Fibrinolytic Activity in Peripheral Atherosclerosis in the Elderly

1999 ◽  
Vol 81 (02) ◽  
pp. 275-280 ◽  
Author(s):  
Johanna van der Bom ◽  
Michiel Bots ◽  
Frits Haverkate ◽  
Piet Meyer ◽  
Albert Hofman ◽  
...  

SummaryIncreased concentrations of plasminogen activator inhibitor type 1 (PAI-1) and of D-dimer have jointly been found in subjects with cardiovascular disease. To understand this apparent paradox of increased inhibition of fibrinolysis (high PAI-1) combined with increased fibrinolytic activity (high D-dimer), we examined the relation between D-dimer, PAI-1 and the activator of fibrinolysis, tissue type plasminogen activator (t-PA) in subjects with varying severity of peripheral atherosclerosis. In 325 subjects selected from the Rotterdam Study, a cohort of 7983 men and women aged 55 years and over, the ankle to brachial systolic blood pressure ratio, t-PA antigen and activity, PAI-1 antigen and D-dimer were measured.T-PA antigen and t-PA activity were, independent from each other, increased with degree of atherosclerosis; t-PA antigen increased with 3.5 ng/ml (SE 1.7, p = 0.04) and t-PA activity with 0.46 IU/ml (0.20, p = 0.02) per unit decrease in ankle to brachial pressure ratio (i.e. increase in atherosclerosis). PAI-1 antigen was not related to atherosclerosis. More marked atherosclerosis was associated with increased D-dimer, mainly in subgroups with PAI-1 antigen below 50 ng/ml, t-PA antigen below 10 ng/ml, or t-PA activity above 1.5 IU/ml. In contrast to current beliefs, we found that only a fraction of the variation of t-PA antigen was due to the variation in circulating PAI-1 antigen. A slight positive association was observed between t-PA antigen and D-dimer. PAI-1 and t-PA activity were not associated with D-dimer concentration.In conclusion, in subjects with peripheral atherosclerosis PAI-1 antigen is not increased, but low PAI-1 levels (and possibly also low levels of t-PA antigen and high levels of t-PA activity) appear to be required to increase circulating D-dimer. This suggests that increased D-dimer levels in subjects with atherosclerosis do not reflect increased inhibition, but rather reflect increased fibrinolysis.

1998 ◽  
Vol 79 (03) ◽  
pp. 587-590 ◽  
Author(s):  
J. A. Cooper ◽  
D. J. Howarth ◽  
T. W. Meade ◽  
G. J. Miller ◽  
P. K. MacCallum

SummaryImpaired whole blood fibrinolytic activity (FA), measured by the dilute clot lysis time (DCLT), is associated with first episodes of ischaemic heart disease (IHD) in the Northwick Park Heart Study in men, especially under 55 years, and in women. In a community-based study to investigate possible determinants of the DCLT, and therefore to assess which fibrinolytic components might be predictors of first IHD events, we measured fibrinolytic variables in a sub-sample of 150 healthy adults (73 males, 77 females) randomly selected from a single general practice.Most of the variance in DCLT (68% in men, 63% in women) was explained by tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) activities. In multiple regression analysis there was a significant difference in the strength of the association of t-PA activity with DCLT in men compared to women (test for interaction p = 0.05), the association of t-PA activity with DCLT being significant in males but not in females. Plasma PAI-1 activity was strongly associated with DCLT in both sexes. There was no independent association of DCLT with plasma fibrinogen, t-PA antigen, other fibrinolytic inhibitors, body mass index, serum lipids or C-reactive protein.Plasma PAI-1 activity in females and both t-PA and PAI-1 activities in males are the main determinants of whole blood FA measured by DCLT. It is therefore likely that these modulators of the plasma fibrinolytic system are associated with the onset of first clinical episodes of IHD. Elevated levels of t-PA antigen were positively associated with DCLT after adjustment for age and sex and therefore indicate impaired rather than enhanced FA. Further studies of the association of FA with risk of IHD should include not only “global” measures but also assessment of t-PA and PAI-1 activities, particularly as our results suggest that their associations with IHD may differ in men and women.


