Overlapping features of thrombotic thrombocytopenic purpura and systemic lupus erythematosus, a diagnostic and a management challenge

Thrombotic thrombocytopenic purpura (TTP) is a rare, potentially fatal blood disorder that can be challenging for clinicians to identify in the setting of autoimmune diseases such as systemic lupus erythematosus (SLE). SLE can present with thrombotic microangiopathy (TMA) and differentiation between the two diseases can be quite difficult. In this case report we present a 62-year-old female with a history of SLE who was hospitalized with thrombocytopenia, dysarthria, dizziness, paresthesia and altered mental status. The laboratory results revealed direct Coombs negative hemolytic anemia, severe thrombocytopenia, significant elevation of lactate dehydrogenase, leukocytosis and presence of few schistocytes in the peripheral film. In addition, we also present evidence for circulating anti-ADAMTS13 antibody/ADAMTS13 antigen. Based on clinical, hematological, and biochemical findings, we concluded that it was a case of TTP-like microangiopathy associated with SLE and indicated treatment with methylprednisolone pulses and plasmapheresis. Later on, she developed psychosis and made plasmapheresis difficult to perform. We continued corticosteroids (dose 1mg/kg), RhoGAM, Chloroquine and Azathioprine, obtaining a satisfactory response after one week of treatment.