Fibrin Clot Lysis by Thrombolytic Agents Is Impaired in Newborns due to a Low Plasminogen Concentration

1992 ◽  
Vol 68 (03) ◽  
pp. 325-330 ◽  
Author(s):  
M Andrew ◽  
L Brooker ◽  
M Leaker ◽  
B Paes ◽  
J Weitz
Keyword(s):  
Thrombolytic Agent ◽  
Fibrin Clot ◽  
Clot Lysis ◽  
Therapeutic Effectiveness ◽  
Thrombolytic Agents ◽  
Cord Plasma ◽  
Tissue Plasminogen ◽  
Adult Plasma ◽  
Low Levels ◽  
Fibrin Clots

SummaryAlthough thrombolytic drugs have been extensively used in adults, there is sparse information on their effectiveness in newborns whose fibrinolytic system differs significantly from adults. The purpose of this study was to determine if low plasma levels of plasminogen in cord plasma limited the therapeutic effectiveness of thrombolytic agents. Urokinase (UK), streptokinase (SK) and tissue plasminogen activator (TPA) were compared for their ability to lyse washed 125I-labelled adult or cord fibrin clots suspended in cord or adult plasma. 125I-labelled fibrin clots were prepared by recalcifying cord or adult plasma spiked with labelled fibrinogen and then placed into cord or adult plasma which contained either saline or differing amounts of a specific thrombolytic agent. After a 60 min incubation, the remaining 125I-fibrin in clots released 125I-fibrin fragments, and concentrations of fibrinogen, α2-antiplasmin, and plasminogen in the bathing plasma were measured and compared to starting values. Cord fibrin clots were more resistant than adult fibrin clots to all thrombolytic drugs tested (p <0.001). On average, the cord system retained 27% more 125I-fibrin in clots, and released 32% less 125I-fibrin fragments into plasma. Fibrinogenolysis was also decreased in cord plasmas compared to adult plasmas. The degree of fibrinolysis and fibrinogenolysis in cord plasma increased to adult values when plasminogen concentrations were increased in the bathing plasma. Thus, cord fibrin clots have an impaired response to thrombolytic agents secondary to low levels of plasminogen. We speculate that the clinical response of newborns to thrombolytic agents is also impaired and will not be enhanced by increasing doses of thrombolytic agents but may be enhanced by increasing the concentration of plasminogen.

scholarly journals Incorporation of α2-Plasmin Inhibitor into Fibrin Clots and Its Association with the Clinical Outcome of Acute Ischemic Stroke Patients

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Zsuzsa Bagoly ◽  
Barbara Baráth ◽  
Rita Orbán-Kálmándi ◽  
István Szegedi ◽  
Réka Bogáti ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Intracranial Hemorrhage ◽  
Intravenous Thrombolysis ◽  
Fibrin Clot ◽  
Clot Lysis ◽  
Stroke Patients ◽  
Plasmin Inhibitor ◽  
Fibrin Clots

Cross-linking of α2-plasmin inhibitor (α2-PI) to fibrin by activated factor XIII (FXIIIa) is essential for the inhibition of fibrinolysis. Little is known about the factors modifying α2-PI incorporation into the fibrin clot and whether the extent of incorporation has clinical consequences. Herein we calculated the extent of α2-PI incorporation by measuring α2-PI antigen levels from plasma and serum obtained after clotting the plasma by thrombin and Ca2+. The modifying effect of FXIII was studied by spiking of FXIII-A-deficient plasma with purified plasma FXIII. Fibrinogen, FXIII, α2-PI incorporation, in vitro clot-lysis, soluble fibroblast activation protein and α2-PI p.Arg6Trp polymorphism were measured from samples of 57 acute ischemic stroke patients obtained before thrombolysis and of 26 healthy controls. Increasing FXIII levels even at levels above the upper limit of normal increased α2-PI incorporation into the fibrin clot. α2-PI incorporation of controls and patients with good outcomes did not differ significantly (49.4 ± 4.6% vs. 47.4 ± 6.7%, p = 1.000), however it was significantly lower in patients suffering post-lysis intracranial hemorrhage (37.3 ± 14.0%, p = 0.004). In conclusion, increased FXIII levels resulted in elevated incorporation of α2-PI into fibrin clots. In stroke patients undergoing intravenous thrombolysis treatment, α2-PI incorporation shows an association with the outcome of therapy, particularly with thrombolysis-associated intracranial hemorrhage.

