Plasma levels of fibrinolytic proteins and the risk of myocardial infarction in men

Blood ◽  
2010 ◽  
Vol 116 (4) ◽  
pp. 529-536 ◽  
Author(s):  
Mirjam E. Meltzer ◽  
Carine J. M. Doggen ◽  
Philip G. de Groot ◽  
Frits R. Rosendaal ◽  
Ton Lisman

AbstractHypofibrinolysis as measured with overall clot lysis assays is associated with risk of arterial thrombosis. Individual components of the fibrinolytic system, however, have not been studied extensively in relation to arterial disease, or results of studies were inconsistent. The relation between plasminogen and α2-antiplasmin levels and cardiovascular risk factors and the association between plasminogen, α2-antiplasmin, tissue-plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) and risk of myocardial infarction was investigated in the Study of Myocardial Infarctions Leiden (555 men with a first myocardial infarction and 635 controls). α2-antiplasmin was associated with age and lipid levels, whereas plasminogen correlated with lipids, C-reactive protein, and smoking. Increased levels of all fibrinolytic factors were associated with myocardial infarction. Age-adjusted odds ratios (ORs; 95% confidence interval) for quartile 4 compared with 1 were 1.7 (1.2-2.3) for plasminogen, 1.9 (1.3-2.6) for α2-antiplasmin, 1.7 (1.2-2.3) for t-PA, and 1.7 (1.2-2.4) for PAI-1. After adjusting for cardiovascular risk factors, only α2-antiplasmin levels remained associated with risk (OR, 1.4; [1.0-2.0]). t-PA and PAI-1 levels predominantly reflected lipid levels, whereas plasminogen reflected the inflammatory state. Concluding, elevated α2-antiplasmin levels are independently associated with risk of myocardial infarction. t-PA, PAI-1, and plasminogen levels appear to reflect other cardiovascular risk factors.

1999 ◽  
Vol 82 (07) ◽  
pp. 104-108 ◽  
Author(s):  
Franck Paganelli ◽  
Marie Christine Alessi ◽  
Pierre Morange ◽  
Jean Michel Maixent ◽  
Samuel Lévy ◽  
...  

Summary Background: Type 1 plasminogen activator inhibitor (PAI-1) is considered to be risk factor for acute myocardial infarction (AMI). A rebound of circulating PAI-1 has been reported after rt-PA administration. We investigated the relationships between PAI-1 levels before and after thrombolytic therapy with streptokinase (SK) as compared to rt-PA and the patency of infarct-related arteries. Methods and Results: Fifty five consecutive patients with acute MI were randomized to strep-tokinase or rt-PA. The plasma PAI-1 levels were studied before and serially within 24 h after thrombolytic administration. Vessel patency was assessed by an angiogram at 5 ± 1days. The PAI-1 levels increased significantly with both rt-PA and SK as shown by the levels obtained from a control group of 10 patients treated with coronary angioplasty alone. However, the area under the PAI-1 curve was significantly higher with SK than with rt-PA (p <0.01) and the plasma PAI-1 levels peaked later with SK than with rt-PA (18 h versus 3 h respectively). Conversely to PAI-1 levels on admission, the PAI-1 levels after thrombolysis were related to vessel patency. Plasma PAI-1 levels 6 and 18 h after SK therapy and the area under the PAI-1 curve were significantly higher in patients with occluded arteries (p <0.002, p <0.04 and p <0.05 respectively).The same tendency was observed in the t-PA group without reaching significance. Conclusions: This study showed that the PAI-1 level increase is more pronounced after SK treatment than after t-PA treatment. There is a relationship between increased PAI-1 levels after thrombolytic therapy and poor patency. Therapeutic approaches aimed at quenching PAI-1 activity after thrombolysis might be of interest to improve the efficacy of thrombolytic therapy for acute myocardial infarction.


1993 ◽  
Vol 70 (02) ◽  
pp. 301-306 ◽  
Author(s):  
Linda A Robbie ◽  
Nuala A Booth ◽  
Alison M Croll ◽  
Bruce Bennett

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.


