Thrombotic Thrombocytopenic Purpura: A Rare Cause of Severe Acute Kidney Injury.

Thrombotic microangiopathy (TMA) is a serious and potentially fatal disorder, especially if there is a delay in diagnosis and appropriate treatment. Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are the two main forms of TMA. Although severe acute kidney injury (AKI) is a common manifestation of TMA, it remains rarely described in reported TTP cases. We present a rare case of TTP in a 76-year-old African American male who presented with severe AKI (stage 3) and uremic symptoms. Early diagnosis and prompt treatment of TTP with plasmapheresis followed by rituximab and caplacizumab were associated with the resolution of the AKI and avoidance of hemodialysis. This case highlights the need to consider TTP as a possible diagnosis even in the setting of severe AKI.