Inhibition of Extrinsic Pathway Inhibitor Shortens the Coagulation Time of Normal Plasma and of Hemophilia Plasma

SummaryAn increasing amount of evidence suggests that coagulation factors VIII and IX play a role not only in the intrinsic but also in the extrinsic pathway of coagulation. In this context the influence of the Extrinsic Pathway Inhibitor (EPI) on the coagulation time of hemophilia plasma lacking FVIII or FIX has been investigated. The coagulation time was measured in a dilute thromboplastin assay. Addition of recombinant EPI (rEPI) prolonged the coagulation time of normal plasma while the addition of an inhibitory antibody against EPI shortened the coagulation time. At low concentrations of thromboplastin the coagulation time of hemophilia plasma was prolonged and at all dilutions of thromboplastin, addition of anti-EPI IgG normalized the coagulation time of a hemophilia plasma. Analysis of 10 individual donor plasma samples and 8 individual hemophilia samples showed that addition of anti-EPI IgG shortened the coagulation time more in hemophilia plasma than in normal plasma. This illustrates the importance of a powerful extrinsic FVII dependent pathway to achieve hemostasis in the case of FVIII or FIX deficiency (hemophilia A and B).

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The Role of Factor XI in a Dilute Thromboplastin Assay of Extrinsic Coagulation Pathway

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615963 ◽

2001 ◽

Vol 85 (06) ◽

pp. 1055-1059 ◽

Cited By ~ 17

Author(s):

Shilong Xiong ◽

Xiaofan He ◽

Fayi Liu ◽

Jianzhong Han ◽

Juncheng Li ◽

...

Keyword(s):

Blood Coagulation ◽

Platelet Rich Plasma ◽

Critical Role ◽

Extrinsic Pathway ◽

Thrombin Inhibition ◽

Normal Plasma ◽

Low Concentrations ◽

Plasma Depletion ◽

Coagulation Pathway

SummaryBlood coagulation has been thought to be composed of both intrinsic and extrinsic pathways. Recent evidence strongly supports the critical role of the extrinsic pathway in the initiation of blood coagulation. This investigation established an assay that examines the role of FXI in the thromboplastin-initiated (extrinsic) coagulation based on this new concept. Plasma clotting times were measured at different concentrations of thromboplastin with activated FXII inhibited (FXIIa-inhibited Diluted Thromboplastin Time, FXIIaiDTT). Only at low concentrations of thromboplastin was FXIIaiDTT of FXI-deficient plasma significantly prolonged than that of normal plasma. Depletion of FXI from normal plasma prolonged its FXIIaiDTT and replenishment of FXI shortened it. FXIIaiDTTs of both FVIII-deficient and FIX-deficient plasma were remarkably prolonged, and addition of normal plasma dose-dependently shortened it. Furthermore, earlier α-thrombin inhibition was directly correlated with decreasing FXa generation. The amount of FXa production was: platelet-rich plasma > platelet-poor plasma > FXI-deficient plasma. Therefore, our findings from the FXIIaiDTT assays not only support the critical role of extrinsic pathway in blood coagulation initiation, but also demonstrate the importance of FXI as an amplifier of thrombin generation in thromboplastin-initiated coagulation.

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THE MODE OF ACTION OF PENTOSAN POLYSULPHATE IN PLASMA

10.1055/s-0038-1643249 ◽

1987 ◽

Author(s):

S Béguin ◽

H C Hemker

Keyword(s):

