Accelerated fibrin clot degradation is associated with arterial thromboembolism in patients following venous thrombosis: a cohort study

AbstractSeveral lines of evidence have suggested that patients following venous thromboembolism (VTE) are at higher risk of arterial thromboembolism (ATE). Prothrombotic fibrin clot characteristics were reported in individuals with cardiovascular risk factors. We investigated whether specific fibrin clot properties measured after 3–4 months of anticoagulation characterize VTE patients with subsequent ATE. We enrolled 320 patients following VTE aged below 70 years (median age, 46). Ten patients were lost to follow-up. ATE occurred in 21 individuals after a median 54 (31–68) months during a follow-up of 87.5 months (incidence 0.94%; 95% confidence interval [CI], 0.59–1.4 per patient-year). Patients with ATE had faster fibrin clot degradation, reflected by maximum rate of D-dimer increase during plasma clot lysis induced by tissue-type plasminogen activator (D-Drate) at baseline. Clot permeability, turbidimetric variables, clot lysis time, and thrombin generation were unrelated to ATE. Univariable Cox proportional hazards analysis showed that age, diabetes, and D–Drate were risk factors for subsequent ATE. Increased D–Drate (by 0.001 mg/L/min; hazard ratio, 1.08; 95% CI 1.02–1.14) was an independent predictor of ATE after adjustment for potential confounders. Faster fibrin clot degradation at 3 months since VTE may increase the risk of ATE among VTE patients during follow-up.

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Zinc delays clot lysis by attenuating plasminogen activation and plasmin-mediated fibrin degradation

Thrombosis and Haemostasis ◽

10.1160/th14-09-0771 ◽

2015 ◽

Vol 113 (06) ◽

pp. 1278-1288 ◽

Cited By ~ 9

Author(s):

Sara J. Henderson ◽

Alan R. Stafford ◽

Beverly A. Leslie ◽

Paul Y. Kim ◽

Nima Vaezzadeh ◽

...

Keyword(s):

Catalytic Efficiency ◽

Fibrin Clot ◽

Tissue Type ◽

Clot Lysis ◽

Plasminogen Activation ◽

Plasma Clot ◽

Activated Platelets ◽

Type Plasminogen Activator ◽

Kd Values ◽

Local Release

SummaryZinc circulates free in plasma at a concentration of 0.1–2 μM, but its levels increase locally when it is released from activated platelets. Although zinc influences many processes in haemostasis, its effect on fibrinolysis has not been thoroughly investigated. Using a fluorescent zinc-binding probe, we demonstrated that zinc binds tissue-type plasminogen activator (tPA) and plasmin with high affinity (Kd values of 0.2 μM), and surface plasmon resonance studies revealed that zinc binds fibrin with a Kd of 12.8 μM. Zinc had no effect on the affinity of plasminogen or plasmin for fibrin, but increased the affinity of tPA by two-fold. In the presence of 5 μM zinc, the catalytic efficiency of plasminogen activation by tPA was reduced by approximately two-fold, both in the absence or presence of fibrin. Zinc attenuated plasminmediated degradation of the fibrinogen alpha-chain by 43 %, but had no effect on trypsin degradation. tPA-mediated fibrin clot lysis was prolonged 2.5-fold by zinc in a concentration-dependent fashion, and tPA-mediated plasma clot lysis was attenuated by 1.5-fold. Therefore, our data indicate that zinc modulates fibrinolysis by attenuating tPAmediated plasminogen activation and plasmin-induced fibrin degradation. These findings suggest that local release of zinc by platelets attenuates fibrinolysis.

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Recombinant Variants of Tissue-Type Plasminogen Activator Containing Amino Acid Substitutions in the Finger Domain

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646342 ◽

1992 ◽

Vol 68 (06) ◽

pp. 672-677 ◽

Cited By ~ 4

Author(s):

Hitoshi Yahara ◽

Keiji Matsumoto ◽

Hiroyuki Maruyama ◽

Tetsuya Nagaoka ◽

Yasuhiro Ikenaka ◽

...

