introduction : activated protein c (apc) inactivates factor v by cleavage of its heavy chain at arg306, arg506, arg679, and lys994. mutational changes, which abolish apc cleavage sites, may predispose thrombosis by altering the inactivation process of factor v.  factor v leiden (arg506glu) has been demonstrated as a strong risk factor for thrombosis. in the current study, we have studied whethe...

Activated protein C (APC) resistance is a major risk factor for venous thrombosis. Factor V (FV) gene mutations like FV(Leiden) (R506Q) and FV(R2) (H1299R) may cause APC resistance either by reducing the susceptibility of FVa to APC-mediated inactivation or by interfering with the cofactor activity of FV in APC-catalyzed FVIIIa inactivation. We quantified the APC cofactor activity expressed by ...

Activated protein C (APC) is a naturally occurring anticoagulant that interacts with factor V and VIII to inhibit the clotting cascade. The prevalence of APC resistance among Korean patients with deep vein thrombosis is ill defined. The aim of the present study was to investigate the prevalence of APC resistance and factor V Leiden mutation in Korean patients with deep vein thrombosis. The pres...

Plasma and platelet factor Va represent different substrates for activated protein C (APC). In this study, we have measured platelet-dependent APC resistance and the effect of aspirin and a platelet glycoprotein IIbIIIa antagonist (GR144053F) on this phenomenon. In platelet rich plasma (PRP), progressive APC resistance was observed with increasing platelet activation. APC sensitivity ratios of ...

Plasma and platelet factor Va represent different substrates for activated protein C (APC). In this study, we have measured platelet-dependent APC resistance and the effect of aspirin and a platelet glycoprotein IIbIIIa antagonist (GR144053F) on this phenomenon. In platelet rich plasma (PRP), progressive APC resistance was observed with increasing platelet activation. APC sensitivity ratios of ...

A coagulation test abnormality, termed activated protein C (APC) resistance, involving poor anticoagulant response to APC is currently the most common laboratory finding among venous thrombophilic patients. Because the anticoagulant activity of APC involves inactivation of factors Va and VIIIa, studies were made to assess the presence of abnormal factors V or VIII. Diluted aliquots of plasma fr...

Inherited resistance to activated protein C (APC) was recently recognized as a novel cause underlying venous thrombophilia. In most cases APC-resistance is due to a single point mutation in the factor V gene leading to a replacement of Arg506 with Gln (factor V Leiden). Amino acid substitution occurs at one of the APC cleavage sites of factor Va, rendering it resistant to APC inactivation. Plas...

A coagulation test abnormality, termed activated protein C (APC) resistance, involving poor anticoagulant response to APC is currently the most common laboratory finding among venous thrombophilic patients. Because the anticoagulant activity of APC involves inactivation of factors Va and Vllla, studies were made to assess the presence of abnormal factors V or VIII. Diluted aliquots of plasma fr...

BACKGROUND Activated protein C (APC) resistance is the most common inherited prothrombotic disorder. The role of APC resistance in ischemic stroke is controversially discussed. OBJECTIVES The aim of this single center follow up study was to investigate the effect of APC resistance on stroke recurrence and survival in stroke patients. PATIENTS/METHODS We retrospectively identified 966 patien...

BACKGROUND The activated protein C (APC) resistance is the most common prothrombotic defect in thrombosis patients, mainly related with alterations in the F5 gene. In this work, we evaluated the presence of variants in the FV gene in Amerindian patients with deep venous thrombosis and APC resistance. METHODS A total of 87 patients with deep venous thrombosis (DVT) confirmed by Doppler ultraso...