Association of elevated lipoprotein(a) level and monocyte subsets with the severity of coronary atherosclerosis

Background

Chronic inflammation associated with the uncontrolled activation of innate and acquired immunity plays a fundamental role at all stages of atherogenesis. Monocytes are a heterogeneous population, and each subset contributes differently to the inflammatory process. High level of lipoprotein(a) [Lp(a)] is a proven atherosclerotic cardiovascular disease (ASCVD) risk factor. The aim of the study was to investigate the association between the increased concentration of Lp(a) and monocyte subsets in patients with different severity of coronary atherosclerosis.

Methods

150 patients (124 males (82.6%)), median age 60 (54; 65) years undergoing coronary angiography were enrolled. Lipids, Lp(a) were assessed by enzyme immunoassay. Monocyte subpopulations (classical CD14++CD16-, intermediate CD14++CD16+, non-classical CD14+CD16++) were analyzed by direct immunofluorescence and flow cytometry.

Results

The patients were divided into two groups depending on the Lp(a) concentration: normal Lp(a) <30 mg/dl (n=82) and hyperLp(a) ≥30 mg/dl (n=68). Patients of both groups were comparable in routine ASCVD risk factors (age, BMI, arterial hypertension, previous myocardial infarction, smoking, lipids). In patients with hyperLp(a) the content (absolute and relative) of non-classical CD14+CD16++ monocytes was higher (71.0 (56.6; 105.7 1000/ml vs. 62.2 (45.7; 82.4) 1000/ml and 17.7 (13.0; 23.3) % vs. 15.1 (11.4; 19.4) %, respectively, p<0.05). The association of the relative content of non-classical CD14+CD16++ monocytes with the Lp(a) concentration retained statistical significance when adjusted for gender and age (r=0.18, p=0.03). The severity of coronary atherosclerosis was correlated with the Lp(a) concentration (r=0.20, p<0.05), as well as the relative (r=−0.16, p<0.05) and absolute (r=−0.21, p<0.05) content of classical CD14++CD16- monocytes. The high content of non-classical CD14+CD16++ monocytes (OR=3.5 (95% CI 1.2–10.8), as well as intermediate CD14++CD16+ monocytes (OR=8.7 (95% CI 2.5–30.6) in patients with hyperLp(a) were associated with stenotic three-vessel coronary artery disease.

Conclusion

Here we demonstrate the correlation between the Lp(a) concentration and the blood content of non-classical monocytes, regardless of gender and age. The hyperLp(a) and decreased quantity of classical CD14++CD16- monocytes were associated with the severity of coronary atherosclerosis. The expansion of CD16+ monocytes (intermediate and non-classical) in the presence of hyperLp(a) significantly increased the risk of stenotic three-vessel coronary artery disease. Further studies of the differentiation and functioning of subsets of monocytes in the presence of congenital disorders of lipid metabolism, and especially hyperLp(a), are needed.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): The study was approved by Russian Ministry of Health

[Analysis of the causes of repeat stenosis of the coronary arteries after elective stenting in patients with stable angina pectoris]

AIM

Coronary stenting is the evidence-based treatment approach of stable angina. The objective was to determine the incidence of restenosis or atherosclerosis progression which led to the need for coronary angiography according to a single center registry data.

MATERIALS AND METHODS

The procedure and clinical data of 3732 (2897 males) consecutive stable coronary artery disease patients undergoing coronary stenting, over five years between March 2010 and September 2014, were subject of this study. Over the next 4 years, 1487 (1173 males) patients were re-evaluated due to angina reoccurrence. 699 patients demonstrated the indications for coronary angiography.

RESULTS

The restenosis of the previously stented segment was detected in 84 (12%) cases, the progression of coronary atherosclerosis in 306 (44%), the combination of restenosis and atherosclerosis progression in 63 (9%), and the absence of these complications in 245 (35%) cases. The progression of coronary atherosclerosis was the leading indication for the repeat angiography and revascularization (44 and 58%, respectively); p0.05. The basal level of hsCRP2 mg/l had a prognostic significance for the development of combined event (the restenosis and atherosclerosis progression): AUC 0.65 (0.500.75), OR 3.0 (1.17.9), p0.05.

CONCLUSION

The progression of coronary atherosclerosis was the leading indication for the repeat angiography and repeat revascularization during 2 years after coronary stenting. The hsCRP level 2 mg/l at baseline had a prognostic significance for the development of restenosis in previously stented segment and coronary atherosclerosis progression.