scholarly journals BβArg448Lys polymorphism is associated with altered fibrin clot structure and fibrinolysis in type 2 diabetes

2017 ◽  
Vol 117 (02) ◽  
pp. 295-302 ◽  
Author(s):  
Katie A. Greenhalgh ◽  
Mark W. Strachan ◽  
Saad Alzahrani ◽  
Paul D. Baxter ◽  
Kristina F. Standeven ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Fibrin Clot ◽  
Clot Lysis ◽  
Plasma Clot ◽  
Lysis Time ◽  
Increased Risk ◽  
Fibrin Network ◽  
Clot Lysis Time ◽  
Fibrin Clots

SummaryBoth type 2 diabetes (T2DM) and Bß448Lys variant of fibrinogen are associated with dense fibrin clots, impaired fibrinolysis and increased cardiovascular risk. It was our objective to investigate whether BßArg448Lys adds to vascular risk by modulating fibrin network structure and/or fibrinolysis in diabetes. The primary aim was to study effects of BßArg448Lys on fibrin network characteristics in T2DM. Secondary aims investigated interactions between gender and BßArg448Lys substitution in relation to fibrin clot properties and vascular disease. Genotyping for BßArg448Lys and dynamic clot studies were carried out on 822 T2DM patients enrolled in the Edinburgh Type 2 Diabetes Study. Turbidimetric assays of individual plasma samples analysed fibrin clot characteristics with additional experiments conducted on clots made from purified fibrinogen, further examined by confocal and electron microscopy. Plasma clot lysis time in Bß448Lys was longer than Bß448Arg variant (mean ± SD; 763 ± 322 and 719 ± 351 seconds [s], respectively; p<0.05). Clots made from plasma-purified fibrinogen of individuals with Arg/Arg, Arg/Lys and Lys/Lys genotypes showed differences in fibre thickness (46.75 ± 8.07, 38.40 ± 6.04 and 25 ± 4.99 nm, respectively; p<0.001) and clot lysis time (419 ± 64, 442 ± 87 and 517 ± 65 s, respectively; p=0.02), directly implicating the polymorphism in the observed changes. Women with Bß448Lys genotype had increased risk of cerebrovascular events and were younger compared with Bß448Arg variant (67.2 ± 4.0 and 68.2 ± 4.4 years, respectively; p=0.035). In conclusion, fibrinogen Bβ448Lys variant is associated with thrombotic fibrin clots in diabetes independently of traditional risk factors. Prospective studies are warranted to fully understand the role of BβArg448Lys in predisposition to vascular ischaemia in T2DM with the potential to develop individualised antithrombotic management strategies.

scholarly journals Kinetics of fibrin clot lysis

1968 ◽  
Vol 106 (1) ◽  
pp. 101-105 ◽  
Author(s):  
R. J. Merrills ◽  
J. T. B. Shaw
Keyword(s):  
Plasminogen Activator ◽  
Experimental Studies ◽  
Fibrin Clot ◽  
Clot Lysis ◽  
Lysis Time ◽  
Kinetics Of ◽  
Fibrin Clots

The principles relating the lysis times of fibrin clots to their contents of fibrin, plasminogen and plasminogen-activator were investigated. Mathematical considerations suggested that the square of the lysis time should correlate linearly with the fibrin content, and inversely with the activator and the plasminogen contents of the system. Experimental studies, during which these parameters were independently varied, showed that the predicted relationships were valid for concentrations that gave clot-lysis times in the range normally used for studies of fibrinolysis.

scholarly journals Decreased Thrombin Activity of Fibrin Clots Prepared in Cord Plasma Compared with Adult Plasma

