Thrombotic thrombocytopenic purpura is a clinical syndrome defined by the pentad 
of thrombocytopenia, microangiopathic hemolytic anemia, fever, and renal and 
neurologic abnormalities. The pathogenesis of this syndrome remains enigmatic, 
though appropriate management usually involves plasma administration. The 
authors report on an alternative therapy, high-dose intravenous immunoglobulin, 
used in the patient after the failure of plasmapheresis. The implications and 
potential applications of this therapy are discussed.