[The prognostic value of high-sensitivity C-reactive protein blood level after coronary stenting for the development of stent restenosis]

Aim      To analyze the relationship between serum concentrations of high-sensitivity C-reactive protein (hsCRP) in dynamics and development of restenosis at 12 months following elective coronary stent placement (CSP).Material and methods  The key role in atherogenesis, neointimal proliferation and restenosis belongs to inflammation. This study included 91 patients (median age, 60 [56; 66] years) with stable exertional angina after an elective CSP using second-generation stents. Follow-up coronarography was performed for 60 patients at 12 months. Concentration of hsCRP was measured immediately prior to CSP and at 1, 3, 6, and 12 months after CSP. Restenosis of the stented segment (50% or more narrowing of the stented segment or a 5-mm vessel segment proximally or distally adjacent to the stented segment) was observed in 8 patients.Results According to results of the ROC analysis, the increase in hsCRP concentration >0.9 mg/l (>25%) at one month after CSP had the highest predictive significance with respect of restenosis (area under the ROC curve, 0.89 at 95 % confidence interval (CI) from 0.79 to 0.99; sensitivity, 87.5 %; specificity, 82.8 %; р=0.0005), which was superior to the absolute value of hsCRP concentration >3.0 mg/l (area under the ROC curve, 0.82 at 95 % CI from 0.68 to 0.96; р=0.0007).Conclusion      Increased concentration of hsCRP ≥0.9 mg /l (≥25 %) at a month after CSP was associated with restenosis of the coronary artery stented segment.

The Molecular and Cellular Mechanisms Associated with a Microvascular Inflammation in the Pathogenesis of Heart Failure with Preserved Ejection Fraction

Heart failure withpreserved ejection fraction (HFpEF) is a severe disease with an often unfavorable outcome. The prevalence of HFpEF continues to increase, while effective treatment options remain elusive. All the medical strategies used toimprove the outcome in a heart failure with reduced ejection fraction proved ineffective in HFpEF, which was probably due to the different mechanisms ofdevelopment of these two types of heart failure and the diversity of the HFpEF phenotypes. According to the current paradigm of HFpEF development, a chronic mild pro-inflammatory statecauses a coronary microvascular endothelial inflammation, with further myocardial fibrosis and diastolic dysfunction progression. This inflammatory paradigm of HFpEF has been confirmed with someevidence, and suppressing the inflammation may become a novel strategy for treating and managing HFpEF. This review summarizes current concepts about a microvascular inflammation in hypertrophied myocardium and provides a translational perspective of the anti-inflammatory and immunomodulatory approaches in HFpEF.

The severity of internal carotid artery stenosis is associated with the circulating Th17 level

Aim

Immune and inflammatory reactions contribute to the progression of atherosclerosis. The walls of the different arteries and segments of the arteries have heterogeneous haemodynamic and histological features. We aimed to explore the relationship between the circulating T-cell subsets and the abundance of carotid atherosclerosis in different segments of carotid arteries.

Methods

70 patients underwent ultrasound duplex scanning to determine the degree of stenosis of the common carotid artery (CCA), the CCA bifurcation or the internal carotid artery (ICA). The blood frequencies of T-, B-, NK-cells, regulatory T cells (Treg), activated T-helpers (Th), IL10-producing Th, Th1 and Th17, as well as blood levels of hsCRP, sCD25, IL10 and IL17a were assessed.

Results

The frequencies of Th17 were increased in patients with ICA stenosis >35% and >50% vs. patients with ICA stenosis <35%. Th17 blood level ≥0.55 % of lymphocytes was associated with more severe stenosis of ICA (OR 4.3 (1.0–17.6), p < 0.05 for ICA stenosis of 35–50% and 6.8 (1.3–35.0), p < 0.05 for ICA stenosis >50%). BMI positively correlated with the CCA bifurcation stenosis degree (r = 0.33, p < 0.05).

Conclusion

The severity of ICA stenosis can be associated with the circulating Th17 level.

[Immunological aspects of Parkinson's disease]

The review summarizes information on immunological disorders in Parkinson's disease (PD). The data on neuroinflammation associated with degeneration of the medial substantia nigra cells are presented. It is pointed out that innate and adaptive immunity cells are involved in the process of neuroinflammation. The authors analyze the cytokine level in the brain, cerebrospinal fluid and peripheral blood as well as the relationship between neuroinflammation and neuron dysfunction and provide information on immunological disorders in people with PD and animal models of PD. Specific features of PD models and data on blood-brain barrier damage and evidence of autoimmune inflammation in PD are presented. Identification of PD preclinical markers, including cytokines, HLA-DR and HLA-DQ antigens, autoantibodies, etc, is discussed. Pre-symptomatic diagnosis of PD, prevention and treatment at the pre-symptomatic stage could lead to interruption or slowdown the neurons death.