Keyword(s):

Amino Acid ◽

Plasminogen Activator ◽

Half Life ◽

Tissue Type ◽

Clot Lysis ◽

Amino Acid Substitutions ◽

Wild Type ◽

Plasma Clot ◽

Tissue Type Plasminogen Activator ◽

Type Plasminogen Activator

SummaryTissue-type plasminogen activator (t-PA) is a fibrin-specific agent which has been used to treat acute myocardial infarction. In an attempt to clarify the determinants for its rapid clearance in vivo and high affinity for fibrin clots, we produced five variants containing amino acid substitutions in the finger domain, at amino acid residues 7–9, 10–14, 15–19, 28–33, and 37–42. All the variants had a prolonged half-life and a decreased affinity for fibrin of various degrees. The 37–42 variant demonstrated about a 6-fold longer half-life with a lower affinity for fibrin. Human plasma clot lysis assay estimated the fibrinolytic activity of the 37–42 variant to be 1.4-fold less effective than that of the wild-type rt-PA. In a rabbit jugular vein clot lysis model, doses of 1.0 and 0.15 mg/kg were required for about 70% lysis in the wild-type and 37–42 variant, respectively. Fibrinogen was degraded only when the wild-type rt-PA was administered at a dose of 1.0 mg/kg. These findings suggest that the 37–42 variant can be employed at a lower dosage and that it is a more fibrin-specific thrombolytic agent than the wild-type rt-PA.

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Vampire Bat Salivary Plasminogen Activator Promotes Robust Lysis of Plasma Clots in a Plasma Milieu Without Causing Fluid Phase Plasminogen Activation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656343 ◽

1992 ◽

Vol 68 (02) ◽

pp. 165-169 ◽

Cited By ~ 12

Author(s):

Timothy R Hare ◽

Stephen J Gardell

Keyword(s):

Plasminogen Activator ◽

Plasma Levels ◽

Fluid Phase ◽

Immunoblot Analysis ◽

Tissue Type ◽

Clot Lysis ◽

Plasma Clot ◽

Type Plasminogen Activator ◽

Iodine 125 ◽

Vampire Bat

SummaryVampire bat salivary plasminogen activator (BatPA), human tissue-type plasminogen activator (tPA) or streptokinase (SK) were incubated in human citrated plasma containing a plasma clot that was radiolabelled with iodine-125 fibrin(ogen). Complete clot dissolution by BatPA (30 nM) was associated with slight activation of “fluid phase” plasminogen; the plasma levels of functional fibrinogen and α2-antiplasmin decreased by only 8 and 19%, respectively. Addition of SK (3,600 IU/ml) to the clot-containing plasma caused complete clot lysis and massive activation of the “fluid phase” plasminogen, leading to >60 and 96% decreases of the functional levels of fibrinogen and α2-antiplasmin, respectively. Incubation of tPA (30 nM) in clot-containing plasma caused complete clot lysis as well as substantial activation of “fluid phase” plasminogen; the plasma levels of functional fibrinogen and α2-antiplasmin decreased by 45 and 79%, respectively. The profound degradation of fibrinogen in the SK and tPA but not BatPA-containing samples was confirmed by immunoblot analysis. Additional experiments showed that the presence of soluble clot lysate in plasma containing tPA enhanced the extent of fibrinogen degradation from 25% to >60%; the addition of soluble clot lysate to the plasma containing BatPA did not prompt further fibrinogen degradation. Finally, studies using exogenous α2-antiplasmin suggested that plasmin generated via tPA-mediated activation of “fluid phase” plasminogen does not play an important role in clot dissolution.

