ADAMTS13 and thrombotic thrombocytopenic purpura: Congenital or acquired deficiency of ADAMTS13 causes the accumulation of the UL-vWF multimers7 and thereby leads to thrombotic thrombocytopenic purpura (TTP), a life-threatening disease characterized by thrombocytopenia, hemolytic anemia, neurological and renal manifestations, as well as fever8,9.