Plasma Fibrin Clot Properties Are Unfavorably Altered in Women following Venous Thromboembolism Associated with Combined Hormonal Contraception

The use of hormonal contraception is associated with an increased risk of venous thromboembolism (VTE). Unfavorably altered fibrin clot phenotype has been reported in patients following unprovoked VTE who are at risk of recurrences. It remains unknown whether fibrin clot characteristics in women with contraception-related VTE differ from those in unprovoked VTE. We studied three age-matched groups of women: (1) after contraception-related VTE, (n=48) (2) after unprovoked VTE (n=48), and (3) controls (n=48). Plasma fibrin clot permeability (Ks), turbidity of clot formation, efficiency of fibrinolysis using clot lysis time (CLT), and rate of increase in D-dimer during lytic clot degradation (D-Drate), along with thrombin generation and fibrinolysis proteins were determined. Compared with the controls, patients following contraception-related and unprovoked VTE formed faster (lag phase, -8.8% and -20.4%, respectively) fibrin clots of increased density (Ks, -8.6% and -13.4%, respectively) displaying impaired fibrinolysis as evidenced by prolonged CLT (+11.5% and +14.5%, respectively) and lower D-Drate (-7.1% and -5.6%, respectively), accompanied with higher plasminogen activator inhibitor-1 (PAI-1, +14.9% and +17.8%, respectively) and elevated peak thrombin generation (+63.8% and +36.7%, respectively). The only differences between women with unprovoked and contraception-related VTE were lower fibrin mass in plasma clots (D-Dmax, -8.6%), along with higher peak thrombin generation (+19.8%) and shorter lag phase (-6.8%) in the latter group. This study suggests that women after contraception-related VTE, similar to those following unprovoked VTE, have denser fibrin clot formation and impaired clot lysis. These findings might imply higher risk of VTE recurrence in women with the prothrombotic clot phenotype.

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Abstract 16668: The Effects of Dabigatran on Fibrin Network Structure and Lysis: A Simple Technique to Monitor Efficacy of Treatment?

Circulation ◽

10.1161/circ.130.suppl_2.16668 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Francesco Franchi ◽

Rhodri King ◽

Fladia Phoenix ◽

Fabiana Rollini ◽

Jung Rae Cho ◽

...

Keyword(s):

Antiplatelet Therapy ◽

Placebo Treatment ◽

Fibrin Clot ◽

Clot Formation ◽

Clot Lysis ◽

Lag Phase ◽

Maximum Absorbance ◽

Lysis Time ◽

Fibrin Network ◽

Clot Lysis Time

Background: Thrombus formation represent the final step in the atherothrombotic process and occurs secondary to a complex interaction between platelets and coagulation factors. Increased platelet reactivity and enhanced clot formation can both determine predisposition to vascular events. Direct platelet inhibition by modern antiplatelet therapy is now effective at controlling the cellular component of coagulation but the fibrin network is not generally targeted in arterial disease. Our aim was to investigate the effects of dabigatran on fibrin network characteristics in individuals dual antiplatelet therapy (DAPT). Methods: This was a prospective, randomized, double-blind study conducted in 30 patients on maintenance (at least 30 days) DAPT with aspirin (81mg/day) and clopidogrel (75mg/day). Patients were randomized to receive either dabigatran 150mg bid or matching placebo for 7 days. Fibrin clot properties were studied using a validated turbidimetric assay and the following parameters were recorded: lag phase and time to full clot formation, both of which measure clotting potential; clot maximum absorbance, representing fibrin network density and fibre thickness; clot lysis time to assess fibrinolytic efficiency. Results: Dabigatran treatment was associated with an increase in lag phase, compared with baseline, of 1013±167 sec , whereas no difference was detected in placebo treated patients (-17±14 sec, p<0.001 for dabigatran vs placebo). Similar results were obtained for clot formation time with an increase of 240±37 sec in dabigatran treated patients with no change following placebo treatment (-24±18 sec; p<0.001 comparing the two groups). The change in clot maximum absorbance after dabigatran and placebo treatment showed no differences (-0.02±0.01 and 0.00±0.01 au, respectively; p=0.2) and clot lysis time was similar. Conclusions: In patients on DAPT with aspirin and clopidogrel, additional treatment with dabigatran delays fibrin clot formation without affecting fibrinolysis. Therefore, triple therapy with dabigatran may be one option to reduce thrombosis potential in high risk individuals. Moreover, our assay, which can be conducted on stored samples, offers the opportunity to monitor response to dabigatran therapy.

