[Immunologic suppressor factors in sera of patients with ovarian cancer].

The suppressive activity of immunologic suppressor factors (ISF) in the sera of 34 patients with ovarian cancer was investigated by using the lymphocyte proliferation and inhibition test. It was found that the sera of the preoperative patients could significantly suppress PHA-induced lymphocyte response, and that the suppression was dose-dependent. When the sera were diluted to 1 : 4,000, the suppressive activity could still be demonstrated. We also observed the suppressive activities in the sera of patients with cervical cancer, endometrial cancer, gastric cancer and lung cancer, and compared them with ovarian cancer patients. The observation showed that the suppressive activity in the sera of preoperative ovarian cancer patients was higher than that in the sera of gastric cancer or lung cancer patients. These results suggested that ISF played an important role in the development of ovarian cancer.