Thelansis

  Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal stem cell disorder characterised by complement-mediated haemolysis, hypercoagulability, and bone marrow failure, probably on an auto-immune basis. Patients with PNH are especially prone to thrombosis in abdominal veins; there are few conditions that confer a high risk. Hypercoagulability may be a consequence of: Decreased fibrinolysis due to abnormal post-translational modification of the GPI-linked uPAR receptor, increased complement-mediated activation of CD59-negative platelets, increased thrombin generation on platelet-derived microparticles, abnormalities of the GPI-linked tissue factor pathway inhibitor, abnormalities of endothelial cells secondary to the presence of a large PNH clone. The clinical symptoms of PNH result from intravascular hemolysis, unusual venous thromboses and bone marrow hypoplasia. The intravascular hemolysis is due to the activation of complement as the abnormal red blood cells lack pro...