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Health
A new Australian study reveals genetic and immune differences that make women more prone to autoimmune diseases like lupus.
Women are up to nine times more likely than men to develop autoimmune diseases such as lupus, and a new Australian study sheds light on the biological reasons behind this disparity. Researchers from the Garvan Institute of Medical Research and the University of New South Wales in Sydney have identified distinct genetic and immune profiles that make the female immune system more active and inflammation-prone.
This heightened activity provides women with a stronger defense against viral infections, but it also increases the risk of the immune system mistakenly attacking the body's own healthy tissues. The study was released ahead of World Lupus Day on May 10.
The team employed advanced techniques to analyze immune cells with unprecedented precision, examining over 1.25 million cells from nearly 1,000 healthy individuals. This data came from the Australian "OneK1K" project, which investigates how genetic factors influence immune system function.
The analysis revealed that women have higher levels of certain inflammation-linked immune cells, including B cells and regulatory T cells. Men, conversely, showed higher proportions of monocytes, which are responsible for initial immune responses and cellular maintenance tasks.
This "elevated immune activity" gives women an advantage in fighting viral infections, but it makes their immune system more susceptible to "friendly fire," where it mistakenly attacks healthy body tissues, leading to autoimmune diseases.
— Dr. Sarah Balouz, study co-author, explained the double-edged nature of the finding.
To understand the genetic underpinnings, the researchers investigated "genetic control switches"—variants that regulate gene activity within immune cells. They identified over 1,000 such switches that operate differently in women and men.
Surprisingly, the study, published in the American Journal of Human Genetics, found that most of these differences were not located on the X or Y sex chromosomes as previously believed. Instead, they were found on the autosomal chromosomes shared by both sexes.
The team also discovered genetic variants that influence the activity of two genes linked to systemic lupus erythematosus in women, potentially explaining the significantly higher rates of the disease among females.
Dr. Sihan Yazar, the study's lead author, stated that the findings confirm autoimmune diseases may not develop in the same way in men and women, and therefore treatment should not rely on a one-size-fits-all approach. He added that many previous medical studies relied heavily on male samples, leading to the neglect of biological sex differences and their impact on understanding diseases and treatment responses.
The researchers believe these results could pave the way for developing more precise therapies that target specific immune and genetic pathways in each patient, rather than relying on general immunosuppressants that weaken the entire immune system.