1996 ◽  
Vol 39 (5) ◽  
pp. 826-830 ◽  
Author(s):  
Paresh Patel ◽  
Jeffrey Weitz ◽  
Lu Ann Brooker ◽  
Bosco Paes ◽  
Lesley Mitchell ◽  
...  
Keyword(s):  
Cord Plasma ◽  
Thrombin Activity ◽  
Adult Plasma ◽  
Fibrin Clots

scholarly journals Physico-Chemical and Biological Properties of Biosimilar and Reference Tissue Plasminogen Activator Products

2019 ◽  
Vol 19 (1) ◽  
pp. 39-49
Author(s):  
V. D. Gusarova ◽  
M. S. Pantyushenko ◽  
V. M. Simonov ◽  
R. R. Shukurov ◽  
R. A. Khamitov ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Specific Activity ◽  
Reference Product ◽  
Fibrin Clot ◽  
Biological Properties ◽  
Clot Lysis ◽  
Physico Chemical ◽  
Tissue Plasminogen

Recombinant tissue plasminogen activator (international nonproprietary name — alteplase) which was developed by «GENERIUM» (Russia) and received a marketing authorisation in Russia is completely analogous to Actilyse® which is used to treat medical conditions accompanied by thrombosis, such as acute myocardial infarction, pulmonary embolism, and ischemic stroke. The aim of the study was to carry out a comprehensive comparison of physico-chemical and biological properties of Revelyse® and the reference product Actilyse® in order to assess their biosimilarity. Materials and Methods: comparative peptide mapping and determination of comparability of chromatographic profiles of tryptic hydrolysates was performed using RP-HPLC and massspectrometry; the molecular weight distribution was determined by mass-spectrometry and polyacrylamide gel electrophoresis (Laemmli method). The purity and homogeneity of products as well as the content of related impurities (oligomers and fragments) were determined using gel filtration; N-glycosylation profile was analysed by hydrophilic HPLC, total sialic acid was quantified by the Svennerholm resorcinol method. Protein binding to fibrin and human fibrinogen was assessed by surface plasmon resonance, and the specific activity was compared by fibrin clot lysis. Results: the research demonstrated a complete overlap of the products’ peptide maps, which indicates the identity of аlteplase amino acid sequences in the two medicines being compared. The authors of the study also determined the molecular weight and the content of the intact single-stranded form of the protein, and quantified post-translational modifications, the content of sialic acids and neutral sugars. The analysis of the N-glycosylation profile revealed insignificant differences in the percentage of multiantenna complex glycans. The specificity of alteplase was evaluated by analysing the formation of protein complexes with natural alteplase ligands – fibrin and plasminogen activator inhibitor-1, but no significant differences were found. The comparison of specific activation of plasminogen fibrinolytic activity was performed based on the results of the assay analysing the fibrin clot lysis rate, and it demonstrated comparability of Revelyse® and Actilyse®. Conclusions: comparative experimental studies have shown no differences in the structure, charge distribution heterogeneity, impurities content, and specific activity of alteplase as a component of Revelyse® and the reference product Actilyse®, which leads to the conclusion that they are similar in terms of physicochemical and biological properties.

The effect of sialic acid content in glycans on thrombolytic activity of tissue plasminogen activators

2020 ◽  
pp. 10-17
Author(s):  
D. V. Chaschinova ◽  
N. V. Stratonova ◽  
D. A. Kudlay
Keyword(s):  
Sialic Acid ◽  
Plasminogen Activators ◽  
Fibrin Clot ◽  
Sialic Acids ◽  
Target Range ◽  
Clot Lysis ◽  
Batch Mode ◽  
Sialic Acid Content ◽  
Thrombolytic Activity ◽  
Tissue Plasminogen

Purpose: to investigate the dependence of the thrombolytic activity of tissue plasminogen activators (tPA) alteplase and tenecteplase on the degree of sialylation of the oligosaccharide component of molecules. Materials and methods: tPA specimens with an average degree of sialylation were obtained by cultivating CHO clones-producers in the fed-batch mode; desialylated forms of tPA were obtained by processing with neuraminidase, and hypersialylated forms of tPA were obtained by cultivating clones-producers in a medium with the addition of butyrate. The content of sialic acids was determined by resorcinol method, and the activity of tPA was determined by fibrin clot lysis. Results: the dependence of tenecteplase activity on the content of sialic acids in the molecule is demonstrated. The activity of tenecteplase falls below the limits of the target range when the content of sialic acids is more than 5 residues per tenecteplase molecule. No such relation was found for alteplase. Conclusion: the content of sialic acid residues affects the biological activity of tenecteplase; the activity of alteplase does not depend on the degree of sialylation of the molecule.

