New research from the Garvan Institute of Medical Research and UNSW Sydney has identified more than 1,000 genetic switches that behave differently in female and male immune cells, potentially explaining why women are diagnosed with autoimmune diseases far more often than men. Autoimmune diseases occur when the immune system mistakenly targets the body’s own healthy tissues, such as in lupus, which affects nine times more women than men.

The study, published in The American Journal of Human Genetics, used single-cell technologies to examine individual immune cells in much greater detail and found clear differences between males and females. Males had larger proportions of monocytes, while females had greater numbers of B cells and regulatory T cells with much more genetic activity associated with inflammatory pathways. These findings suggest that a more reactive immune system gives females an advantage in fighting viral infections but comes with a biological trade-off: a greater predisposition to autoimmune diseases.

The researchers identified sex-specific genetic switches located on autosomes, the non-sex chromosomes shared by males and females, rather than being concentrated on the sex chromosomes as previously thought. Some of these genetic controls were directly associated with autoimmune disease, potentially helping explain why lupus occurs about nine times more often in women than in men. The findings could lead to more personalized treatments for autoimmune conditions such as lupus, where current therapies do not work equally well for everyone and often broadly suppress immune activity throughout the body.

This is a summary. Read the original at sciencedaily.com.