ADAMTS13 and thrombotic thrombocytopenic purpura: One must differentiate between secondary iTTP due to infection (that is, anti-ADAMTS13 autoantibodies developed due to the presence of the infectious microorganism) from secondary TTP caused either by the systemic inflammation and/or endothelial damage which commonly accompanies infections (13, 52, 115), or secondary TTP caused by drugs, or liver cirrhosis, or excessive alcohol intake (116, 117), as well as from other coagulation disorders well known to occur with infectious diseases (118, 119).