Factor Viii ◽

Linear Increase ◽

Factor Ix ◽

Factor X ◽

Heparin Cofactor Ii ◽

Normal Plasma ◽

Viii And Ix ◽

Pentosan Polysulphate ◽

Lag Times ◽

Prothrombinase Activity

We developed a method which enables as to compute the course of prothrombinase activity in clotting plasma (H.C. Hemker, G.M. Willems, S. Béguin: Thromb. Haemostas. 56, 9-17, 1986) and used this for a study of the effect of pentosan polysulphate (PPS) on thrombin generation.When added to normal plasma in the concentration range of 0-8 μg/ml PPS induces a linear increase of the pseudo first order decay constant of endogenous thrombin like heparin does, 1 ug of PPS being equivalent to 0.045 Aig of heparin. Contrary to heparin this action is partly (∼ 65%) dependent upon AT III and partly (∼ 35%) upon heparin cofactor II.In normal plasma PPS causes an inhibition of both extrinsic and intrinsic prothrombinase formation. Only in the intrinsic system an increase of the lag time of prothrombinase appearance is observed. Unlike heparin, PPS does not inhibit factor IXa induced thrombin formation neither does it inhibit prothrombinase formation in the presence of preactivated factor VIII. The prolongation of the lag times must therefore be ascribed to inhibition by PPS of the activation of factor VIII.The inhibition of extrinsic prothrombinase formation by PPS increases with progressive dilution of thromboplastin and is not seen in haemophilia A or B plasma. This demonstrates the existance of a factor VIII and IX dependent process in extrinsic coagulation that gains in importance when the potency of factgr VII-tissue factor complex decreases, i.e. the Josso pathway.PPS, but also heparin causes an unexplained increase of prothrombinase action in haemophIIic plasma. The same phenomenon may be expected to exist in normal plasma, be it obscured by a concomitant inhibition. This, together with the incomplete inhibition of factor VIII activation by PPS makes that we cannot use this inhibitor as a means to quantitate the Josso pathway. The best estimate that we can obtain is that, in the presence of 2% thromboplastin, the factor IX dependent activation of factor X contributes more then 20% to prothrombinase generation.

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HIV Replication Alters the Composition of Extrinsic Pathway Coagulation Factors and Increases Thrombin Generation

Journal of the American Heart Association ◽

10.1161/jaha.113.000264 ◽

2013 ◽

Vol 2 (4) ◽

Cited By ~ 35

Author(s):

Jason V. Baker ◽

Kathleen Brummel‐Ziedins ◽

Jacqueline Neuhaus ◽

Daniel Duprez ◽

Nathan Cummins ◽

...

Keyword(s):

Thrombin Generation ◽

Coagulation Factors ◽

Hiv Replication ◽

Extrinsic Pathway

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Manganese-induced Trafficking and Turnover of the cis-Golgi Glycoprotein GPP130

Molecular Biology of the Cell ◽

10.1091/mbc.e09-11-0985 ◽

2010 ◽

Vol 21 (7) ◽

pp. 1282-1292 ◽

Cited By ~ 45

Author(s):

Somshuvra Mukhopadhyay ◽

Collin Bachert ◽

Donald R. Smith ◽

Adam D. Linstedt

Keyword(s):

Mammalian Cells ◽

Essential Element ◽

Multivesicular Bodies ◽

Low Concentrations ◽

Early Endosomes ◽

Rapid Changes ◽

Golgi Protein ◽

Elevated Exposure ◽

Dependent Pathway ◽

Mn Concentrations

Manganese is an essential element that is also neurotoxic at elevated exposure. However, mechanisms regulating Mn homeostasis in mammalian cells are largely unknown. Because increases in cytosolic Mn induce rapid changes in the localization of proteins involved in regulating intracellular Mn concentrations in yeast, we were intrigued to discover that low concentrations of extracellular Mn induced rapid redistribution of the mammalian cis-Golgi glycoprotein Golgi phosphoprotein of 130 kDa (GPP130) to multivesicular bodies. GPP130 was subsequently degraded in lysosomes. The Mn-induced trafficking of GPP130 occurred from the Golgi via a Rab-7–dependent pathway and did not require its transit through the plasma membrane or early endosomes. Although the cytoplasmic domain of GPP130 was dispensable for its ability to respond to Mn, its lumenal stem domain was required and it had to be targeted to the cis-Golgi for the Mn response to occur. Remarkably, the stem domain was sufficient to confer Mn sensitivity to another cis-Golgi protein. Our results identify the stem domain of GPP130 as a novel Mn sensor in the Golgi lumen of mammalian cells.

