ADAMTS13 and thrombotic thrombocytopenic purpura: Trigger of platelet and vascular endothelial cells activation are reported to be a marked decrease in the ADAMTS13 levels in TTP [27], the detection of STEC in STEC-HUS [15] and the detection of abnormalities in the complement system in aHUS [16], along with other factors, such as transplantation, pregnancy, drugs and immune diseases, in secondary TMA [28].