ADAMTS13 and thrombotic thrombocytopenic purpura: Without prompt recognition and plasma exchange treatment (standard therapy), TTP has a mortality of 90%,1 but with early recognition and treatment, 78% to 90% of patients will survive beyond their acute episode.2, 3 Modern understanding is that TTP is caused by autoantibody‐induced severe deficiency of a plasma enzyme, adisintegrin and metalloprotease with thrombospondin 1‐like domains (ADAMTS13)2, 4, 5, 6.