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Effect of Tranexamic Acid on Coagulation and Fibrin Clot Properties in Children Undergoing Craniofacial Surgery

Thrombosis and Haemostasis ◽

10.1055/s-0039-3402762 ◽

2020 ◽

Vol 120 (03) ◽

pp. 392-399 ◽

Cited By ~ 1

Author(s):

Christian Fenger-Eriksen ◽

Alexander D'Amore Lindholm ◽

Lisbeth Krogh ◽

Tobias Hell ◽

Martin Berger ◽

...

Keyword(s):

Data Analysis ◽

Blood Loss ◽

Tranexamic Acid ◽

Thrombin Generation ◽

Blood Clot ◽

Fibrin Clot ◽

Clot Formation ◽

Clot Lysis ◽

Clot Strength ◽

Clot Structure

Abstract Objective Craniosynostosis surgery in small children is very often associated with a high blood loss. Tranexamic acid (TXA) reduces blood loss during this procedure, although the potential underlying coagulopathy in these children is not known in detail. Objective was to determine the nature of any coagulopathy found during and after craniosynostosis surgery and to characterize the effect of TXA on fibrin clot formation, clot strength, and fibrinolysis. Materials and Methods Thirty children received either TXA (bolus dose of 10 mg/kg followed by 8 hours continuous infusion of 3 mg/kg/h) or placebo. Dynamic whole blood clot formation assessed by thromboelastometry, platelet count, dynamic thrombin generation/thrombin-antithrombin, clot lysis assay, and fibrinogen/factor XIII (FXIII) levels were measured. Additionally, clot structure was investigated by real-time live confocal microscopy and topical data analysis. Results Increased ability of thrombin generation was observed together with a tendency toward shortened activated partial thromboplastin time and clotting time. Postoperative maximum clot firmness was higher among children receiving TXA. FXIII decreased significantly during surgery in both groups.Resistance toward tissue plasminogen activator-induced fibrinolysis was higher in children that received TXA, as evidenced by topical data analysis and by a significant longer lysis time. Fibrinogen levels were higher in the TXA group at 24 hours. Conclusion A significant coagulopathy mainly characterized by changes in clot stability and not parameters of thrombin generation was reported. Tranexamic acid improved clot strength and reduced fibrinolysis, thereby avoiding reduction in fibrinogen levels.

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Maturity onset diabetes of the young and fibrin-related thrombosis risk

Diabetes and Vascular Disease Research ◽

10.1177/1479164120963048 ◽

2020 ◽

Vol 17 (6) ◽

pp. 147916412096304

Author(s):

RC Sagar ◽

F Phoenix ◽

G Thanabalasingham ◽

K Naseem ◽

RA Ajjan ◽

...

Keyword(s):