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Abstract P323: Pulse Pressure and Incident Acute Coronary Heart Disease Events in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Circulation ◽

10.1161/circ.127.suppl_12.ap323 ◽

2013 ◽

Vol 127 (suppl_12) ◽

Author(s):

Stephen P Glasser ◽

Daniel L Halberg ◽

Charles Sands ◽

Paul Muntner ◽

Monika Safford

Keyword(s):

Risk Factors ◽

Coronary Heart Disease ◽

Heart Disease ◽

Racial Differences ◽

Pulse Pressure ◽

Proportional Hazards ◽

Linear Trend ◽

Cox Proportional Hazards ◽

Cvd Risk

Background: Increased attention has been given to pulse pressure (PP) as a potential independent risk factor of cardiovascular disease. We examined the relationship between PP and incident acute coronary heart disease (CHD). Methods: We used data from the REasons for Geographic And Racial Differences in Stroke (REGARDS) national cohort study of 30,239 black and white participants aged 45 years or older and enrolled between 2003 and 2007. Baseline data included a 45-minute interview and in-home visit during which blood pressure was assessed and recorded as the average of two measurements obtained after a 5 minute seated rest. PP (SBP-DBP) was classified into 4 groups (<45, 45-54, 54.1-64, >64.1 mmHg). Telephone follow-up occurred every six months for self or proxy-reported suspected events, triggering medical record retrieval and adjudication by experts. Cox-proportional hazards models examined the association of incident CHD with PP groups, adjusting for socio-demographic and clinical risk factors. Results: This analysis included 22,909 participants free of CHD at baseline, with mean age 64.7±9.4 years; 40.4%were black, 44.6% were male and they experienced a total of 515 incident CHD events over a mean 3.4 yrs of follow-up (maximum 6 years). In unadjusted analyses, compared with PP<45 mmHg, each higher PP group had incrementally higher hazard ratios (HR) for incident CHD (HR 1.28 {95% CI 1.02-1.60}, 2.05 {1.63-2.56}, 3.82 {3.08-4.74}, p<0.001 for linear trend). This relationship persisted after fully adjusting including SBP for the highest PP group (HR 0.96 {0.75-1.21}, 1.12 {0.86-1.46}, 1.51 {1.09-2.10}, p trend <0.0001). Conclusions: High PP was associated with incident CHD, even when accounting for SBP and numerous other CVD risk factors.

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Risk factors for disease progression in low-teens normal-tension glaucoma

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2018-313375 ◽

2019 ◽

Vol 104 (1) ◽

pp. 81-86 ◽

Cited By ~ 2

Author(s):

Sung Uk Baek ◽

Ahnul Ha ◽

Dai Woo Kim ◽

Jin Wook Jeoung ◽

Ki Ho Park ◽

...

Keyword(s):

Risk Factors ◽

Disease Progression ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Normal Tension Glaucoma ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Hazards Model ◽

Diurnal Iop

Background/AimsTo investigate the risk factors for disease progression of normal-tension glaucoma (NTG) with pretreatment intraocular pressure (IOP) in the low-teens.MethodsOne-hundred and two (102) eyes of 102 patients with NTG with pretreatment IOP≤12 mm Hg who had been followed up for more than 60 months were retrospectively enrolled. Patients were divided into progressor and non-progressor groups according to visual field (VF) progression as correlated with change of optic disc or retinal nerve fibre layer defect. Baseline demographic and clinical characteristics including diurnal IOP and 24 hours blood pressure (BP) were compared between the two groups. The Cox proportional hazards model was used to identify the risk factors for disease progression.ResultsThirty-six patients (35.3%) were classified as progressors and 66 (64.7%) as non-progressors. Between the two groups, no significant differences were found in the follow-up periods (8.7±3.4 vs 7.7±3.2 years; p=0.138), baseline VF mean deviation (−4.50±5.65 vs −3.56±4.30 dB; p=0.348) or pretreatment IOP (11.34±1.21 vs 11.17±1.06 mm Hg; p=0.121). The multivariate Cox proportional hazards model indicated that greater diurnal IOP at baseline (HR=1.609; p=0.004), greater fluctuation of diastolic BP (DBP; HR=1.058; p=0.002) and presence of optic disc haemorrhage during follow-up (DH; HR=3.664; p=0.001) were risk factors for glaucoma progression.ConclusionIn the low-teens NTG eyes, 35.3% showed glaucoma progression during the average 8.7 years of follow-up. Fluctuation of DBP and diurnal IOP as well as DH were significantly associated with greater probability of disease progression.

