Acquired thrombotic thrombocytopenic purpura associated with reversible severe renal failure requiring hemodialysis.

Thrombotic thrombocytopenic purpura (TTP) is an uncommon hematologic disorder characterized by microangiopathic hemolytic anemia (MHA) and thrombocytopenia with or without fever, renal failure, and neurologic manifestations. Although the full pentad was required for the diagnosis of TTP until recently, because of the high mortality of untreated TTP and the varying manifestations of the disease itself, diagnostic criteria for TTP have been relaxed since the emergence of plasma exchange as effective treatment for TTP. The occurrence of MHA and thrombocytopenia without an alternate cause is now sufficient to initiate therapy. Renal dysfunction in acquired TTP, when it occurs, is transient and responds to therapeutic plasma exchange readily. Here we report a patient with acquired TTP who had no preexisting renal pathology but developed severe prolonged renal failure requiring multiple rounds of hemodialysis with eventual complete recovery of renal function. We adopted an intensive approach including steroids, rituximab, cyclosporine, twice daily plasma exchange, and hemodialysis. We believe that this was responsible for complete recovery of the patient. However, the reason for this unusually severe renal manifestation needs further study.