Marked Elevation of Macrophage Migration Inhibitory Factor in the Peritoneal Fluid of Women with Endometriosis

Objective: To evaluate the presence of macrophage migration inhibitory factor (MIF) in the peritoneal fluid of normal fertile women and patients with endometriosis and its growth-promoting activity toward human endothelial cells.

Design: Retrospective study using ELISA to measure peritoneal fluid MIF, and [3H]-thymidine incorporation into the DNA of human endothelial cells to assess its mitogenic activity.

Setting: Gynecology clinic and human reproduction research laboratory.

Patient(s): Thirty-six healthy women and 57 women with endometriosis.

Intervention(s): Peritoneal fluid samples were obtained at laparoscopy.

Main Outcome Measure(s): Macrophage migration inhibitory factor concentrations in the peritoneal fluid samples and [3H]-thymidine incorporation into the DNA of human microvascular endothelial cells to assess proliferation.

Result(s): This study demonstrated the presence of MIF in the peritoneal fluid and a 238% increase of MIF levels in women with endometriosis as compared with healthy women. Both fertile and infertile women with endometriosis had significantly higher MIF concentrations than did fertile women with normal gynecological status, but the difference was more significant in infertile endometriosis patients. Anti-MIF antibody significantly inhibited proliferation of human microvascular endothelial cells in response to peritoneal fluids from healthy women and women with endometriosis stages I-II and III-IV, as assessed by [3H]-thymidine incorporation.

Conclusion(s): This study revealed the presence of MIF in the peritoneal fluid and its increased levels in endometriosis and suggests that MIF may be involved in endometriosis-associated infertility and angiogenesis.