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Restoration of thrombolytic potential in plasminogen-deficient mice by bolus administration of plasminogen

Blood ◽

10.1182/blood.v88.3.870.870 ◽

1996 ◽

Vol 88 (3) ◽

pp. 870-876 ◽

Cited By ~ 2

Author(s):

HR Lijnen ◽

P Carmeliet ◽

A Bouche ◽

L Moons ◽

VA Ploplis ◽

...

Keyword(s):

Bolus Injection ◽

Fibrin Clot ◽

Tissue Type ◽

Clot Lysis ◽

Bolus Administration ◽

Activity Levels ◽

Wild Type ◽

Type Plasminogen Activator ◽

Deficient Mice ◽

Pai 1

Abstract Homozygous plasminogen-deficient (Plg-/-) mice had a significantly reduced thrombolytic capacity toward intravenously injected 125I-fibrin labeled plasma clots prepared from Plg-/- murine plasma (9% +/- 3% lysis after 8 hours; (mean +/- SEM, n = 6), as compared with 82% +/- 8% in wild-type mice; P < .0001). Bolus injection of 1 mg purified murine plasminogen in 10- to 17-week-old Plg-/- mice increased the plasminogen antigen and activity levels at 8 hours to normal levels (130 +/- 5 micrograms/mL). Plasminogen administration was associated with significant restoration of thrombolytic potential (64% +/- 7% spontaneous clot lysis; P < .0001 versus lysis without plasminogen injection). Bolus injection of 1 mg plasminogen in homozygous tissue- type plasminogen activator-deficient (t-PA-/-) mice doubled the plasminogen antigen and activity levels after 8 hours and increased 125I-fibrin clot lysis at 8 hours from 13% +/- 3% to 34% +/- 5% (P = .008). Fibrinogen, t-PA antigen and alpha 2-antiplasmin activity levels after 8 hours were not significantly different in the groups with or without plasminogen injection. Injection of plasminogen induced a variable increase (on average 7- to 10-fold) of PAI-1, but no correlation with the extent of spontaneous clot lysis was observed. Histopathologic examination at the end of the experiments revealed that fibrin deposition in the liver of Plg-/- mice was slightly reduced 8 hours after bolus plasminogen injection (P = .007) and markedly reduced after 24 hours (P < .0001). Plasminogen antigen levels in liver extracts were comparable with those found in wild-type mice at 8 hours (130 +/- 20 versus 110 +/- 15 ng/mg protein) and decreased to 25 +/- 3.2 ng/mg protein at 24 hours. Thus, restoration of normal plasminogen levels in Plg-/- mice normalized the thrombolytic potential toward experimentally induced pulmonary emboli, and resulted in removal of endogenous fibrin deposits within 24 hours.

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Faktor risiko loss to follow up terapi ARV pada pasien HIV

Berita Kedokteran Masyarakat ◽

10.22146/bkm.12732 ◽

2017 ◽

Vol 33 (4) ◽

pp. 173

Author(s):

Listy Handayani ◽

Riris Andono Ahmad ◽

Yanri Wijayanti Subronto

Keyword(s):

Risk Factors ◽

Health Insurance ◽

Antiretroviral Therapy ◽

Protective Factor ◽

Proportional Hazards ◽

Cox Proportional Hazards ◽

Loss To Follow Up ◽

Kaplan Meier ◽

Adherence Counseling

Risk factors for loss to follow up of antiretroviral therapy in HIV patientsPurposeThis study aimed to determine risk factors for loss to follow-up of antiretroviral therapy among HIV-infected patients in Dr. Sardjito Yogyakarta, 2011-2014.MethodsA retrospective cohort study was conducted involving 499 HIV patients. Observations were conducted for four years using medical records. Data analysis was performed using Kaplan-Meier and Cox proportional hazards regression tests.ResultsThere were 190 loss to follow-up patients. Risk factors for loss to follow-up of ARV therapy were: a student (AHR = 2.42; 95% CI = 1.20-4.89), the distance ≥ 10 km (AHR = 1.58; 95% CI = 1:09 to 2:31), using health insurance (AHR = 1.67; 95% CI = 1:11 to 2:51) and homosexual as a protective factor of loss to follow-up of antiretroviral therapy (HR = 0:49; 95% CI = 0.30-0.80).ConclusionBeing a college student, the distance between home and ARV service ≥10 km and using health insurance were the risk factors for loss to follow-up of ARV treatment. Adherence counseling for students, cooperation with the drug taking supervisor and decentralization ARV service, as well as effective and efficient services for patients who use health insurance need to be strengthened.

