Serial changes in plasma levels of soluble P-selectin in patients with acute myocardial infarction

Chronic Immune Platelet Activation Is Followed by Platelet Refractoriness and Impaired Contractility

Autoimmune diseases, including systemic lupus erythematosus (SLE), have a high risk of thrombotic and hemorrhagic complications associated with altered platelet functionality. We studied platelets from the blood of SLE patients and their reactivity. The surface expression of phosphatidylserine, P-selectin, and active integrin αIIbβ3 were measured using flow cytometry before and after platelet stimulation. Soluble P-selectin was measured in plasma. The kinetics of platelet-driven clot contraction was studied, as well as scanning and transmission electron microscopy of unstimulated platelets. Elevated levels of membrane-associated phosphatidylserine and platelet-attached and soluble P-selectin correlated directly with the titers of IgG, anti-dsDNA-antibodies, and circulating immune complexes. Morphologically, platelets in SLE lost their resting discoid shape, formed membrane protrusions and aggregates, and had a rough plasma membrane. The signs of platelet activation were associated paradoxically with reduced reactivity to a physiological stimulus and impaired contractility that revealed platelet exhaustion and refractoriness. Platelet activation has multiple pro-coagulant effects, and the inability to fully contract (retract) blood clots can be either a hemorrhagic or pro-thrombotic mechanism related to altered clot permeability, sensitivity of clots to fibrinolysis, obstructiveness, and embologenicity. Therefore, chronic immune platelet activation followed by secondary platelet dysfunction comprise an understudied pathogenic mechanism that supports hemostatic disorders in autoimmune diseases, such as SLE.

Thrombin Generation in Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention

BACKGROUND

The optimal antithrombotic treatment for patients with atrial fibrillation (AF) that undergo percutaneous coronary intervention (PCI) is controversial. Dual therapy (clopidogrel and a direct oral anticoagulant [DOAC]) is safer than triple therapy (warfarin, aspirin, and clopidogrel), while efficacy is unclear. We aimed to evaluate thrombin generation (TG) under dual and triple therapy.

METHODS

A noninterventional prospective trial in patients with AF undergoing PCI. Patients received 4 weeks of triple therapy with aspirin, clopidogrel, and a DOAC followed by aspirin withdrawal. TG was measured in platelet-rich plasma (PRP) and platelet-poor plasma (PPP) at 3 five to 21 points, day 1 after PCI (TIME 0), 4 weeks after PCI (TIME 1), and 2 weeks after aspirin withdrawal (TIME 2).

RESULTS

Twenty-three patients (18 men, median age 78 years, 83% with acute coronary syndrome) were included. Endogenous thrombin potential (ETP) in PPP was high at TIME 0 compared with TIME 1 (ETP 3,178 ± 248 nM vs. 2,378 ± 222 nM, p = 0.005). These results remained consistent when measured in PRP. No significant difference in ETP was found before (TIME 1) and after aspirin withdrawal (TIME 2) although few patients had high ETP levels after stopping aspirin.

CONCLUSIONS

TG potential is high immediately after PCI and decreases 4 weeks after PCI in patients receiving triple therapy. TG remains constant after aspirin withdrawal in most patients, suggesting that after 1 month the antithrombotic effect of dual therapy may be similar to triple therapy.

The P-selectin and PSGL-1 axis accelerates atherosclerosis via activation of dendritic cells by the TLR4 signaling pathway

P-selectin and dendritic cells (DCs) are associated with atherosclerosis. However, their interactions in this setting are undefined. Herein, we investigated the role of P-selectin and its receptor P-selectin glycoprotein ligand (PSGL)-1 on atherosclerosis via activation of DCs. In the current study, a total of 34 patients with ST elevation myocardial infarction (STEMI) and 34 healthy control subjects were enrolled. Serum concentration of P-selectin was higher and the myeloid DC/plasmacytoid DC (mDC/pDC) ratio was lower in STEMI patients than in normal individuals. Interestingly, in STEMI patients, P-selectin was decreased and the mDC/pDC ratio was increased at 5–7 days after successful percutaneous coronary intervention, as compared with values on admission. Serum P-selectin was inversely correlated with the mDC/pDC ratio. Moreover, ApoE^−/−P^−/− and ApoE^−/−PSGL-1^−/− mice developed small atherosclerotic plaques after feeding of a western diet for 12 weeks and DC infiltration was significantly reduced. P-selectin stimulation markedly induced phenotypic maturation, enhanced secretion of inflammatory cytokines, communication with T cells, and the adhesion and migration of DCs. In vivo, DC maturation was significantly attenuated in P-selectin and PSGL1 knockout mice under hypercholesterolemic and inflammatory conditions. These effects were associated with the activation of myeloid differentiation primary response 88 (MYD88)-dependent and MyD88-independent Toll-like receptor 4 (TLR4) signaling pathways. Taken together, binding of P-selectin to PSGL-1 on DCs contributes to atherosclerosis progression via DC activation via the TLR4 signaling pathway.

Melatonin: Protection against age-related cardiac pathology

Aging is a complex and progressive process that involves physiological and metabolic deterioration in every organ and system. Cardiovascular diseases are one of the most common causes of mortality and morbidity among elderly subjects worldwide. Most age-related cardiovascular disorders can be influenced by modifiable behaviours such as a healthy diet rich in fruit and vegetables, avoidance of smoking, increased physical activity and reduced stress. The role of diet in prevention of various disorders is a well-established factor, which has an even more important role in the geriatric population. Melatonin, an indoleamine with multiple actions including antioxidant properties, has been identified in a very large number of plant species, including edible plant products and medical herbs. Among products where melatonin has been identified include wine, olive oil, tomato, beer, and others. Interestingly, consumed melatonin in plant foods or melatonin supplementation may promote health benefits by virtue of its multiple properties and it may counteract pathological conditions also related to cardiovascular disorders, carcinogenesis, neurological diseases and aging. In the present review, we summarized melatonin effects against age-related cardiac alterations and abnormalities with a special focus on heart ischemia/reperfusion (IR) injury and myocardial infarction.

Influence of High Polyphenol Beverage on Stress-Induced Platelet Activation

OBJECTIVES

Platelets are playing a crucial role in acute cardiovascular events. We investigated if physical stress activates platelets and whether this activation can be inhibited by a polyphenol-enriched diet.

METHODS

Blood samples were taken from a total of 103 athletes three weeks before, one day before, immediately as well as 24 hours and 72 hours after a marathon run. Participants were randomized, double-blinded and divided into two groups. One group received a polyphenol-rich beverage the other the same beverage without polyphenols. Besides analysis of platelet counts and impedance-aggregometric-measurement of platelet activity, soluble P-selectin and Endothelin-A measurements were performed.

RESULTS

In the control group, runners showed a 2.2-fold increased platelet aggregation directly after completing a marathon and within the following three days when compared with baseline values (p<0.01). In accordance, significant increases in sP-selectin (57.52ng/ml vs. 94.86ng/ml;p<0.01) were detectable. In contrast, for the group consuming a beverage with increased polyphenol content (upper quartile of study beverage intake) we did not find any increase of platelet aggregation.

DISCUSSION

Physical stress causes a significant increase in platelet activity. Our results demonstrate that a diet enriched in polyphenols is capable of preventing platelet activation. These findings might indicate a diminished cardiovascular stress-reaction following pre-exposition to polyphenol-enriched diet.

