Natural killer cell activity in endometriosis: correlation between serum estradiol levels and cytotoxicity.

Abstract

To evaluate the correlation between natural killer cell activity and serum estradiol (E2) levels in patients with different stages of endometriosis. Natural killer cell activity of peripheral blood lymphocytes and serum E2 levels were evaluated in 73 women who underwent laparoscopy for pelvic pain, infertility, and benign adnexal masses. The 33 patients (45%) with endometriosis showed a significant decrease in natural killer cell activity in relationship to an increase in disease stage (correlation coefficient r = -0.83, P < .001). A significant inverse relationship was observed between cytotoxicity and serum E2 levels (correlation coefficient r = -0.89, P < .001). The relationship between natural killer cell activity and serum E2 levels suggests that an immunoendocrine interaction plays an important role in the progression of endometriosis.