Increased expression of neutrophil and monocyte adhesion molecules in unstable coronary artery disease

Thrombin Generation Is Associated With Extracellular Vesicle and Leukocyte Lipid Membranes in Atherosclerotic Cardiovascular Disease

BACKGROUND

Clotting, leading to thrombosis, requires interactions of coagulation factors with the membrane aminophospholipids (aPLs) phosphatidylserine and phosphatidylethanolamine. Atherosclerotic cardiovascular disease (ASCVD) is associated with elevated thrombotic risk, which is not fully preventable using current therapies. Currently, the contribution of aPL to thrombotic risk in ASCVD is not known. Here, the aPL composition of circulating membranes in ASCVD of varying severity will be characterized along with the contribution of external facing aPL to plasma thrombin generation in patient samples.

METHODS

Thrombin generation was measured using a purified factor assay on platelet, leukocyte, and extracellular vesicles (EVs) from patients with acute coronary syndrome (n=24), stable coronary artery disease (n=18), and positive risk factor (n=23) and compared with healthy controls (n=24). aPL composition of resting/activated platelet and leukocytes and EV membranes was determined using lipidomics.

RESULTS

External facing aPLs were detected on EVs, platelets, and leukocytes, elevating significantly following cell activation. Thrombin generation was higher on the surface of EVs from patients with acute coronary syndrome than healthy controls, along with increased circulating EV counts. Thrombin generation correlated significantly with externalized EV phosphatidylserine, plasma EV counts, and total EV membrane surface area. In contrast, aPL levels and thrombin generation from leukocytes and platelets were not impacted by disease, although circulating leukocyte counts were higher in patients.

CONCLUSIONS

The aPL membrane of EV supports an elevated level of thrombin generation in patient plasma in ASCVD. Leukocytes may also play a role although the platelet membrane did not seem to contribute. Targeting EV formation/clearance and developing strategies to prevent the aPL surface of EV interacting with coagulation factors represents a novel antithrombotic target in ASCVD.

Galectin-9: A novel promoter of atherosclerosis progression

BACKGROUND AND AIMS

Atherosclerosis is widely accepted to be an inflammatory disease driven by lipid accumulation and leukocyte recruitment. More recently, galectins, a family of β-galactoside binding proteins, have been shown to play a role in leukocyte recruitment among other immunomodulatory functions. Galectin (Gal) -9, a tandem repeat type galectin expressed by the endothelium in inflammatory environments, has been proposed to promote leukocyte recruitment. However, the role of Gal-9 in the context of monocyte recruitment remains elusive.

METHODS AND RESULTS

Here, we characterise the immunomodulatory role of Gal-9 in context of atherosclerosis. We show that ApoE-/-Gal-9-/- mice have a significantly reduced aortic plaque burden compared to their ApoE-/- littermate controls after 12 weeks of high fat diet. RNA sequencing data from two independent studies reveal Lgals9 expression in leukocyte clusters isolated from murine atherosclerotic plaques. Additionally, soluble Gal-9 protein induces monocyte activation and a pro-inflammatory phenotype in macrophages. Furthermore, we show that immobilised recombinant Gal-9 acts as capture and adhesion molecule for CD14+ monocytes in a β2-integrin and glycan dependent manner, while adhesion of monocytes to stimulated endothelium is reduced when Gal-9 is knocked down. Gal-9 also facilitates enhanced recruitment of leukocytes from peripheral arterial disease (PAD) patients compared to healthy young and aged controls. We further characterise the endothelium as source of circulating Gal-9, which is increased in plasma of PAD patients compared to healthy controls.

CONCLUSIONS

These results highlight a pathological role for Gal-9 as promoter of monocyte recruitment and atherosclerotic plaque progression, making it a novel target in the prevention of plaque formation and progression.

