TMAs include (i) congenital Thrombotic Thrombocytopenic Purpura (cTTP) characterized by no evidence of anti-ADAMTS-13 IgG antibodies and severe deficiency of ADAMTS13 activity and (ii) autoimmune TTP characterized by the presence of anti-ADAMTS-13 IgG antibodies. Here, ADAMTS13 is linked to thrombotic thrombocytopenic purpura.