Severe deficiency of von Willebrand factor (VWF)-cleaving protease (ADAMTS-13) activity (<5% of normal) is a specific finding for acute idiopathic thrombotic thrombocytopenic purpura (TTP), a disorder that presents as thrombocytopenia, microangiopathic hemolytic anemia, and often organ dysfunction such as neurological disturbances or renal failure, and fever.
This anti-thrombotic mechanism would protect the normal kidney during inflammation and could also explain why most patients with ADAMTS13 deficiency do not develop severe kidney failure.
These data suggested that severe secondary ADAMTS13 deficiency can be associated with sepsis-induced DIC and may contribute to the development of renal failure.
Our experience appears to indicate the importance of assays of ADAMTS13 activity and its inhibitor in patients who have episodes of renal insufficiency in association with thrombotic microangiopathy, for diagnosis and choice of treatment.