Cardioprotective potential of annexin-A1 mimetics in myocardial infarction

Myocardial infarction (MI) and its resultant heart failure remains a major cause of death in the world. The current treatments for patients with MI are revascularization with thrombolytic agents or interventional procedures. These treatments have focused on restoring blood flow to the ischemic tissue to prevent tissue necrosis and preserve organ function. The restoration of blood flow after a period of ischemia, however, may elicit further myocardial damage, called reperfusion injury. Pharmacological interventions, such as antioxidant and Ca(2+) channel blockers, have shown premises in experimental settings; however, clinical studies have shown limited success. Thus, there is a need for the development of novel therapies to treat reperfusion injury. The therapeutic potential of glucocorticoid-regulated anti-inflammatory mediator annexin-A1 (ANX-A1) has recently been recognized in a range of systemic inflammatory disorders. ANX-A1 binds to and activates the family of formyl peptide receptors (G protein-coupled receptor family) to inhibit neutrophil activation, migration and infiltration. Until recently, studies on the cardioprotective actions of ANX-A1 and its peptide mimetics (Ac2-26, CGEN-855A) have largely focused on its anti-inflammatory effects as a mechanism of preserving myocardial viability following I-R injury. Our laboratory provided the first evidence of the direct protective action of ANX-A1 on myocardium, independent of inflammatory cells in vitro. We now review the potential for ANX-A1 based therapeutics to be seen as a "triple shield" therapy against myocardial I-R injury, limiting neutrophil infiltration and preserving both cardiomyocyte viability and contractile function. This novel therapy may thus represent a valuable clinical approach to improve outcome after MI.

Time course of soluble P-selectin and von Willebrand factor levels in trauma patients: a prospective observational study

Background

Coagulopathy often develops in patients with serious trauma and is correlated with the clinical outcome. The contribution of platelet activity and endothelial dysfunction to trauma-induced coagulopathy remain to be defined. The purpose of this study was to investigate the time courses of soluble P-selectin (sPsel, an index of platelet activation) and von Willebrand factor (VWF, an index of endothelial dysfunction) in trauma patients and elucidate their relationship to coagulation parameter levels, the presence of coagulopathy, and patient outcome.

Methods

This prospective observational study, which took place in a university hospital intensive care unit (ICU), included 82 severely injured trauma patients. The sPsel, VWF antigen, protein C, and factor VII levels were measured and routine coagulation tests were performed upon admission to ICU and daily within the first week. The 30-day mortality rate was also determined.

Results

Thirty-seven (45.1%) patients developed coagulopathy upon admission to the ICU, and the 30-day mortality rate was 20.7% (n = 17). Both the admission sPsel and VWF levels were lower in patients with coagulopathy than in those without (p < 0.05) and were significantly correlated with the protein C and factor VII levels, respectively (all p < 0.05). The VWF levels were lower during the first 3 days and higher on day 7 after admission in nonsurvivors than in survivors (all p < 0.05). No significant differences in sPsel levels were found between nonsurvivors and survivors on each day during the first week.

Conclusion

In severely injured trauma patients in the ICU, lower levels of sPsel and VWF on admission were associated with the presence of coagulopathy and might not predict a better outcome. An increase in the VWF level at the end of the first week after admission to ICU was associated with increased 30-day mortality.

Biomarkers of platelet activation in acute coronary syndromes

The most convincing evidence for the participation of platelets in arterial thrombosis in humans comes from studies of platelet activation in patients with acute coronary syndromes (ACS) and from trials of antiplatelet drugs. Both strongly support the concept that repeated episodes of platelet activation over the thrombogenic surface of a vulnerable plaque may contribute to the risk of death from coronary causes. However, the relation of in vivo platelet activation and adverse clinical events to results of platelet function tests remains largely unknown. A valuable marker of in vivo platelet activation should be specific, unaltered by pre-analytical artefacts and reproducibly measured by easily performed methods. This article describes current biomarkers of platelet activation in ACS, reviews their advantages and disadvantages, discusses their potential pitfalls, and demonstrates emerging data supporting the positive clinical implications of monitoring in vivo platelet activation in the setting of ACS.

Chinese herb and formulas for promoting blood circulation and removing blood stasis and antiplatelet therapies

Atherothrombosis, which directly threatens people's health and lives, is the main cause of morbidity and mortality all over the world. Platelets play a key role in the development of acute coronary syndromes (ACSs) and contribute to cardiovascular events. Oral antiplatelet drugs are a milestone in the therapy of cardiovascular atherothrombotic diseases. In recent years, many reports have shown the possibility that “resistance” to oral anti-platelet drugs and many adverse reactions, such as serious bleeding risk, which provides an impetus for developing new anti-platelet drugs possesses highly efficiency and fewer adverse effects. Study on the blood stasis syndrome and promoting blood circulation and removing blood stasis is the most active field of research of integration of traditional and western medicine in China. Blood-stasis syndrome and platelet activation have close relationship, many Chinese herb and formulas for promoting blood circulation and removing blood stasis possess definite anti-platelet effect. This paper covers the progress of anti-platelet mechanism of Chinese herb and formulas for promoting blood circulation and removing blood stasis and is to be deeply discussed in further research.

A case-control study on platelet reactivity in patients with coronary stent thrombosis

BACKGROUND

The pathophysiology of stent thrombosis (ST) has evolved from the identification of single causative factors to a complex multifactorial model.

OBJECTIVES

The aim of the present study was to investigate whether patients with a history of ST exhibit heightened platelet reactivity to clopidogrel and aspirin.

PATIENTS/METHODS

Pretreatment and on-treatment platelet reactivity to clopidogrel and aspirin, as well as dual antiplatelet therapy resistance, was determined in 84 patients with a history of definite ST (cases: 41 early ST; 43 late ST) and in 103 control patients with a previously implanted coronary stent but no ST after the index procedure. Platelet function was evaluated with optical aggregometry, the VerifyNow P2Y12 and aspirin assays, the PFA-100 Innovance P2Y* cartridge, the flow cytometric vasodilator-stimulated phosphoprotein assay and urine 11-dehydrothromboxane B(2) measurement before and after the administration of a 600-mg loading dose of clopidogrel and 100 mg of aspirin. The study was registered at ClinicalTrials.gov, number NCT01012544.

RESULTS

Patients with a history of early ST clearly demonstrated higher on-clopidogrel platelet reactivity than controls. Patients with both early and late ST exhibited heightened on-aspirin platelet reactivity status, and dual antiplatelet therapy resistance was more frequent.

CONCLUSIONS

Patients with a history of early ST exhibit a poor response to clopidogrel. Furthermore, both early and late ST are strongly and independently associated with heightened on-aspirin platelet reactivity, and dual antiplatelet therapy resistance is more frequent.

Periodontopathogens induce soluble P-selectin release by endothelial cells and platelets

INTRODUCTION

Soluble P-selectin plays a pivotal role in inflammation and the development of thrombotic and cardiovascular disease. Accordingly, elevated levels of soluble P-selectin are found in periodontitis and (other forms of) inflammatory diseases. However, the cellular source of soluble P-selectin in periodontitis and the effects of periodontopathogens on P-selectin release are unknown.

MATERIAL AND METHODS

Soluble P-selectin was determined in 26 patients with periodontitis and 19 controls. Furthermore, human endothelial cells and platelets were investigated for their ability to elicit soluble and surface P-selectin in response to periodontopathogens A. actinomycetemcomitans Y4 and P. gingivalis. Moreover surface E-selectin and ICAM-1 expression as well as NFκB translocation in response to these bacteria were determined on endothelial cells as well as the formation of platelet-leukocyte complexes.

