The effects of TNF alpha inhibition on plasma fibrinolytic balance in patients with chronic inflammatory rheumatical disorders

OBJECTIVE: Recent studies support an inflammatory basis for atherosclerosis. Patients with chronic inflammatory rheumatical disorders are at increased risk for cardiovascular events, and this can be partially attributed to the inhibition of fibrinolytic system. TNF a inhibitors such as infliximab are shown to retard the progression of inflammatory arthritides. In this study, we investigated the effects of infliximab on plasma fibrinolytic parameters. METHODS: Thirteen patients (7 female, 6 male; mean age: 44 +/- 11 years) with a clinical indication for infliximab (rheumatoid arthritis (RA) (n = 8), ankylosing spondylitis (AS) (n = 5)) were selected. Plasma plasminogen activator inhibitor (PAI-1), tissue plasminogen activator (t-PA) antigens (Ag) and high sensitive C-reactive protein (hs-CRP) levels were measured during low salt intake at baseline. All patients received infliximab (Remicaide, i.v. infusion, 3 mg/kg). Plasma PAI-1 Ag, t-PA Ag and hs-CRP were measured during low salt intake at the end of 2 weeks. All samples were collected at 9 AM. Antigen levels were determined using a 2-site enzyme-linked immunosorbent assay. RESULTS: Patients experienced significant improvement in disease related activity scores after infliximab treatment. DAS score (for rheumatoid arthritis) and BASDAI index (for ankylosing spondylitis) decreased significantly after treatment (p = 0.01 and p = 0.04 respectively). Infliximab significantly reduced the marker of inflammation (hs-CRP) (8.3 +/- 3.9 vs. 4 +/- 4.1 mg/L, p < 0.01). Plasma PAI-1 antigen (64.7 +/- 26.9 vs. 40 +/- 31.1 ng/ml, p = 0.03) and PAI-1/t-PA ratio (10.8 +/- 5.9 vs. 6.6 +/- 3.8, p = 0.02) were significantly lower after the treatment. In contrast, plasma t-PA levels were unchanged (9.4 +/- 4.4 vs. 9.0 +/- 4.3 ng/ml, p = 0.73). CONCLUSION: This study provides evidence that TNF alpha inhibition with infliximab decreases PAI-1 Ag level and PAI-1/t-PA ratio, and hence activates fibrinolytic system in patients with chronic inflammatory disorders.     

The role of strict metabolic control by insulin infusion on fibrinolytic profile during an acute coronary event in diabetic patients

BACKGROUND: Many clinical and laboratory observations give support to the hypothesis that strict metabolic control by insulin infusion during acute coronary events may improve the ischemic damage and prognosis. HYPOTHESIS: We investigated the impact of intensive insulin treatment on fibrinolytic parameters during an acute ischemic myocardial event (unstable angina or acute myocardial infarction) in patients with type 2 diabetes mellitus. METHODS: The study group consisted of 48 type 2 diabetic patients, of whom 24 were randomized to conventional therapy plus intensive insulin treatment (Group 1) and 24 to conventional therapy only (Group 2). The two groups were comparable according to gender, age, body mass index, waist:hip ratio, duration of diabetes, previous antidiabetic treatment, type of ischemic events, concomitant therapy, and the classic risk factors for coronary disease. Insulin-treated patients were excluded from the study. Plasma levels of fibrinogen, tissue plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) were measured on admission and discharge. Fibrinogen (fibr) was measured using the photometric method. PAI-1 and t-PA were measured by enzyme-linked immunosorbent assays. RESULTS: T-PA increased in both groups during hospitalization (t-PA(admission) vs. t-PA(discharge): Group 1: 15.42 +/- 4.4 ng x ml(-1) vs. 21.2 +/- 5.74 ng x ml(-1), p = 0.000037; Group 2: 14.47 +/- 6.31 ng x ml(-1) vs. 19.18 +/- 6.88 ng x ml(-1), p = 0.001). On the other hand, fibr and PAI-1 levels increased remarkably in controls (Group 2, fibr(admission) vs. fibr(discharge): 2.98 +/- 1.04 g x l(-1) vs. 3.59 +/- 1.01 g x l(-1), p = 0.002, and PAI-1admission vs. PAI-1 discharge: 30.6 +/- 17.34 ng x ml(-1) vs. 40.62 +/- 23.48 ng x ml(-1), p = 0.003). This finding was not observed in the intensive insulin treatment group (Group 1, fibr(admission) vs. fibr(discharge): 2.87 +/- 0.73 g x l(-1) vs. 2.67 +/- 0.72 g x l(-1), p = 0.101, and PAI-1 admission vs. PAI-1 discharge: 30.75 +/- 15.81 ng x ml(-1) vs. 27.75 +/- 6.43 ng x ml(-1), p = 0.484). CONCLUSION: Intensive insulin treatment during an acute coronary event improves fibrinolytic profile in patients with diabetes mellitus. This is a possible mechanism for the reduced short- and long-term mortality in diabetic patients treated with intensive insulin treatment protocol.     

