Altered immune mechanisms are implicated in the pathogenesis of endometriosis. CTLA-4 is a membrane receptor that favors the anergic state of lymphocytes, which may disrupt the immune system response in the endometriotic environment. In this study, we examined the expression of CTLA-4 on T and B cells by flow cytometry and its levels in blood serum and peritoneal fluid by ELISA. Levels of CTLA-4+ T cells were significantly higher in patients with more advanced endometriosis than in those with less advanced disease. Additionally, the negative correlation of CTLA-4+ T lymphocytes and the percentage of NK and NKT-like cells in women with endometriosis and infertility may indicate a different etiopathogenesis of endometriosis accompanying infertility. Our findings shed light on the potential of CTLA-4 in developing new diagnostic and therapeutic approaches in endometriosis management.
