Hypercoagulable state in sickle cell disease.

Chronic activation of coagulation is one of the features of sickle cell disease (SCD). Increased tissue factor expression, phosphatidylserine exposure, thrombin generation and fibrinolysis, as well as decreased levels of natural anticoagulants have been reported in SCD patients and in the mouse models of SCD. Consistent with this, patients with SCD are prone to develop thrombotic complications. In addition, the altered morphology of sickle red blood cells (RBC) may also alter the properties and dynamics of clot formation in SCD patients. Clinical data and results from animal models have revealed complex interactions between coagulation, chronic hemolysis, and inflammation suggesting that activation of coagulation may contribute to the pathophysiology of SCD.