Tissue-type plasminogen activator and its inhibitor (PAI-1) in plasma in cases of non-insulin-dependent diabetes mellitus (NIDDM)

Parameters of fibrinolysis, including plasminogen, alpha 2 plasmin-inhibitor (alpha 2 PI), tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) antigens, and fibrinogen were assayed in 53 patients (28 women and 27 men; mean age: 64 years, age range: 32-87 years) with non-insulin-dependent diabetes mellitus (NIDDM). The control group was similarly aged (mean age: 60.4 years, age range: 38-81). The levels of t-PA and t-PA/PAI-1 ratio of the diabetic group (mean +/- SD; 9.8 +/- 4.3 ng/ml, 0.94 +/- 0.47, respectively) were significantly higher than that of the control group (5.5 +/- 2.5 ng/ml, 0.51 +/- 0.23, respectively). The increased levels of t-PA antigen and t-PA/PAI-1 ratio in diabetics mean that free t-PA has been released. However, there was no significant difference in the level of PAI-1 between the diabetic group (12.9 +/- 6.4 ng/ml) and the control group (12.1 +/- 5.6 ng/ml). Levels of fibrinogen, plasminogen and alpha 2 PI in plasma were not different in the two groups. Duration of the disease, levels of glycosylated hemoglobin, differences in treatment and presense of diabetic nephropathy or retinopathy did not affect the fibrinolytic parameters. The levels of fibrinogen was higher in those with nephropathy than in the diabetics without nephropathy and retinopathy (p less than 0.05). There were no significant differences in the levels of t-PA, t-PA/PAI-1 ratio and PAI-1 between younger (less than 65 years) and older (65 years or more) subjects, in either the control or diabetic groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

The release of plasminogen activators (t-PA and u-PA) and plasminogen activator inhibitor (PAI-1) after venous stasis.

The aim of the present study was to compare plasma levels of urokinase-type plasminogen activator (u-PA), before and after 20 min of venous stasis, with those of tissue-type plasminogen activator (t-PA), type 1 plasminogen activator inhibitor (PAI-1) and t-PA/PAI-1 complexes, to determine whether both plasminogen activators and their inhibitor respond similarly to the same stimulus. We studied 36 patients with recurrent venous thrombosis in whom no coagulation defects predisposing them to thrombosis had been detected (mean age 38.2 years, range 15-70 years). Twenty healthy individuals (mean age 34.3 years, range 20-60 years) served as a control group. t-PA, PAI-1 and u-PA activity and antigen, as well as the t-PA/PAI-1 complex antigen, were measured before and after venous stasis. Post-stasis fibrinolytic parameters were corrected for the haemoconcentration which occurred during the venous occlusion test. Pathologically high PAI-1 levels (antigen and activity) were found in four out of 36 patients who were excluded from study. Functional and antigenic u-PA increased significantly after venous stasis when analysed as the absolute differences between paired samples (P less than 0.01). This increase in u-PA did not correlate with changes in t-PA or PAI-1 (r = 0.28 and r = 0.36 respectively). This leads us to suggest that different mechanisms relating to clearance and/or release from diverse sources might be involved in elevations of u-PA in response to a local endothelial stimulus. We conclude that venous stasis might not be the elective choice when evaluating 'bad responders' predisposed to thrombosis.     

Coagulation and fibrinolysis in preeclampsia and neonates.