Optical Coherence Tomography of Plaque Vulnerability and Rupture: JACC Focus Seminar Part 1/3

Plaque rupture is the most common cause of acute coronary syndromes and sudden cardiac death. Characteristics and pathobiology of vulnerable plaques prone to plaque rupture have been studied extensively over 2 decades in humans using optical coherence tomography (OCT), an intravascular imaging technique with micron scale resolution. OCT studies have identified key features of plaque vulnerability and described the in vivo characteristics and spatial distribution of thin cap fibroatheromas as major precursors to plaque rupture. In addition, OCT data supports the evolving understanding of coronary heart disease as a panvascular process associated with inflammation. In the setting of high atherosclerotic burden, plaque ruptures often occur at multiple sites in the coronary arteries, and plaque progression and healing are dynamic processes modulated by systemic risk factors. This review details major investigations with intravascular OCT into the biology and clinical implications of plaque vulnerability and plaque rupture.

Effect of Intravenous Abciximab on Coronary Flow Improvement After Re-vascularization in Primary Coronary Intervention and Short Term Impact

INTRODUCTION

Of recognized fact the importance of early diagnosis and early management of ST-elevation myocardial infarction, to regain a normal or at least adequate coronary flow in the Primary Percutaneous Intervention. Slow or no-reflow is suboptimal myocardial reperfusion, without angiographic evidence of mechanical obstruction. Adenosine, Verapamil and saline flush are manoeuvres proved useful. The resolution of ST-segment is associated with successful revascularization and regarded as a predictor for future events. Glycoprotein IIB/IIIA inhibitors are a group of anti-platelets widely used in acute coronary syndrome.

AIM

The aim of the study was to investigate that: uses of intra venous Abciximab, does not improve coronary flow in patients with MI that develop sub optimal flow after primary PCI within 30 minutes, but the improvement need 12 to 24 hour as founded in other studies, and its beneficial effect is related to early improvement in LV function and decrease of re-infarction and re-hospitalization.

METHOD

Prospective, case-control study, enrolled fifty patients randomly assigned into two matching groups, first group (25 patients) received an intravenous Abciximab while the second group (25 patients) received intracoronary saline flush. Repeated angiography after 30 minutes, for immediate resultant flow assessment, Electrocardiographic changes resolution, bleeding and death. After a 30 days, a clinical assessment for primary outcome including, death, recurrent Myocardial infarction and Heart failure While the Secondary outcome including stent thrombosis, target vessel revascularization in addition to the primary outcome.

RESULT

There was no significant difference in the flow Improvement and ECG resolution between both groups. These findings not affected by the door to balloon time. However, patients with flow improvement had a significant resolution in their ECG. Bleeding propensity and mortality were not significantly affected. Literatures proved the benefit of Abciximab in acute coronary syndrome.

CONCLUSION

Both intravenous Abciximab and intracoronary saline flush had comparable effect on coronary flow improvement post primary percutaneous intervention, with minimal variation in the bleeding and in-hospital mortality.

Impact of hepatitis B virus (HBV) infection on platelet response to clopidogrel in patients undergoing coronary stent implantation

BACKGROUND

Hepatitis B virus (HBV) infection has been reported to down-regulate the expression of CYP2C19 gene, which may decrease the bioactivation of clopidogrel into active metabolites. We aimed to evaluate the impact of HBV infection on platelet response to clopidogrel in patients undergoing coronary stent implantation.

METHODS

A total of 1805 patients who had received coronary stent implantation and taken aspirin 100 mg in combination with clopidogrel 75 mg daily ≥5 days were consecutively recruited. The serologic identifications for HBV, platelet aggregations in response to arachidonic acid (PL_AA) and adenosine diphosphate (PL_ADP), as well as ABCB1, CYP2C19, CYP3A5, PON1 and P2RY12 genotypes were determined. Clopidogrel low response (CLR) was defined as PL_ADP > 40%.

RESULTS

Among the recruited subjects, 102 patients showed hepatitis B surface antigen (HBsAg) positive and 1703 patients negative. PL_ADP was significantly higher in HBsAg positive group than that in HBsAg negative group [38 (24-48) % vs. 29 (20-39) %, p < 0.001] while the difference of PL_AA was not statistically significant (p = 0.329). The incidence of CLR was significantly higher in HBsAg positive group compared with that in HBsAg negative group (43.1% vs. 23.4%, p < 0.001). After adjusted for CYP2C19 genotype and known risk factors, HBsAg positive patients exhibited a significantly higher risk of CLR (adjusted odds ratio: 2.81, 95% confidence interval: 1.73 to 4.58, p < 0.001).

