Study of A Disintegrin and Metalloproteinase with ThromboSpondin Type 1 Repeats 13 (ADAMTS 13) in Children with Idiopathic Nephrotic Syndrome

Abstract

IntroductionMany predisposing factors for TE were reported in nephrotic patients , abnormalities in platelet activation and aggregation, activation of prothrombotic factors of coagulation system e.g. factors V,VII, VIII, X, von Willebrand factor (vWF), fibrinogen, and α 2-macroglobulin, decreased activity of fibrinolytic system such as plasminogen [1] and decreased endogenous anticoagulants, antithrombin III, protein C, protein S and tissue factor pathway inhibitor resulting in local activation of the glomerular hemostasis system [2]. vWF mediates platelet adhesion and aggregation at sites of vascular injury [3]. It is released from the stimulated endothelium as unusually large (UL) multimer [4]. ULvWF favor platelet aggregation and formation of microvascular thrombi [5]. A disintegrin and metalloprotease with thrombospondin type-1 motif 13 (ADAMTS 13) can cleaves and thus converses ULvWF into a less active form [6]. Reduced ADAMTS 13 activity due to gene mutation or presence of autoimmune IgM and IgG inhibitors [7] results in deficient proteolysis of ULvWF with formation of disseminated platelet-rich thrombi in the microcirculation seen in thrombotic microangiopathies (TMA) [8,9]. Study of A Disintegrin and