scholarly journals Synergistic effect of antithrombin III, activated protein C and heparin on the inhibition of the tissue thromboplastin-mediated coagulation.

1989 ◽  
Vol 37 (3) ◽  
pp. 692-696 ◽  
Author(s):  
Keizo HIRAHARA ◽  
Yuko ETOH ◽  
Tetsuro MATSUISHI ◽  
Nobuo SUZUKI ◽  
Munetsugu KURATA
Keyword(s):  
Synergistic Effect ◽  
Protein C ◽  
Antithrombin Iii ◽  
Activated Protein C ◽  
Tissue Thromboplastin

DEVELOPMENT OF A PROTEIN C CONCENTRATE

1987 ◽  
Author(s):  
Prabir Bhattacharya ◽  
Carolyn L Orthner ◽  
Dudley K Strickland
Keyword(s):  
Protein C ◽  
Antithrombin Iii ◽  
Activated Protein C ◽  
Protein S ◽  
Exchange Chromatography ◽  
Factor Ix ◽  
Human Protein ◽  
Red Cross ◽  
American Red Cross ◽  
Protein C Concentrate

A Protein C (PC) concentrate may be useful in treating patients with congenital or acquired Protein C deficiencies. A method for preparation of a human Protein C concentrate has been developed using a by-product of American Red Cross Factor IX production as the starting material (Menache et. al. Blood, 64, 1220). Levels of other vitamin K dependent proteins in the Protein C concentrate were measured and found to be <10 units per 100 units of PC, except for Protein S. The level of Protein S as judged by immunological assay was 30 u/100 u PC. Assay of the PC concentrate using chrcmogenic substrates revealed that levels of thrombin, Factor 3�a and Factor IXa were less than 0.006 u/mL. In addition, Antithrombin III and ax -macroglobulin were not detected. The vivo effects of Protein C concentrate and Protein C activated by thrombin have been tested in anesthetized rabbits. Thrombin was removed from the activated Protein C by ion-exchange chromatography; depletion was verified by S-2238 or by a clotting assay (< 0.006 u/mL). Rabbits were injected with Protein C concentrate (400 ug/kg) or activated Protein C 24 - 48 ug/Kg). The activated partial thromboplastin time (APTT), FactorV (FV) and Factor VIII (FVIII) levels were measured in samples collected over the next three hours. Infusion of PC concentrate elevated the level of PC to 150% of the preinfusion level within 30 min. It did not change the levels of FV, FVIII, fibrinogen or platelet count. In contrast, infusion of activated Protein C produced progressive prolongation of the APTT. Levels of FV and FVIII were decreased to 25% and 50% of preinfusion levels, respectivelv, three hours after the infusion. Fibrinogen and platelet levels were unchanged during that period. These data demonstrate that activated human Protein C concentrate induces an anticoagulant effect that can be readily measured in rabbits.

Patients with APC Resistance Compared with Those with Other Clotting Inhibitor Deficiencies Show Later Onset of Venous Thrombosis During Oral Contraception

1995 ◽  
Vol 1 (4) ◽  
pp. 274-276 ◽  
Author(s):  
Antonio Girolami ◽  
Paolo Simioni ◽  
Sandra Zanardi ◽  
Luigi Scarano ◽  
Bruno Girolami
Keyword(s):  
Deep Vein Thrombosis ◽  
Protein C ◽  
Antithrombin Iii ◽  
Activated Protein C ◽  
Protein S ◽  
Oral Contraception ◽  
Vein Thrombosis ◽  
Apc Resistance ◽  
At Iii ◽  
Deep Vein

The prevalence of deep vein thrombosis in female patients with antithrombin III (AT III), protein C, or protein S deficiency who are on oral contraception has been compared with that of patients with activated protein C (APC) resistance. In the latter case the prevalence was lower (36.4%) than in the AT III deficiency group (71.4%) but similar to that seen in the protein C and protein S group (25%).' Furthermore, venous thrombosis occurred with APC resistance much later than with AT III, protein C, or protein S defects. The time lag between onset of oral contraception and thrombosis (~16 cycles) was not statistically different from that seen in a group of women who were known to have no antithrombin III, protein C, or protein S defects. It appears that as far as the interaction with oral contraception is concerned APC resistance is a much less severe condition compared with other clotting inhibitor defects. Key Words: Oral contraceptive—Activated protein C resistance—Deep vein thrombosis.

A SECOND INHIBITOR OF ACTIVATED PROTEIN C (APC)

1987 ◽  
Author(s):  
F J M van der Meer ◽  
N H van Tilburg ◽  
I K van der Linden ◽  
E Briét ◽  
R M Bertina
Keyword(s):  
Protein C ◽  
Antithrombin Iii ◽  
Binding Protein ◽  
Activated Protein C ◽  
Fast Inactivation ◽  
Heparin Cofactor Ii ◽  
First Order ◽  
First Order Kinetics ◽  
Sds Page ◽  
I 11