RESULTS

Plasma levels of soluble P-selectin are significantly elevated in periodontitis and correlate with severity of disease and bacterial infection. Stimulation of endothelial cells with periodontopathogens results in rapid surface expression of P-selectin but does not induce NFκB translocation and subsequent de novo synthesis of P-selectin, E-selectin or ICAM-1. In platelets, bacterial stimulation leads to surface expression of P-selectin and fosters the formation of platelet-leukocyte aggregates within minutes. P-selectin is rapidly shed from the surface of platelets and endothelial cells and results in increased levels of soluble P-selectin.

CONCLUSIONS

Periodontopathogens are able to directly cause activation of endothelial cells and platelets within minutes. Given that transient periodontitis-associated bacteremia commonly occurs after tooth brushing or chewing, our data suggest that reduction of periodontopathogens might result in potential cardiovascular benefits.

Levels of soluble CD40 ligand and P-Selectin in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is linked to an increased risk of cardiovascular disease. We aimed to research whether the levels of soluble P-selectin (sP-selectin) and soluble CD40 ligand (sCD40L), markers of endothelial function, are altered in subjects with NAFLD having no confounding factors for atherosclerosis. sCD40L, sP-selectin, and high-sensitivity C-reactive protein (hsCRP) levels, and homeostasis model assessment of insulin resistance (HOMA-IR) indexes were measured in 50 NAFLD subjects and 30 healthy controls. sCD40L, sP-selectin, and hsCRP levels were not significantly different between two groups (P = 0.48, 0.51, and 0.34, respectively). Body mass index, waist circumference, and insulin levels and HOMA indexes were significantly higher in subjects with NAFLD (all P < 0.001). The present data show that sCD40L and sP-selectin may not contribute to the accelerated atherogenesis associated with this clinically relevant condition.

Association of circulating adhesion molecules with lung function. The CARDIA study

BACKGROUND

Systemic inflammation has been associated with reduced lung function. Adhesion molecules, such as intercellular adhesion molecule (ICAM)-1 and P-selectin, figure importantly in initiating the inflammatory response. We studied the association between ICAM-1 and P-selectin concentrations and lung function in the Coronary Artery Risk Development in Young Adults study.

METHODS

Spirometry testing was conducted at years 5, 10, and 20. ICAM-1 and P-selectin were assayed at year 15.

RESULTS

Complete data were obtained from 2,455 participants. We first predicted year-20 lung function from year-15 ICAM-1 concentration data. After controlling for race, gender, height, age, physical activity, smoking status, alcohol intake, BMI, and asthma status, all taken at year 15, the year-20 FVC was 164 mL higher (p < 0.0001) and FEV(1) was 164 mL higher (p = 0.0003) in the lowest ICAM-1 concentration quartile than the highest ICAM-1 quartile, whereas the FEV(1)/FVC ratio showed no association (p = 0.25). We then predicted the year-15 ICAM-1 concentration from year-5 lung function and change in lung function (year 10 - year 5). The year-15 ICAM-1 concentration was about 13 ng/mL higher in the lowest vs highest quartile of either the year-5 FVC (p = 0.01) or year-5 FEV(1) (p = 0.005). Year-15 ICAM-1 concentration was unrelated to year-5 FEV(1)/FVC ratio. Greater loss in FVC and FEV(1) (year 10 - year 5) also was associated with higher year-15 ICAM-1 concentrations. Associations between P-selectin and lung function followed a similar but weaker pattern to that observed for ICAM-1.

CONCLUSIONS

These data suggest a bidirectional association between circulating adhesion molecules, such as ICAM-1 and P-selectin, and pattern of lung function change in adults.

Increased levels of plasma thrombomodulin in patients with acute myocardial infarction who had thrombolytic therapy and achieved successful reperfusion

BACKGROUND

There is a growing body of evidence from animal and in vitro studies for the existence of reperfusion injury after thrombolytic therapy for acute myocardial infarction (AMI), but the patient data are limited.

HYPOTHESIS

We aimed to examine the plasma thrombomodulin (TM) levels as a marker of endothelial injury and to investigate the effect of successful reperfusion on these levels.

METHODS

The study included 32 patients who had a first episode of acute myocardial infarction (AMI) and received intravenous streptokinase therapy.

RESULTS

Thrombomodulin levels increased significantly at 60 min after thrombolysis compared with the levels before thrombolytic therapy (0 min) in 21 (66%) patients who had successful reperfusion (49.09 +/- 10.51 vs. 25.76 +/- 5.55 ng/ml, p < 0.001). There was no difference between the TM levels at 0 and at 60 min of thrombolysis in the remaining 11 (34%) patients who could not achieve reperfusion (27.81 +/- 6.32 vs. 28.72 +/- 7.28 ng/ml, p = 0.35).

CONCLUSION

There was a significant increase in TM levels at 60 min after thrombolysis in a group of patients with AMI who achieved successful reperfusion; this increase may have been caused by the activation/injury of endothelial cells. Data also suggest that the increment in TM levels may be predictive of the potential success of thrombolytic therapy.

P-selectin polymorphisms' influences on P-selectin serum concentrations and on their familial correlation: the STANISLAS family study

BACKGROUND

P-selectin is an adhesion molecule known to be involved in the pathogenesis of several diseases through its major role in the initial phase of leukocytes recruitment during inflammation. However, genetic characterization of soluble P-selectin remains unclear.

OBJECTIVES

In the STANISLAS cohort, we study the familial correlations of P-selectin levels and investigate the association of six P-selectin polymorphisms (C-2123G, A-1969G, S290N, N562D, V599L and T715P) and cardiovascular risk factors with P-selectin concentrations.

PATIENTS/METHODS

Full phenotypic and genotypic information was available for 136 healthy families composed of both natural parents and at least one child (boys, n = 125; and girls, n = 139) aged more than 4 years.

RESULTS

While no correlation was observed between spouses, family correlations of P-selectin concentrations were highly significant for sibling (0.50 +/- 0.12, P < 10(-3)) and child-parent pairs (0.42 +/- 0.04, P < 10(-3)). P-selectin haplotypes explained about 25% of the variability of P-selectin concentrations, this effect being mainly due to the additive effects of two polymorphisms, V599L and T715P. After adjusting for the effect of the P-selectin polymorphisms, the sibling and child-parent correlations decreased to (0.39 +/- 0.08, P < 10(-4)) and (0.32 +/- 0.06, P < 10(-4)), respectively.

CONCLUSIONS

In the present study, we showed that two P-selectin polymorphisms, V599L and T715P, explained about 25% of the variability of P-selectin concentrations and accounted for about 40% of their family resemblance. These results would suggest a genetic influence on P-selectin concentrations beyond the contribution of the P-selectin gene.