1995 ◽  
Vol 73 (02) ◽  
pp. 261-267 ◽  
Author(s):  
Rosaire P Gray ◽  
Vidya Mohamed-Ali ◽  
David L H Patterson ◽  
John S Yudkin

SummaryA significant relationship has been described between plasminogen activator inhibitor-1 (PAI-1) and plasma insulin concentrations. However, most radioimmunoassays (RIA) substantially overestimate plasma insulin concentrations because of cross reaction with proinsulin-like molecules and it has been proposed that proinsulin-like molecules may be important determinants of PAI-1 activity. We measured fasting plasma immunoreactive insulin by conventional RIA, fasting plasma insulin (EIMA) by specific two site immuno-enzymometric assay, and intact proinsulin and des-31,32-proinsulin by two site immunoradiometric assay (IRMA) in 74 (50 nondiabetic and 24 diabetic) subjects who had survived a myocardial infarction between 6 and 24 months previously. In univariate analysis, PAI-1 activity correlated with serum triglycerides (rs=0.43; p <0.0001), insulin sensitivity (rs = -0.30; p = 0.004), and immunoreactive insulin (rs = 0.45; p <0.0001). However, the relationship between PAI-1 activity and plasma specific insulin (IEMA) was weaker (rs = 0.24; p = 0.019) than those with intact proinsulin (rs = 0.53; p <0.0001) and des-31,32-proinsulin (rs = 0.54; p <0.0001) despite the low concentrations of these proinsulin-like molecules. In multiple regression analysis, only des-31,32-proinsulin (p = 0.001) and serum triglycerides (p = 0.013) were significant determinants of PAI-1 activity. In conclusion, these results suggest that proinsulin-like molecules and serum triglycerides are important determinants of PAI-1 activity in survivors of myocardial infarction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Zuo ◽  
Mark Warnock ◽  
Alyssa Harbaugh ◽  
Srilakshmi Yalavarthi ◽  
Kelsey Gockman ◽  
...  

AbstractPatients with coronavirus disease-19 (COVID-19) are at high risk for thrombotic arterial and venous occlusions. However, bleeding complications have also been observed in some patients. Understanding the balance between coagulation and fibrinolysis will help inform optimal approaches to thrombosis prophylaxis and potential utility of fibrinolytic-targeted therapies. 118 hospitalized COVID-19 patients and 30 healthy controls were included in the study. We measured plasma antigen levels of tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) and performed spontaneous clot-lysis assays. We found markedly elevated tPA and PAI-1 levels in patients hospitalized with COVID-19. Both factors demonstrated strong correlations with neutrophil counts and markers of neutrophil activation. High levels of tPA and PAI-1 were associated with worse respiratory status. High levels of tPA, in particular, were strongly correlated with mortality and a significant enhancement in spontaneous ex vivo clot-lysis. While both tPA and PAI-1 are elevated among COVID-19 patients, extremely high levels of tPA enhance spontaneous fibrinolysis and are significantly associated with mortality in some patients. These data indicate that fibrinolytic homeostasis in COVID-19 is complex with a subset of patients expressing a balance of factors that may favor fibrinolysis. Further study of tPA as a biomarker is warranted.


Blood ◽  
1991 ◽  
Vol 78 (2) ◽  
pp. 401-409 ◽  
Author(s):  
J Keijer ◽  
M Linders ◽  
AJ van Zonneveld ◽  
HJ Ehrlich ◽  
JP de Boer ◽  
...  