Coagulation and fibrinolysis were determined in 67 Indonesian women admitted to the University Hospitals for delivery in Medan. They were diagnosed to be at term gestation (mean 39.3 +/- 1.1 weeks) with moderate and severe preeclampsia (n=32) and in labor, and 8 had preterm labor (gestation mean 33.5 +/- 2.6 weeks). Twenty-seven normal pregnant women in labor (gestation mean 39.7 +/- 1.0 weeks) served as controls. Cord blood from 23 neonates from normal pregnancy and 31 neonates from preeclampsia was also evaluated. Preeclamptic women in labor showed further enhanced coagulation activation (F(1+2)) with raised urokinase-like plasminogen activator (u-PA) activity and reduced plasminogen activator inhibitor-2 (PAI-2) levels. In preterm preeclampsia, significantly reduced antithrombin III (ATIII) and PAI-2 levels with further elevated tissue-type PA (t-PA) antigen and plasminogen activator inhibitor-1 (PAI-1) antigen were seen compared to normal pregnancy. These would suggest a state of enhanced thrombin generation with elevated fibrinolytic/inhibitor proteins in preterm preeclampsia. The reduced PAI-2 levels seen in preeclampsia have been suggested to be associated with reduced placental function. Neonates born to mothers of either normal pregnancy or preeclampsia at term showed similar hemostatic changes with reduced fibrinogen, ATIII, t-PA, u-PA antigen, PAI-1 levels, and coagulation activation compared to their respective maternal plasma levels. No significant differences in hemostatic parameters studied between the neonates of both cohorts were seen, and this would suggest that the neonates were protected from the adverse effects of preeclampsia and their hemostatic system was physiologically balanced.     

Effects of physical conditioning on fibrinolytic variables and fibrinogen in young and old healthy adults

BACKGROUND. The effects of 6 months of intensive endurance exercise training on resting tissue-type plasminogen activator (t-PA) activity, plasminogen activator inhibitor type 1 (PAI-1) activity, t-PA antigen, and fibrinogen were studied in 10 young (24-30 years) and in 13 old male subjects (60-82 years). METHODS AND RESULTS. After training, maximum oxygen consumption was increased in the young group by 18% (44.9 +/- 5.0 to 52.9 +/- 6.6 ml/kg/min, p less than 0.001), whereas it was increased in the old group by 22% (29.0 +/- 4.2 to 35.5 +/- 3.6 ml/kg/min, p less than 0.001). The young group had no significant changes in any of the measured variables, whereas the old group had a 39% increase in t-PA activity (0.82 +/- 0.47 to 1.14 +/- 0.42 IU/ml, p less than 0.03), a 141% increase in the percentage of t-PA in the active form (11.1 +/- 7.7 to 26.8 +/- 15.1%, p less than 0.01), a 58% decrease in PAI-1 activity (8.4 +/- 4.9 to 3.5 +/- 1.7 AU/ml, p less than 0.01), and a 13% decrease in fibrinogen (3.57 +/- 0.79 to 3.11 +/- 0.52 g/l, p less than 0.01). CONCLUSIONS. We conclude that intensive exercise training enhances resting t-PA activity and reduces fibrinogen and PAI-1 activity in older men. These effects are potential mechanisms by which habitual physical activity might reduce the risk of cardiovascular disease.     

Plasma t-PA/PAI-1 complex and blood coagulability in patients with coronary artery disease.

The t-PA/PAI-1 complex is a good indicator of the release of fibrinolysis activators and inhibitors from the vascular wall, but its clinical significance in chronic ischemic heart disease is unclear. The plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), and the t-PA/PAI-1 complex (including various coagulation factors) were assayed in 72 patients with coronary artery disease (CAD) and 29 control (C) subjects. The CAD patients were subdivided into 3 groups: single-vessel disease (G1, n = 30), double-vessel disease (G2, n = 20), and triple-vessel disease (G3, n = 22). The patients with triple-vessel disease had higher fibrinogen values (G3: 318 +/- 75 mg/dl, C: 263 +/- 56), factor VII activity (G3: 143 +/- 36%, C: 123 +/- 14), and t-PA antigen levels (G3: 4.7 +/- 0.8 ng/ml, C: 3.3 +/- 0.7) than controls. Patients with double- and triple-vessel disease also showed higher levels of factor VIII, vWF antigen, thrombin-antithrombin III complex (G1: 2.3 +/- 0.6 ng/ml, G2: 2.7 +/- 0.5, G3: 3.1 +/- 0.5, C: 2.0 +/- 0.5), and t-PA/PAI-1 complex (G1: 13.9 +/- 6.1 ng/ml, G2: 16.4 +/- 4.6, G3: 18.2 +/- 5.9, C: 10.7 +/- 4.9) than control subjects. The t-PA/PAI-1 complex levels were correlated significantly with the activities of factors VII and VIII and the thrombin-antithrombin III complex. These findings suggest that patients with CAD have greater blood coagulability than controls, and that this difference is related to the severity of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increase in the D-dimer levels during treatment in patients with acute myelogenous leukemia.