Reduced plaque formation induced by rosiglitazone in an STZ-diabetes mouse model of atherosclerosis is associated with downregulation of adhesion molecules

Adhesion molecules have been implicated in the development and progression of cardiovascular disease, which is highly prevalent in people with diabetes. Adhesion molecules can mediate adhesion of leukocytes to the endothelium. Furthermore, P-selectin expressed on platelets is able to mediate the adhesion of leukocytes to platelets. In this study, we examine the in-vivo and in-vitro effects of rosiglitazone with particular emphasis on three important adhesion molecules (VCAM-1, ICAM-1 and P-selectin). In the aorta of STZ-diabetic apolipoprotein E-deficient (apoE KO) mice, rosiglitazone significantly reduced both total and arch plaque area. The mechanism for this appeared to be reduced macrophage infiltration into the atherosclerotic plaque which was also associated with reduced mRNA levels for VCAM-1, ICAM-1, MCP-1 and P-selectin in the aorta. In-vitro studies revealed reduced cell adhesion of monocytic cells (THP-1) to fibrinogen and endothelial cells (HUVEC) after incubation with rosiglitazone. Furthermore, the reduction in leukocyte adhesion also correlated with significant reductions in mRNA levels for VCAM-1, ICAM-1 and P-selectin indicating that reduced macrophage infiltration in atherosclerotic plaques may occur as a result of a direct effect of rosiglitazone on adhesion molecules in both monocytes and endothelial cells. Thus, we have shown that rosiglitazone appears to have direct anti-atherosclerotic effects in an animal model of diabetes-associated atherosclerosis which are at least partly due to effects on VCAM-1, ICAM-1, MCP-1 and P-selectin expression which leads to decreased leukocyte adhesion and macrophage infiltration.

Light/dark patterns of soluble vascular cell adhesion molecule-1 in relation to melatonin in patients with ST-segment elevation myocardial infarction

Elevated levels of soluble cellular adhesion molecules have been reported in patients with acute coronary syndromes. Likewise, a relation between decreased nocturnal melatonin levels and coronary artery disease has been suggested. The aim of the present study was to investigate the day-night variations in the concentration of soluble vascular cell adhesion molecule-1 (sVCAM-1) in patients with ST-segment elevation myocardial infarction (STEMI) in relation to the light/dark melatonin pattern. Ninety consecutive patients with STEMI who were admitted to the Coronary Care Unit of our institution were studied. We also recruited 70 age- and gender-matched healthy normal subjects. Blood samples were drawn at 09:00 and 02:00 hr, while patients were at rest, for the assessment of sVCAM-1 and melatonin, which were measured using commercially available ELISA. In STEMI patients, melatonin concentrations maintained a diurnal variation, but the difference between nocturnal and diurnal levels was less than that in healthy subjects (P < 0.0001). In contrast to findings with melatonin, sVCAM-1 levels showed no diurnal variations in control subjects. In the STEMI group, however, sVCAM-1 concentration at 02:00 hr was significantly higher than that during the light phase (09:00 hr; 1391 +/- 38 versus 1200 +/- 43 ng/mL, P < 0.05). The results suggest that diurnal variations in endogenous sVCAM-1 production in STEMI patients might be related to an attenuated circadian secretion of melatonin.

Effects of nebivolol on platelet activation in hypertensive patients: A comparative study with metoprolol

OBJECTIVES

We evaluated the effects of nebivolol on platelet activation in hypertensive patients by measuring mean platelet volume (MPV) and plasma soluble P-selectin (sP-sel) levels and compared with those of the patients taking metoprolol.

MATERIALS AND METHODS

Eighty newly diagnosed hypertensive patients in grade 1 hypertension were enrolled in this prospective, blinded randomized study. Seventy two patients completed the study. After baseline assessment, each patient was randomly allocated to 5 mg daily dose of nebivolol (n=37, 20 male) or 100 mg daily dose of metoprolol (n=35, 18 male) and treated for 6 months. Blood pressure, heart rate, lipid profile, plasma glucose, sP-selectin levels, platelet counts and MPV were measured before and after treatment.

RESULTS

At the end of 6 months, nebivolol significantly decreased MPV and plasma sP-selectin levels (7.59+/-0.78 fl vs. 7.42+/-0.74 fl, p<0.001; 1.29+/-0.46 ng/ml vs. 1.21+/-0.36 ng/ml, p=0.002, respectively) compared to those of pretreatment. Although pretreatment sP-selectin levels of the two groups were similar, posttreatment plasma sP-selectin levels were significantly reduced with nebivolol compared with those of metoprolol group (1.21+/-0.36 ng/ml vs. 1.46+/-0.30 ng/ml, p=0.008). In contrast, metoprolol treatment did not cause any significant change in platelet activation parameters after treatment.

CONCLUSION

Beneficial effects of nebivolol on platelet activation were more potent than those of metoprolol. We consider that decreased platelet activation with nebivolol might play a role to reduce thrombotic risk in hypertensive patients.

Relationship between soluble P-selectin and inflammatory factors (interleukin-6 and C-reactive protein) in colorectal cancer

BACKGROUND

Platelets are an important element in the thrombotic process, inflammation and cancer progression. We tested the hypothesis that there is a relationship between platelet activation and inflammation in colorectal cancer patients (CRC).

PATIENTS/METHODS

We measured soluble (s) P-selectin (marker of platelet activation), interleukin-6 (IL-6) and C-reactive protein (CRP) (indexes of inflammation) in 42 CRC patients and 38 healthy subjects. CRC patients were divided into two groups: A-24 patients in stages I and II; B-18 patients in stage III. Soluble P-selectin, Interleukin-6 concentration was measured using commercially available immunoenzymatic methods. High sensitivity C-reactive protein (RCRP) concentration was measured by a high sensitivity latex particle turbidimetric immunoassay.

RESULTS

Soluble P-selectin, CRP and IL-6 levels were significantly increased as compared to the control group (p<0.001). Plasma levels of sP-selectin, CRP and IL-6 were higher in group B (with metastases) than in group A (without metastases) (p<0.001). CRC patients had a positive correlation between IL-6 and CRP (r=0.7638, p<0.01) and between sP-selectin and IL-6 (r=0.5633, p<0.03).

CONCLUSION

We observed hyperactivation of blood platelets and inflammatory response in patients with colorectal cancer, also the inflammatory process and platelet activation progress along with colorectal cancer advancement. Our results seem to confirm the relationship of platelet activation with inflammatory response in colorectal cancer patients.

Elevation of rat plasma P-selectin in acute lung injury

Acute lung injury in the rat caused by intravenous (i.v.) infusion of cobra venom factor (CVF) or lipopolysaccharide (LPS) is mediated by P-selectin-dependent neutrophil infiltration into the lung. In these lung injury models, P-selectin expression is induced on lung vascular endothelial cells after the CVF or LPS infusion, suggesting soluble P-selectin derived from inflamed sites might also be elevated. Here we established a sensitive enzyme-linked immunosorbent assay (ELISA) to measure soluble P-selectin in plasma, a potential marker of lung injury. Nine anti-rat P-selectin monoclonal antibodies that we established previously were first classified into 5 groups based on real-time biospecific interaction analyses, and used to develop a sandwich ELISA for accurately measuring the amount of soluble P-selectin in plasma. We then used this ELISA to measure the plasma P-selectin levels in Long Evans, Wistar, and Sprague-Dawley rats after the i.v. infusion of CVF or LPS. The elevation in P-selectin levels was significantly different among the strains, but it consistently correlated with the extent of lung inflammation, measured by myeloperoxidase levels in the lung tissues. Thus, our results indicate that the soluble P-selectin in plasma could serve as a sensitive biomarker reflecting lung inflammation, which is of clinical importance for detecting and preventing severe lung injury.

The plasma levels of soluble P-selectin in subjects with prediabetes

Prediabetes has been associated with an increased risk of cardiovascular disease and mortality. Soluble P-selectin (sP-selectin) is an index of platelet activation and also a risk factor for future vascular events. sP-selectin levels were investigated in prediabetic subjects who had no confounding factors such as hypertension, obesity or dyslipidaemia. sP-selectin, hsCRP levels and HOMA-IR indexes were measured in 40 prediabetic subjects (n = 24 for IFG and n = 16 for IGT) and age-, sex- and BMI-matched 40 healthy controls. sP-selectin levels in prediabetic subjects were not significantly different compared with those in controls (p = 0.12). Prediabetic group had similar hsCRP (p = 0.29), higher HOMA-IR indexes (p < 0.001) and lower HDL cholesterol levels (p = 0.001) when compared with healthy controls. The power of the study was 0.93 for sP-selectin, 0.7 for hsCRP and 1.0 for HOMA. Our data suggest that sP-selectin may not contribute to the prothrombotic state as well as the accelerated atherogenesis associated with prediabetes.

