Coronavirus: women can develop a stronger immune response
Why does the coronavirus hit men the most? A hypothesis emerges with a study conducted by researchers at Yale University. They found that women produce a stronger immune response than men, regardless of age, by activating a specific type of white blood cell. These results highlight the idea of a gender approach to patient treatment.
A new study looking at men's and women's immune responses to coronavirus may shed new light on why men are more likely to be severely affected. Published in the journal Nature, the Yale researchers say they have identified differences in the way your immune system responds to the virus. They note that since the outbreak of the epidemic, there is evidence of gender differences in this area, but scientists do not know why immune responses to SARS-CoV-2 differ between the sexes, and if this can explain the sensitivity of men. to COVID-19.
Therefore, the scientists wanted to find possible biological mechanisms that would explain why men are more likely than women to suffer from severe forms of COVID-19 and die from the disease. "What we found is that men and women develop different types of immune responses to COVID-19," explains the study's lead author, Professor Akiko Iwasaki. The immunity specialist estimates that "these differences may be the basis for a greater susceptibility to the disease in men", who represent around 60% of deaths from COVID-19 worldwide according to the estimates of the scientific team.
Women's immune systems respond better
The researchers took blood, saliva and nasal samples every three to seven days from 59 uninfected people, as well as patients with the disease (17 men and 22 women). They followed all of these patients over time to see how immune responses differed between those recovering from the disease and those progressing to severe forms. In general, the scientists found that sick women developed a better immune response because their bodies produced more than one class of immune cells, T lymphocytes, white blood cells capable of recognizing viruses and eliminating them.
This trend was similar in older women, while older men had lower T-cell activity: the older they were, the weaker the response. Men have also produced more cytokines, inflammatory proteins that are deployed as part of the body's innate immune response. However, severe cases of COVID-19 have been linked to an excessive accumulation of cytokines, a phenomenon called a "cytokine storm." However, this runaway immune system can severely damage the patient's lungs, leading to acute respiratory distress syndrome, tissue damage, and organ failure.
Should patients be treated differently based on sex?
The researchers found that men who showed significant levels of cytokines early in the infection were more likely to suffer from a severe form of the disease, as were women. But certain types of cytokines, called interleukin-8 and interleukin-18, were high in all men and only some women. Based on these results, the researchers suggest exploring different treatment interventions for different genders.
"For men, we should improve the T-cell response with vaccines, while women could be treated to block the cytokine response," says Professor Akiko Iwasaki.
However, this study has limitations. Based on the fact that the number of patients studied was very limited and that the mean age of the group was also high, around sixty years, which makes it difficult to assess the evolution of the immune response with age. Commenting on the results, Professor Eleanor Riley from the University of Edinburgh said that some of the discrepancies seen in the study "could be due to age or body mass index (BMI), or even timing rather than gender. For this one specialist, therefore, it is better to favor personalized treatments according to the case of each patient, instead of defining them solely on the basis of gender.