The Molecular and Cellular Mechanisms Associated with a Microvascular Inflammation in the Pathogenesis of Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a severe disease with an often unfavorable outcome. The prevalence of HFpEF continues to increase, while effective treatment options remain elusive. All the medical strategies used to improve the outcome in a heart failure with reduced ejection fraction proved ineffective in HFpEF, which was probably due to the different mechanisms of development of these two types of heart failure and the diversity of the HFpEF phenotypes. According to the current paradigm of HFpEF development, a chronic mild pro-inflammatory state causes a coronary microvascular endothelial inflammation, with further myocardial fibrosis and diastolic dysfunction progression. This inflammatory paradigm of HFpEF has been confirmed with some evidence, and suppressing the inflammation may become a novel strategy for treating and managing HFpEF. This review summarizes current concepts about a microvascular inflammation in hypertrophied myocardium and provides a translational perspective of the anti-inflammatory and immunomodulatory approaches in HFpEF.

The Incidence and Possible Predictors of Coronary Restenosis

Objective. Assess time and possible predictors of restenosis after the implantation of first- and second-generation coronary stents and bare metal stents (BMSs) in patients with stable coronary artery disease after elective coronary stenting.

Materials and Methods. From 2010 to 2014, 3,732 (2,897 males, 60 [53; 68] years old) patients with stable exertional angina of functional class I–III underwent coronary stenting. From 2014 to 2017, 1,487 (1,173 males and 314 females) patients returned. Repeat coronary angiography was performed in 699 patients.

Results. A total of 644 first-generation stents, 5,321 second-generation stents, and 473 BMSs were implanted. During the control coronary angiography, contrasting was repeated for 193 first-generation stents, 899 second-generation stents, and 77 BMSs. Restenosis (stenosis of 50 % or more in the previously stented segment) was detected in 28 (14 % of angiographic control) first-generation drug-eluting stents, 94 (10 %) second-generation drug-eluting stents, and 21 (27 %) BMSs. Patients with BMS restenosis returned significantly earlier than patients with restenosis of the first- and second-generation drug-eluting stents (11 [6, 27] months vs. 32 [11; 48]) months and 24 [12; 42] months, respectively; p<0.05). The initial and repeat levels of high-sensitivity C-reactive protein (hs-CRP) were higher in patients with restenosis (2.2 [1.2, 5.0] mg / L vs. 2.1 [1.0, 4.6] mg / L, respectively; p> 0.05) than in patients without restenosis (2.0 [0.9, 4.2] mg / L vs. 1.9 [0.7, 3.5] mg / L respectively, p>0.05). Blood levels of hs-CRP ≥2 mg / L according to receiver operating characteristic curve (ROC) analysis at return visit were used as a predictor to identify restenosis of stents with a diameter <3 mm and a length >25 mm – area under the curve (AUC) 0.67 (95 % confidence interval (CI) 0.51–0.84), p <0.05, odds ratio 3.7 (95 % CI 1.1–12.1), p<0.05. Stent type had a significant effect on the time to restenosis in the survival analysis (p<0.0005).

Conclusion. The time from coronary stenting to the return visit of patients presenting with restenosis after the implantation of first- and second-generation drug-eluting stents is consistent; median time of the return visit of patients with restenosis of the first-generation stents was 2–3 years after coronary stenting. Blood levels of hs-CRP ≥2 mg / L at the return visit is a predictor of restenosis of stents with a diameter <3 mm and a length >25 mm.

[Preprocedural high - sensitivity C-reactive protein (hsCRP) decrease during intensive atorvastatin therapy: the presumable impact on atherosclerosis progression after coronary stenting]

Proinflammatory status is the risk factor for coronary atherosclerosis progression after coronary stenting (CS). Intensive statin treatment is associated with hsCRP concentration decline.

AIM

to evaluate prognostic significance of preprocedural hsCRP level reduction with intensive statin regimen for coronary atherosclerosis progression during one year after CS.

