Case report: thrombotic thrombocytopenic purpura in a patient with polymyositis: therapeutic importance of early recognition and discussion of pathogenic mechanisms.

Thrombotic thrombocytopenic purpura (TTP) is characterized by the pentad of fever, thrombocytopenia, microangiopathic hemolytic anemia, fluctuating neurologic symptoms, and renal dysfunction. Thrombotic thrombocytopenic purpura has recently been reported in association with rheumatic diseases (RDs). The authors present a patient with TTP and polymyositis and speculate on the pathophysiology linking these two conditions. Thrombotic thrombocytopenic purpura and RDs may present with overlapping clinical and laboratory features. It is important to identify TTP as a cause of thrombocytopenia and hemolysis when occurring in patients with RDs since management, treatment, and prognosis differ. Early recognition and prompt institution of plasmapheresis may improve the outcome in patients with TTP.