Confocal Microscopy ◽

Plasminogen Activator Inhibitor ◽

Fibrin Clot ◽

Complement C3 ◽

Clot Lysis ◽

Maturity Onset Diabetes ◽

Plasminogen Activator Inhibitor 1 ◽

Onset Diabetes ◽

Increased Risk ◽

Fibrin Network

Background: Fibrin network characteristics determine predisposition to cardiovascular disease (CVD). Individuals with type 1 (T1DM) and type 2 diabetes mellitus (T2DM) have higher risk of CVD and display deranged fibrin network structure. Those with maturity onset diabetes of the young (MODY) may also be at increased risk but their fibrin clot properties have not been studied. Methods: Plasma clots properties from 13 individuals with HNF1A-MODY, 12 matched-individuals with T2DM and 12 with T1DM were studied using a validated turbidimetric assay and confocal microscopy. Plasma levels of fibrinogen, plasminogen activator inhibitor-1, complement C3 and C-reactive protein were also measured. Results: MODY clot maximum absorbance was 0.37 ± 0.03 AU, similar to T1DM (0.32 ± 0.03 AU; p = 0.26), but lower than T2DM (0.49 ± 0.03 AU; p = 0.02), with confocal microscopy confirming structural differences. Clot lysis time in MODY was similar to T1DM (456 ± 50 and 402 ± 20 s, respectively; p = 0.09) but shorter than T2DM (588 ± 58 s; p = 0.006). Comparing inflammatory/thrombotic proteins in HNF1A-MODY and T2DM, C3 levels were lower in MODY than T2DM (0.58 ± 0.09 and 0.80 ± 0.1 mg/ml, respectively; p < 0.01). Conclusions: HNF1A-MODY fibrin network alterations are at least as pronounced as in T1DM but less thrombotic than T2DM clots. Differences in fibrin clot characteristics comparing HNF1A-MODY and T2DM may, in part, relate to lower C3 levels.

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Altered fibrin clot structure and dysregulated fibrinolysis contribute to thrombosis risk in severe COVID-19

Blood Advances ◽

10.1182/bloodadvances.2021004816 ◽

2021 ◽

Author(s):

Malgorzata Wygrecka ◽

Anna Birnhuber ◽

Benjamin Seeliger ◽

Laura Michalick ◽

Oleg Pak ◽

...

Keyword(s):

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Fibrin Clot ◽

Clot Lysis ◽

Lag Phase ◽

Factor Xii ◽

Plasminogen Activator Inhibitor 1 ◽

Effect Analysis ◽

High Incidence ◽

Fibrinolysis Inhibitor

The high incidence of thrombotic events suggests a possible role of the contact system pathway in COVID-19 pathology. Here, we demonstrate altered levels of factor XII (FXII) and its activation products in critically ill COVID-19 patients in comparison to patients with severe acute respiratory distress syndrome due to influenza virus (ARDS-influenza). Compatible with this data, we report rapid consumption of FXII in COVID-19, but not in ARDS-influenza, plasma. Interestingly, the lag phase in fibrin formation, triggered by the FXII activator kaolin, was not prolonged in COVID-19 as opposed to ARDS-influenza. Using confocal and electron microscopy, we showed that increased FXII activation rate, in conjunction with elevated fibrinogen levels, triggers formation of fibrinolysis-resistant, compact clots with thin fibers and small pores in COVID-19. Accordingly, clot lysis was markedly impaired in COVID-19 as opposed to ARDS-infleunza subjects. Dysregulatated fibrinolytic system, as evidenced by elevated levels of thrombin-activatable fibrinolysis inhibitor, tissue-plasminogen activator, and plasminogen activator inhibitor-1 in COVID-19 potentiated this effect. Analysis of lung tissue sections revealed wide-spread extra- and intra-vascular compact fibrin deposits in COVID-19 patients. Together, compact fibrin network structure and dysregulated fibrinolysis may collectively contribute to high incidence of thrombotic events in COVID-19.

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Fibrin clot characteristics in acute ischaemic stroke patients treated with thrombolysis: the impact on clinical outcome

Thrombosis and Haemostasis ◽

10.1160/th16-12-0954 ◽

2017 ◽

Vol 117 (07) ◽

pp. 1440-1447 ◽

Cited By ~ 10

Author(s):

Jan P. Bembenek ◽

Maciej Niewada ◽

Jakub Siudut ◽

Krzysztof Plens ◽

Anna Członkowska ◽

...

Keyword(s):