MATERIALS AND METHODS

We enrolled 102 patients with stable angina who were on list for scheduled CS. Group I (n=37) patients received atorvastatin 80 mg for 7 days before and 3 months after CS with further dose adjustment according to LDL; group II (n=65) patients received atorvastatin 20-40 mg/day for LDL goal achievement. HsCRP level was assessed at baseline, before CS and after 1, 3, 6 and 12 months. Coronary atherosclerosis progression was defined as new ≥50% stenosis or ≥30% increase of ≥20% pre - existing stenosis according to coronary angiography (CA) 1 year after CS.

RESULTS

Baseline concentration of hsCRP was comparable: 0.21 (0.13; 0.38) vs. 0.20 (0.1; 0.44) mg/dl in groups I and II, respectively (p>0.05). In group I significant hsCRP level decrease to 0.14 (0.07; 0.32) mg/dl (p.

Immunotropic Effects and Proposed Mechanism of Action for 3-Hydroxy-3-methylglutaryl-coenzyme A Reductase Inhibitors (Statins)

Inhibitors of HMG-CoA reductase (statins) are the major group of lipid-lowering drugs. Along with hypocholesterolemic activity, statins exhibit anti-inflammatory and immunomodulatory properties that expand their clinical use, particularly, in the treatment of chronic inflammatory and autoimmune disorders. In this review, we critically analyze the data of statin effects on immune cells (e.g., monocytes and T cells) involved in the development of atherosclerosis and other chronic inflammatory diseases. We (i) discuss the properties of statins and routes of cell entry, as well as their major intracellular targets; (ii) evaluate the data on the effects of statins on the subset composition of circulatory monocytes, ability of monocytes to migrate to the site of inflammation (cell motility and expression of adhesion molecules and chemokine receptors), production of cytokines, matrix metalloproteinases, and reactive oxygen species by monocytes/macrophages, and antigen-presenting activity in peripheral blood monocyte-derived dendritic cells; and (iii) summarize the data on the regulation of proliferation and differentiation of various CD4+ T cell subsets (type 1/2/17 helper T cells and regulatory T cells) by statins.

[Subpopulation Composition of CD4+ T-lymphocytes as Factor Contributing to the Progression of Atherosclerosis of Carotid Arteries]

AIM

to assess prognostic significance of blood content of regulatory and effector T-lymphocytes for progression of atherosclerosis (AS) of carotid arteries.

MATERIAL AND METHODS

We enrolled in this study 33 men with various severity of carotid AS. Carotid artery duplex scan was done at admission and in 1 year after enrollment. AS progression was defined as appearance of novel stenosis in common or internal carotid artery or more or equal 5% increase of preexisting stenosis. Peripheral blood lymphocyte phenotyping was performed by direct immunofluorescence and flow cytometry at the enrollment. T-helpers (Th) 1 were identified as CD4+IFNgamma+ cells, Th2 - CD4+IL4+, activated T-cells (T-act) - D4+CD25lowCD127high, regulatory T-cells (T-reg) - D4+CD25highCD127 low and CD4+FoxP3+, Th17 - CD4+IL17a+ cells.

RESULTS

Progression of carotid AS was observed in 18 patients. Basal values of Th17 were higher while ratio T-reg/Th17 was lower in patients with compared with those without AS progression. ROC-analysis showed high sensitivity and specificity of blood levels of Th17, T-act and T-reg/Th17 ratio for carotid AS progression during one year in patients with low density lipoprotein cholesterol (LDLCH) level below 3.5 mmol/l.

CONCLUSION

The imbalance between circulating levels of regulatory T-cells and T-helpers 17 with the prevalence of proinflammatory T-helpers 17 may reflect a predisposition for carotid AS progression, what also refers to patients with relatively low LDLCH.

[Lipoprotein(a), its autoantibodies, and circulating T lymphocyte subpopulations as independent risk factors for coronary artery atherosclerosis]

AIM

To study the role of lipoprotein(a) [Lp(a)] as a potential autoantigen causing the activation of immunocompetent cells in atherosclerosis.

SUBJECTS AND METHODS

A total of 104 men with stable coronary artery (CA) disease and different degrees of progressive coronary atherosclerosis were examined. Clinical blood analysis was carried out and lymphocyte subpopulations (CD4+, Th1, Th17, and Treg) were determined using immunofluorescence and flow cytometry. In addition, the indicators of blood lipid composition, Lp(a), autoantibody (autoAb) titer to Lp(a), and low-density lipoproteins (LDL), and the lymphocyte activation marker sCD25 were also measured.

