Gender as risk factor for autoimmune diseases

Area of Science:

• Immunology
• Reproductive Immunology
• Autoimmunity

Background:

• Autoimmune diseases disproportionately affect women, a phenomenon lacking a definitive explanation.
• Existing theories focus on hormonal influences (estrogen and Th2 response) and genetic predispositions (X chromosome).
• Recent research explores the role of fetal-maternal microchimerism in immune tolerance and autoimmunity.

Purpose of the Study:

• To investigate the potential link between fetal-maternal microchimerism and the higher incidence of autoimmune diseases in women.
• To propose a novel explanation for female preponderance in autoimmunity based on immune cell traffic and microchimerism.

Main Methods:

• The study reviews existing literature and proposes a theoretical framework.
• It draws analogies to allogeneic organ transplantation to explain immune tolerance mechanisms.
• The evolutionary perspective is used to contextualize autoimmune disease occurrence.

Main Results:

• Increased allogeneic cell traffic in females, compared to males, may lead to a higher risk of persistent fetal-maternal microchimerism.
• Persistent microchimerism could contribute to the breakdown of immune tolerance, fostering autoimmune responses.
• This mechanism offers a potential explanation for the observed female preponderance in autoimmune diseases.

Conclusions:

• Female preponderance in autoimmune diseases may be an unavoidable consequence of increased fetal-maternal cell traffic and microchimerism.
• Autoimmunity in women could represent an evolutionary price for successful reproduction and immune tolerance during pregnancy.
• Further research into microchimerism is warranted to fully understand its role in autoimmune disease pathogenesis.