Clinical Outcome ◽

Ischaemic Stroke ◽

Acute Ischaemic Stroke ◽

Thrombin Generation ◽

Fibrin Clot ◽

Clot Lysis ◽

Lag Phase ◽

Excellent Outcome ◽

Good Outcome ◽

The Impact

SummaryFibrin clot properties in acute ischaemic stroke (AIS) are unfavourably altered, including faster formation of denser and poorly lysable fibre networks. We investigated clot properties in AIS patients treated with recombinant tissue plasminogen activator (rtPA) and their impact on clinical outcome. In 74 consecutive AIS patients eligible for rtPA treatment, we assessed ex vivo plasma fibrin clot formation, permeability (Ks), and rtPA-induced lysis, along with peak thrombin generation, fibrinolysis proteins and inhibitors at three time points – on admission, after 24 hours and 3 months since stroke. Clinical outcome was assessed using the NIHSS and mRS scores. Compared with the pretreatment values, fibrin networks assessed 24 hours since thrombolysis were formed more slowly (+20.5 % lag phase on turbidimetry), were less compact (+36.9 % Ks), composed of thinner fibres (-10.6 % lower maximum absorbancy [ΔAb]), which were lysed more rapidly (-20.8 % clot lysis time [CLT] and +7.1 % the rate of rtPA-induced D-dimer release from clots [D-Drate]). Thrombin generation and fibrinolysis proteins remained elevated. Lower ΔAb (<0.86 at 405 nm), shorter CLT (<105 min), and higher D-Drate (>0.072 mg/l/min) assessed at baseline predicted good outcome (mRS 0–2) at 3 months after adjustment for age and fibrinogen. Logistic regression adjusted for potential confounders showed that good outcome at 3 months was predicted by pretreatment D-Drate, while pretreatment CLT predicted excellent outcome (mRS of 0–1). In conclusion, formation of denser fibrin clots displaying impaired lysability and pattern of their changes induced by thrombolysis may affect clinical outcome in AIS patients.

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The Roles of α2-Antiplasmin and Plasminogen Activator Inhibitor 1 (PAI-1) in the Inhibition of Clot Lysis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649570 ◽

1993 ◽

Vol 70 (02) ◽

pp. 301-306 ◽

Cited By ~ 51

Author(s):

Linda A Robbie ◽

Nuala A Booth ◽

Alison M Croll ◽

Bruce Bennett

Keyword(s):

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Fibrin Clot ◽

Clot Lysis ◽

Plasminogen Activator Inhibitor 1 ◽

Dependent Inhibition ◽

Activator Inhibitor ◽

Pai 1

SummaryThe relative importance of the two major inhibitors of fibrinolysis, α2-antiplasmin (α2-AP) and plasminogen activator inhibitor (PAI-1), were investigated using a simple microtitre plate system to study fibrin clot lysis in vitro. Cross-linked fibrin clots contained plasminogen and tissue plasminogen activator (t-PA) at concentrations close to physiological. Purified α2-AP and PAI-1 caused dose-dependent inhibition. All the inhibition due to normal plasma, either platelet-rich or poor, was neutralised only by antibodies to α2-AP. Isolated platelets, at a final concentration similar to that in blood, 2.5 × 108/ml, markedly inhibited clot lysis. This inhibition was neutralised only by antibodies to PAI-1. At the normal circulating ratio of plasma to platelets, α2-AP was the dominant inhibitor. When the platelet:plasma ratio was raised some 20-fold, platelet PAI-1 provided a significant contribution. High local concentrations of PAI-1 do occur in thrombi in vivo, indicating a role for PAI-1, complementary to that of α2-AP, in such situations.

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Altered fibrin clot structure/function in patients with antiphospholipid syndrome: association with thrombotic manifestation

Thrombosis and Haemostasis ◽

10.1160/th13-11-0980 ◽

2014 ◽

Vol 112 (08) ◽

pp. 287-296 ◽

Cited By ~ 21

Author(s):

Magdalena Celińska-Löwenhoff ◽

Teresa Iwaniec ◽

Agnieszka Padjas ◽

Jacek Musiał ◽

Anetta Undas

Keyword(s):

