Impairment of macrophage activating factor (MAF) production in lymphocytes from cancer patients

Lymphocytes from patients with either head and neck, breast or hematologic cancer were studied for their ability to be stimulated with the specific antigen streptokinase to produce (MAF). Only 9 of the 48 patients studied possessed lymphocytes which were capable of producing MAF. In addition, breast cancer patients were found to possess suppressor cells which were capable of suppressing the ability of normal lymphocytes to produce MAF. Further experiments were conducted to determine whether the suppressor cells need to be incubated with normal lymphocytes to obtain suppression or whether the cancer patients' suppressor cells secrete a soluble factor which in itself suppresses the ability of normal lymphocytes to produce MAF. It was found that 7 of the 10 breast cancer patients studied possessed such a soluble suppressor factor.