Image courtesy of Wikimedia Commons.
Male patients account for 60% of COVID-19 deaths globally, and studies have shown that they are two times more likely to die from the virus than female patients. A team of Yale researchers, studying samples from SARS-CoV-2-positive patients admitted to Yale New Haven Hospital, recently investigated the underlying immune mechanisms that might help explain why.
According to their results, a key difference may lie in the activation of certain cells and signaling molecules. Male patients had higher levels of cytokines, molecules that stimulate inflammation in response to invasion by foreign agents as part of the non-specific innate immune response. Conversely, female patients exhibited stronger activation of CD8+ T-cells, “killer” cells that target specific viruses as part of the adaptive immune response. While female patients’ T-cell activity stayed consistent regardless of age, older male patients’ T-cells tended to become less effective.
These results can’t account for an individual patient’s specific outcome, but with this new knowledge, doctors may be able to narrow their approaches based on patient sex. And in a disease as unknown and fast-acting as COVID-19, such molecular changes might have a big impact.