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Rapid Loss of Factor XII- and XI-Activity in Ellagic Acid Activated Normal Plasma: Role of Plasma Inhibitors and Implications for Automated Aptt-Recording

10.1055/s-0039-1680362 ◽

1977 ◽

Author(s):

J. H. Joist ◽

J. F. Cowan ◽

M. Khan

Keyword(s):

Ellagic Acid ◽

Clinical Laboratory ◽

Coagulation Factors ◽

Activation Process ◽

Factor Xii ◽

Naturally Occurring ◽

Normal Plasma ◽

Factor Xiia ◽

Loss Of Contact

Rapid prolongation of the activated partial thromboplastin time (aPTT) of normal plasma upon incubation with ellagic acid containing aPTT reagents was observed. The aPTT prolongation was not due to time dependent changes in pH in the incubation mixtures or loss of activity of the labile coagulation factors VIII and V, but occurred as a result of rapid progressive inactivation of ellagic acid activated factors XII and XI. Prolongation of the aPTT and loss of contact factor activities was not observed in plasma incubated with particulate activator reagents. This finding seemed to indicate that adsorption of factors XII and XI to larger particles during the activation process may protect these factors from inactivation by naturally occurring plasma inhibitors. Evidence is presented which supports previous observations that Ci-inhibitor, α1-antitrypsin and antithrombin III (in the presence of heparin contribute to factor XIIa- and XIa-inactivation in ellagic acid activated plasma and that plasma albumin may compete with factor XII for ellagic acid binding. The findings indicate that ellagic acid containing aPTT reagents have unfavorable properties which seriously limit their usefulness in the clinical laboratory, particularly in respect to recording of the aPTT with certain fully automated clot timers.

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Recombinant factor VIIa

Thrombosis and Haemostasis ◽

10.1160/th05-01-0032 ◽

2005 ◽

Vol 93 (06) ◽

pp. 1027-1035 ◽

Cited By ~ 33

Author(s):

Marco Zaffanello ◽

Dino Veneri ◽

Massimo Franchini

Keyword(s):

Recombinant Factor Viia ◽

Factor Viia ◽

Current Knowledge ◽

Coagulation Factors ◽

Factor Vii ◽

Recombinant Activated Factor Vii ◽

Activated Factor Vii ◽

Viii And Ix ◽

Bleeding Episodes ◽

Uncontrolled Bleeding

SummaryRecombinant activated factor VII (rFVIIa, Novo Seven®) has been successfully used to treat bleeding episodes in patients with antibodies against coagulation factors VIII and IX. In recent years, rFVIIa has also been employed for the management of uncontrolled bleeding in a number of congenital and acquired haemos- tatic abnormalities. Based on a literature search, this review examines the current knowledge on therapy with rFVIIa, from the now well-standardized uses to the newer and less well-characterised clinical applications.

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FACTOR II ACTIVATING ACTIVITY IN EXTRACTS OF TUMORAL NECROSIS FROM TWO MURINE BREAST ADENOCARCINOMAS

10.1055/s-0038-1643206 ◽

1987 ◽

Author(s):

A Blanco ◽

R Bonfil ◽

O Bustoabad ◽

M Lazzari

Keyword(s):