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Biochemical and Biological Properties of a Recombinant Tissue-Type Plasminogen Activator Derived from the Rat JMI-229 Cell Line

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648419 ◽

1992 ◽

Vol 67 (02) ◽

pp. 239-247 ◽

Cited By ~ 8

Author(s):

H R Lijnen ◽

P D Webb ◽

B Van Hoef ◽

F De Cock ◽

J M Stassen ◽

...

Keyword(s):

Cell Line ◽

Human Plasma ◽

Plasminogen Activator ◽

Tissue Type ◽

Clot Lysis ◽

Chain Molecule ◽

Single Chain ◽

Plasma Clot ◽

Tissue Type Plasminogen Activator ◽

Type Plasminogen Activator

SummaryRecombinant tissue-type plasminogen activator (rt-PA), produced by expression of the genomic t-PA DNA from the JMI-229 cell line, which is of rat origin, in the host cell line, was purified to homogeneity. JMI-229 rt-PA was obtained essentially as a single chain molecule which was quantitatively converted to a two-chain moiety by treatment with plasmin. The plasminogen activating potential of single chain JMI-229 rt-PA was 5-fold lower than that of commercially available human rt-PA (Actilyse®) in the absence of fibrin, but comparable in the presence of fibrin; it showed a concentration-dependent binding to fibrin, with a significantly more pronounced binding than Actilyse® at low fibrin concentration (85 ± 8% versus 20 ± 7% at 0.025 mg/ml fibrin; p = 0.004). In human plasma in the absence of fibrin, the concentrations of both single chain and two-chain JMI-229 rt-PA required to induce 50% fibrinogen degradation in 2 h, were about 15-fold higher than those of Actilyse®. Both single chain and two-chain forms of JMI-229 rt-PA and of Actilyse® induced a similar time- and concentration-dependent lysis of a 125I-fibrin-labeled plasma clot immersed in human plasma, in the absence of significant systemic fibrinolytic activation. Equally effective concentrations (causing 50% clot lysis in 2 h) were 0.11 or 0.10 pg/ml for single chain or two-chain JMI-229 rt-PA, as compared to 0.11 or 0.15 pg/ml for single chain or two-chain Actilyse®. Continuous infusion over 60 min of single chain JMI-229 rt-PA or Actilyse® in hamsters with a 125I-fibrin-labeled pulmonary embolus, revealed a very similar thrombolytic potency (clot lysis versus dose) and specific thrombolytic activity (clot lysis versus steady state plasma antigen level of t-PA). The initial plasma half-life following intravenous bolus injection of 0.10 mg/kg in hamsters was equally short for JMI-229 rt-PA or Actilyse® (1.2 or 1.4 min respectively).It is concluded that JMI-229 rt-PA has a higher fibrin-affinity and a higher fibrin-specificity in human plasma in the absence of fibrin than Actilyse®, but a comparable thrombolytic potency in a hamster pulmonary embolism model.

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EVIDENCE FOR SYNERGISM BETWEEN TISSUE-TYPE PLASMINOGEN ACTIVATOR AND SINGLE CHAIN UROKINASE ON IN VITRO PLASMA CLOT LYSIS

10.1055/s-0038-1642908 ◽

1987 ◽

Author(s):

R S Rappaport ◽

M R Blume ◽

R L Vogel ◽

M H Levner ◽

P P Hung

Keyword(s):

