Role of natural killer cell activity in the pathogenesis of endometriosis.

Natural Killer (NK) cells are cytotoxic effector lymphocytes with the ability to lyse target cells in a major histocompatibility complex (MHC) class Ι-independent manner and without the need for prior antigen exposure. Data strongly suggested that NK cells play an important role in human reproduction and disturbance in their function can favor development of the gynecological disorders. In our study the role of NK cells in pathogenesis of endometriosis is reviewed and summarized from available literature. Endometriosis is related to a defect of NK cell cytotoxicity function in the ability to eliminate endometrial cells in ectopic sites. Alternations of the innate immunity mediated by NK cells may promote impairments or disrupt functions of adaptive immunity, which can contribute to development and progression of endometriosis and infertility associated with endometriosis. Aberrant immune responses by NK cells in affected women may represent risk factors for endometriosis and the repaired function can be a new treatment target of the affected women.