Thrombotic thrombocytopenic purpura and systemic lupus erythematosus. Three cases with simultaneous presentation.

Thrombotic thrombocytopenic purpura (TTP) is a clinical syndrome characteri zed by microangiopathic hemolytic anemia, thrombocytopenia, fever, neurolog ical symptoms, and renal involvement. The relationship of TTP to systemic l upus erythematosus (SLE) has been recognized in the medical literature sinc e 1939. The differential diagnosis is difficult because both diseases have similar clinical features. The mainstay for recognizing TTP in the context of active SLE is the presence of helmet red cells, marked reticulocytosis, and negative direct Coomb's test. We report three female patients with simu ltaneous presentation of TTP and SLE. We suggest combined treatment with im munosuppressive therapy and plasma exchange using fresh frozen plasma.