Immunology and Endometriosis

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.