Coagulation Factors ◽

Factor Vii ◽

Factor V ◽

Factor X ◽

Extrinsic Pathway ◽

Factor Ii ◽

Metastatic Capacity ◽

Plasma Recalcification Time ◽

Recalcification Time ◽

Breast Adenocarcinomas

Increased deposition and lysis of fibrin, associated with malignant tissue, has led to look for activators of both the coagulation and fibrinolytic systems produced by tumor cells. We report the evidences of a procoagblant activity (PA) in the extracts of intratumoral necrosis from two experimental breast adenocarcinomas in murine model (BALB/c). The tumors have different metastatic capacity (MC). M3 without MC and MM3 with high MC.The addition of the extracts to: 1- Normal Plasma, 2- Deficient substrates in coagulation factors, 3- Purified, fibrinogen (I), showed: 1- Shortening of the plasma recalcification time (PRT) and APTT, without ;modification on prothrombin time (PT), 2- Reduction of the PRT on deficient substrates in factors: VIII; VII; VII and X; V; V, VII and X; without modification on II deficient substrate, 3- No PA on I. Table:C: Control, s: seconds, m: minutes. The PA was not affected by heparin. The results suggest that the PA is independent of the presence of either factor VIII or factor VII (intrinsic or extrinsic pathway respectively), as well as presence of either factor V or factor X. Any effect was observed either on factor II deficient substrate or on I, so, there was no evidence of thrombin activity The PA could be act directly on factor II, suggesting that fibrin formation could be induced by a “non-classical” activation pathway. No significant differences (p>0.5) in PA were observed between both tumoral necrosis extracts. The necrotic area in M3 (37%) is bigger than in MM3 (18%). So, much more PA could be present in MM3 and this could play a role in the MC of this tumor.

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Activators of Inactive Renin (‘Prorenin’) in Human Plasma: Their Connection with Kinin Formation, Coagulation and Fibrinolysis

Clinical Science ◽

10.1042/cs057089s ◽

1979 ◽

Vol 57 (s5) ◽

pp. 89s-92s ◽

Cited By ~ 6

Author(s):

F. H. M. Derkx ◽

B. N. Bouma ◽

H. L. Tan-Tjiong ◽

M. A. D. H. Schalekamp

Keyword(s):

Human Plasma ◽

Hageman Factor ◽

Active Renin ◽

Normal Plasma ◽

Inactive Renin ◽

Fletcher Factor ◽

Free Plasma ◽

Renin Activation ◽

Dependent Pathway ◽

Proteolytic Pathways

1. Human plasma was treated at 4°C with acid, trypsin, plasmin, streptokinase, urokinase, active Hageman factor fragment (β-XIIa) and β-XIIa-activated plasma prekallikrein (Fletcher factor). The conversion of inactive into active renin (activation) was studied in normal plasma (n = 10), Hageman factor-deficient plasma (n = 2), Fletcher factor-deficient plasma (n = 1) and plasminogen-free plasma (n = 4). 2. In normal plasma inactive renin was activated at pH 7·5 after treatment at pH < 4·0; at pH 3·3 the results were the same as with trypsin. This was also the case in plasminogen-free plasma. In Hageman factor-deficient plasma and in Fletcher factor-deficient plasma, however, the quantities of renin that were activated after acidification were much smaller than with trypsin. The addition of physiological amounts of active kallikrein to pH 3·3-pretreated Hageman factor-deficient plasma caused complete activation of renin. In contrast, the addition of active Hageman factor fragment to pH 3·3-pretreated Fletcher factor-deficient plasma had little or no effect. 3. Plasmin, streptokinase-activated plasminogen and urokinase-activated plasminogen activated inactive renin in pH 4·0-pretreated normal plasma as well as in pH 4·0-pretreated Hageman factor-deficient plasma and Fletcher factor-deficient plasma. 4. It is concluded that inactive renin is activated by two separate proteolytic pathways: one pathway depends on both Hageman factor and plasma prekallikrein, and the other pathway depends on plasminogen. In the Hageman factor-dependent pathway plasma kallikrein and not Hageman factor is the major activator of inactive renin. It is assumed that pH 3·3-treatment of plasma destroys the major inhibitors of kallikrein and that pH 4·0-treatment destroys the major inhibitor of plasmin.