Newborns Are Hyperfibrinolytic at Physiologic tPA Concentrations and the Increased Fibrinolysis Is Related to Decreased Apparent TAFIa.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1756-1756
Author(s):  
Lesley G. Mitchell ◽  
Laszlo Bajzar ◽  
Amal Rahal
Keyword(s):  
Specific Inhibitor ◽  
Lag Time ◽  
Fibrin Clot ◽  
Molecular Devices ◽  
Clot Lysis ◽  
Activity Inhibition ◽  
Carboxypeptidase Inhibitor ◽  
Adult Plasma ◽  
Fibrinolytic Capacity ◽  
Normal Adults

Abstract INTRODUCTION: Differences in both quantitative and qualitative components of the fibrinolytic system in newborns are well described. The overall impact of these variations in components on actual fibrinolytic capacity in response to various concentrations of tPA has not been assessed. There were two objectives for the current study, To determine the relative clot lysis capacity of the newborn compared to the adult at various rt-PA levels. To determine the effect of endogenous thrombin activated fibrinolytic inhibitor (TAFIa) on clot lysis in newborns compared to adults. METHODS: Plasma from 20 normal adults and 20 normal cords were pooled. Plasma, 2.5 pM tissue factor, 5mM CaCl2 and 8 concentrations of rt-PA ranging from physiologic levels (0.02nM) to therapeutic levels (3.0 nM) was added to microtitre plates. Plates were sealed and clot turbidity was monitored at 405nm using a SpectraMax Platereader (Molecular Devices, USA) at 37°C over 72 hours. The following parameters of clot lysis were calculated: lag time to clot lysis initiation (lag time), slope/maximum absorbance-minimum absorbance correcting for differences in fibrin clot formed (slope), time at which clot turbidity equals one-half of the full-scale value (t 1/2) and iv) end of clot lysis (end time). In some experiments, potato tuber carboxypeptidase inhibitor (PTCI) a specific inhibitor of TAFIa, was added to plasma. RESULTS: Comparison of newborn to adult: for clarity only 2 concentrations of r-tPA are shown (Table I). At therapeutic concentrations of rt-PA (3.0 nM) newborns were comparable to adults on all parameters of clot lysis. In contrast, at physiologic concentrations of rt-PA (0.023nM) when compared to adults, newborns demonstrated decreased lag time more rapid completion of clot lysis more rapid t1/2 clot lysis increased slope of clot lysis. Effect of endogenous TAFI activity: Inhibition of TAFIa had no effect on the slope of lysis in either adult or newborn (data not shown). However, there was a large effect on decreasing lag time to lysis initiation in adults but little effect in newborns (Figure I). The lag time was comparable in adults with PTCI and to newborns. These data show that TAFIa activity has little effect on inhibiting fibrinolysis in newborns. CONCLUSIONS: The concentration of rt-PA has a profound effect on the relative clot lysis in newborns compared to adults. At physiologic rt-PA concentrations the newborn initiates and completes clot lysis earlier and lyses clots at a faster rate than adults. Therefore, the newborn appears hyperfibrinolytic as compared to the adult at endogenous rt-PA concentrations. The hyperfibrinolytic response in the newborn can be explained, in part, by low apparent TAFIa concentrations. In contrast, at therapeutic rt-PA concentrations newborn clot lysis is comparable to the adult. Table I Comparision of clot lysis in newborn and adult plasma Lag time t 1/2 Slope Completion ** p&lt;0.0001 when compared to adult 0.023nM tPA Adult 24,881±3628 74,267±6394 1.6±0.5 127,441±13,958 Newborn 11,971±2148** 27,469±3413** 3.6±0.7** 39,505±3,408** 3.0 nM tPA Adult 496±92 709±39 203±17 839±106 Newborn 577±47 734±44 228±26 900±42 Figure Figure

