Ionizing radiation increases TNF/cachectin production by human peripheral blood mononuclear cells in vitro

Human peripheral blood mononuclear cells (PBMC) and monocytes produce a large amount of tumor necrosis factor/cachectin (TNF) in vitro. Our data suggest that X-irradiation can increase TNF production by these cells. After 900 cGy irradiation there were 7-fold (24 h incubation) and 2.3-fold (48 h incubation) increases of TNF production by stimulated PBMC. The irradiation also increased TNF production by both stimulated and unstimulated human monocytes. These findings suggest that TNF overproduction can play an important role in the pathogenesis of radiation disease.