Thrombotic thrombocytopenic purpura at presentation of juvenile systemic lupus erythematosus patients.

Thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening hematological abnormality characterized by thrombocytopenia and microangiopathic hemolytic anemia, with neurological abnormalities and/or renal disease. TTP has been rarely reported in juvenile systemic lupus erythematosus (JSLE) patients and, to our knowledge, its prevalence in a paediatric lupus population has not been studied. Therefore, from January 1983 to December 2010, we reviewed the charts of 5,508 patients followed-up at the Paediatric Rheumatology Unit of our university hospital. We identified 279 (5.1%) JSLE cases that met the American College of Rheumatology classification criteria. Two (0.7%) of them had TTP, both at JSLE onset, and were described herein. Both patients had fever, microangiopathic hemolytic anemia (with schistocytes in blood smears), and thrombocytopenia. The male patient had hemiparesis and proteinuria and the female patient had persistent headache and hematuria. Both were treated with intravenous methylprednisolone and courses of plasma exchange therapy at TTP diagnosis. After treatment, TTP did not recur and their hematocrit, platelet count, and lactic dehydrogenase remained normal. In conclusion, TTP is a rare and severe manifestation at JSLE onset. The case reports reinforce the importance of early diagnosis and early aggressive treatment for patients with TTP, due to its high morbidity.