CONCLUSIONS

HBV infection is an independent risk factor of CLR, in addition to CYP2C19 gene mutations. (Pharmacogenetic and Pharmacokinetic Study of Clopidogrel; NCT01968499).

Three-Dimensional Echographic Evaluation of Carotid Artery Disease

The introduction of three-dimensional echography (3D echo) in vascular field is not recent, but it still remains a seldom-used technique because of the costs of ultrasound probe and the need of dedicated laboratories. Therefore, despite significant prognostic implications, the high diagnostic accuracy in plaque definition, and the relative ease of use, 3D echo in vascular field is a niche technique. The purpose of this review is mainly clinical and intends to demonstrate the potential strength of a 3D approach, including technical aspects, in order to present to clinicians and imagers the appealing aspects of a noninvasive and radiation-free methodology with relevant diagnostic and prognostic correlates in the assessment of carotid atherosclerosis. A comprehensive literature search (since 1990s to date) using the PubMed, MEDLINE, and Cochrane libraries databases has been conducted. Articles written in English have been assessed, including reviews, clinical trials, meta-analyses, and interventional/observational studies. Manual cross-referencing was also performed, and relevant references from selected articles were reviewed. The search was limited to studies conducted in humans. Search terms, retrieved also with PubMed Advanced search and AND/OR Boolean operators (mainly in title and abstract), included three-dimensional, echo, stroke/transient ischemic attack, predictors, carotid, imaging, and biomarkers.

Predictive prognostic value of neutrophil-lymphocytes ratio in acute coronary syndrome

OBJECTIVE

To assess the relationship between neutrophil-lymphocytes ratio (NLR) at admission and patient outcome over a period of six month in subjects with acute coronary syndrome (ACS).

METHODS

A total of 435 consecutive patients presenting with ACS were enrolled and 400 patients completed the study. Patients were categorized into 2 groups: the NLR group 1 (NLR≤5.25; n=265, 66.25%) and the NLR group 2 (NLR>5.25; n=135, 33.75%). The primary outcomes were in-hospital and 6 months mortality.

RESULTS

Forty-seven (11.8%) patients died during 6 months follow up. Higher mortality was seen in NLR group 2 (42/135, 34.1%) compared to NLR group 1 (5/265, 1.9%) with p value <0.001.

CONCLUSION

Our study suggest that elevated NLR (>5.25) is independently associated with higher all-cause mortality rate up to 6 months period irrespective of ACS type.

Platelet, monocyte and neutrophil activation and glucose tolerance in South African Mixed Ancestry individuals

Platelet activation has been described in patients with chronic inflammation, however in type 2 diabetes mellitus it remains controversial. We compared levels of platelet leucocyte aggregates, monocyte and granulocyte activation across glucose tolerance statuses in mixed ancestry South Africans. Individuals (206) were recruited from Bellville-South, Cape Town, and included 66% with normal glucose tolerance, 18.7% pre-diabetes, 8.7% screen-detected diabetes and 6.3% known diabetes. Monocyte and neutrophil activation were measured by calculating the percentage of cells expressing CD142 and CD69 while platelet monocyte aggregates were defined as CD14⁺⁺ CD42b⁺ events and platelet neutrophil aggregates as CD16⁺⁺ CD42b⁺ events. The percentage of monocytes and neutrophils expressing CD69 and CD142 was significantly higher in known diabetes and prediabetes, but, lowest in screen-detected diabetes (both p ≤ 0.016). The pattern was similar for platelet monocyte and neutrophil aggregates (both p ≤ 0.003). In robust linear regressions adjusted for age and gender, known diabetes was significantly and positively associated with the percentage of monocytes expressing CD69 [beta 11.06 (p = 0.016)] and CD42b (PMAs) [19.51 (0.003)] as well as the percentage of neutrophils expressing CD69 [14.19 (<0.0001)] and CD42b [17.7 (0.001)]. We conclude that monitoring platelet activation in diagnosed diabetic patients may have a role in the management and risk stratification.

