Autoimmune diseases are conditions where the immune system mistakenly attacks the body’s own healthy cells.
They disproportionately affect women and while both sexes can develop autoimmune diseases, us gals are far more likely to suffer from conditions like rheumatoid arthritis, multiple sclerosis (MS), or lupus.
This gender disparity has confused doctors and other medical professionals for decades, and according to Trinity College professor Luke O'Neill, it’s a topic that has been historically under-researched.
Speaking on his podcast Show Me the Science, Professor O’Neill highlighted the lack of attention given to this issue.
“Tragically, it’s been neglected and overlooked,” he said before adding how frustrating it is that more progress hasn’t been made.
He speculated that if men were the ones disproportionately affected, research might have advanced more rapidly.
However, O’Neill pointed out that there’s now growing interest in understanding why women are at higher risk.
“There’s a big focus on this area now,” he said, adding that studying the differences between the sexes in terms of disease susceptibility could provide useful insights for both men and women.
“It’s just a very interesting scientific topic,” he noted.
One potential explanation for the increased susceptibility in women could lie in the difference between male and female chromosomes.
Generally, men have one X and one Y chromosome, while women have two X chromosomes.
According to Professor O'Neill, the X chromosome carries a significant number of genes - around 1,000 - compared to the Y chromosome, which only has about 70.
“Having two X chromosomes might mean that women are getting a double dose of certain genes,” O'Neill explained.
Some of these genes, when "overexpressed, can lead to harmful immune responses".
Two particular genes on the X chromosome, TLR7 and CD40L, have been linked to inflammation.
Overactivity of these genes can trigger an immune response that spirals out of control, potentially leading to autoimmune diseases.
“Women might be expressing two doses of TLR7 or CD40L, and that’s what could be driving their immune system into overdrive,” O'Neill said.
Emerging research supports this theory, suggesting that the "double whammy" of having two X chromosomes could provoke an overactive immune response, increasing the likelihood of autoimmune diseases in women.
While there is still so much to learn, this growing understanding of genetic differences between men and women may eventually lead to more effective treatments for autoimmune diseases.
By focusing on what makes women more susceptible, scientists could discover new approaches to managing or even preventing these conditions.
For now, though, autoimmune diseases remain a major health issue, with women bearing the brunt of the burden.