Abstract Plasminogen activator inhibitor 1 (PAI-1), an essential regulatory protein of the fibrinolytic system, harbors interaction sites for plasminogen activators (tissue-type [t-PA] and urokinase-type [u-PA]) and for fibrin. In this study, anti-PAI-1 monoclonal antibodies (MoAbs) were used to identify interaction sites of PAI-1 with these components. The binding sites of 18 different MoAbs were established and are located on five distinct “linear” areas of PAI-1. MoAbs, binding to two distinct areas of PAI-1, are able to prevent the inhibition of t-PA by PAI-1. In addition, two interaction sites for fibrin were identified on PAI-1. The area located between amino acids 110 and 145 of PAI-1 contains a binding site for both components and its significance is discussed in the context of the t-PA inhibition by fibrin-bound PAI-1. Subsequently, the MoAbs were used to assess the role of platelet-PAI-1 in clot-lysis. An in vitro clot-lysis system was used to demonstrate that clot-lysis resistance is dependent on the presence of activated platelets and that PAI-1 is a major determinant for lysis-resistance. We propose that, upon activation of platelets, PAI-1 is fixed within the clot by binding to fibrin and retains its full capacity to inhibit t-PA and u-PA.


Blood ◽  
1997 ◽  
Vol 90 (4) ◽  
pp. 1527-1534
Author(s):  
Peter Carmeliet ◽  
Jean-Marie Stassen ◽  
Ilse Van Vlaenderen ◽  
Robert S. Meidell ◽  
Désiré Collen ◽  
...  

Impaired fibrinolysis, resulting from increased plasminogen activator inhibitor-1 (PAI-1) or reduced tissue-type plasminogen activator (t-PA) plasma levels, may predispose the individual to subacute thrombosis in sepsis and inflammation. The objective of these studies was to show that adenovirus-mediated gene transfer could increase systemic plasma t-PA levels and thrombolytic capacity in animal model systems. Recombinant adenovirus vectors were constructed that express either human wild type or PAI-1–resistant t-PA from the cytomegalovirus (CMV) promoter. Both t-PA-deficient (t-PA−/−) and PAI-1–overexpressing transgenic mice were infected by intravenous injection of these viruses. Intravenous injection of recombinant adenovirus resulted in liver gene transfer, t-PA synthesis, and secretion into the plasma. Virus dose, human t-PA antigen, and activity concentrations in plasma and extent of lysis of a 125I-fibrin–labeled pulmonary embolism were all closely correlated. Plasma t-PA antigen and activity were increased approximately 1,000-fold above normal levels. Clot lysis was significantly increased in mice injected with a t-PA–expressing virus, but not in mice injected with saline or an irrelevant adenovirus. Comparable levels of enzyme activity and clot lysis were obtained with wild type and inhibitor-resistant t-PA viruses. Adenovirus-mediated t-PA gene transfer was found to augment clot lysis as early as 4 hours after infection, but expression levels subsided within 7 days. Adenovirus-mediated transfer of a t-PA gene can effectively increase plasma fibrinolytic activity and either restore (in t-PA–deficient mice) or augment (in PAI-1–overexpressing mice) the thrombolytic capacity in simple animal models of defective fibrinolysis.


1991 ◽  
Vol 66 (04) ◽  
pp. 474-478 ◽  
Author(s):  
Tetsumei Urano ◽  
Kenichi Sumiyoshi ◽  
Michal H Pietraszek ◽  
Yumiko Takada ◽  
Akikazu Takada

SummaryThe antigen levels of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) were assayed in the plasma and in the euglobulin fraction, and their contributions to the euglobulin clot lysis time (ECLT) and t-PA activity were analyzed. Total and free PAI-1 levels in both fractions showed significant positive correlation with ECLT (p <0.001), whereas t-PA antigen level did not have a high correlation coefficient with ECLT. t-PA activity showed significant negative correlation with ECLT (p <0.001) and positive correlation with free t-PA level (p <0.001), which was calculated by the ratio of the concentrations of t-PA-PAI-1 complex and the free PAI-1. Thus free t-PA seems to dissolve the euglobulin clot and its concentration seems to be controlled by the concentration of free PAI-1. These findings were confirmed by the analyses of the effects of C1-inactivator and antibody against t-PA to regular ECLT and kaolin activated ECLT, the latter of which was only inhibited by the addition of C1-inactivator whereas the former was inhibited by anti-t-PA antibody.