Leucocyte-bound apolipoprotein B in the circulation is inversely associated with the presence of clinical and subclinical atherosclerosis

BACKGROUND

Atherosclerosis is a pro-inflammatory condition, in which leucocyte activation plays an important role. The interaction between circulating leucocytes and apolipoprotein (apo) B-containing lipoproteins results in pro-inflammatory changes of these cells. We aimed to evaluate the relationship between apo B bound to circulating leucocytes and atherosclerosis.

METHODS

Apo B on circulating leucocytes was measured by flow cytometry in subjects with and without cardiovascular disease (CVD), expressed as mean fluorescent intensity in arbitrary units (au). Carotid intima-media thickness (cIMT) was measured using B-mode ultrasound. Data are given as median (interquartile range).

RESULTS

A total of 396 subjects were included, of whom 183 had a history of CVD. Compared to subjects without CVD, patients with CVD had lower apo B bound to neutrophils (12·7 au (9·8-16·2) and 14·2 au (10·1-17·5), respectively, P = 0·038) and to monocytes (2·5 au (1·7-3·1) and 2·7 (1·9-3·6) au, respectively, P = 0·025). No differences were found for lymphocyte-bound apo B. Neutrophil- and monocyte-bound apo B were inversely correlated with cIMT (Spearman's rho: -0·123, P = 0·017 and -0·108, P = 0·035, respectively). Both monocyte- and neutrophil-bound apo B were inversely associated with different factors related to the metabolic syndrome, such as body mass index, triglycerides and complement C3. There was a positive association between erythrocyte-bound apo B and apo B bound to each of the leucocyte classes, possibly reflecting a similar mechanism. Discontinuation of statins in 54 subjects did not influence leucocyte-bound apo B.

CONCLUSION

Unexpectedly, the presence of noninternalized apo B-containing lipoproteins on circulating neutrophil and monocyte membranes may represent a protective mechanism against atherosclerosis.

Leucocyte-depleted Blood Cardioplegia

The effect of the depletion of leucocytes from cardioplegic and initial myocardial reperfusion blood on the inflammatory response and myocardial protection in patients with unstable angina undergoing cardiopulmonary bypass (CPB) was studied. Patients were allocated randomly to a leucocyte-depleted (LD) group or a control group. The LD group received continuous retrograde LD isothermic blood cardioplegia and the control group received isothermic blood cardioplegia. Blood samples were collected at seven time-points before, during and after the procedure. Total leucocyte counts of cardioplegia blood in the LD group were significantly lower than in the control group, but systemic leucocyte and neutrophil counts after CPB did not differ between the groups. The levels of adhesion molecules, cytokines, elastase and malondialdehyde were significantly increased after CPB in both groups and reached peak values 2-6 h after surgery; no other significant differences were found. LD cardioplegia and myocardial reperfusion did not attenuate the endothelial and neutrophil-mediated components of the CPB-induced inflammatory response, which may lead to myocardial reperfusion injury.

Coronary leukocyte activation in relation to progression of coronary artery disease

Leukocyte activation has been linked to atherogenesis, but there is little in vivo evidence for its role in the progression of atherosclerosis. We evaluated the predictive value for progression of coronary artery disease (CAD) of leukocyte activation markers in the coronary circulation. Monocyte and neutrophil CD11b, neutrophil CD66b expression and intracellular neutrophil myeloperoxidase (MPO) in the coronary arteries were determined by flow cytometry in patients undergoing coronary angiography. The primary outcome included fatal and nonfatal myocardial infarction or arterial vascular intervention due to unstable angina pectoris. In total 99 subjects who were included, 70 had CAD at inclusion (26 patients had single-vessel disease, 18 patients had twovessel disease and 26 patients had three-vessel disease). The median follow-up duration was 2242 days (interquartile range: 2142-2358). During follow-up, 13 patients (13%) developed progression of CAD. Monocyte CD11b, neutrophil CD11b and CD66b expression and intracellular MPO measured in blood obtained from the coronary arteries were not associated with the progression of CAD. These data indicate that coronary monocyte CD11b, neutrophil CD11b and CD66b expression and intracellular MPO do not predict the risk of progression of CAD.