Strong correlation between serum levels of inflammatory mediators and their distribution in infarct-related coronary artery

BACKGROUND

Little is known regarding the correlation between circulating levels of inflammatory mediators and their distribution within the infarct-related coronary artery (ICA).

METHODS AND RESULTS

Atherothrombotic tissue and blood were aspirated by export suction catheter from the ICA in 49 patients with an acute myocardial infarction (AMI) < 6 h duration who underwent primary percutaneous coronary intervention (PCI). Blood samples were collected before PCI for levels of high-sensitivity (hs) C-reactive protein (CRP), soluble P-selectin (sP-selectin) and white blood cell (WBC) counts. Immunohistochemical staining was performed for localization of CRP within the ICA. Staining intensity was graded for macrophage and extracellular tissue (0: no staining; 1+: < 30%, 2+: 30% to 60%, and 3+: > 60%). The hs-CRP levels were markedly higher in grade 3+ compared with both grade 2+ and grade 1+ of macrophage and extracellular staining of CRP (all p values < 0.0001), and in grade 2+ compared with grade 1+ (p < 0.001). Additionally, the ICA had a significantly higher sP-selectin level and WBC count compared with the systemic circulation (p < 0.0001). Furthermore, the ICA level of sP-selectin was noticeably higher in patients with a total atherothrombus volume > or = 0.5 cm3 than in patients with total volume < 0.5 cm3 (p < 0.0001). Moreover, correlation analysis demonstrated that the increase in the ICA level of sP-selectin was significantly related to the increase in the WBC count in the artery (r = 0.548, p < 0.0001). Multiple analysis identified an increased circulating level of hs-CRP as the only independent predictor of > or = 2+ in macrophage (p < 0.0001) and > or = 2+ in extracellular (p < 0.0001) staining of CRP.

CONCLUSIONS

Following AMI, the sP-selectin level and WBC count were markedly higher in the ICA than in the circulation. Moreover, the circulating level of hs-CRP was strongly associated with ICA localization of CRP.

Association of educational level with inflammatory markers in the Framingham Offspring Study

Socioeconomic position consistently predicts coronary heart disease; however, the biologic mechanisms that may mediate this association are not well understood. The objective of this study was to determine whether socioeconomic position (measured as educational level) is associated with inflammatory risk factors for coronary heart disease, including C-reactive protein, interleukin-6, soluble intercellular adhesion molecule-1, monocyte chemoattractant protein-1, and P-selectin. The study sample included 2,729 participants (53.4% women; mean age, 62 +/- 10 years) from the US Framingham Offspring Study cohort who attended examination cycles 3 (1984-1987) and 7 (1998-2001) and provided educational attainment data. Inflammatory markers were measured in fasting serum samples. Multivariable linear regression analyses were performed, adjusting for potential confounders including age, sex, and clinical risk factors. In age- and sex-adjusted analyses, educational attainment was significantly inversely associated with C-reactive protein (p < 0.0001), interleukin-6 (p < 0.0001), soluble intercellular adhesion molecule-1 (p < 0.0001), and monocyte chemoattractant protein-1 (p = 0.0004). After further adjustment for clinical risk factors, educational level remained significantly associated with C-reactive protein (p = 0.0002), soluble intercellular adhesion molecule-1 (p = 0.01), and monocyte chemoattractant protein-1 (p = 0.01). In conclusion, educational attainment is associated with inflammatory risk factors for coronary heart disease. The association provides evidence suggestive of a biologic pathway by which socioeconomic position may predispose to coronary heart disease.

Serum levels of soluble P-selectin are increased and associated with disease activity in patients with Behçet's syndrome

Behçet's syndrome (BS) is a relapsing, chronic, inflammatory disease characterized by endothelial dysfunction, atherothromboembogenesis, and leukocytoclastic vasculitis with complex immunologic molecular interactions. Generalized derangements of the lymphocyte and neutrophil populations, activated monocytes, and increased PMNLs motility with upregulated cell surface molecules such as ICAM-1, VCAM-1, and E-selectin, which are found on the endothelial cells, leukocytes, and platelets, have all been demonstrated during the course of BS. Our aim is to investigate the association of serum concentrations of soluble P-selectin in patients with BS, and to evaluate whether disease activity has an effect on their blood levels. This multicenter study included 31 patients with BS (15 men and 16 women) and 20 age- and sex-matched healthy control volunteers (11 men and nine women). Neutrophil count, erythrocyte sedimentation rate, and acute-phase reactants as well as soluble P-selectin levels were determined. The mean age and sex distributions were similar (P > .05) between BS patients (35 years) and control volunteers (36 years). Serum levels of soluble P-selectin in patients with BS (399 +/- 72 ng/mL) were significantly (P < .001) higher when compared with control subjects (164 +/- 40 ng/mL). In addition, active BS patients (453 +/- 37 ng/mL) had significantly (P < .001) elevated levels of soluble P-selectin than those in inactive period (341 +/- 52 ng/mL). This study clearly demonstrated that serum soluble P-selectin levels are increased in BS patients when compared with control subjects, suggesting a modulator role for soluble P-selectin during the course of platelet activation and therefore, atherothrombogenesis formation in BS, especially in active disease.

Systemic inflammatory markers in acute coronary syndrome: association with cardiovascular risk factors and effect of early lipid lowering

BACKGROUND

Evidence for statin therapy in prevention of coronary artery disease is overwhelming. In spite of theoretical benefits, any additional advantage of its early introduction in the management of acute coronary syndrome is, however, uncertain. We therefore investigated differences between plasma levels of the systemic inflammatory markers intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, C-reactive protein and interleukin-6 in patients presenting with unstable angina or acute myocardial infarction, and assessed whether the 30-day levels of these markers are influenced by early instigation of the HMG-CoA reductase inhibitor pravastatin.

MATERIALS AND METHODS

170 (134 male) patients presenting with acute coronary syndrome, but without previous statin therapy, participated. Blood was taken within 24 h of onset of ischaemic pain and again at 30 days. In all, 87 (71 male) participants were treated with pravastatin (20-40 mg daily) and 83 (63 male) with a matched placebo.

RESULTS

At presentation, interleukin-6 was higher in males than in females (P=0.008) and lower in those with a pre-existing history of myocardial infarction (P=0.038). C-reactive protein and interleukin-6 were greater in myocardial infarction, but this difference was lost at 30 days. Thirty-day changes in all parameters were inversely related to level at presentation but not to treatment with pravastatin. Hypertension (P=0.011) and smoking (P=0.042) were associated with elevation of C-reactive protein with no difference between unstable angina or acute myocardial infarction. The effect of these individual factors was cumulative.

CONCLUSIONS

Interleukin-6 was greater in acute myocardial infarction than in unstable angina; E-selectin was positively associated with a previous myocardial infarction and inversely related to age. We found no effect of early introduction of pravastatin on systemic inflammatory markers 30 days after acute coronary syndrome.

SOLUBLE BIO-MARKERS IN VASCULAR DISEASE: MUCH MORE THAN GAUGES OF DISEASE?