Structure Function ◽

Antiphospholipid Syndrome ◽

Thrombotic Event ◽

Fibrin Clot ◽

Clot Lysis ◽

Lag Phase ◽

Lysis Time ◽

Clot Structure ◽

Clot Lysis Time ◽

D Dimer

SummaryWe tested the hypothesis that plasma fibrin clot structure/function is unfavourably altered in patients with antiphospholipid syndrome (APS). Ex vivo plasma clot permeability, turbidity and susceptibility to lysis were determined in 126 consecutive patients with APS enrolled five months or more since thrombotic event vs 105 controls. Patients with both primary and secondary APS were characterised by 11% lower clot permeability (p<0.001), 4.8% shorter lag phase (p<0.001), 10% longer clot lysis time (p<0.001), and 4.7% higher maximum level of D-dimer released from clots (p=0.02) as compared to the controls. Scanning electron microscopy images confirmed denser fibrin networks composed of thinner fibres in APS. Clots from patients with “triple-antibody positivity” were formed after shorter lag phase (p=0.019) and were lysed at a slower rate (p=0.004) than in the remainder. Clots from APS patients who experienced stroke and/or myocardial infarction were 8% less permeable (p=0.01) and susceptible to lysis (10.4% longer clot lysis time [p=0.006] and 4.5% slower release of D-dimer from clots [p=0.01]) compared with those following venous thromboembolism alone. Multivariate analysis adjusted for potential confounders showed that in APS patients, lupus anticoagulant and “triple-positivity” were the independent predictors of clot permeability, while “triple-positivity” predicted lysis time. We conclude that APS is associated with prothrombotic plasma fibrin clot phenotype, with more pronounced abnormalities in arterial thrombosis. Molecular background for this novel prothrombotic mechanism in APS remains to be established.

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Plasma fibrin clot properties in the G20210A prothrombin mutation carriers following venous thromboembolism: the effect of rivaroxaban

Thrombosis and Haemostasis ◽

10.1160/th17-01-0060 ◽

2017 ◽

Vol 117 (09) ◽

pp. 1739-1749 ◽

Cited By ~ 8

Author(s):

Agnieszka Janion-Sadowska ◽

Joanna Natorska ◽

Jakub Siudut ◽

Michal Zabczyk ◽

Andrzej Stanisz ◽

...

Keyword(s):

Venous Thromboembolism ◽

Fibrin Clot ◽

Clot Lysis ◽

Mutation Carriers ◽

Lysis Time ◽

Prothrombin Mutation ◽

Fibrinolysis Inhibitor ◽

Heterozygous Carriers ◽

Mutation Group ◽

Clot Structure

SummaryWe sought to investigate whether the G20210A prothrombin mutation modifies plasma fibrin clot properties in patients after venous thromboembolism (VTE) and how rivaroxaban treatment affects these alterations. We studied 34 prothrombin mutation heterozygous carriers and sex- and age-matched 34 non-carriers, all at least three months since the first VTE episode, before and during treatment with rivaroxaban. Clot permeability (Ks) and clot lysis time (CLT) with or without elimination of thrombin activatable fibrinolysis inhibitor (TAFI) were assessed at baseline, 2–6 hours (h) after and 20–25 h after intake of rivaroxaban (20 mg/day). At baseline, the prothrombin mutation group formed denser clots (Ks −12 %, p=0.0006) and had impaired fibrinolysis (CLT +14 %, p=0.004, and CLT-TAFI +13 %, p=0.03) compared with the no mutation group and were similar to those observed in 15 healthy unrelated prothrombin mutation carriers. The G20210A prothrombin mutation was the independent predictor for Ks and CLT before rivaroxaban intake. At 2–6 h after rivaroxaban intake, clot properties improved in both G20210A carriers and non-carriers (Ks +38 %, and +37 %, CLT −25 % and −25 %, CLT-TAFI −20 % and −24 %, respectively, all p<0.001), but those parameters were worse in the prothrombin mutation group (Ks −12.8 %, CLT +17 %, CLT-TAFI +13 %, all p<0.001). Rivaroxaban concentration correlated with fibrin clot properties. After 20–25 h since rivaroxaban intake most clot properties returned to baseline. Rivaroxaban-related differences in clot structure were confirmed by scanning electron microscopy images. In conclusion, rivaroxaban treatment, though improves fibrin clot properties, cannot abolish more prothrombotic fibrin clot phenotype observed in prothrombin mutation carriers following VTE.

