Thrombosis in paroxysmal nocturnal hemoglobinuria: sites, risks, outcome. An overview

Hypercoagulability and Hypofibrinolysis and Risk of Deep Vein Thrombosis and Splanchnic Vein Thrombosis

“…Remarkably, thrombosis of the splanchnic veins is a frequent complication, particularly of the hepatic veins and the inferior vena cava, in which more than 45% of the thrombotic episodes are located, accounting for the majority of deaths in this disorder. 101 PNH has been reported in 9% to 19% of tested BCS patients, 74,102 whereas a prevalence of 0% to 2% has been reported in PVT. 72,73 Several mechanisms, including intravascular hemolysis, increased platelet activation and aggregation, procoagulant microparticles resulting from complement-mediated platelet damage, hypofibrinolysis, and increased tissue factor expression, may contribute to the pathogenesis of venous thrombosis in PNH.…”

Hemoglobin interaction with GP1b induces platelet activation and apoptosis: a novel mechanism associated with intravascular hemolysis

“…2 Once the Hb-scavenging capacity of haptoglobin and other Hb-binding plasma proteins is saturated, an elevated plasma Hb is associated with vascular dysfunction and thrombotic complications [3][4][5][6][7][8] that is particularly well described in paroxysmal nocturnal hemoglobinuria (PNH), a prototype of intravascular hemolysis. Direct correlation of a broad range of plasma Hb concentrations with the occurrence and severity of thromboembolisms and intravascular thrombosis in PNH patients was reported, 9,10 where venous 11,12 and arterial 13,14 thrombosis are principal causes of PNH morbidity and mortality.…”

Hypercoagulability and thrombotic complications in hemolytic anemias

“…1 In addition to increased thrombin and fibrin generation, increased tissue factor activity, and increased platelet activation (Figure 1), patients with hemolytic anemias manifest thrombotic complications, including venous thromboembolism, in situ pulmonary thrombosis and stroke. [1][2][3][4][5][6][7] Furthermore, the risk of thromboembolic complications appears to be higher following splenectomy. 1,3,6 The mechanism of coagulation activation in hemolytic anemias is likely multifactorial.…”