Increased production of procoagulant activity (tissue factor) by human peripheral blood monocytes after Intralipid infusion

Intralipid can produce functional and structural changes in the mononuclear phagocyte system. We have investigated the effect of Intralipid on the capacity of peripheral blood human monocytes to produce procoagulant activity when incubated in short term cultures. Twenty-three patients were studied before and after a single infusion of Intralipid 10%. Procoagulant activity was measured on isolated mononuclear cells after incubation (4 h at 37 degrees C) with and without endotoxin, using a one-stage clotting assay. Mononuclear cells obtained after Intralipid infusion produced significantly increased procoagulant activity as compared to their pre-infusion control samples (p < 0.005). Similar results were obtained when freshly collected whole blood was incubated with and without endotoxin (4 h at 37 degrees C) and procoagulant activity was measured on subsequently isolated mononuclear cells (p < 0.005). In all instances procoagulant activity was identified as tissue factor. Patients in the need of Intralipid are often at increased risk for thromboembolic complications and/or disseminated intravascular coagulation because of malignant disease, surgery or infection and there is evidence that the procoagulant activity of mononuclear phagocytes could play a major role in these processes. Our findings suggest that Intralipid might cause a further accentuation of the thrombotic tendency as a result of increased procoagulant activity.