Plasma concentration of thrombin-antithrombin III complex (TAT), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1), PAI-2, D-dimer complex and urokinase-plasminogen activator (u-PA) activity were studied in 30 patients with acute nonlymphoblastic leukemia (ANLL), before and during antileukemic therapy. Fifteen patients showed signs of disseminated intravascular coagulation (DIC), 10 of them classified as M3, 2 as M2 and 3 as M5 subtypes. The initial levels of TAT complex were elevated in all ANLL patients. This increase was more pronounced in patients with DIC (p less than 0.05). TAT increased significantly during the treatment period in all cases. u-PA and PAI-1 levels were elevated but there were no statistically significant differences between patients with and without DIC. PAI-2 levels were below the limit of detection in controls and in patients. However, the initially elevated D-dimer complex levels were significantly higher in DIC cases (p less than 0.01) and they increased during the treatment period. A significant and positive correlation between D-dimer and TAT complex values was found in DIC patients (r = 0.68, p less than 0.001). The high TAT complex and D-dimer levels further increased during chemotherapy treatment strongly suggest a hypercoagulable state with secondary activation of fibrinolysis not severe enough to manifest itself as clinically evident DIC in the majority of cases.     

Acute inflammatory intestinal vascular lesions and in situ abnormalities of the plasminogen activation system in Crohn's disease.

OBJECTIVES: The distribution of the intestinal vascular lesions and their relation with the fibrinolysis process are poorly known in Crohn's disease (CD). The mediators of the plasminogen activator system, namely urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1), are a key complex involved in fibrinolysis. The aims of this study were: (1) to further define vascular lesions and their distribution in the intestine; and (2) to study concomitantly the qualitative in situ expression and the levels of u-PA, t-PA and PAI-1 in the ileum of patients with CD. PATIENTS AND METHODS: Histological, immunohistochemical and ultrastructural studies of vascular lesions in the resected ileum of 27 patients with CD were performed and compared with 36 control patients. Levels of u-PA, t-PA and PAI-1 measured by ELISA methods were compared in healthy and inflamed ileal tissues of 17 patients with CD. RESULTS: Acute vascular lesions involving mainly serosal venules and capillaries were present in 63% of patients with CD vs 3/36 controls and were associated with PAI-1 expression. They were prominent on the mesenteric border beneath macroscopically normal mucosa. In contrast, chronic vascular lesions were present in all layers beneath mucosal ulcerations, where a significant increase of PAI-1 levels was found. CONCLUSIONS: These results suggest that vascular involvement associated with abnormalities of PAI-1 expression is an early and widespread event in CD. Their prominence on the mesenteric border might explain the characteristic location of CD ulceration along the mesenteric margin.     

Influence of homocysteine on fibrin network lysis.

To elucidate some of the links between homocysteine and vascular disease, we have evaluated the effect of the amino acid on the formation (by kinetics studies), structure (by electron microscopy) and lysis of the fibrin network, using tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA). We have studied whether homocysteine could alter the activity of the components involved in fibrinolysis (by amidolytic and thrombolytic methods). The results showed that homocysteine-associated networks were more compact and branched than controls (52 +/- 6 vs 44 +/- 5 fibers/field, P = 0.008), and were formed by shorter and thicker fibers. This clot proved to be more resistant to fibrinolysis with u-PA than control [lysis time 50%: 257 +/- 16 (homocysteine) vs 187 +/- 6 min (control); P < 0.004], but there were no differences with t-PA. Homocysteine did not affect the biological activities of plasmin, or plasminogen activation by t-PA and u-PA. Defective fibrinolysis with u-PA was therefore associated with homocysteine-fibrin structural alterations rather than the homocysteine effect on the biological activities of the fibrinolytic components evaluated. Results suggest that hyperhomocysteinemic patients could produce tight clots, were more resistant to lysis, and generated a procoagulant environment in situ. We believe that our findings may contribute to understanding the mechanisms involved in the homocysteine harmful effect.     

