Thrombotic microangiopathy (TMA) is a pathologic description characterized by arteriole and capillary endothelial vessel wall damage that results in platelet activation, thrombosis, and damaged erythrocytes (schistocytes) leading to ischemia and organ failure.
Several different clinical syndromes can present with the characteristic features of TMA.
4 Interesting Facts of Thrombotic microangiopathy
(eg, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome)
- Characterized by occlusive microvascular thrombosis resulting in red cell trauma and hemolytic anemia as well as ischemic damage to kidneys and other organs; neurologic manifestations are common in some forms (eg, thrombotic thrombocytopenic purpura)
- As in rapidly progressive glomerulonephritis, presentation includes oliguria, hypertension, and edema; laboratory findings include rapidly declining renal function and hematuria
- Distinguished from nephritic syndrome by laboratory markers of hemolysis (declining hemoglobin/hematocrit levels, low serum haptoglobin level, elevated L-lactate dehydrogenase level) and presence of schistocytes on peripheral smear; unlike in nephritic syndrome, thrombocytopenia is common
- Diagnosis is based on thrombocytopenia and laboratory indicators of microangiopathic hemolytic anemia, often with associated neurologic dysfunction; in thrombocytopenic purpura, ADAMTS13 activity is subnormal