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Hormonal contraception and the risk of venous thrombosis: Management recommendations from the Piedmont Region and the Consensus Conference of the Italian National Institute of Health

Italian Journal of Medicine ◽

10.4081/itjm.2010.150 ◽

2013 ◽

pp. 150-153

Author(s):

Valentina Donvito ◽

Maria R. Giolito

Keyword(s):

Venous Thromboembolism ◽

Absolute Risk ◽

Hormonal Contraception ◽

Consensus Conference ◽

The Public ◽

Increased Risk ◽

Italian National Health ◽

Management Recommendations ◽

Italian National Institute ◽

Piedmont Region

Hormonal methods are used by many fertile women who require contraception. They are highly effective, but their use is associated with an increased risk of venous thromboembolism. This report summarizes the recommendations of the Public Health Service of Italy’s Piedmont Region for the prescription of hormonal contraception (November 2007) and the results of the Consensus Conference of the Italian National Health Institute on the prevention of thromboembolism related to hormonal contraception (July 2009). Although hormonal contraception increases the relative risk for venous thromboembolism, both documents agreed that the absolute risk remains very small. Assessments of eligibility for hormonal contraception must be based on complete medical history that include medical conditions, drugs used, and family history. Unnecessary medical barriers, such as routine screening for thrombophilia, are not recommended. Most women can safely use hormonal contraception. Physicians and women should discuss the risks, benefits, and uncertainties associated with hormonal contraception so that women will be able to make informed decisions regarding their use.

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A monoclonal antibody specific for two-chain urokinase-type plasminogen activator. Application to the study of the mechanism of clot lysis with single-chain urokinase-type plasminogen activator in plasma

Blood ◽

10.1182/blood.v75.9.1794.1794 ◽

1990 ◽

Vol 75 (9) ◽

pp. 1794-1800 ◽

Cited By ~ 27

Author(s):

PJ Declerck ◽

HR Lijnen ◽

M Verstreken ◽

H Moreau ◽

D Collen

Keyword(s):

Monoclonal Antibody ◽

Human Plasma ◽

Plasminogen Activator ◽

Fibrin Clot ◽

Clot Lysis ◽

Enzyme Linked Immunosorbent Assay ◽

Single Chain ◽

Plasminogen Activator Inhibitor 1 ◽

Type Plasminogen Activator ◽

Urokinase Type Plasminogen Activator

Abstract A murine monoclonal antibody (MA-12E6A8) was raised against human urokinase-type plasminogen activator (u-PA), which, in an enzyme-linked immunosorbent assay (ELISA), reacted 15,000-fold better with recombinant two-chain u-PA (rtcu-PA) than with recombinant single-chain u-PA (rscu-PA). The antibody had no effect on the activity of rtcu-PA or on its inhibition by a chloromethylketone, but reduced the inhibition of rtcu-PA by recombinant plasminogen activator inhibitor-1 (rPAI-1) at least 10-fold. The dissociation constant of the rtcu-PA/MA- 12E6A8 complex was 7 nmol/L. An ELISA was developed using MA-12E6A8 as capture antibody and a horseradish peroxidase conjugated u-PA specific antibody for tagging. It recognized free and active site blocked rtcu- PA but not rtcu-PA in complex with rPAI-1 or with alpha 2-antiplasmin. This ELISA was used to monitor the generation of rtcu-PA during fibrin clot lysis with rscu-PA in human plasma. Addition of 5 micrograms/mL rscu-PA to 3 mL plasma containing a 0.2 mL 125I-fibrin labeled plasma clot caused 50% clot lysis in 62 +/- 13 minutes (mean +/- SD, n = 6), at which time 99 +/- 28 ng/mL rtcu-PA was detected but no fibrinogen breakdown had occurred. Fifty percent fibrinogen breakdown did occur only when rtcu-PA had reached a level of 1,000 +/- 270 ng/mL (at 150 +/- 21 minutes). rscu-PA, 2 micrograms/mL, induced 50% clot lysis in 160 +/- 41 minutes (n = 6); no fibrinogen degradation occurred within 4 hours and rtcu-PA levels did not exceed 80 ng/mL. In the absence of a fibrin clot, 5 micrograms/mL rscu-PA added to human plasma did not result in significant generation of rtcu-PA (less than 50 ng/mL after 4 hours) and no fibrinogen degradation was observed. These results indicate that clot lysis with rscu-PA in a plasma milieu does not require extensive systemic conversion of rscu-PA to rtcu-PA, and that fibrinogen degradation occurs secondarily to systemic conversion of rscu-PA to rtcu-PA.

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