Thursday, 27 August 2020_The immune system of women may induce more appropriate responses to the coronavirus, a small study suggests, providing a clue to why COVID-19 tends to be more severe in men.
Among 98 mostly older adults who were hospitalized with mild or moderate COVID-19, women overall had more "robust" and "sustained" attacks on the virus by their immune systems' T cells, researchers reported on Wednesday in Nature.
Poor T cell responses in men were linked with worse outcomes, they found.
There were also gender differences in production of signaling molecules - known as chemokines and cytokines - that recruit immune cells to sites of inflammation.
On average, men had higher levels of these molecules, but when women did have high levels, they tended to do poorly.
The findings "provide an important basis for the development of a sex-based approach to the treatment and care of men and women with COVID-19," researchers said.
Men may benefit from therapies that boost their T cell responses, whereas women may benefit from therapies that dampen the signaling molecule response, they said.
Hormones may add to women’s COVID-19 survival benefit
Sex hormones may contribute to gender differences in COVID-19 mortality, another new research suggests.
While women have lower COVID-19 death rates than men, the difference is narrower among older men and women.
Levels of the female hormone estradiol - which are naturally higher in younger women - might help explain that pattern.
Researchers studied electronic health records of nearly 37,000 female COVID-19 patients from 17 countries, comparing pre- and post-menopausal women and taking into account the use of estradiol in contraceptives or hormone replacement therapy (HRT).
Birth control drugs were not linked with any significant effect on COVID-19 mortality risk. But among women over age 50, those receiving HRT with estradiol had a two-thirds lower risk of death from the coronavirus compared to non-users in that age group.
The study does not prove that HRT caused the reduced risk. In their report posted on medRxiv on Monday ahead of peer review, the researchers warned that hormones can have side-effects and women should not start using them on their own.
The researchers call for large prospective trials to test the theory that estradiol therapy might help lower older women's risk of death from COVID-19.
Source: Agencies