Names of the syndromes
| Name . | Definition . | Comments . |
|---|---|---|
| Pathologic name | ||
| TMA | The characteristic histologic abnormalities (swelling of endothelial cells and the subendothelial space) of capillaries and arterioles that cause microvascular thrombosis and result in microangiopathic hemolytic anemia and thrombocytopenia | In addition to TTP and HUS, TMA may occur in other disorders, such as malignant hypertension, scleroderma, antiphospholipid antibody syndrome, systemic lupus erythematosus, preeclampsia, radiation nephropathy, renal allograft rejection, HIV infection, allogeneic HSCT, disseminated malignancy. |
| Clinical names | ||
| Typical HUS | A syndrome of microangiopathic hemolytic anemia, thrombocytopenia, and renal failure with a diarrhea prodrome caused by infection with Shiga toxin-producing bacteria | Occurs primarily in children younger than 5 years. Accounts for 90% to 95% of childhood HUS. E. coli O157:H7 is the most common etiology. |
| aHUS | A syndrome of microangiopathic hemolytic anemia, thrombocytopenia, and renal failure without a diarrhea prodrome | Occurs primarily in children younger than 5 years. Accounts for 5% to 10% of childhood HUS. Abnormalities of complement regulation may be the most common etiology. |
| TTP | Adults with microangiopathic hemolytic anemia and thrombocytopenia, with or without renal or neurologic abnormalities, without another etiology, such as systemic infection or another cause of TMA | Children without renal failure are also diagnosed as TTP. The diagnosis of TTP requires treatment with plasma exchange. |
| Congenital TTP (Upshaw-Schulman syndrome) | A rare syndrome caused by congenital ADAMTS13 deficiency | Symptoms may first occur at any age. Treatment with plasma infusion is sufficient. In some subjects, symptoms of TTP never occur. |
| Name . | Definition . | Comments . |
|---|---|---|
| Pathologic name | ||
| TMA | The characteristic histologic abnormalities (swelling of endothelial cells and the subendothelial space) of capillaries and arterioles that cause microvascular thrombosis and result in microangiopathic hemolytic anemia and thrombocytopenia | In addition to TTP and HUS, TMA may occur in other disorders, such as malignant hypertension, scleroderma, antiphospholipid antibody syndrome, systemic lupus erythematosus, preeclampsia, radiation nephropathy, renal allograft rejection, HIV infection, allogeneic HSCT, disseminated malignancy. |
| Clinical names | ||
| Typical HUS | A syndrome of microangiopathic hemolytic anemia, thrombocytopenia, and renal failure with a diarrhea prodrome caused by infection with Shiga toxin-producing bacteria | Occurs primarily in children younger than 5 years. Accounts for 90% to 95% of childhood HUS. E. coli O157:H7 is the most common etiology. |
| aHUS | A syndrome of microangiopathic hemolytic anemia, thrombocytopenia, and renal failure without a diarrhea prodrome | Occurs primarily in children younger than 5 years. Accounts for 5% to 10% of childhood HUS. Abnormalities of complement regulation may be the most common etiology. |
| TTP | Adults with microangiopathic hemolytic anemia and thrombocytopenia, with or without renal or neurologic abnormalities, without another etiology, such as systemic infection or another cause of TMA | Children without renal failure are also diagnosed as TTP. The diagnosis of TTP requires treatment with plasma exchange. |
| Congenital TTP (Upshaw-Schulman syndrome) | A rare syndrome caused by congenital ADAMTS13 deficiency | Symptoms may first occur at any age. Treatment with plasma infusion is sufficient. In some subjects, symptoms of TTP never occur. |