The suppression of peritoneal cellular immunity in women with endometriosis could be restored after gonadotropin releasing hormone agonist treatment

Problem: Our previous study reported that peritoneal natural killer (NK) cytotoxicity and CD3 ⁺ CD25 ⁺ lymphocyte subpopulation were suppressed in women with advanced endometriosis. Whether these phenomena are general for all stages of endometriosis and whether these alterations could be restored by long-term use of gonadotropin releasing hormone agonist (GnRHa) are further tested in this study. Method: Lymphocyte subpopulations (B cells, NK cells, T cells, and T-cell activation markers such as CD69, HLA-DR, and CD25) and NK cell cytotoxicity of peripheral blood and peritoneal fluid by dual-color flow cytometry and ⁵¹ Cr release assay in 30 cases of endometriosis were compared with those in 26 controls. We also compared these changes before and after 6-month treatment with GnRHa for advanced endometriosis. Results: Compared with the controls, only those women with advanced endometriosis showed lower NK cytotoxicity in peritoneal fluid mononuclear cells (PFMC). The CD3 ⁺ CD69 ⁺ lymphocyte subpopulation decreased in peripheral blood mononuclear cells (PBMC) of advanced endometriosis, while the CD3 ⁺ CD25+ lymphocyte subpopulation decreased in both PBMC and PFMC of mild and advanced endometriosis. After GnRHa treatment, the CD3 ⁺ CD69 ⁺ lymphocyte subpopulation increased in both PBMC and PFMC and the CD3 ⁺ CD25 ⁺ lymphocyte subpopulation increased in PFMC, but not in PBMC. Conclusion: Impaired local immunological function in the PF of endometriosis was confirmed by this study and the impairments could be restored after long-term GnRHa therapy.