The inactivation of APC in plasma, as measured with the chromogenic substrate S2366, follows, in the absence of heparin, pseudo-first order kinetics. The ti of about 20 minutes is independent of the APC concentration (31-500 nM) and increases linearly with the dilution of the plasma. These observations suggest that the concentration of the APC inhibitor in plasma is much higher than 500 nM, which is much higher than the concentration of 88 nM reported by Suzuki for the protein C inhibitor (PCI).In the presence of heparin (5 IU/ml) the inactivation of APC becomes biphasic. Fast inactivation with an apparent ti of 8 minutes is followed by slower inactivation with a ti of 20 minutes.Removal of PCI from the plasma with α-PCI antibodies (kindly provided by Dr. Suzuki) has no effect on APC inactivation in the absence of heparin. However, in this plasma APC inactivation could not be stimulated by addition of heparin (absence of fast phase of APC-inactivation). These data suggest the presence of two APC inhibitors in plasma: the heparin dependent PCI (PCI-I), earlier reported by Suzuki, and a sofar unknown heparin-independent inhibitor (PCI-II).Further experiments showed that this PC I-11 has a molecular weight of 60 kD and is different from the APC-binding protein reported by Kisiel. Using Heparin-Sepharose affinity chromatography we could separate PCI -II from both PCI-I and the APC binding protein. In this PC I-11 preparation APC inactivation was accompanied by the formation of an APC-PCI -11 complex of about 105 kD as demonstrated by immunoblotting with a-PC antibodies after SDS-PAGE. The identity of PCI-II is unknown; however, it is different from antithrombin III, heparin cofactor II, α1-antitrypsin and β2-antiplasmin.The demonstration of the presence of two APC inhibitors in plasma will require a re-evaluation of the current functional assays for the APC inhibitor.

Resistance to activated protein C, the FV: Q506 allele, and venous thrombosis

1998 ◽  
Vol 18 (01) ◽  
pp. 1-10
Author(s):  
A. Hillarp ◽  
S. Rosen ◽  
B. Zöller ◽  
B. Dahlbäck
Keyword(s):  
Venous Thrombosis ◽  
Protein C ◽  
Antithrombin Iii ◽  
Single Point ◽  
Activated Protein C ◽  
Factor Xa ◽  
Protein S ◽  
Single Point Mutation ◽  
Factor V ◽  
Endothelial Cell Surface

SummaryVitamin K-dependent protein C is an important regulator of blood coagulation. After its activation on the endothelial cell surface by thrombin bound to thrombomodulin, it cleaves and inactivates procoagulant cofactors Va and Villa, protein S and intact factor V working as cofactors. Until recently, genetic defects of protein C or protein S were, together with antithrombin III deficiency, the established major causes of familial venous thromboembolism, but they were found in fewer than 5-10% of patients with thrombosis. In 1993, inherited resistance to activated protein C (APC) was described as a major risk factor for venous thrombosis. It is found in up to 60% of patients with venous thrombosis. In more than 90% of cases, the molecular background for the APC resistance is a single point mutation in the factor V gene, which predicts substitution of an arginine (R) at position 506 by a glutamine (Q). Mutated factor V (FV: Q506) is activated by thrombin or factor Xa in normal way, but impaired inactivation of mutated factor Va by APC results in life-long hypercoagulability. The prevalence of the FV:Q506 allele in the general population of Western countries varies between 2 and 15%, whereas it is not found in several other populations with different ethnic backgrounds. Owing to the high prevalence of FV:Q506 in Western populations, it occasionally occurs in patients with deficiency of protein S, protein C, or antithrombin III. Individuals with combined defects suffer more severely from thrombosis, and often at a younger age, than those with single defects, suggesting severe thrombophilia to be a multigenetic disease.

Adverse pregnancy outcomes and inherited thrombophilia

2018 ◽  
Vol 46 (4) ◽  
pp. 411-417 ◽  
Author(s):  
Dominik Dłuski ◽  
Radzisław Mierzyński ◽  
Elżbieta Poniedziałek-Czajkowska ◽  
Bożena Leszczyńska-Gorzelak
Keyword(s):  
Pregnant Women ◽  
Pregnancy Outcomes ◽  
Protein C ◽  
Antithrombin Iii ◽  
Activated Protein C ◽  
Protein S ◽  
Adverse Pregnancy Outcomes ◽  
Control Group ◽  
Inherited Thrombophilia ◽  
Adverse Pregnancy

Abstract Aim: (1) To evaluate the prevalence of inherited thrombophilia in pregnant women with adverse pregnancy outcomes: intrauterine growth retardation (IUGR), preeclampsia (PE) and placental abruption. (2) To assess the impact of inherited thrombophilia on the nature of obstetric complications. (3) To assess levels of protein S, protein C, antithrombin III and homocysteine in pregnant women with adverse pregnancy outcomes. Subjects and methods: The study comprised 162 pregnant women. The patients were divided into three test groups and one control group. In all 162 patients the following tests were completed: activated protein C resistance (APC-R), the level of free protein S, activity of protein C, antithrombin III and the level of homocysteine. The data were statistically analyzed via χ2 of independence or homogeneity test. Results: In 32 of 162 patients participating in clinical research thrombophilia was diagnosed (10 patients with APC-R, 21 patients with protein S deficiency, one patient with hyperhomocysteinemia): seven patients belonged to the control group and 25 patients had diagnosed adverse pregnancy outcomes (P=0.04). In 32 patients with diagnosed thrombophilia, level of protein S was decreased (P=0.04). Protein S deficiency was diagnosed, when level of protein S was lower than 30% in the second trimester and lower than 24% in the third trimester. The incidence of activated protein C resistance caused by the mutation of factor V Leiden was in six patients (5.9%) with adverse pregnancy outcomes, and in four patients (6.6%) from the control group. Results were not statistically significant. No protein C deficiency was diagnosed (diagnosis: level<60%), but in 50% of patients with thrombophilia level of protein C was over the norm (P=0.02). The level of antithrombin III was often decreased in patients with preeclampsia – (32.4%), then in the other patients – (17.2%) (P=0.04), but no patient was diagnosed with antithrombin III deficiency (diagnosis: level<60%). Conclusions: Tests for thrombophilia should be carried out in women with adverse pregnancy outcomes in their history, who are planning pregnancy, to start anticoagulant prophylaxis. Our study supports the thesis that tests for thrombophilia should be carried out in women with a history of adverse pregnancy outcomes and who are planning a pregnancy to start anticoagulant prophylaxis.

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