Search

The production of gamma interferon (IFN-γ) by peripheral blood lymphocytes was studied in 38 patients with gastric cancer. Purified protein derivative (PPD) as a specific antigen and three kinds of mitogens, phytohemagglutinin-P (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM), were used as IFN-γ inducers. IFN-γ production by lymphocytes was markedly reduced in patients with gastric cancer when these inducers were used. Reduction of IFN-γ production was observed more often in patients of Stage IV than in those of Stage I when PPD or Con A was used. PPD-induced IFN-γ production significantly increased in patients who were operated on curatively, while it decreased in those who were operated on noncuratively. IFN-γ production by lymphocytes, especially when PPD is used as an IFN-γ inducer, reflects cell-mediated immunity in patients with gastric cancer. It may be useful as quantitative parameter to predict therapeutic effects and prognosis in cancer patients.