2000 ◽  
Vol 83 (06) ◽  
pp. 853-860 ◽  
Author(s):  
A. Günther ◽  
P. Mosavi ◽  
C. Ruppert ◽  
S. Heinemann ◽  
B. Temmesfeld ◽  
...  

SummaryBronchoalveolar lavage fluids (BALF) from patients with hyper- sensitivity pneumonitis (HP; n = 35), idiopathic pulmonary fibrosis (IPF, n = 41) and sarcoidosis (SARC, n = 48) were investigated for alterations in the alveolar hemostatic balance. Healthy individuals (n = 21) served as Controls. Procoagulant activity (PCA), tissue factor (TF) activity and F VII activity were assessed by means of specific recalcification assays. The overall fibrinolytic activity (FA) was measured using the 125I-labeled fibrin plate assay. Fibrinopeptide A (FP-A), D-Dimer, plasminogen activators (PA) of the urokinase (u-PA) or tissue type (t-PA), PA-Inhibitor I (PAI-1) and α2-antiplasmin (α2-AP) were determined by ELISA technique. As compared to Controls, all groups with interstitial lung disease (ILD) displayed an increase in BALF PCA by approximately one order of magnitude, and this was ascribed to enhanced TF activity by >98%. Accordingly, F VII-activity was increased in all ILD groups, and elevated FP-A levels were noted. There was no significant difference in procoagulant activi- ties between the different ILD entities, but the increase in TF was significantly correlated with deterioration of lung compliance. Overall fibrinolytic activity did not significantly differ between ILD entities and Controls, although some reduction in IPF subjects was observed. Nevertheless, changes in the profile of the different pro- and anti- fibrinolytic compounds were noted. U-PA, but not t-PA levels were significantly reduced in all ILD groups. α2-AP was markedly elevated throughout, whereas PAI-1 levels were lowered. As a balance of enhanced procoagulant and sustained overall fibrinolytic activity, lavage D-dimer levels were elevated by more than one order of magnitude in all ILD patients. We conclude that the predominant alteration in alveolar hemostatic balance in all groups of ILD patients is an enhancement in TF factor pathway activity. Concomitantly, various compounds of the (anti-)fibrinolytic pathways present with altered concentrations, but the overall BALF fibrinolytic activity is largely unchanged. The net enhancement of fibrin turnover is significantly correlated with the decrease in lung compliance. Abbreviations: α2-AP – α2-antiplasmin; ARDS – acute respiratory distress syndrome; BAL – bronchoalveolar lavage; BALF – BAL fluids; BSA – bovine serum albumin; FEV1 – forced expired volume within 1 s; FP-A – fibrinopeptide A; FVC – forced vital capacity; ILD – interstitial lung disease; IPF – idiopathic pulmonary fibrosis; HP – hypersensitivity pneumonitis; PAI-1 – plasminogen-activator-inhibitor-1; PBS – phosphate buffered saline; PCA – procoagulant activity; PL – phospholipid; PPQ – phospholipid-proteinquotient; SARC – sarcoidosis; t-PA – tissue-type plasminogen activator; u-PA – urokinase-type plasminogen activator


1994 ◽  
Vol 72 (01) ◽  
pp. 054-057 ◽  
Author(s):  
N Semeraro ◽  
P Montemurro ◽  
P Giordano ◽  
N Santoro ◽  
D De Mattia ◽  
...  

