Induction of tumor necrosis factor by administration of OK-432 in cancer patients.

We examined whether OK-432, a streptococcal preparation, could induce tumor necrosis factor in cancer patients. OK-432 was administered at a dose of 100 KE intratumorally to 4 advanced gastric cancer patients and 10KE intracavitary to 8 patients with malignant pleuroperitoneal effusion. The cytostatic activity of the sera and malignant effusions was assayed by the growth inhibition of L929 cells. OK-432 induced significant cytostatic activity in the sera and malignant effusions. The activity was partially neutralized by the monoclonal antibody against human recombinant tumor necrosis factor. These data suggest that OK-432 induces tumor necrosis factor in the sera and malignant effusions of cancer patients.