1. In recent years demonstration of a direct association between slightly elevated serum levels of soluble proteins including the acute phase response proteins, selectins and intercellular adhesion molecules and the risk of developing vascular disease have been widely reported. These studies may provide the clinician with an insight into disease diagnosis, prognosis and disease activity. 2. The simplest interpretation of this data is that soluble proteins are just sensitive markers of inflammation. However, they may in fact be modulating inflammation directly through interaction with circulating cells. 3. Recent work has shown that these soluble proteins do indeed remain active and can bind to functional ligands expressed by circulating leucocytes. The current review focuses on the soluble proteins C-reactive protein and soluble P-selectin and describes previous studies characterizing their interaction with immune cells to modulate the pathogenesis of vascular disease. 4. The current review focuses on the soluble proteins C-reactive protein and soluble P-selectin and describes previous studies characterizing their interaction with immune cells to modulate the pathogenesis of vascular disease.

Levels of soluble adhesion molecules in various clinical presentations of coronary atherosclerosis

Adhesion molecules play an important role in the development and course of coronary atherosclerosis. In this study, soluble forms of vascular cell adhesion molecule (VCAM-1) intercellular adhesion molecule-1 (ICAM-1), E-selectin and P-selectin were evaluated in patients with various clinical presentations of coronary atherosclerosis and compared them to those with angiographically documented normal coronary arteries. Venous plasma samples were collected from 43 patients with acute myocardial infarction (AMI), 45 with unstable angina pectoris (UAP), 34 with stable angina pectoris (SAP) and 29 subjects with normal coronary arteries (control). The VCAM-1 level was significantly higher in patients with AMI (mean +/- SEM; 799.8 +/- 26.3 ng/ml) than those with UAP (644.2 +/- 26.7 ng/ml) and SAP (526 +/- 32.5 ng/ml) and controls (270 +/- 26.8 ng/ml). In patients with UAP, VCAM-1 was found to be significantly elevated as compared to the SAP group and controls. VCAM-1 level was also higher in SAP group than the controls. Serum levels ICAM-1 were similar among patients with AMI (424.1 +/- 15.2 ng/ml), UAP (403 +/- 12.3 ng/ml) and SAP (381.2 +/- 16.2 ng/ml); however, levels of ICAM-1 was significantly elevated in these groups as compared to the controls (244.3 +/- 11). The mean level of E-selectin was not different in AMI and UAP groups (47.2 +/- 2.2 vs. 42.6 +/- 2.1 ng/ml; respectively). However, it was significantly higher in acute coronary syndrome groups as compared to SAP (33.4 +/- 2.3 ng/ml) and control subjects (30.7 +/- 1.9 ng/ml). Serum levels of E-selectin were similar in SAP group and controls. For P-selectin, no significant difference was observed between AMI and UAP groups (187.5 +/- 7.2 vs. 181.7 +/- 4.7 ng/ml; respectively), however, it was significantly higher in both groups as compared to SAP group (146.1 +/- 7.4 ng/ml) and controls (108 +/- 6.6 ng/ml). Serum level of P-selectin was significantly higher in patients with SAP than the control group. In conclusion, determination of serum VCAM-1, E-selectin and P-selectin levels seems more useful for detecting coronary plaque destabilization.

P-selectin in haemostasis

During the past decade, interrelationships between inflammation and thrombosis have been the subject of extensive works, and it is now commonly recognized that inflammation (notably leucocyte recruitment) directly affects thrombosis, and that thrombosis also constitutes a pro-inflammatory event. This tight link is partly attributable to P-selectin, which is functional not only when expressed on the surface of activated platelets and endothelial cells, but also when shed, generating its soluble form, termed sP-selectin. In this review, we will provide an overview of the relative roles of the different compartments of P-selectin (platelet, endothelial cell, plasma) in haemostasis and vascular pathologies, and the potential therapeutic benefits achievable in targeting this molecule.

Blockade of cell adhesion by a small molecule selectin antagonist attenuates myocardial ischemia/reperfusion injury

Reperfusion injury is related closely to inflammatory reactions such as the activation and accumulation of neutrophils. We investigated the efficacy of a novel small molecule selectin antagonist (bimosiamose) in a rat model of transient left coronary artery occlusion (30 min) and reperfusion (24 h). Treatment with bimosiamose (25 mg/kg, intravenously at reperfusion) showed a significant reduction in infarction area/area at risk of approximately 41% compared to vehicle control (P=0.01) and preserved the left ventricular function. The accumulation of polymorphonuclear neutrophils at the site of area at risk was decreased significantly, accompanied by 78% reduction of the myeloperoxidase activity. Parallel-plate flow chamber analysis revealed that bimosiamose showed a significant inhibition in rolling (62%, P<0.001) and adhesion (38%, P<0.05) of HL-60 cells to activated human umbilical vein endothelial cells compared with vehicle control. This study demonstrates for the first time that bimosiamose, a novel small molecule selectin antagonist, attenuates significantly ischemia/reperfusion injury.

HIV infection, HAART, and endothelial adhesion molecules: current perspectives

In this review we summarise the data on the effects of HIV infection and its therapy with antiretroviral drugs on adhesion molecules, considered to be potential biomarkers of endothelial cell function. This is a recent area of interest, given the unexpected associations between antiretroviral therapy, metabolic alterations of lipid profile, and the risk of cardiovascular disease in the absence of clear pathogenetic links. Although convincing prospective data are still scarce, it seems timely to elucidate the potential value of non-invasive, inexpensive tests for predicting cardiovascular risk in HIV-infected patients undergoing highly active antiretroviral therapy (HAART). Endothelial function, the most plausible link between infection, inflammation, and atherosclerosis, has been investigated since the beginning of the HIV epidemic. Increased concentrations of soluble adhesion molecules, such as those from the selectin and immunoglobulin families, have consistently been reported in HIV-positive patients. The introduction of HAART has renewed interest in the study of endothelial function in HIV-positive patients, in view of some HAART-related metabolic abnormalities (hyperlipidaemia, hyperglycaemia, fat redistribution) and several large reports of premature coronary artery disease. Whether HAART reduces endothelial injury associated with HIV infection or contributes to further endothelial cell activation is still a matter of controversy. Also unclear is whether HAART acts directly or indirectly, and if protease inhibitors and other classes of antiretroviral drugs differ in their proatherosclerotic effects. This article attempts to define the state of these emerging issues, identifies areas of controversy and of potential clinical relevance, and suggests some directions for future research.

Cellular adhesion molecules and cardiovascular disease. Part II. Their association with conventional and emerging risk factors, acute coronary events and cardiovascular risk prediction

The role of cellular adhesion molecules in the patho-genesis of atherosclerosis has now been clearly demonstrated. Plasma levels of adhesion molecules, which have been shed from the cell surface, have also been associated with the presence of clinical atherosclerotic disease, cardiovascular risk factors and acute coronary syndromes. However, there is little consensus in the literature, including between the large well-designed population studies. This may be explained either by unrecognized confounding factors or, alternatively, by the unpredictable relationship between cell surface expression and activity of cellular adhesion molecules and their shedding into the plasma under different circumstances. Probably for the latter reasons, there is at present little evidence that the measurement of circulating adhesion molecules is likely to offer any additional benefit for individual patients above the assessment of conventional cardiovascular risk factors in the assessment of either the extent of, or future risk from, cardiovascular disease.

