Red Blood Cells and Relation to Thrombosis

Blood coagulation and thrombin generation are primarily a function of platelets, coagulation factors, and endothelial cells. Red blood cells (RBCs) have generally been viewed as innocent bystanders in the clotting process. However, there has been a steadily growing clinical data revealing the active roles of erythrocytes in hemostasis. RBCs may contribute to thrombosis in several ways. In polycythemia, RBCs increase blood viscosity and marginate platelets toward the endothelium. The increased incidence of thrombosis is also associated with hemolytic anemia, especially with sickle cell disease and paroxysmal nocturnal hemoglobinuria. RBCs express phosphatidylserine and microparticles, supporting thrombin generation. They interact with platelets, endothelial cells, and fibrinogen, and these interactions lead their incorporation into the thrombi. The presence of RBCs in clots suppresses plasmin generation and reduces clot dissolution. Decreasing thrombus RBC content would accelerate thrombus resolution. In conclusion, RBCs are important complements of the complex reactions of clot formation