Thrombotic thrombocytopenic purpura (TTP) was previously defined by the following pentad of symptoms: (1) microangiopathic hemolytic anemia, (2) thrombocytopenia, (3) renal abnormalities, (4) fever, and (5) neurologic abnormalities. However, at initial presentation, only 10% of acute TTP patients have all of these symptoms. Most TTP patients will have severe thrombocytopenia (usually < 30,000/mm3), microangiopathic hemolytic anemia (schistocytes in the blood smear), and a constellation of clinical findings (petechia, purpura, neurologic symptoms, myocardial ischemia, mesenteric ischemia, and renal abnormalities). Approximately 50% of TTP presentations have an associated comorbidity that may trigger the disease (autoimmune diseases, antiphospholipid syndrome, pregnancy, medications, HIV infection, pancreatitis, malignancy, and organ transplantation), whereas the other 50% are idiopathic.
Management and Disposition
The cornerstone of primary TTP therapy is total plasma exchange transfusion (plasmapheresis) with fresh frozen plasma. Emergent consultation with hematology will establish the most expeditious management strategy available.
Total plasma exchange transfusions have increased TTP survival rate to 80% to 90%.
Understanding the varied presentation of TTP patients will lower your threshold to identify them earlier and expedite definitive treatment.
Pediatric TTP cases represent only 10% of all TTP cases and are often misdiagnosed.
Thrombotic Thrombocytopenic Purpura. Bleeding at initial presentation is seen in about 30% to 40% of patients with TTP. (Photo contributor: James J. Nordlund, MD.)