Elevated Concentration of Soluble Vascular Endothelial Cadherin Is Associated With Coronary Atherosclerosis

BACKGROUND

Vascular endothelial (VE)-cadherin, a Ca(2+)-dependent cell adhesion molecule, is expressed in atherosclerotic lesions by endothelial cells and is associated with neovascularization, although the relationship between circulating VE-cadherin and coronary artery disease has not been studied.

METHODS AND RESULTS

The plasma concentration of VE-cadherin was measured in peripheral blood (femoral artery) and the coronary sinus of 24 patients with acute myocardial infarction (AMI), 26 with stable angina pectoris (AP), 18 with old myocardial infarction (OMI), and 30 control subjects (Control) who had no coronary artery stenosis on angiography. For the patients with AMI, blood samples were obtained in the acute (day 1) and chronic (day 21) phases. The plasma concentration of VE-cadherin was measured by enzyme-linked immunosorbent assay. The correlation between the plasma VE-cadherin concentration and the Gensini score was also determined as an index of the severity of coronary atherosclerosis. The plasma concentrations of VE-cadherin (ng/ml) in both the peripheral and coronary sinus blood were higher in patients with AMI, AP, and OMI than in the control subjects, and were similar in the 3 groups with coronary artery disease (femoral artery: AMI 5.1+/-2.5, AP 4.7+/-2.4, OMI 4.5+/-3.3, Control 2.6+/-2.3; coronary sinus: AMI 5.6+/-2.6, AP 5.0+/-2.3, OMI 5.0+/-2.9, Control 2.4+/-2.1, respectively). Plasma VE-cadherin concentrations were higher in the coronary sinus than peripheral blood samples in patients with AMI (p<0.01), AP (p<0.01), and OMI (p<0.05). The plasma VE-cadherin concentration was the same in the acute and chronic phases in patients with AMI. In the 3 groups of patients with coronary disease, both the peripheral plasma VE-cadherin concentration and the coronary sinus concentration correlated with the Gensini score (r=0.32, p<0.01 and r=0.42, p<0.001, respectively). Multiple regression analysis revealed that the plasma VE-cadherin concentration predicted the Gensini score independently of sex, age, hypertension, diabetes mellitus, smoking, and the lipid profiles.

CONCLUSION

Increased secretion of VE-cadherin from the epicardial arteries is associated with the degree of coronary atherosclerosis, indicating the presence of atherosclerosis rather than disease activity.

Increased soluble platelet/endothelial cell adhesion molecule-1 in the early stages of acute coronary syndromes

Specific molecules including inflammatory cell adhesion molecules mediate attachment of blood leukocyte and platelets to the endothelium and mononuclear cell migration into the arterial intima. However, the clinical significance of soluble cell adhesion molecules very early in the course of acute coronary syndrome is not known. We assayed platelet/endothelial cell adhesion molecule-1 (PECAM-1, CD31), intercellular adhesion molecule-1 (ICAM-1, CD54), and P-selectin (CD62P) in plasma obtained from 20 patients within 3 h after the onset of acute myocardial infarction (AMI); 16 patients with unstable angina pectoris; 20 patients with stable angina pectoris, and 28 controls. Blood samples were obtained on hospital admission and again 1 week after onset of AMI and unstable angina, and on admission in patients with stable angina and controls. Plasma PECAM-1 concentration (ng/ml) on admission was higher in patients with AMI (25.6+/-4.7) and unstable angina (24.7+/-4.4) than in stable angina (20.5+/-4.4) and control (18.8+/-3.8) groups. In both AMI and unstable angina, plasma PECAM-1 had decreased significantly by 1 week (AMI, 20.8+/-4.0; unstable angina, 21.0+/-4.1). Plasma ICAM-1 concentration (ng/ml) on admission was higher in patients with AMI (254+/-70), unstable angina (264+/-78), and stable angina (245+/-68) than in controls (201+/-56), but did not differ between the three coronary syndromes. Plasma P-selectin concentration did not differ between the four groups, including controls. Therefore, soluble PECAM-1 concentration may be a sensitive markers providing early diagnostic aid in acute coronary syndromes.

Novel predictors of acute coronary syndrome outcomes

Morbidity and mortality rates among patients with acute coronary syndrome (ACS) remain high, and it is difficult to determine which patients will progress satisfactorily and which patients will have poor outcomes. Research has indicated that the inflammatory process is involved in coronary disease. There is great interest within the research community in determining if inflammatory markers could be used to determine the severity of the disease process and therefore serve as a prognostic tool for clinicians. This article describes the inflammatory process in ACS and provides a review of the current diagnostic studies of endothelial inflammatory markers (EIMs) in heart disease. Although research results of EIMs have not all been significant in determining outcomes, there is some evidence that they may be more specific than other generalized inflammatory markers, such as C-reactive protein. Future research of EIMs in patients with ACS might provide evidence of easy-to-measure and economically feasible markers that are sound prognosticators.

Time course of plasma adhesion molecules in acute coronary syndromes

BACKGROUND

Atherosclerosis is an inflammatory process in which adhesion molecules play an intimate role in both the initiation and progression of lesions. It is postulated that they also play a role in the presentation of acute coronary syndromes and that plasma levels thereafter may be of potential prognostic significance. The stability of sample levels under different laboratory conditions is unknown.

METHODS

Stability of plasma levels was assessed in six healthy subjects under four different laboratory conditions. The time course of levels was studied in 57 patients with acute chest pain, 21 of non-cardiac aetiology, 23 unstable angina and 13 acute myocardial infarction, at mean times of 2.3, 8.2 and 17.3 h after the onset of pain. Samples were assayed for intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin, E-selectin and C-reactive protein (CRP).

RESULTS

ICAM-1, VCAM-1, P-selectin and E-selectin levels did not differ under different laboratory conditions. Levels were similar at presentation in patients with acute chest pain of non-cardiac aetiology, unstable angina or acute myocardial infarction (median levels ICAM-1 269 microg/l, VCAM-1 379 microg/l, P-selectin 167 microg/l and E-selectin 53 microg/l). Levels did not change in the 24 h following the onset of pain. CRP levels did not differ at presentation between groups (median level 2.1 mg/l), but rose more than 12 h after the onset of pain in the group with acute myocardial infarction (P < 0.05).

CONCLUSION

Adhesion molecule levels are stable under normal laboratory sample handling conditions. Levels do not change in the 24 h following the onset of chest pain of non-cardiac or acute ischaemic aetiology.

Role of inflammatory mediators in thrombogenesis

The role of inflammation in cardiovascular disease and especially in thrombogenesis has become increasingly recognized as an important component of the overall disease process. Plaque rupture promotes activation of the inflammatory response and increased expression of tissue factor (TF), which in turn acts as one of the major initiators of extrinsic coagulation. It is becoming apparent that the expression of TF on endothelial cells, underlying smooth muscle cells and monocytes is regulated, in part, by proinflammatory cytokines including tumor necrosis factor and IL-1. In addition to initiating coagulation, interaction of TF with the adhesion molecule, P-selectin, has been demonstrated to accelerate the rate and extent of fibrin formation and deposition. P-selectin is expressed on activated platelets and endothelium and serves as the receptor for the endogenous ligand, P-selectin glycoprotein-1 (PSGL-1), expressed on various leukocytic cell types. In addition to mediating transient interactions between endothelial cells and leukocytes, P-selectin has been reported to mediate adherence of platelets to monocytes and neutrophils via specific interaction with PSGL-1. P-selectin is rapidly cleaved off the surface of the platelet membrane and appears in the circulation as a soluble form, which has been reported to be elevated in patients with acute coronary syndromes including unstable angina and non-Q-wave myocardial infarction. This review will focus on the role of cytokines in mediating TF expression and also explore the significance of the relationship between P-selectin and tissue factor in thrombus generation. In addition, possible pharmacological mechanisms to interrupt this disease process will be discussed.