SummaryBlood clotting activation and fibrin deposition are common findings in lymphoma patients. We evaluated the capacity of peripheral blood mononuclear cells to produce procoagulant activity (PCA) and plasminogen activator inhibitor (PAI) in 12 children with newly diagnosed lymphoma (8 non-Hodgkin’s, 4 Hodgkin’s) and in 12 matched healthy donors. In the same subjects we also measured plasma antigen levels of tissue-type PA (t-PA), urokinase-type PA (u-PA), PAI-1, PAI-2, and D-dimer. PCA generated by mononuclear cells after incubation for 20 h at 37° C was significantly higher in patients than in controls (p = 0.027). In all samples it was identified as tissue factor by functional criteria (dependence on factor VII). Moreover, culture medium obtained from patients’ mononuclear cells after incubation for 20 h at 37° C contained significantly higher amounts of PAI activity and PAI-2 antigen than control samples (p <0.001). Plasma PAI-1 and t-PA antigens were significantly augmented in patients (p <0.005), the mean increase of PAI-I being about 5 times higher than that of t-PA. Plasma levels of D-dimer wete markedly increased in the patients’ group (p <0.001), whereas u-PA and PAI-2 antigens did not differ from controls. It is suggested that monocytes from lymphoma patients are endowed with functional abnormalities leading to the simultaneous expression of tissue factor and antifibrinolytic activity. These abnormalities, coupled with a reduced plasma fibrinolytic potential, could play an important pathogenetic role in blood clotting activation and fibrin deposition associated with lymphoma.


1988 ◽  
Vol 59 (03) ◽  
pp. 495-499 ◽  
Author(s):  
V Grimaudo ◽  
J Hauert ◽  
F Bachmahh ◽  
E K O Kruithof

AbstractTo elucidate which component(s) of thei fibrinolytic system is (are) responsible for the diurnal variation of fibrinolytic activity we have studied several parameters of this system in 8 healthy male volunteers during a period of. 24 h. Blood was collected at 8 a. m., 10 a. m., 12 a. m., 4 p.m., 8 p.m. and 8 a. m. next morning. The following tests were performed: euglobulin clot lysis time (ECLT), fibrinolytic activity of euglobulins on fibrin plates in the presence and absence of blocking antibodies to tissue-type plasminogen activator (t-PA) and/or urokinase (u-PA), overall plasminogen activator inhibitor (PAI) activity, antigen levels of t-PA, u-PA and PAI-I and zymography of the euglobulin fraction after SDS-PAGE. From 8-10 a. m. to 4-8 p. m., total fibrinolytic activity increased by 1l3% (p <0.01) or 71%h (p <0.01) when measured by ECIX or by fibrin plate assay, respectively. The immunoquenching experiments showed that this increase was entirely due to t-PA related activity whereas u-PA activity and t-PA/u-PA independent activity remained constant during the day. Average antigen levels of u-PA and t-PA in the afternoon were 6% and 25% lower than those measured in the morning. During this period, overall PAI activity and PAI-1 antigen decreased by 3l% (p <0.01) and 52% (p <0.01) respectively. Electrophoretic-zymographic analysis of_ the euglobulins revealed that throughout the day the majority of t-PA was present in the form of the 110 kDa t-PA/PAI-I complex. The intensity of this cornplex was lowest in the afternoon. Free t-PA was almost undetectable in morning samples, but constituted a significant proportion of total t-PA in the afternoon. The diurnal increase of fibrinolytic activity, therefore, is not due to an augmentation of antigen levels of t-PA and/or u-PA but to a decline of those of PAI-1.


2019 ◽  
Author(s):  
Radosław Wieczór ◽  
Anna Maria Wieczór ◽  
Danuta Rość

Abstract Background Chronic lower extremity artery disease (LEAD) involves progressive arterial narrowing manifested by intermittent claudication (IC). LEAD entails endothelial dysfunction and fibrinolytic disorders. The main objective of the present study was to analyze selected parameters of the fibrinolytic system in the blood of patients with symptomatic LEAD depending on clinical parameters. Methods The test group consisted of 80 patients with LEAD (27F/53M) with an average age of 63.5±9 years. The control group included 30 healthy, non-smoking volunteers (10F/20M), with their median age of 56±6 years. The research material comprised venous blood to determine concentrations of tissue-type plasminogen activator (t-PA Ag), plasminogen activator inhibitor type 1 (PAI-1 Ag) and D-dimer, fibrinogen and platelet count (PLT). Results Elevated concentrations of t-PA Ag and PAI-1 Ag as well as D-dimer and fibrinogen were found in the plasma of subjects with symptomatic LEAD. Various stages of the Fontaine classification demonstrated a gradual, statistically significant increase in the concentrations of fibrinogen and PLT count as the disease progressed. The subgroup of LEAD patients aged ≥ 65 years was reported to have significantly higher levels of D-dimer than the group of younger subjects. Besides, the LEAD group demonstrated: negative correlations between IC distance and fibrinogen concentrations, and PLT count, negative correlations between ABI at rest and concentrations of D-dimer and PLT count, and positive correlations between age and D-dimer levels. Conclusion High t-PA Ag concentrations in LEAD patients reflect damaged endothelium which comprises the main source of this factor. With high PAI-1 Ag levels, inactive fibrinolytic t-PA-PAI-1 complexes are formed. Increasing fibrinogen concentrations at the subsequent stages in accordance with the Fontaine classification, suggest a growing inflammatory condition. Elevated values of D-dimer reflect the aggregation of secondary fibrinolysis activation as the patient ages and along with impaired extremity vascularization manifested by the decreasing ABI.


