[Tissue factor expression at the site of inflammation: a cross-talk between inflammation and the blood coagulation...

Recent studies have revealed a close association of the blood coagulation system with inflammation and immune reactions. The products of the cascade reaction of blood coagulation can work as inflammatory mediators or immune modulators, and, vice versa, some inflammatory or immune stimuli are linked to induction of blood coagulation. First, tissue factor (the blood coagulation initiator), the monocyte/macrophage tissue factor expression regulatory factors associated with inflammation and immune reactions, and the assembly of coagulation factors on leukocytes were reviewed. Second, evidence of leukocyte tissue factor expression and subsequent fibrin deposition were demonstrated at sites of infection or allergic reactions, using immunohistochemical staining. Third, the progress in the investigation of thrombin was reviewed from the viewpoint of its effects on inflammation (vascular permeability enhancement, leukocyte chemotaxis, chemical mediator release, etc.) and immune reactions (T-cell proliferation, cytokine production, etc.). The evidence presented here indicates a cross-talk between blood coagulation and inflammatory and immune reactions, suggesting that the products of the clotting reaction (e.g., thrombin) in lesions are real-time markers of inflammatory diseases.