RESULTS

The Lp(a) level was shown to predict the severity of CA lesions (β=0.28, p<0.05), regardless of age, the level of cholesterol, different T-lymphocyte subpopulations, sCD25, and autoAb. A combination of the concentration of Lp(a) above 11.8 mg/dl, that of Th17 over 11.4∙103 cells/ml and the reduced levels of regulatory T cells and IL-10-producing CD4+ T cells showed a manifold increase in the risk of severe and progressive CA atherosclerosis. There was a direct correlation of the blood level of Th1 with that of IgG autoAb specific to all atherogenic apoB-containing lipoproteins, including Lp(a). There was an inverse correlations of the lymphocyte activation marker sCD25 with IgM anti-Lp(a) autoAb titers (r=-0.36; p<0.005), but this was less significant with autoAbs to native and oxidized LDL (r=-0.21 and r=-0.24; p<0.05, respectively).

CONCLUSION

The slightly elevated Lp(a) concentration along with changes in the level of T lymphocyte subpopulations was first shown to significantly potentiate the risk of progressive and multiple CA lesion in the examinees. The correlation of IgM anti-Lp(a) autoAb with the lymphocyte activation marker sCD25 and that of IgG anti-Lp(a) autoAb with Th1 have demonstrated that Lp(a) is involved in the autoimmune inflammatory processes in atherosclerosis.

Changes in the concentration of monocytic chemotaxic protein-1 in patients with unstable angina treated with arixtra

The time course of inflammatory reaction markers in the blood of patients with unstable angina was studied during therapy including arixtra. Plasma concentration of monocytic chemotaxic protein-1 (MCP-1) decreased on days 2 and 3 in patients receiving arixtra and a trend to an increase in MCP-1 concentration was observed on day 7 after the drug was discontinued. After 1 month, MCP-1 level decreased in all patients. The concentration of highly sensitive C-reactive protein also decreased 1 month after the disease onset; no changes in the concentrations of IL-8 and IL-2 receptor α-subunit were detected during these periods. It seems that arixtra is characterized by an anti-inflammatory effect manifesting by reduction of plasma chemokine MCP-1 concentration.

Synthetic peptide fragment (65-76) of monocyte chemotactic protein-1 (MCP-1) inhibits MCP-1 binding to heparin and possesses anti-inflammatory activity in stable angina patients after coronary stenting

OBJECTIVE AND DESIGN

The peptide from C-terminal domain of MCP-1 (Ingramon) has been shown to inhibit monocyte migration and possess anti-inflammatory activity in animal models of inflammation and post-angioplasty restenosis. Here, we investigate the effect of Ingramon treatment on blood levels of acute-phase reactants and chemokines in patients after coronary stenting and the mechanisms of Ingramon anti-inflammatory activity.

SUBJECTS

Eighty-seven patients with ischemic heart disease (IHD) who faced the necessity of coronary angiography (CA) were enrolled. In 67 patients, one-stage coronary stenting was performed; 33 of them were treated with Ingramon in addition to standard therapy. Twenty patients underwent CA only.

METHODS

High-sensitivity C-reactive protein (hsCRP) and fibrinogen blood levels were detected routinely. The chemokine concentration in plasma was measured by enzyme-linked immunosorbent assay (ELISA) or cytometric bead array-based immunoassay. Intracellular Ca(2+) levels and cell surface integrin exposure were assayed by flow cytometry. MCP-1 dimerization was studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). MCP-1-heparin binding was assessed with a biosensor and ELISA.

RESULTS AND CONCLUSIONS

Ingramon treatment was accompanied by less pronounced elevation of hsCRP and fibrinogen levels and decreased MCP-1 concentration in plasma in patients after coronary stenting. Ingramon had no effect on MCP-1 interaction with cell receptors or MCP-1 dimerization, but inhibited MCP-1 binding to heparin. The anti-inflammatory activity of the peptide may be mediated by an impaired chemokine interaction with glycosaminoglycans.

Expression of markers of regulatory CD4+CD25+foxp3+ cells in atherosclerotic plaques of human coronary arteries

The content of marker foxp3 of regulatory T cells and chemokines in atherosclerotic plaques of human coronary arteries was measured by the polymerase chain reaction. In vitro migration of regulatory CD4(+)CD25(+)foxp3(+) cells in the CD4(+) lymphocyte population from healthy donors was studied after treatment with chemokines I-309, IP-10, and SDF-1. mRNA for the factor foxp3 and chemokines SDF-1, I-309, and MIP-1beta were found in the majority of samples from atherosclerotic plaques. SDF-1 induced maximum migratory response of CD4(+)CD25(+)foxp3(+) cells.

