MONOCYTE TISSUE FACTOR ACTIVITY IN CANCER-PATIENTS

Monocytes produce tissue factor in response to endotoxin and other stimulants generated under pathologic conditions, which contributes to the pathogenesis of thrombosis and disseminated intravascular coagulation (DIC). We studied the relationship of monocyte tissue factor with cancer-associated hyper-coagulability in 21 patients. The basal tissue factor activity of monocytes and mononuclear cells (MNC) from the patients, was not high as compared with that from normal subjects. When incubated with and without endotoxin, the monocytes from the patients produced tissue factor in a significantly larger quantity than those from normal subjects. The tissue factor production and the difference between the normal and patient groups were more pronounced when examined with MNC. The conditioned medium prepared by culture of MNC from the patients enhanced the tissue factor production of normal monocytes to a greater extent than that obtained from MNC from normal subjects. Based on these results we postulated that the monocytes are preactivated in cancer patients by cytokine-mediated interactions with lymphocytes so that the cells acquire an increased potential in tissue factor production, and the preactivation of monocytes is related to the progression of DIC in cancer patients with infections or other pathologic conditions.