ADAMTS13 and thrombotic thrombocytopenic purpura: High-dose steroids should be used in conjunction with PE for acquired TTP, and in all patients treated empirically with PE pending the results of ADAMTS13 testing (for example, oral prednisolone 1 mg/kg per day or, for the most severe cases, pulse intravenous methylprednisolone 1 g daily for the first 3 days).