In vivo evidence for chylomicrons as mediators of postprandial inflammation

BACKGROUND AND AIMS

The postprandial situation is a pro-inflammatory condition most likely linked to the development of atherosclerosis. We evaluated the relationship between apolipoprotein (apo) B48 and fasting and postprandial leukocyte activation markers.

METHODS

Leukocyte activation markers and apo B48 were determined in 80 subjects with and without coronary artery disease (CAD). Twelve healthy subjects underwent an oral fat loading test (up to 8 h).

RESULTS

Fasting apo B48 was significantly higher in patients with CAD (n = 47, 8.1 ± 5.2 mg/L) than in subjects without CAD (n = 33, 5.9 ± 3.9 mg/L, p = 0.022). Fasting apo B48 and triglycerides correlated positively with fasting monocyte CD11b and neutrophil CD66b expression. Plasma apo B48 and leukocyte activation markers increased after an oral fat load. No correlations were found between fasting or postprandial triglycerides and postprandial leukocyte activation markers. We observed no correlations between postprandial apo B48 and postprandial neutrophil CD11b or CD66b expression.

CONCLUSION

This study suggests that chylomicron remnants may be responsible for postprandial leukocyte activation in the circulation. The postprandial chylomicron response may be a stronger mediator of postprandial inflammation than postprandial triglyceridemia.

Effect of inflammatory factor-induced cyclo-oxygenase expression on the development of reperfusion-related no-reflow phenomenon in acute myocardial infarction

No reflow after reperfusion therapy for myocardial infarction is a strong predictor of clinical outcome. Increased levels of inflammatory factors, including C-reactive protein (CRP), in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI) may affect myocardial perfusion. However, why the no-reflow phenomenon increases in inflammation stress after PCI is not clear. The aim of the present study was to determine the effects and molecular mechanisms underlying the effects of CRP on the expression of cyclo-oxygenase (COX) on the development of the no-reflow phenomenon. There was a significant increase in plasma levels of CRP and interleukin (IL)-6 in no-reflow patients, suggesting that inflammatory factors play an important role in the development of the no-reflow phenomenon. The mechanisms involved were further evaluated after reperfusion in a rat model mimicking the no-reflow phenomenon. Compared with normal reflow rats, there were significant increases in both COX-1 and COX-2 in cardiac tissue from no-reflow rats. The COX inhibitor indomethacin (5 mg/kg, i.p.) significantly reduced the no-reflow area. In another series of experiments, human coronary artery endothelial cells (HCAEC) were treated with CRP at clinically relevant concentrations (5-25 μg/mL). C-Reactive protein significantly increased COX-1 and COX-2 levels in a time- and concentration-dependent manner. In addition, extracellular signal-regulated kinase (ERK) and Jun N-terminal kinase (JNK) were activated in CRP (5, 10, 25 μg/mL)-treated HCAEC cultures. Furthermore, the ERK inhibitor pd98059 (30 μmol/L) and the JNK inhibitor sp600125 (10 μmol/L) blocked CRP-induced COX-1 and COX-2 expression for 12 h. Together, the findings of the present study suggest that CRP can promote the development of the no-reflow phenomenon by increasing COX-1 and COX-2 expression, which is regulated, in part, via ERK and JNK activity.

Increased neutrophil-to-lymphocyte ratio predicts persistent coronary no-flow after wire insertion in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

OBJECTIVES

Acute ST-segment elevation myocardial infarction patients presenting persistent no-flow after wire insertion have a lower survival rate despite successful mechanical intervention. The neutrophil-to-lymphocyte ratio has been associated with increased mortality and worse clinical outcomes in ST-segment elevation myocardial infarction. We hypothesized that an elevated neutrophil-to-lymphocyte ratio would also be associated with a persistent Thrombolysis In Myocardial Infarction flow grade of 0 after wire insertion in patients undergoing primary percutaneous coronary intervention.

