Increased procoagulant activity of peripheral blood monocytes in human and experimental obstructive jaundice.

We studied the procoagulant activity of peripheral blood monocytes in 41 patients with severe obstructive jaundice and in 27 nonjaundiced control patients using a one-stage clotting assay. Mononuclear cells from jaundiced patients, tested immediately after isolation, expressed low levels of procoagulant activity, which were, however, significantly higher than in cells from controls (p less than 0.01). In addition, after incubation in short-term cultures with and without endotoxin, these cells generated more procoagulant activity than did the control ones (p less than 0.001). No significant difference in procoagulant activity was found between patients with and without malignancy in either group. The relief of biliary obstruction resulted in the reduction of both serum bilirubin levels and monocyte procoagulant activity. Endotoxin-induced monocyte procoagulant activity was about threefold higher in the jaundiced patients who died than in the survivors (p less than 0.001). In rabbits made icteric by bile duct ligation and separation (15 days), the endotoxin-induced monocyte procoagulant activity was markedly increased as compared with sham-operated animals (p less than 0.005). In all instances, procoagulant activity was identified as tissue factor. The increased capacity of mononuclear phagocytes to produce procoagulant activity might help explain the activation of blood coagulation in severe obstructive jaundice.