Tissue factor in trauma and organ dysfunction.

Tissue factor (TF) performs an essential role in the blood clotting system by activating the extrinsic coagulation pathway following vascular injury. In addition to this physiological hemostatic role for wound repair, TF also plays pivotal roles in organ dysfunction in trauma patients by triggering pathological disseminated thrombosis and inflammation. Constitutively expressed TF in subendothelial cells is released into the circulation following trauma and can be detected as slightly elevated TF levels in the plasma. Liberation of constitutive TF into the blood and inducible tissue factor expression on monocytes and the other cells may synergistically increase plasma TF levels to higher values at the early stage of posttrauma, especially in patients with disseminated intravascular coagulation (DIC) in association with sustained systemic inflammatory response syndrome. Marked TF generation not adequately balanced by physiological coagulation inhibitors such as tissue factor pathway inhibitor in posttrauma DIC patients has been observed. Based on these pieces of evidence, it has now been accepted that combined activation of TF-dependent coagulation inadequately regulated by anticoagulant mechanisms and inflammation may synergistically play important roles in the pathogenesis of posttrauma multiple organ dysfunction syndrome.