METHODS

A total of 644 patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention within 12 hours of symptom onset were included in our study. Blood samples were drawn immediately upon hospital admission. The patients were divided into 3 groups according to their Thrombolysis In Myocardial Infarction flow grade: Thrombolysis In Myocardial Infarction flow grade 0 after wire insertion, Thrombolysis In Myocardial Infarction flow grade 1-3 after wire insertion and Thrombolysis In Myocardial Infarction flow grade 1-3 at baseline.

RESULTS

The neutrophil-to-lymphocyte ratio was significantly higher in the group with Thrombolysis In Myocardial Infarction flow grade 0 after wire insertion compared with the group with Thrombolysis In Myocardial Infarction flow grade 1-3 after wire insertion and the group with Thrombolysis In Myocardial Infarction flow grade 1-3 at baseline. The group with Thrombolysis In Myocardial Infarction flow grade 0 after wire insertion also had a significantly higher in-hospital mortality rate. Persistent coronary no-flow after wire insertion was independently associated with the neutrophil-to-lymphocyte ratio.

CONCLUSIONS

An increased neutrophil-to-lymphocyte ratio on admission is significantly associated with persistent coronary no-flow after wire insertion in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Comparative study of the effect of rivaroxaban and fondaparinux on monocyte's coagulant activity and cytokine release

OBJECTIVES

Tissue factor (TF) exposed on activated monocytes and macrophages is involved in thrombosis through activation of factor X and cytokine release, responsible for inflammation and thrombosis. We investigated the effect of two anti-factor Xa drugs: rivaroxaban, a direct anti-Xa inhibitor, and fondaparinux, an antithrombin dependent anti-Xa inhibitor, on monocyte/macrophage procoagulant activity and cytokine release.

METHODS

Rivaroxaban and fondaparinux were tested at pharmacological concentrations on LPS-activated monocytes and on THP-1 cells, a human monocytic cell line, to assess 1) TF expression by flow cytometry 2) prothrombinase activity by its coagulant activity and 3) cytokine release in cell supernatants by antibody based cytokine array and ELISA for IL-8 and TNFα.

RESULTS AND CONCLUSION

Rivaroxaban and fondaparinux did not modify TF expression level on activated cells. In contrast procoagulant activity associated to monocytes and macrophages was dose dependently inhibited by rivaroxaban, but not significantly by fondaparinux. These results could explain why patients undergoing major orthopedic surgery with rivaroxaban prophylaxis were able to achieve significant reductions in venous thromboembolism, compared with drugs commonly used, i.e. fondaparinux and low molecular weight heparin. In addition, rivaroxaban and fondaparinux suppressed some chemokine secretion produced by activated macrophages. This may also contribute to their antithrombotic effect in clinic.

Correlation between the major components of Phyllanthus amarus and Phyllanthus urinaria and their inhibitory effects on phagocytic activity of human neutrophils

Background

Recently, we have highlighted the immunomodulatory activity of the standardized extracts of Phyllanthus amarus and P. urinaria. The present study was carried out to correlate between the prevalent constituents of the herbs and their inhibitory effects on phagocytic activity of human neutrophils.

Methods

The compounds, gallic acid, ellagic acid, corilagin, geraniin, phyllanthin and hypophyllanthin were identified and quantitatively analyzed in the extracts of Phyllanthus amarus and P. urinaria obtained from Malaysia and Indonesia by using a validated reversed phase high performance liquid chromatography (RP-HPLC) method. The standardized extracts and the pure compounds were evaluated for their effects on chemotaxis, β2 integrin (CD18) expression, phagocytosis and chemiluminescence of human phagocytes. Chemotactic activity was assessed using the Boyden chamber technique, inhibition of CD18 expression and phagocytic ability were tested with the aid of flow cytometry, while effect on the respiratory burst was investigated using a luminol-based chemiluminescence assay.

