[Unusual cause of macrohematuria in a 29-year-old woman].

We report on the case of a young women presenting with macrohaematuria, petechiae and strong headaches. Laboratory showed a thrombotic microangiopathy with helmet cells, increased LDH levels (>600 U/l), and thrombocytopenia (<40,000/μl). Due to strong haemolytic activity and headache with blurred vision, immediate plasma separation with fresh frozen plasma was commenced. Markedly decreased ADAMTS13 activity and detection of anti-ADAMTS13 antibodies were consistent with the diagnosis of idiopathic thrombotic thrombocytopenic purpura. In total, 11 plasma separations were required to stop disease activity. In parallel, immunosuppressive therapy using glucocorticoids was initiated. The patient was discharged from the hospital in a good general condition and with normalized laboratory findings 26 days after hospitalization. All patients with anemia and thrombocytopenia should be tested for haemolysis and helmet cells. An early diagnosis and initiation of necessary therapy are determining for the clinical outcome.