Plasminogen Activator ◽

Tissue Type ◽

Clot Lysis ◽

Single Chain ◽

Plasma Clot ◽

Tissue Type Plasminogen Activator ◽

Molar Ratios ◽

Type Plasminogen Activator

There is mounting evidence from animal models and the clinic that combination thrombolytic therapy with tissue-type plasminogen activator (tPA) and single chain urokinase (scuPA) is synergistic. Yet, efforts to demonstrate synergism between these two plasminogen activators in vitro have met with discordant results. Collen et al (Thromb. Haemostasis, 56:35, 1986) reported an absence of synergism between these two agents on clot lysis in an in vitro plasma milieu when they were evaluated at molar ratios of 1:4 (tPA:scuPA and vice versa). Gurewich and Pannell (Thromb. Res., 44:217, 1986), however, reported a synergistic effect on fibrin-specific clot lysis in vitro when the agents were combined in concentrations exceeding molar ratios of 1:4 (tPA:scuPA). Here, we present evidence that synergism between tPA and scuPA may be demonstrated in vitro provided that the molar ratio of tPA to scuPA exceeds 1:4 and that the concentration of clot bound or unbound tPA is minimized. In order to achieve this experimental condition, the standard in vitro plasma clot lysis assay was modified. Human plasma clots were incubated first for a short time in plasma containing varying amounts of tPA. After incubation, the clots were washed thoroughly and reimmersed in plasma alone or in plasma containing varying amounts of scuPA or tPA. Under these conditions, lysis proceeded at a greater rate and to a greater extent when tPA clots were immersed in plasma containing an appropriate amount of scuPA than when they were immersed in plasma alone or in plasma containing appropriate amounts of tPA. Lysis of untreated clots or clots exposed first to scuPA and then to plasma containing varying amounts of scuPA proceeded far less efficiently with a characteristic lag. The enhanced lysis produced by tPA and scuPA obeyed the classical definition of synergy: the same biological effect can be obtained with two drugs together at algebraic fractional combinations of less than 1 (Berenbaum, M.C., Clin. Exp. Immunol., 28:1-18, 1977). Thus, conditions that more closely mimic the in vivo situation resulting from a bolus injection of tPA followed by infusion with scuPA, may provide a system for duplication of in vivo synergism in. vi tro and investigation of the mechanism thereof.

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A monoclonal antibody preventing binding of tissue-type plasminogen activator to fibrin: useful to monitor fibrinogen breakdown during t-PA infusion

Blood ◽

10.1182/blood.v67.5.1482.1482 ◽

1986 ◽

Vol 67 (5) ◽

pp. 1482-1487 ◽

Cited By ~ 16

Author(s):

P Holvoet ◽

HR Lijnen ◽

D Collen

Keyword(s):

Plasminogen Activator ◽

Tissue Type ◽

Clot Lysis ◽

Plasminogen Activation ◽

Plasma Clot ◽

Tissue Type Plasminogen Activator ◽

Type Plasminogen Activator ◽

Additional Support

Abstract One (MA-1C8) of 36 monoclonal antibodies obtained by fusion of P3X63- Ag8–6.5.3 myeloma cells with spleen cells of mice immunized with purified human tissue-type plasminogen activator (t-PA) blocked the activity of t-PA on fibrin plates but not on chromogenic substrates. MA- 1C8 at a concentration of 200 micrograms/mL inhibited plasma clot lysis and binding of t-PA to the clot. MA-1C8 had no influence on the activation of plasminogen by t-PA, which obeys Michaelis-Menten kinetics with Km = 105 mumol/L and kcat = 0.05 s-1; however, it abolished the influence of CNBr-digested fibrinogen on Km. These findings confirm that the stimulatory effect of fibrin on the activation of plasminogen by t-PA is mediated by binding of t-PA to fibrin and provide additional support for the kinetic model. Addition of t-PA to pooled fresh human plasma to a concentration of 5 micrograms/mL resulted in extensive fibrinogen breakdown after incubation for one hour at 37 degrees C or during storage at -20 degrees C for one day. In both instances, fibrinogen degradation was completely prevented by addition of MA-1C8 to a concentration of 200 micrograms/mL of plasma. MA-1C8 also effectively prevented in vitro fibrinogen degradation and in vitro plasminogen activation in plasma samples obtained during infusion of recombinant t-PA in patients with thromboembolic disease. Thus, MA-1C8 is a useful tool for discriminating between in vivo and in vitro fibrinolysis during thrombolytic therapy with t-PA.

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