1988 ◽  
Vol 59 (02) ◽  
pp. 299-303 ◽  
Author(s):  
Grazia Nicoloso ◽  
Jacques Hauert ◽  
Egbert K O Kruithof ◽  
Guy Van Melle ◽  
Fedor Bachmann

SummaryWe analyzed fibrinolytic parameters in 20 healthy men and 20 healthy women, aged from 25 to 59, before and after 10 and 20 min venous occlusion. The 10 min post-occlusion fibrinolytic activity measured directly in diluted unfractionated plasma by a highly sensitive 125I-fibrin plate assay correlated well with the activity of euglobulins determined by the classical fibrin plate assay (r = 0.729), but pre-stasis activities determined with these two methods did not correlate (r = 0.084). The enhancement of fibrinolytic activity after venous occlusion was mainly due to an increase of t-PA in the occluded vessels (4-fold increase t-PA antigen after 10 min and 8-fold after 20 min venous occlusion). Plasminogen activator inhibitor (PAI) activity and plasminogen activator inhibitor 1 (PAI-1)1 antigen levels at rest showed considerable dispersion ranging from 1.9 to 12.4 U/ml, respectively 6.9 to 77 ng/ml. A significant increase of PAI-1 antigen levels was observed after 10 and 20 min venous occlusion. At rest no correlation was found between PAI activity or PAI-1 antigen levels and the fibrinolytic activity measured by 125I-FPA. However, a high level of PAI-1 at rest was associated with a high prestasis antigen level of t-PA and a low fibrinolytic response after 10 min of venous stasis. Since the fibrinolytic response inversely correlated with PAI activity at rest, we conclude that its degree depends mainly on the presence of free PAI.


1988 ◽  
Vol 60 (02) ◽  
pp. 328-333 ◽  
Author(s):  
N J de Fouw ◽  
Y F de Jong ◽  
F Haverkate ◽  
R M Bertina

summaryThe effect of purified human activated protein G (APC) on fibrinolysis was studied using a clot iysis system consisting of purified glu-plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor (released from endothelial cells or blood platelets), fibrinogen, 125T-fibrinogen and thrombin. All proteins were of human origin.In this system APC could increase fibrinolysis in a dose dependent way, without affecting fibrin formation or fibrin crosslinking. However, this profibrinolytic effect of APC could only be observed when plasminogen activator inhibitor (PAI-l) was present. The effect of APC was completely quenched by pretreatment of APC with anti-protein C IgG or di-isopropylfluorophosphate. Addition of the cofactors of APC:protein S, Ca2+-ions and phospholipid-alone or in combination did not enhance the profibrinolytic effect of APC. These observations indicate that human APC can accelerate in vitro clot lysis by the inactivation of PAI-1 activity. However, the neutralization of PAI-1 by APC is independent of the presence or absence of protein S, phospholipid and Ca2+-ions.


