Thrombotic thrombocytopenic purpura and systemic lupus erythematosus: a rare and life-threatening association.

Introduction: The association between thrombotic thrombocytopenic purpura (TTP) and systemic lupus erythematosus (SLE) is uncommon. Diagnosis is often difficult because of their clinical and biological similarities. The presence of TTP in SLE worsens the prognosis and causes high mortality in the absence of early therapeutic interventions.

Case Report: We report the case of a 20 year-old man, admitted with nephrotic range proteinuria, hematuria and rapidly progressive renal failure. He also had anemia, thrombocytopenia and pericardial effusion. The diagnosis of SLE was made based on these clinical findings along with positive antinuclear and anti dsDNA antibodies. Renal biopsy revealed class IV/ V lupus nephritis (LN) with active lesions of thrombotic microangiopathy. The evolution of neurological deficit, persistent thrombocytopenia and active microangiopathic changes suggested the diagnosis of associated TTP. The patient was treated initially with corticosteroids and cyclophosphamide. Plasmapheresis could only be started 16 days later. Mycophenolate mofetil and rituximab were successively tried in the absence of improvement in renal function and persistent thrombocytopenia. The patient's neurological condition deteriorated necessitating transfer to the intensive care unit and mechanical ventilation. There he developed pneumonia and died of septic shock two months after presentation.

Conclusion: The coexistence of TTP and SLE needs to be considered early in SLE patients with complicated course. It may not respond to the conventional immunosuppressive treatment of SLE.