ADAMTS13 and thrombotic microangiopathy: Thrombotic thrombocytopenic purpura is a rare life-threatening thrombotic microangiopathy caused by a deficiency in ADAMTS13 enzymatic activity as a consequence of congenital, autosomal recessive, or aberrant autoimmune activity.[16] Owing to the poor enzymatic functionality of ADAMTS13, VWF multimers accumulate, resulting in a dramatic increase in thrombus formation and platelet consumption.[17]