ABSTRACT
Vascular thrombotic disorders are among the most common causes of morbidity and mortality in the Western world. A remarkable feature of these disorders is the focal nature of their distribution (Tables 1 and 2). For example, veno-occlusive disease of the liver, a relatively common complication of myeloablative treatment and bone marrow transplantation, affects the sinusoids of the liver. Hemolytic uremia syndrome and thrombotic thrombocytopenia purpura are part of a spectrum of micro-angiopathic hemolytic anemias that are characterized by pathology in virtually all microvascular beds with the notable exception of the liver and lung. The congenital hypercoagulable states, as exemplified by the factor V Leiden mutation, predispose patients to an increased risk of venous, but not arterial, thrombosis (1,2). Perhaps
Disease/Disorder Site of Thrombosis Acquired TTP All organs except lung and liver
HUS Predominantly kidney
MPD Portal/hepatic veins
PNH Portal/hepatic veins
DIC Microvessels; all organs are susceptible
HIT Arteries, veins, often in unusual sites
APL Arteries and veins
Atherosclerosis Conduit arteries
Congenital Sickle cell disease Microvessels, especially joints a Primary and secondary hemostasis are integrally linked; therefore most of these diseases are also associated with activation of the clotting cascade. This is particularly true in the
case of DIC, HIT, and APL. TTP: thrombotic thrombocytopenic purpura; HUS: hemolytic uremic syndrome; MPS: myeloproliferative disease; PNH: paroxysmal nocturnal hemoglobinuria; DIC: disseminated intravascular coagulation; HIT: heparin induced thrombocytopenia; APL: antiphospholipid antibody syndrome.
