Macrophage migration inhibitory factor expression in the intrauterine endometrium of women with endometriosis varies with disease stage, infertility status, and pelvic pain

Objective To evaluate the concentrations of macrophage migration inhibitory factor (MIF) in the eutopic endometrial tissue of women with and without endometriosis. Design Retrospective study using ELISA to measure MIF concentrations in total endometrial tissue proteins extracts. Setting Gynecology clinic and human reproduction research laboratory. Patient(s) Forty-five women with endometriosis and 25 normal women. Intervention(s) Endometrial biopsies were obtained a few days before laparoscopy. Main Outcome Measure(s) Concentrations of MIF in tissue protein extracts. Result(s) Levels of MIF were significantly higher in women with endometriosis, increased with disease stage, and were cycle phase dependent. Of note is the significant increase in MIF levels occurring in the midsecretory phase in women with endometriosis as compared with controls, particularly in infertile patients, as well as in the late secretory phase preceding menstruation. Furthermore, MIF levels seemed to be particularly elevated in women with endometriosis who were infertile and who suffered from pelvic pain. Conclusion(s) This study showed a significant increase in MIF concentrations in the intrauterine endometrial tissue of women with endometriosis, occurring at specific phases of the menstrual cycle, a relationship between MIF concentrations and disease stage, and a possible role for this factor in endometriosis-associated pain and infertility.