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Ham-Wasserman Lecture

Hematology ◽

10.1182/asheducation-2002.1.1 ◽

2002 ◽

Vol 2002 (1) ◽

pp. 1-9 ◽

Cited By ~ 40

Author(s):

Pier M. Mannucci

Keyword(s):

Large Scale ◽

Coagulation Factors ◽

Gene Replacement ◽

Infectious Complications ◽

Inherited Disorders ◽

Secondary Tumors ◽

Human Immunodeficiency Viruses ◽

First Millennium ◽

Viii And Ix ◽

Bloodborne Infections

Abstract Known since the beginning of the first millennium, the hemophilias are among the most frequent inherited disorders of blood coagulation and definitely the most severe. In the 1970s, with the availability of concentrated preparations of the deficient coagulation factors VIII and IX and with the large-scale adoption of home treatment, hemophilia care became one of the most gratifying examples of successful secondary prevention of a chronic disease. Unfortunately, in the early 1980s it was recognized that factor concentrates prepared from plasma pooled from thousands of donors transmitted the hepatitis and the human immunodeficiency viruses. The scientific community reacted promptly to the devastation brought about by hepatitis and AIDS. The last 15 years of the second millennium have witnessed the development of methods that, when applied during concentrate manufacturing, inactivate viruses escaping the screening procedures. The adoption of these measures has reduced dramatically the risk of transmission of bloodborne infections. The production of recombinant factors and their availability for patients’ treatment epitomize progress in hemophilia care through DNA technology. Methods based on the polymerase chain reaction (PCR) have unraveled an array of gene lesions associated with hemophilia, permitting improved secondary control of the disease through carrier detection in women from affected families and prenatal termination of their affected male infants. This article will review the aforementioned areas of progress and discuss unresolved problems (such as treatment of patients with antibodies, the risk of new infectious complications, and the issue of secondary tumors). Hopes and expectations for further improvement in the third millennium and particularly the prospects of hemophilia cure though gene replacement therapy will also be mentioned.

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A Novel Congenital Bleeding Disorder Related to High Plasma Heparin-Like Anticoagulant Activity.

Blood ◽

10.1182/blood.v106.11.4074.4074 ◽

2005 ◽

Vol 106 (11) ◽

pp. 4074-4074

Author(s):

Zhaoyue Wang ◽

Haiyen Yang ◽

Xia Bai ◽

Wei Zhang ◽

Changgeng Ruan

Keyword(s):

Ex Vivo ◽

Anticoagulant Activity ◽

Coagulation Factors ◽

High Plasma ◽

Bleeding Disorder ◽

Normal Plasma ◽

Normal Ranges ◽

Coagulation Tests ◽

Plasma Heparin

Abstract Heparin or heparin-like compounds present in human plasma in minute amounts. It has been reported that a very few patients with such diseases as plasma cell neoplasms, acute monoblastic leukemia and acquired immune deficincy syndrome have an increased plasma heparin-like anticoagulant activity. Recently, we found a 10-year-old girl who was physically and developmentally normal, but had recurrent episodes of prolonged bleeding and hematoma starting in her early childhood, which could be stopped by transfusion of fresh frozen plasma or prothrombin complex concentrate. The coagulation tests of her plasma were regularly repeated since she was 2 years old, and always revealed a markedly prolonged APTT (61.8–104 seconds, normal 28–40 seconds) and TT (36–50.1 seconds, normal 14–21 seconds), and a slightly prolonged PT (15.9–25 seconds, normal 11–14.5 seconds). Fibrinogen, prothrombin and other coagulation factors as well as anticoagulant and fibrinolytic systems were all normal. The results of immunologic measurements were either negative or within normal ranges. Treatment of the patient’s plasma in vitro with either protamine or heparinase could completely normalize the coagulation abnormalities, but not with normal plasma. The anticoagulant activity of her plasma corresponded to 0.2 heparin U/mL when measured by a TT assay using normal plasma as substrate and standardized with porcine heparin. Her plasma heparin concentration was 0.22 heparin U/mL when measured using a colometric assay. In ex vivo study, the abnormal coagulation tests could effectively be corrected when the patient was intravenously administed with protamine. Considering these characteristic laboratory features of the patient, we suppose it would probably represent a novel congenital bleeding disorder related to high plasma heparin-like anticoagulant activity which, to our knowledge, had not been described before.

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