Disseminated intravascular coagulation and its immune mechanisms.

Disseminated intravascular coagulation (DIC) is a syndrome triggered by infectious and non-infectious pathologies characterized by excessive generation of thrombin within the vasculature and widespread proteolytic conversion of fibrinogen. Despite diverse clinical manifestations ranging from thrombo-occlusive damage to bleeding diathesis, DIC etiology commonly involves excessive activation of blood coagulation and overlapping dysregulation of anticoagulants and fibrinolysis. Initiation of blood coagulation follows intravascular expression of tissue factor or activation of contact pathway in response to pathogen-associated or host derived damage-associated molecular patterns. The process is further amplified through inflammatory and immuno-thrombotic mechanisms. Consumption of anticoagulants and disruption of endothelial homeostasis lower the regulatory control and disseminate microvascular thrombosis. Clinical DIC development in patients associates with worsening morbidities and increased mortality regardless of the underlying pathology, therefore timely recognition of DIC is critical to reduce the pathologic burden. Due to diversity of triggers and pathogenic mechanisms leading to DIC, diagnosis is based on algorithms that quantify hemostatic imbalance, thrombocytopenia and fibrin/ogen conversion. Since current diagnosis primarily assesses overt consumptive coagulopathies, there is a critical need for better recognition of non-overt DIC and/or pre-DIC states. Therapeutic strategies for DIC patients involve resolution of the eliciting triggers and supportive care for the hemostatic imbalance. Despite medical care, mortality in DIC patients remains high and new strategies, tailored to the underlying pathologic mechanisms, are needed.