Intracellular signal cascade in CD4+ T-lymphocyte migration stimulated by interferon-gamma-inducible protein-10

The intracellular signal cascades involved in chemokine-stimulated migration of in vitro activated human peripheral blood CD4+ T-lymphocytes were investigated. IP-10-mediated chemotactic response of lymphocytes was decreased in the presence of selective inhibitors of Src-kinases (by 40-45%), PI3-kinases (35-40%), and MAP-kinases ERK1/2 (35-40%) and p38 (20%). Combined addition of specific inhibitors of Src-kinases and PI3-kinases and inhibitors of Src-kinases and ERK1/2 MAP-kinases did not result in the further increase of the inhibitory effect, while the combined addition of specific inhibitors of PI3-kinases and ERK1/2 MAP-kinases decreased migration of CD4+ T-lymphocytes more effectively (by 55-60%) than any individual inhibitor. Immunoblotting analysis of activation of MAP-kinases ERK1/2 and p38 revealed increased level of phosphorylation of ERK1/2 and p38 MAP-kinases in the presence IP-10. Selective inhibitors of Src-kinases and PI3-kinases significantly inhibited phosphorylation of p38 but did not influence phosphorylation of ERK1/2 MAP-kinases. Our results suggest that Src-kinases, PI3-kinases, and ERK1/2 MAP-kinases are involved in intracellular signal cascade activated during IP-10-stimulated migration of T-lymphocytes, whereas p38 MAP-kinases do not participate in the migration process, although its activation induced by IP-10 depends on Src-kinases and PI3-kinases.

Monocyte integrin expression and monocyte-platelet complex formation in humans with coronary restenosis

1. In the present study, we sought to determine whether patients with restenosis after coronary stenting possess increased monocyte reactivity, as manifested by a higher level of adhesion molecule expression and an enhanced propensity to form monocyte-platelet aggregates after activation in vitro. 2. Anti-coagulated peripheral venous blood from 24 patients, 10 with and 14 without angiographically verified restenosis, was obtained. Leucocyte antigen expression and the number of leucocyte-platelet complexes were measured by flow cytometry after activation in whole blood. 3. Surface integrin Mac-1 (CD11b/CD18) and VLA-4 (CD49d/ CD29) expression on monocytes and the relative number of monocyte-platelet complexes after in vitro activation were significantly elevated in patients with restenosis compared with patients without restenosis (fluorescence intensities of 1425 +/- 76 vs 1195 +/- 71, 87 +/- 7 vs 65 +/- 6 and 47 +/- 4 vs 29 +/- 3% for for Mac-1, VLA-4 and monocyte-platelet complexes, respectively; P < 0.05 for each parameter). 4. The results suggest that restenosis is associated with increased monocyte VLA-4 and Mac-1 integrin expression and monocyte-platelet complex formation, which can be revealed after activation in vitro.

Urokinase plasminogen activator system in humans with stable coronary artery disease

1. The present study compares plasma urokinase plasminogen activator (uPA) peptide levels, plasma plasminogen inhibitor (PAI-1) activity and urokinase receptors (uPAR) on peripheral blood monocytes of patients with stable coronary artery disease (SCAD) and healthy volunteers. 2. Urokinase plasminogen activator levels were analysed by ELISA and PAI-1 activity was determined by a plasmin generation method using the chromogenic substrate S2390. Relative uPAR numbers and the adhesion molecules CD11b/CD18 on peripheral blood monocytes were estimated using specific antibodies and flow cytometry. 3. Patients with SCAD were found to have higher plasma uPA peptide levels than age-matched healthy subjects (10.40 +/- 0.99 vs 8.25 +/- 0.53 pmol/L, respectively; P < 0.05). 4. Plasma PAI-1 activity was also higher in patients with SCAD than in healthy subjects (13.6 +/- 2.5 vs 5.2 +/- 1.0 IU/mL, respectively; P < 0.05). 5. Relative uPAR and CD11b/CD18 adhesion molecules were similar on peripheral blood monocytes of patients with SCAD and in healthy subjects. 6. The data indicate a pattern of expression/activity of uPA and PAI-1 in patients with SCAD suggestive of an impaired fibrinolytic ability.