.IL-18,known to induce NET formation,was significantly higher in men. Macrophage-derived chemokine levels showed similar sex-dependent differences and increased disease severity in men.
“We saw that the increase in the inflammatory cytokine IL-18 was sex-dependent and that the activation of neutrophils was sex-dependent,” said Constantin Urban, professor at Umeå University. “On average, both the amount of this cytokine and neutrophil activation markers were higher in blood plasma from men with severe COVID-19 compared to blood plasma