PROS1 mutations associated with protein S deficiency in Polish patients with residual vein obstruction on rivaroxaban therapy

摘要

Protein S (PS) is a vitamin K-dependent glycoprotein that acts as a natural anticoagulant. Approximately 60% of PS forms a non-covalent complex with the complement 4b-binding protein (C4BP) while the remaining 40% is free [1]. Both forms of PS, free and complexed with C4BP, serve as cofactors of activated protein C (PC) in the proteolysis of activated factor (F)V and FVIII [2], but free PS is more potent [3,4]. PS also has an ability to stimulate the FXa inactivation by tissue factor pathway inhibitor (TFPI) via the APC-independent mechanism [5].PS deficiency is an autosomal dominant disorder with a prevalence of less than 0.5% in the general European population and 2% to 12% in patients with deep-vein thrombosis (DVT) or pulmonary embolism (PE) [6],