Some Aspects of Fibrin Clot Lysis and Its Inhibition by Human Serum

1967 ◽  
Vol 18 (01/02) ◽  
pp. 101-113 ◽  
Author(s):  
M. J Gallimoke ◽  
J. T. B Shaw
Keyword(s):  
Sodium Chloride ◽  
Fibrin Clot ◽  
Chloride Ions ◽  
Clot Lysis ◽  
Irreversible Inhibitors ◽  
Zero Order Kinetics ◽  
Lysis Time ◽  
Kinetics Of ◽  
Clot Lysis Time ◽  
Fibrin Clots

SummaryThe lysis by plasmin of fibrin clots prepared from plasminogen-deficient fibrinogen, and by urokinase of similar clots prepared from plasminogen-rich fibrinogen has been studied. In a simple system containing no plasminogen the clot lysis time is inversely proportional to the concentration of added plasmin, and zero order kinetics are obeyed. The reciprocal of the lysis time is a measure of the fibrinolytic activity in the system, and may be used to study antiplasmins. When serum was included a reduction in reciprocal lysis time resulted, the extent of which varied linearly with the amount of serum added. These relationships persisted whether soluble or insoluble plasmin preparations were used and whether or not chloride ions were present. They indicate that serum antiplasmins behave as irreversible or pseudo-irreversible inhibitors. It was found that sodium chloride exerts a potentiating effect on fibrinolysis by plasmin, but does not influence the extent to which the enzyme is inhibited by serum antiplasmins.When fibrin clots were prepared from plasminogen-rich fibrinogen, and urokinase was included, a direct relationship was found to exist between the concentration of urokinase and the square of the reciprocal clot lysis time. When serum was added, vigorous inhibition of fibrinolysis resulted when sodium chloride was present; no inhibition was observed in its absence. It is proposed that sodium chloride weakens the interaction between plasminogen and fibrin in the clots, and renders the plasmin produced by the action of urokinase more susceptible to inhibition by antiplasmins. Evidence in support of this hypothesis is presented and the kinetics of fibrinolysis by plasmin, and its inhibition, are discussed.

scholarly journals Canine Neutrophil Extracellular Traps Enhance Clot Formation and Delay Lysis

2017 ◽  
Vol 55 (1) ◽  
pp. 116-123 ◽  
Author(s):  
Unity Jeffery ◽  
Dana N. LeVine
Keyword(s):  
Autoimmune Diseases ◽  
Neutrophil Extracellular Traps ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Clot Lysis ◽  
Elastase Activity ◽  
Platelet Poor Plasma ◽  
Extracellular Traps ◽  
Tissue Plasminogen

Autoimmune diseases increase the risk of thrombosis. Neutrophil extracellular traps (NETs) are webs of DNA and protein that may mediate thrombosis in autoimmune diseases. Human and murine studies show NET-releasing neutrophils within a thrombus promote its growth, but it is unclear to what extent NET fragments released into circulation during inflammation are prothrombotic. This study hypothesized that canine NETs promote clot formation and impair lysis even in the absence of neutrophils. NETs were prepared from PMA-stimulated neutrophils and added to fibrinogen and thrombin or to recalcified pooled canine platelet-poor plasma, tissue factor, and tissue plasminogen activator. Clot formation and lysis were measured spectrophotometrically. NETs did not alter fibrin clot formation, but NETs increased maximum clot formation velocity ( P = .001) and delayed lysis ( P = .009) of plasma clots compared with supernatants from nonstimulated neutrophils. DNase digestion of NETs reduced their effect on clot lysis but not maximum clot formation velocity. This suggested impaired lysis was principally mediated by DNA within NETs but that NET proteins were principally responsible for increased speed of clot formation. Previous reports suggested elastase or histones might be responsible for the effect of NETs on clot formation. Elastase activity was greatly reduced by plasma, and addition of histones to plasma did not increase formation velocity, suggesting these proteins were not responsible for increasing maximum formation velocity. This study showed that NETs enhanced clot formation and impaired clot lysis in canine platelet-poor plasma. These in vitro findings suggest both NET proteins and DNA may contribute to thrombosis in inflammatory disease.

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