Natural killer cell activity in patients with ovarian tumors and uterine myomas.

Natural killer (NK) cells are considered to play a role in surveillance against neoplasia. Therefore, the aim of our study was to evaluate peripheral blood NK cell activity in patients with benign and malignant ovarian tumors as well as uterine myomas. NK cell activity was evaluated by means of 51/Cr-release cytotoxicity assay using K562 erythroleukemic cells as a target. We found that natural cytotoxicity of peripheral blood mononuclear cells was significantly (P > 0.01) decreased in patients suffering from both benign and malignant ovarian tumors as compared to healthy women. A degree of NK cell activity abrogation was higher in patients with malignant tumors. Similar decrease was also observed in patients with uterine myomas. Since ovarian tumors and uterine myomas are known to be associated with an increased serum levels of estrogens it is possible that abrogation of NK cell activity in these patients is related to immunosuppression mediated by these hormones.