ADAMTS13 and thrombotic thrombocytopenic purpura: TMA is subdivided based on etiology into major forms including hemolytic uremic syndrome (HUS) caused by Shiga toxin-producing enterohemorrhagic Escherichia coli (EHEC), or atypical HUS, associated with complement overactivation, as well as thrombotic thrombocytopenic purpura (TTP) [2], associated with deficiency or dysfunction of ADAMTS13 (A Disintegrin And Metalloproteinase with a ThromboSpondin 1 motif, member 13) [3].