ADAMTS13 and thrombotic thrombocytopenic purpura: Although the ADAMTS13 deficiency in TTP is mainly caused by anti-ADAMTS13 antibody, the mild deficiency of ADAMTS13 in a variety of conditions including sepsis, infection and other subtypes of TMA may be caused by the processing of ADAMTS13 through the continuous cleavage of vWF in microthrombi during the inflammatory process [14, 15].