Umeå University Discovers Why Men Suffer More From Severe COVID-19

Umeå, Sweden — Researchers at Umeå University have shed light on why men tend to experience more severe symptoms of COVID-19 compared to women. This finding, published in the European Journal of Immunology, could inform treatment strategies for those facing severe COVID-19 complications.

Despite similar infection rates, men are three times more likely to require intensive care when battling COVID-19. Johan Normark, an infectious disease physician at the university, emphasized the importance of this research, stating, “Our study contributes to understanding how this sex-related difference in severe COVID-19 arises.”

COVID-19 is caused by the SARS-CoV-2 virus and first emerged in Wuhan, China in December 2019, leading to a worldwide pandemic. While a significant portion of infected individuals experience mild symptoms, about 20% suffer severe reactions that can necessitate hospitalization.

The study analyzed samples from over 200 Swedish COVID-19 patients, focusing particularly on immune responses involving neutrophils, a type of white blood cell. Doctoral student Remigius Gröning was responsible for mapping cytokine profiles, while Emelie Backman quantified neutrophil activation markers. Their results showed higher levels of cytokines and neutrophil activation in men suffering from severe COVID-19.

“We saw that the increase in the inflammatory cytokine IL-18 was sex-dependent,” Prof. Urban noted, emphasizing its significance. The heightened activation of neutrophils in men was identified as a crucial factor linking to more severe disease outcomes, which poses risks like tissue damage and even death.

The findings are important as they align with ongoing studies aiming to mitigate symptoms of severe COVID-19 through approaches that suppress neutrophil activation. Researchers stress that understanding these differences is vital for developing effective treatment strategies tailored to individual immune responses.

In future studies, the team plans to further investigate the molecular mechanisms behind these sex-related differences, with aims to verify results in larger patient groups.

More information is found in the study: “Elevated Plasma Levels of NET Components in Men with Severe COVID-19 Correlates to Increased Amounts of IL-18,” published in the European Journal of Immunology.