[Expression of major histocompatibility complex-class I antigen on endometrial stroma cells in patients with endometriosis].

OBJECTIVE: To study the possible effect of major histocompatibility complex-class I (MHC-I) antigen on endometrial stromal cells in endometriosis patients. METHODS: The stromal cells of endometrium was separated and cultured in vitro. gamma-interferon (gamma-IFN) was added to modulate the MHC-I antigen level which was assessed by flowcytometry, and the sensitivity of endometrial stromal cells to cytotoxic lymphocytes was examined by methyl thiazolyl tetrazolium (MTT). RESULTS: Our study demonstrated that in vitro cultured stromal cells with significant reduced MHC-I antigen levels showed enhanced susceptibility to lysis (51.28%) mediated by lymphokine-activated killer (LAK) cells, whereas gamma-IFN treated in vitro cultured stromal cells with restored MHC-I antigen levels showed more resistance to lysis (28.64%). CONCLUSIONS: MHC-I antigen on endometrial stromal cells may inhibit the cytotoxicity of natural killer (NK) cells and NK-like T cells, which might play a key role in the pathogenesis of endometriosis. The level of MHC-I antigen could be regulated by culture or some biologic factors such as gamma-IFN.