Inhibition of macrophage migration inhibitory factor reduces endometriotic implant size in mice with experimentally induced disease.

Endometriosis is a debilitating disease common in women of reproductive age characterized by pain and infertility. Macrophage migration inhibitory factor (MIF) is a cytokine whose expression is elevated in endometriotic tissue from women with the disease but the functional role of this factor in the pathogenesis of the disease is uncertain. To examine the role of MIF in the pathogenesis of endometriosis, we induced experimental disease in mice and examined the ability of the MIF antagonist, ISO-1, to reduce endometriotic implant size. Administration of ISO-1 resulted in a significant reduction in implant size and vascularity (as assessed by Flk1 mRNA expression) which was not associated with an alteration in the reproductive cycle. These data suggest that inhibition of MIF activity is associated with a significant reduction in endometriotic implant size and leads us to speculate that a similar approach of targeting MIF may prove useful in treating endometriosis in humans.