Increased plasma fibrinolysis and tissue-type plasminogen activator/tissue-type plasminogen activator inhibitor ratios after ethanol withdrawal in chronic alcoholics.

The effects of alcohol withdrawal on fibrinolysis were studied in 10 middle-aged male chronic alcoholics institutionalized for withdrawal therapy. All patients were sampled on admission [day 1 (D1)] and 21 days after alcohol withdrawal [day 22 (D22)]. The overall plasma fibrinolytic capacity (OFC) was assayed by measuring the ability of patient plasma to generate D-dimers from a standardized fibrin clot, and tissue-type plasminogen activator (t-PA) and t-PA inhibitor (PAI-1) levels were assayed together with serum cholesterol, triglyceride and cholesterol fractions. At D22, the OFC significantly increased in seven patients [D1 = 10 +/- 0.7 microg/h (mean +/- SD), D22 = 17 +/- 7.4 microg/h; P < 0.01], while t-PA and PAI-1 levels decreased in all patients but two (t-PA: D1 = 16.6 +/- 5 ng/ml, D22 = 10.2 +/- 3.8 ng/ml; P < 0.001; and PAI-1: D1 = 46 +/- 39 ng/ml, D22 = 21 +/- 28 ng/ml; P < 0.01). This study clearly demonstrates an increase in overall fibrinolytic activity after alcohol withdrawal, which is mainly due to a decrease in PAI-1 levels. These changes induced by alcohol abstinence might provide clear benefit by reducing the risk of thromboembolic events and particularly of stroke associated with elevated PAI-1 levels described in heavy drinkers.     

Alterations in the fibrinolytic system components during acute myocardial infarction

The purpose of this study was to evaluate the changes in tissue-plasminogen activator (t-PA), plasminogen activator inhibitor - type 1 (PAI-1) and D-dimer (DD) antigen plasma levels in acute myocardial infarction (AMI) patients after thrombolytic therapy with two different thrombolytic agents, rt-PA or acetyl-streptokinase and to find out any correlation between the plasma t-PA, PAI-1 and DD levels with the infarct size as it is estimated from the peak of serum CPK levels. The plasma antigen levels of t-PA, PAI-1 and DD were measured by the enzyme immunoassay method (Stago), in 57 consecutive patients (M = 46, F = 11, mean age 55.6 +/- 8.8 years) and in 25 normal subjects (M = 18, F = 7, mean age 54.0 +/- 5.5 years). In 47 out of the 57 patients who were treated successfully with 100 mg of rt-PA (26 patients) or with 1.5 MU 21 of acetyl-streptokinase, as well as in 10 patients who were not treated, samples were obtained again 4 and 24 hours after the end of thrombolytic therapy or admission, respectively. During the acute phase of myocardial infarction the t-PA, PAI-1 and DD antigen plasma levels were significantly higher than in healthy people. There were no significant changes in the t-PA, PAI-1 and DD plasma levels of the patients who were not treated with a thrombolytic agent. We found a significant elevation of t-PA (p < 0.001), PAI-1 (p < 0.05) and DD (p < 0.001) after 4 hours in comparison with the baseline (at presentation, before therapy). After 24 hours the t-PA and DD plasma levels remained significantly higher (p < 0.001) while the PAI-1 plasma levels returned to the pre-therapy levels. There were no significantly different changes in the t-PA, PAI-1 and DD plasma levels of either group of patients, treated with rt-PA or acetyl-streptokinase while the t-PA and PAI-1 levels were positively correlated with infarct size as estimated from peak serum CPK levels.     

