Slightly decreased ADAMTS13 activity is also reported in other clinical conditions, like DIC, SLE, liver cirrhosis, ITP and others.15,21-23 Overall, these and our observations provide a reasonable explanation why perplexing clinical scenarios occur in which decreased ADAMTS13 activity level does not parallel the clinical symptoms of TTP.13 Here, ADAMTS13 is linked to autoimmune thrombocytopenic purpura.