1992 ◽  
Vol 68 (05) ◽  
pp. 486-494 ◽  
Author(s):  
Malou Philips ◽  
Anne-Grethe Juul ◽  
Johan Selmer ◽  
Bent Lind ◽  
Sixtus Thorsen

SummaryA new assay for functional plasminogen activator inhibitor 1 (PAI-1) in plasma was developed. The assay is based on the quantitative conversion of PAI-1 to urokinase-type plasminogen activator (u-PA)-PAI-l complex the concentration of which is then determined by an ELISA employing monoclonal anti-PAI-1 as catching antibody and monoclonal anti-u-PA as detecting antibody. The assay exhibits high sensitivity, specificity, accuracy, and precision. The level of functional PAI-1, tissue-type plasminogen activator (t-PA) activity and t-PA-PAI-1 complex was measured in normal subjects and in patients with venous thromboembolism in a silent phase. Blood collection procedures and calibration of the respective assays were rigorously standardized. It was found that the patients had a decreased fibrinolytic capacity. This could be ascribed to high plasma levels of PAI-1. The release of t-PA during venous occlusion of an arm for 10 min expressed as the increase in t-PA + t-PA-PAI-1 complex exhibited great variation and no significant difference could be demonstrated between the patients with a thrombotic tendency and the normal subjects.


1995 ◽  
Vol 74 (02) ◽  
pp. 718-721 ◽  
Author(s):  
Jørgen Gram ◽  
Johannes Sidelmann ◽  
Jørgen Jespersen

SummaryMany reports have demonstrated an abnormal fibrinolysis in a subset of patients with deep vein thrombosis. We have studied systemic global fibrinolytic activity and protein concentrations of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) in plasma of 25 young patients with a previous instance of spontaneous deep vein thrombosis documented by phlebography and in 50 healthy controls. The two populations were comparable with respect to a number of base-line variables (age, height, weight, etc.), while the patients had significantly lower fibrinolytic activity (p <0.02), and significantly higher protein concentrations of t-PA (p <0.0001) and PAI-1 (p <0.0006).We used probit scale plots to identify the consequence of different cut-off points to separate patients from controls. Reasonable separation could be obtained for t-PA with a cut-off point of 5.2 ng/ml and for PAI-1 18 ng/ml. The sensitivity and specificity for these cut-off points were for t-PA 73% (95% confidence interval 63%-84%) and for PAI-1 67% (confidence interval 55%-77%). The negative predictive value with a cut-off point t-PA concentration of 5.2 ng/ml was 85% (95% confidence interval 70%-94%). We observed a significantly negative association between concentration of t-PA and fibrinolytic activity (rs = -0.47; p <0.005) and also between PAI-1 and fibrinolytic activity (rs = -0.78; p <0.005).We conclude that a young healthy population is characterized by low protein concentration of t-PA (and PAI-1) compared with young patients with a previous instance of spontaneous vein thrombosis, and we tentatively state that a low protein concentration of t-PA predicts a low risk of spontaneous deep vein thrombosis.


1998 ◽  
Vol 18 (02) ◽  
pp. 74-79
Author(s):  
K.-H. Zurborn ◽  
H. D. Bruhn ◽  
H. Mönig

SummaryIn order to study the acute and prolonged effects of hypoglycemia on the hemostatic and fibrinolytic system we measured prothrombin fragment (F1+2), thrombin-antithrombin III complex (TAT), platelet factor 4 (PF4), β-thromboglobulin (âTG), factor VIII antigen (F VIII antigen), D-dimer, tissue-type plasminogen activator (t-PA) antigen, and plasminogen activator inhibitor (PAI-1) in 22 patients during insulin tolerance test. F1+2 and TAT increased significantly 15 and 90 minutes after administration of insulin, as did PF4 and âTG. At 4 and 24 hours, these parameters were not different from baseline. Factor VIII antigen was not significantly altered. D-dimer concentration did not change. However, the D-dimer/TAT ratio significantly decreased at 15 and 90 minutes but increased markedly above baseline at 4 and 24 hours. t-PA antigen was also found to be elevated at 15 and 90 minutes but had returned to baseline at 4 and 24 hours. PAI-1 concentration did not change. We conclude from these data that both coagulation and fibrinolysis are activated in the short-term response to acute insulin-induced hypoglycemia, followed by a prolonged activation of fibrinolysis. Our study may explain why patients undergoing insulin tolerance test, despite marked clotting and platelet activation, almost never develop thromboembolic complications.


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