Association between P-selectin gene polymorphisms and soluble P-selectin levels and their relation to coronary artery disease

P-selectin is a cellular adhesion molecule that mediates the interaction of activated endothelial cells or platelets with leukocytes. Increased levels of soluble P-selectin have been reported in various cardiovascular disorders. We measured serum soluble P-selectin levels as well as 3 polymorphisms of the P-selectin gene (C-2123G, A-1969G, and Thr715Pro) in a large cohort of patients with documented coronary artery disease (n=869) and a healthy control group (n=334). The 3 P-selectin polymorphisms were strongly associated with P-selectin levels and altogether explained 7.3% and 18.6% of the P-selectin variability in patients and controls, respectively. Genotype distributions did not significantly differ between patients and controls. P-selectin levels were increased in patients younger than 55 years of age compared with controls (135.2 vs 114.3 ng/mL, P<0.01). On the contrary, patients older than 65 years of age had significantly lower P-selectin levels than did controls (121.5 vs 134.7 ng/mL, P<0.02). In intermediate age groups, P-selectin levels did not significantly differ between the 2 groups. In conclusion, this study revealed a strong association between P-selectin gene polymorphisms and serum P-selectin levels and a complex age-dependent relation between soluble P-selectin levels and coronary artery disease, which suggests that this molecule might have different roles in the atherothrombotic process.

Pathologic markers of allograft arteriopathy: insight into the pathophysiology of cardiac allograft chronic rejection

Transplant-associated coronary artery disease (CAD) is the principal limiting factor for the long-term survival of heart transplant patients. This review discusses early risk factors for the subsequent development of transplant-associated CAD. Early risk factors associated with a prothrombogenic microvasculature, such as deposition of microvascular fibrin, depletion of vascular tissue plasminogen activator, presence of endothelial activation of the allograft arterial tree, and loss of vascular antithrombin, as well as changes in circulation (ie, detectable serum cardiac troponin I and elevated serum soluble intercellular adhesion molecule-1 levels) are presented and discussed. New therapies that could improve the status of the allograft microvasculature and may prevent or mitigate the development of transplant-associated CAD are considered.

Soluble P-selectin and the risk of future cardiovascular events

BACKGROUND

P-selectin, a cell-surface adhesion molecule involved in leukocyte rolling and attachment, has been hypothesized to play a role in the initiation of atherosclerosis. However, little clinical data are available evaluating the role of soluble P-selectin in determining vascular risk.

METHODS AND RESULTS

In a large-scale prospective study of apparently healthy women, we measured baseline plasma concentration of soluble P-selectin among 115 participants who subsequently developed cardiovascular events and among 230 age- and smoking-matched participants who remained free of disease during 3.5 years of follow-up. Overall, mean levels of soluble P-selectin were significantly higher at baseline among women who subsequently experienced cardiovascular events compared with those who did not (83.2 versus 69.3 ng/mL; P:=0.003). The risk of future cardiovascular events increased with increasing quartiles of soluble P-selectin (P:=0.02), such that women in the highest quartile at study entry had an age- and smoking-matched relative risk 2.2 times higher than those in the lowest quartile (95% confidence interval, 1.2 to 4.2; P:=0.01). This effect was independent of traditional risk factors. For each quartile increase in soluble P-selectin, the risk of future cardiovascular events increased 28% (P:=0.03) after additional adjustment for obesity, hypertension, hyperlipidemia, diabetes, and exercise frequency. The highest risks were observed among women with the very highest levels of P-selectin (>137.3 ng/mL, the 95th percentile cut point of the control distribution).

CONCLUSIONS

Soluble P-selectin levels are elevated among apparently healthy women at risk for future vascular events.

Effect of coronary thrombolysis on the plasma concentration of osteonectin (SPARC, BM40) in patients with acute myocardial infarction

Osteonectin is a phosphoglycoprotein exclusively located in bone and platelet alpha-granules. Human platelet-derived osteonectin is released into plasma after thrombin-induced activation. Recognizing the unique distribution of the osteonectin pool, we first sought to investigate whether osteonectin could serve as a sensitive marker of platelet activity, and identify patients with acute myocardial infarction (AMI). The second objective was to define the effects of thrombolytic therapy in these patients on the plasma concentrations of osteonectin at prespecified time points following attempted reperfusion. Osteonectin levels by ELISA were determined in AMI patients before thrombolysis and at 3, 6, 12, and 24 hours thereafter and compared with 12 healthy controls. At baseline, soluble osteonectin plasma levels were similar between controls (447. 7+/-20.6 ng/ml) and AMI patients (425.7+/-43.3 ng/mL; p=NS). A significant increase of the soluble osteonectin was observed at 3 hours after thrombolysis (519.4+/-26.9 ng/mL; p=0.03), and was followed by a decrease to baseline levels at 6 hours after attempted reperfusion. Contrary to expectations, the plasma osteonectin level in our pilot study was not a sensitive marker distinguishing patients with AMI. The early peak of soluble osteonectin at 3 hours after thrombolytic therapy is most likely not related to coronary thrombolysis per se but rather to the phasic changes of platelet activity during myocardial ischemia-reperfusion. The unquestionable platelet origin of this protein and the lack of elevated plasma levels of this alpha-granule constituent, challenge the postulate of uniform platelet activation in AMI patients.

Reperfusion injury after focal myocardial ischaemia: polymorphonuclear leukocyte activation and its clinical implications

The only way to rescue ischaemic tissue is to re-instate the oxygen supply to the tissue. However reperfusion of the ischaemic area not only oxygenates the tissue but also initiates a cascade of processes, which may in some cases result in temporary dysfunction of the myocardium. In order to devise protective measures, it is essential to understand the mechanisms and the triggers of this reperfusion phenomenon. In this review we will mainly focus on the inflammatory response caused by reperfusion. We will cover the different steps of polymorphonuclear leukocyte activation and will briefly discuss the molecular biology of the receptors involved. The currently used pharmacological medications in acute cardiology will be reviewed and in particular their actions on polymorphonuclear leukocyte activation, adhesion and degranulation. This review is a compilation of the current knowledge in the field and the therapeutic progress in the prevention of reperfusion injury made today.

Microvascular dysfunction in acute myocardial infarction: focus on the roles of platelet and inflammatory mediators in the no-reflow phenomenon

Recent interest has shifted from infarct artery patency to microvascular perfusion in the evaluation of patients with acute myocardial infarction (AMI). Microvascular dysfunction occurs in a substantial proportion of patients, despite aggressive therapy with thrombolytic agents and/or percutaneous mechanical revascularization techniques. Patients with impaired microvascular perfusion after immediate reperfusion therapy have an adverse clinical prognosis. Recent studies have extended our understanding of the pathophysiology of this so-called no-reflow phenomenon, focusing on the critical roles of platelet and inflammatory mediators leading to microvascular obstruction and reperfusion injury. Moving beyond the Thrombolysis in Myocardial Infarction (TIMI) flow grade system, new techniques have been developed to assess microvascular perfusion, including TIMI frame counting, angiographic myocardial perfusion grading, myocardial contrast echocardiography, Doppler flow wire studies, nuclear scintigraphy, and magnetic resonance imaging. Armed with a greater understanding of the primary mediators of microvascular dysfunction, these tools may identify improved therapy directed at optimizing myocardial perfusion in patients with AMI.