ADAMTS13 and thrombotic thrombocytopenic purpura: Deficiency in ADAMTS13 results in TTP, a disorder of thrombotic microangiopathy, characterized by an abnormal persistence of UL-VWF multimers.36Similar to the pathology in systemic inflammation/sepsis, thrombotic microangiopathies such as TTP are associated with acute dysfunctional endothelial cell activation, indicated by up to fourfold increased VWF antigen (VWFAg) and VWF propeptide (VWFpp).37