• Autoimmunity;
  • chemokines;
  • cytokines;
  • endometrium;
  • macrophage;
  • natural killer cell

Problem: Accumulating data suggests that aberrant immune responses during retrograde menstruation may be involved in the development of endometriosis.

Method of Study: The role of immunology in the etiology of endometriosis is reviewed and summarized from the available literature.

Results: Immunologic factors may affect a woman's susceptibility to implantation of exfoliated endometrial cells. Immune alterations include increased number and activation of peritoneal macrophages, decreased T cell reactivity and natural killer cell cytotoxicity, increased circulating antibodies, and changes in the cytokine network.

Conclusion: There is substantial evidence that immunologic factors play a role in the pathogenesis of endometriosis and endometriosis-associated infertility. Decreased natural killer cell cytotoxicity leads to an increased likelihood of implantation of endometriotic tissue. In addition, macrophages and a complex network of locally produced cytokines modulate the growth and inflammatory behavior of ectopic endometrial implants.