The dynamic changes of plasma tissue-type plasminogen activator level and the activity of its inhibitor during coronary vasospasm

This study aimed to examine the dynamic changes of the fibrinolytic system during coronary vasospasm. Tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI) and fibrinopeptide A (FPA) levels were measured in the great cardiac venous and arterial blood of 9 patients with clinically and angiographically proven vasospastic angina and 11 controls. Before ergonovine provocation, although there was no difference between the above 2 groups in t-PA levels in the aorta or the great cardiac vein, the PAI level in patients with variant angina was lower than in the controls both in the aorta (4.2 +/- 3.5 IU/ml vs 10.9 +/- 5.2 IU/ml) and in the great cardiac vein (2.3 +/- 2.9 IU/ml vs. 11.9 +/- 4.9 IU/ml). During ergonovine-induced coronary vasospasm in patients with variant angina, the t-PA level in the great cardiac vein significantly increased from 3.4 +/- 0.7 ng/ml to 4.4 +/- 0.5 ng/ml (p less than 0.05), but it did not change in the aorta. The maximal dose of ergonovine (0.4 mg) induced mild diffuse coronary vasoconstriction in the controls, and this diffuse coronary vasoconstriction induced a reduction of PAI levels in the great cardiac vein from 11.9 +/- 4.9 IU/ml to 9.5 +/- 4.8 IU/ml (p less than 0.05). FPA levels in the great cardiac vein did not change during ergonovine-induced coronary vasospasm in either group. Thus, the coronary vasospasm induced the release of t-PA from endothelial cells of coronary vessels and resulted in the reduction in the PAI activity in the great cardiac vein.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endogenous fibrinolytic system in chronic large-vessel thromboembolic pulmonary hypertension.

BACKGROUND. Chronic thromboembolic pulmonary hypertension (CTEPH) is a disorder characterized by pulmonary arterial hypertension as a consequence of organized thrombotic material in the central pulmonary arteries. Incomplete resolution of acute pulmonary emboli is believed to be pathogenically important; however, the mechanism for poor thrombus dissolution remains to be explained. We undertook this study to assess the major determinants of plasma fibrinolysis in patients with CTEPH (n = 32). METHODS AND RESULTS. Immunological and functional levels of tissue-type plasminogen activator (t-PA) and type 1 plasminogen activator inhibitor (PAI-1) were quantified in platelet-poor plasma (PPP) from patients with CTEPH as well as age-matched controls. Although basal PPP t-PA antigen levels (CTEPH mean, 29.5 ng/ml; control mean, 2.7 ng/ml) and PAI-1 antigen levels (CTEPH mean, 55.8 ng/ml; control mean, 21.0 ng/ml) were higher in the CTEPH group, no between-group differences were detected in the enzymatic activities of these two molecules. The CTEPH group demonstrated a greater rise in t-PA antigen (CTEPH mean rise, 53.0 ng/ml; control mean rise, 5.6 ng/ml) and PA activity (CTEPH mean rise, 10.5 IU/ml; control mean rise, 1.2 IU/ml) than controls in response to an experimentally induced venous occlusion. Immunoprecipitation and fibrin autography of PPP from two patients with markedly elevated basal t-PA antigen levels demonstrate that the t-PA antigen was present in PPP primarily in complex with PAI-1. CONCLUSIONS. Although abnormalities of the fibrinolytic system were detected, neither a high resting plasma PAI-1 activity nor a blunted response of t-PA to venous occlusion can be invoked as an etiology for CTEPH.     

Plasminogen activator inhibitor 2 and urokinase-type plasminogen activator in plasma and leucocytes in patients with severe sepsis

Proteins influencing plasminogen activation to plasmin, namely plasminogen activators tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) and their principal inhibitors, plasminogen activator inhibitor 1 (PAI-1) and PAI-2, were measured in the plasma, the polymorph and mononuclear cell fractions taken from patients with major sepsis who were entering a general intensive care unit. The purpose of this study was to elucidate the factors favouring the persistence of fibrin in the microvasculature and thus contributing to multiple organ failure. Levels of u-PA antigen in plasma rose in sepsis and u-PA activity, not detectable in normal plasma, appeared. Levels of u-PA antigen in the cell fractions fell concomitantly. t-PA antigen in plasma and in the mononuclear cell fraction rose in sepsis, but t-PA activity was not detectable. Plasma PAI-1 antigen levels were strikingly raised in sepsis, presumably accounting for the complete neutralization of t-PA activity. PAI-2 antigen, not normally detected in plasma, appeared in the plasma of some patients, whereas it disappeared from the cellular fractions. Appearance of PAI-2 in plasma was associated with non-survival of the patient. The observations indicate that all the agents involved in plasminogen activation are released into the plasma in major sepsis. The levels of PAI-1 reached were quantitatively sufficient to suppress all activity of the released t-PA, but the inhibitors did not prevent expression of u-PA activity in the circulation. Circulating active u-PA and PAI-2 in the plasma of patients with severe sepsis may represent material originating from leucocytes. Leucocyte release of these agents within fibrin deposits may influence the persistence of fibrin and thus the development of multiple organ failure.     

