Thrombotic microangiopathy

Thrombotic microangiopathy is a group of disorders in which small-vessel injury produces platelet-rich clots, consumes platelets, and fragments red blood cells.

Endothelial cell: A cell lining blood and lymphatic vessels that regulates barrier function, inflammation, and clotting. Endothelial injury initiates many forms of microvascular clot formation.
Thrombocytopenia: A lower-than-normal platelet count in the blood. Platelet consumption produces a key laboratory feature of the syndrome.
Thrombotic thrombocytopenic purpura: A thrombotic microangiopathy usually caused by severe deficiency of the von Willebrand factor-cleaving enzyme ADAMTS13. It is a life-threatening subtype in which urgent plasma-directed treatment is central.
ADAMTS13: A plasma metalloprotease that cleaves unusually large von Willebrand factor multimers. Severe deficiency or inhibition identifies the mechanism behind most thrombotic thrombocytopenic purpura.
Immune thrombocytopenia: An autoimmune disorder in which platelet destruction causes thrombocytopenia, usually without microangiopathic hemolysis. Low platelets alone do not establish a microangiopathy; fragmented red cells distinguish the patterns.
Microangiopathic hemolytic anemia: Anemia caused by red blood cells breaking apart as they pass through damaged or obstructed small vessels. Fragmented cells are a defining blood-film clue to this process.
Hemolysis: The destruction of red blood cells, releasing their contents into the blood. Red-cell destruction explains anemia and laboratory evidence of cell breakdown.
Hemolytic uremic syndrome: A thrombotic microangiopathy characterized by hemolysis, thrombocytopenia, and acute kidney injury. Renal injury is prominent in this clinical syndrome.
Plasma exchange: A procedure that removes a patient's plasma and replaces it with donor plasma or another replacement fluid. It is urgent initial treatment when thrombotic thrombocytopenic purpura is suspected.
Evans syndrome: A rare autoimmune condition combining immune thrombocytopenia with autoimmune hemolytic anemia. It can cause anemia and low platelets without the vessel-driven red-cell fragmentation of this syndrome.

Linked from 7 pages