a case of acquired thrombotic thrombocytopenic purpura without renal dysfunction

objective: thrombotic thrombocytopenic purpura (ttp) is the most malignant variant of microangiopathy that usually presents by typical symptoms including thrombocytopenia, hemolytic anemia, neurological abnormalities, fever and renal impairment. report of the case: we report a 12-year-old male presented by cytopenia, fever, purpura on his extremities, seizure and lethargy. peripheral blood smear revealed low platelet and increased schistocyte, but renal function tests were normal. final diagnosis of ttp was confirmed by measuring adamts-13 autoantibody (> 60). conclusion: atypical ttp can presents without renal impairment. in these cases the measurement of adamts-13 activity as a specific test as well as ruling out secondary ttp should be considered. key word: renal dysfunction, thrombotic thrombocytopenic purpura, adamts-13.