丹红注射液对不稳定型心绞痛病人炎症反应物及纤溶活性的影响

目的探讨丹红注射液对不稳定型心绞痛(UA)病人血浆炎症反应物及纤溶活性的影响。方法140例UA病人随机分为常规治疗组(67例)和丹红治疗组(73例),另设正常对照组50名。丹红治疗组于常规治疗基础上加用丹红注射液20mL静脉输注,每日1次,疗程为3周。两组分别于治疗前及结束时测定血清C-反应蛋白(CRP)、白细胞介素-6(IL-6)、纤维蛋白原(FIB)、D-二聚体(DD)浓度和组织型纤溶酶原激活物(t-PA)、纤溶酶原激活物抑制物-1(PAI-1)活性。结果丹红注射液治疗3周后,CRP,IL-6,FIB,DD,PAI-1水平下降(P<0.05或P<0.01),t-PA活性升高(P<0.01)。治疗前UA病人的CRP与IL-6,PAI-1,DD呈正相关(P<0.05或P<0.01),与t-PA呈负相关(P<0.01)。丹红治疗组治疗后CRP与IL-6,PAI-1呈正相关(P<0.05或P<0.01),与t-PA呈负相关(P<0.05)。结论UA病人应用丹红注射液治疗,可能有利于抑制炎症反应,改善内皮功能,提高纤溶活性,稳定斑块。     

Interleukin-4 Modulation of Platelet-Derived Growth Factor–Induced Smooth Muscle Cell Urokinase Plasminogen Activator

Platelet-derived growth factor (PDGF) stimulates smooth muscle cell (SMC) migration owing to stimulation of SMC tissue plasminogen activator (t-PA) production. In this study we examined the effects of the T-cell lymphokine interleukin-4 (IL-4) on PDGF induction of human aortic SMC antigen levels of urokinase-type plasminogen activator (u-PA) and those of plasminogen activator inhibitor-1 (PAI-1), the endogenous inhibitor of t-PA and u-PA, measured by enzyme-linked immunosorbent assays (ELISAs). u-PA antigen levels from human aortic SMC incubated with PDGF 100 ng/mL and IL-4 500 U/mL were significantly greater than those incubated with PDGF 100 ng/mL alone. Coincubation of PDGF with IL-4 did not significantly increase SMC u-PA antigen levels in cellular lysates. Coincubation with PDGF 100 ng/mL and IL-4 500 U/mL did not significantly affect SMC PAI-1 antigen levels in conditioned media or cellular lysates. Therefore, interleukin-4 modulates vascular SMC u-PA production induced by PDGF.     

Residual plasminogen activator inhibitor activity after venous stasis as a criterion for hypofibrinolysis: a study in 83 patients with confirmed deep vein thrombosis

