Women are more prone to persistent chronic pain than men. This difference has led scientists to examine its biological foundations, beyond perceptions alone.
A study published in
Science Immunology, conducted by specialists from Michigan State University, provides some answers to explain this difference. This work demonstrates the involvement of specific immune cells, monocytes, in the natural decrease of pain sensation.
Illustration image Pixabay
These cells produce a molecule called IL-10, which functions as a soothing signal for pain neurons. The team observed a higher production of this molecule in male subjects, an effect correlated with higher levels of sex hormones such as testosterone.
To confirm these findings, several experiments were conducted on animal models. The scientists used techniques to analyze the cells and found that monocyte activity decreases when male hormones are blocked.
The work also examined human data, in collaboration with researchers from the University of North Carolina. They revealed a comparable trend, with faster pain recovery in men, associated with enhanced activity of IL-10-producing monocytes.
This research thus demonstrates that the disappearance of pain is not a passive process. It is actively driven by the immune system, with notable distinctions between the sexes.
These side-by-side microscopic images show lower levels of IL-10 receptor subunits, in yellow, in female skin cells (left) compared to male cells (right).
Credit: Laumet laboratory
These discoveries could, in the long run, pave the way for non-opioid treatments. By targeting IL-10 production mechanisms, it would be conceivable to help the body better control chronic pain, thus offering new options to improve patients' daily lives.
The influence of sex hormones on immunity
Sex hormones, such as testosterone and estrogens, play a key role in modulating the immune system. They act on various cell types, influencing their development and function.
For example, testosterone tends to promote the production of anti-inflammatory molecules by monocytes. Conversely, estrogens can in some cases favor more active or pro-inflammatory immune responses.
These hormonal distinctions explain why men and women present distinct immune profiles. They have direct implications on how each sex manages conditions like chronic pain. Integrating these factors into medical research allows for more personalized treatments to be considered.