Secondary thrombotic thrombocytopenic purpura with features of Evans syndrome in a patient with SLE

A female in her early 40s with systemic lupus erythematosus (SLE) and prior immune thrombocytopenic purpura presented with dizziness, dyspnoea, haematuria and fatigue. Investigations revealed a life-threatening thrombotic microangiopathy triad (platelets 3000/µL, microangiopathic haemolytic anaemia, acute kidney injury) and the strongly positive Coombs test with haemolysis markers supported autoimmune haemolysis in addition to microangiopathic haemolysis. Together with her prior history of immune thrombocytopenia, these findings are consistent with an Evans syndrome overlap, though consumptive thrombocytopenia from thrombotic thrombocytopenic purpura (TTP) could not be excluded. There was evidence of SLE vasculitis. Despite diagnostic overlap obscuring TTP, empiric plasma exchange (PLEX), steroids and rituximab induced rapid haematologic and clinical recovery. Days later, severe ADAMTS13 deficiency (<0.03 IU/mL) confirmed SLE-associated secondary TTP. This case highlights the critical need for empiric PLEX in suspected TTP when possible Evans syndrome complicates SLE and the efficacy of combined immunomodulation targeting both entities.