In eighty-three patients with confirmed deep vein thrombosis, the fibrinolytic system was studied before and after a 10-minute venous occlusion. Blood was collected at least 3 months after the last acute episode, and PAI-1 antigen and activity, as well as tissue-type plasminogen activator (t-PA) antigen, urokinase-type plasminogen activator (u-PA) antigen, and fibrinolytic activity were measured in these samples. During venous stasis, plasminogen activator inhibitor (PAI) activity decreased in almost all patients (81 of 83), from a median value of 8.2 to 2.9 U/mL (P less than .001, Wilcoxon signed-rank test). Because PAI-1 antigen augmented from a median value of 16 to 19.2 ng/mL (P less than .001), the decline in PAI activity was attributed to an increase in t-PA antigen from a median value of 10 to 21.7 ng/mL (P less than .001). Neutralization of PAI activity thus reflects the patient's capacity to overcome basal inhibitory potential through t-PA release. Based on residual PAI activity after 10-minute stasis, patients were classified as good or bad responders (PAI activity below detection limit, ie, less than or equal to 1.0 and greater than 1.0 U/ml, respectively). Good responders had a significantly higher fibrinolytic response after stasis than bad responders (median euglobulin clot lysis time 60 v 180 minutes; dilute whole blood clot lysis time 60 v 120 minutes; fibrinolytic activity on fibrin plates 7.7 v 0 U/mL). Furthermore, good responders, as compared with bad responders, had higher t-PA release (median 16.5 v 11.5 ng/mL), lower basal PAI activity (median 4.8 v 11.2 U/mL), and lower basal PAI-1 (median 11 v 21 ng/mL) and u-PA antigen (median 7.9 v 9.0 ng/mL, P less than .02). Hypofibrinolysis, as defined by the inability of released t-PA to overcome PAI-1 basal inhibitory potential, was observed in 45 of 83 patients (54%) and resulted either from an insufficient release of t-PA or from an increased basal PAI activity.     

Plasminogen activator in acute myeloid leukaemic marrows: u-PA in contrast to t-PA in normal marrow

Leukaemic and normal bone marrow samples were compared in terms of their content of the fibrinolytic agents, tissue plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) and their inhibitors, plasminogen activator inhibitors 1 and 2 (PAI-1 and PAI-2). Normal marrow contained t-PA as the principal plasminogen activator, whereas in leukaemic marrow samples u-PA was the predominant activator. Both normal and leukaemic marrows contained PAI-1 in similar amounts, but whereas normal marrow contained significant amounts of PAI-2 the leukaemic marrows contained very little. Plasminogen activators were present in uncomplexed, active forms and plasmin–α₂-antiplasmin complexes were generated locally more prominently in leukaemic marrows. u-PA associated with blast cells may contribute to the severe forms of haemorrhage sometimes occurring in myeloid types of leukaemia.     

Plasma adiponectin, T94G gene polymorphism and PAI-1 in patients with and without hypertension

BACKGROUND: Reduced adiponectin level has been associated with metabolic syndrome, type 2 diabetes, coronary artery disease and gene polymorphisms, but the interrelationships of T94G genotype, plasma adiponectin and plasminogen activator inhibitor-1 (PAI-1) are less understood. PATIENTS AND METHODS: The T94G genotypes and plasma levels of adiponectin, and PAI-1 were determined in 568 Chinese patients, 212 with and 356 without hypertension, to study the possible associations of T94G genotype, plasma adiponectin, PAI-1 and blood pressure. RESULTS: Hypertensive patients showed significantly lower plasma adiponectin (9.7 +/- 11.1 vs. 11.5 +/- 10.0 microg/ml, p = 0.04) and higher PAI-1 (p < 0.001) levels but not significantly greater adiponectin TT genotype percentage (38.7 vs. 33.5%) and T allele frequency (0.620 vs. 0.585) than normotensive subjects. Plasma adiponectin was inversely related to PAI-1 activity (r = -0.09, p = 0.03) and antigen (r = -0.202, p < 0.001). Furthermore, the TT genotypic group showed significantly lower plasma adiponectin level (10.4 +/- 10.5 vs. 13.4 +/- 10.8 mug/ml, p = 0.03) and higher plasma PAI-1 activity (17.0 +/- 9.7 vs. 13.5 +/- 7.6 IU/ml, p = 0.003) and antigen (32.3 +/- 22.7 vs. 25.9 +/- 14.7 ng/ml, p = 0.01) than the GG genotypic group. Multiple linear regression analysis in all study subjects, in men and in normotensives documented an impact of adiponectin T94G genotype on plasma levels of adiponectin (p = 0.007, 0.003 and 0.03) and PAI-1 activity (p = 0.02, 0.03 and 0.04) and antigen (p = 0.03, 0.007 and 0.04) after adjustment for potential confounding factors. CONCLUSIONS: The present study demonstrated a significant correlation of the TT genotype with lower plasma adiponectin and higher plasma PAI-1 levels in a Chinese population. The contribution of this genotype seemed greater in men and normotensives. It suggested the adiponectin gene T94G polymorphism might affect the regulation of circulating adiponectin and PAI-1.