1992 ◽  
Vol 68 (04) ◽  
pp. 396-399 ◽  
Author(s):  
J N Primrose ◽  
J A Davies ◽  
C R M Prentice ◽  
R Hughes ◽  
D Johnston

SummaryThe aim of this study was to determine the effects of the surgical treatment of morbid obesity on some aspects of haemostatic and fibrinolytic function. Measurement of haemostatic and fibrinolytic factors was performed before and again 6 and 12 months after operation in 19 patients suffering from morbid obesity. Surgical treatment resulted in a mean decrease in body weight of 50 kg at 6 months and 64 kg at 12 months. Weight loss was accompanied at 12 months by significant reductions in median (interquartile range) concentrations of serum cholesterol from 5.3 (4.5–6.2) mmol/1 to 3.6 (2.9–4.6) mmol/1; factor VII from 113 (92–145)% of normal to 99 (85–107)%; of fibrinogen from 3.5 (3–9.3) g/1 to 2.8 (2.4–3.8) g/1; and of plasminogen activator inhibitor-1 (PAI-1) activity from 21 (11–30) IU/ml to 6.3 (5–10) IU/ml. The decrease in PAI-1 activity probably accounted for a significant reduction in euglobulin clot lysis time. Tissue plasminogen activator activity was undetectable in most patients pre-operatively but increased slightly after 1 year to 110 (100–204) mIU/ml. There were no significant changes in plasma levels of KCCT, factor VIII, von Willebrand factor antigen, alpha-2-antiplasmin, antithrombin III, protein C antigen, beta thromboglobulin, platelet factor 4, fibrinopeptide A or platelet count. These findings provide support for the hypothesis that the surgical treatment of morbid obesity may have a long-term beneficial effect on mortality from cardiovascular and thromboembolic disease.


1994 ◽  
Vol 72 (06) ◽  
pp. 900-905 ◽  
Author(s):  
Harold A R Stringer ◽  
Peter van Swieten ◽  
Anton J G Horrevoets ◽  
Annelies Smilde ◽  
Hans Pannekoek

SummaryWe further investigated the role of the finger (F) and the kringle-2 (K2) domains of tissue-type plasminogen activator (t-PA) in fibrin-stimulated plasminogen activation. To that end, the action of purified (wt) t-PA or of variants lacking F (del.F) or K2 (del.K2) was assessed either in a static, human whole blood clot-lysis system or in whole blood thrombi generated in the “Chandler loop”. In both clot-lysis systems, significant differences were observed for the initiation of thrombolysis with equimolar concentrations of the t-PA variants. A relatively minor “lag phase” occurred in thrombolysis mediated by wt t-PA, whereas a 6.4-fold and 1.6-fold extension is found for del.F and del.K2, respectively. We observed identical lag-times, characteristic for each t-PA variant, in platelet-rich heads and in platelet-poor tails of thrombi. Since plasminogen activator inhibitor 1 (PAI-1) is preferentially retained in the platelet-rich heads, we conclude that the inhibitor does not interfere with the initial stage of thrombolysis but exerts its action in later stages, resulting in a reduction of the rate of clot lysis. A complementation clot-lysis assay was devised to study a potential interplay of del.F and del.K2. Accordingly, clot lysis was determined with combinations of del.F and del.K2 that were inversely varied in relation to equipotent dosage to distinguish between additive, antagonistic or synergistic effects of these variants. The isobole for combinations of del.F and del.K2 shows an independent, additive action of del.F and del.K2 in clot lysis. Under the conditions employed, namely a relatively high concentration of fibrin and Glu-plasminogen and a low concentration of t-PA variant, our data show: i) the crucial role of the F domain and the lack of effect of PAI-1 in initiation of thrombolysis, ii) the lack of importance of the fibrimbinding domains of t-PA and the regulatory role of PAI-1 in advanced stages of thrombolysis.


Sign in / Sign up

Export Citation Format

Share Document