Diagnosis>Organ System>

CLINICAL

• Multisystem disease caused by platelet thrombi in various organs.
• Thrombocytopenia, hemolytic anemia, renal impairment, fever (can be high), and neurologic abnormalities (agitation, disorientation, headache early, late focal deficits, seizure, coma).
• Relatively rare; mortality <10% if recognized and treated early.
• Associated with early and late HIV, malignancy, chemotherapy, pregnancy.
• Drugs associated with TTP: quinine, ticlopidine, cyclosporine.

DIAGNOSIS

• Low platelet count (5000-100,000), hemolytic anemia (causing high indirect bilirubin and high LDH), fragmented RBCs on peripheral smear (schistocytes, spherocytes), azotemia, neurologic dysfunction.
• Low von Willebrand factor-cleaving protease level (<5-10%) and presence of inhibitor may be demonstrated.

TREATMENT

• Early Dx and urgent treatment required. Mortality rate 60-80% without treatment.
• Plasma exchange with fresh frozen plasma (FFP) daily until normal PLT count and LDH. Average of 7-16 exchanges may be needed. HIV+ may respond better than HIV- to FFP.
• HAART use in addition to plasma exchange is beneficial
• Mild disease may respond to prednisone at 200 mg/d, but plasma exchange needed if no response within 48 hrs. Prednisone can be added if poor response to initial treatment with plasma exchange.
• Aspirin and dipyridamole not effective if given alone.
• FFP daily until normal platelets and LDH.

Drug Comments

FOLLOW UP

• Relapse can occur, usually within 60 days (~10%), but can occur years later.
• Plasma exchange usually effective for relapse.

REFERENCES