Systemic lupus erythematosus and thrombotic thrombocytopenia purpura: a refractory case without lupus activity.

The association between systemic lupus erythematosus (SLE) and thrombotic thrombocytopenic purpura (TTP) has been infrequently reported. Usually, patients with TTP have more SLE activity and frequent renal involvement. Here we present a case of TTP associated to low-activity SLE. The absence of renal and major organ involvement increased the difficulty in making the initial diagnosis. ADAMTS13 activity in plasma in this patient was very low, as seen in other similar cases. The evolution of the patient was poor, needing plasma exchanges and immunosuppressive therapy, including the use of rituximab.