Results

All plant extracts strongly inhibited migration of the phagocytes with the Malaysian P. amarus depicting the highest inhibitory activity. Amongst the compounds tested, geraniin demonstrated the strongest inhibitory activity on chemotaxis of polymorphonuclear leukocytes (PMNs) and monocytes with IC₅₀ values of 1.09 and 1.69 μM, respectively, which were lower than that of ibuprofen. All plant extracts and pure compounds exhibited high inhibitory activity on the oxidative burst of zymosan and PMA stimulated leukocytes. Geraniin and corilagin exhibited exceptionally strong inhibition on the reactive oxygen species (ROS) activity with IC₅₀ values lower than aspirin. The plant extracts exhibited moderate inhibition of E. coli uptake by monocytes but weak effect on PMNs. Of all the compounds, phyllanthin at 50 μg/mL exhibited the highest engulfment inhibitory activity with percentage of phagocytizing cells of 14.2 and 27.1% for PMNs and monocytes, respectively. All plants and compounds tested possessed weak effect on CD18 expression on leukocytes except for hypophyllanthin and phyllanthin which exhibited significant inhibitory effect.

Conclusion

The strong inhibition of the extracts on the phagocytic activity of neutrophils was due to the presence of their major constituents especially geraniin, corilagin, phyllanthin and hypophllanthin which were able to modulate the innate response of phagocytes at different steps.

Eosinophil count is related with coronary thrombus in non ST-elevated acute coronary syndrome

BACKGROUND

White blood cells are reported as important not only in plaque vulnerability but also in thrombus formation and thrombus growth in acute coronary syndromes. Eosinophils contain granules that promote thrombus formation and thrombus growth in some heart diseases. In this study we aimed to investigate the relation of eosinophil count with coronary thrombus formation in patients with non ST-elevated acute coronary syndrome (NST-ACS).

METHOD

A total of 251 consecutive patients were hospitalized in our hospital with a diagnosis of NST-ACS. Venous blood is collected for measurement of hematologic indices in all patients undergoing the coronary angiography. Coronary angiographies were performed in our clinic using the standard Judkins technique and angiographic assessment of the presence of thrombus was made.

RESULTS

During coronary angiography, coronary thrombus was not detected in 82 patients (Group 1). In the coronary angiography of 169 patients, coronary thrombus was detected at various grades (Group 2). While the neutrophil count (6.84±1.94 vs. 5.53±1.37; P<0.001) and eosinophil count (0.257±0.125 vs. 0.163±0.114; P<0.005) was significnatly increased in the group with coronary thrombus, the lymphocyte count (1.87±0.66 vs. 2.00±0.70; P<0.001) was significantly decreased in the group with coronary thrombus as compared to the patient group without coronary thrombus. In the correlation analyzes; presence of coronary thrombus is correlated with total cholesterol, LDL-C, total CK, CK-MB, troponin, total number of diseased coronary, platelet count, neutrophil count, lymphocyte count and eosinophil count. On multivariate linear regression analysis, total leukocyte count, neutrophil count, lymphocyte count, eosinophil count, troponin and total cholesterol was found to be independent predictor of coronary thrombus in patients with NST-ACS.

CONCLUSION

Beside the increased neutrophil count, increased eosinophil count in CBC should alert the clinician about coronary thrombus development in patients with NST-ACS in order to make early medical interventions at acute phase of the disease.

Integrative DNA, RNA, and protein evidence connects TREML4 to coronary artery calcification

Coronary artery calcification (CAC) is a heritable and definitive morphologic marker of atherosclerosis that strongly predicts risk for future cardiovascular events. To search for genes involved in CAC, we used an integrative transcriptomic, genomic, and protein expression strategy by using next-generation DNA sequencing in the discovery phase with follow-up studies using traditional molecular biology and histopathology techniques. RNA sequencing of peripheral blood from a discovery set of CAC cases and controls was used to identify dysregulated genes, which were validated by ClinSeq and Framingham Heart Study data. Only a single gene, TREML4, was upregulated in CAC cases in both studies. Further examination showed that rs2803496 was a TREML4 cis-eQTL and that the minor allele at this locus conferred up to a 6.5-fold increased relative risk of CAC. We characterized human TREML4 and demonstrated by immunohistochemical techniques that it is localized in macrophages surrounding the necrotic core of coronary plaques complicated by calcification (but not in arteries with less advanced disease). Finally, we determined by von Kossa staining that TREML4 colocalizes with areas of microcalcification within coronary plaques. Overall, we present integrative RNA, DNA, and protein evidence implicating TREML4 in coronary artery calcification. Our findings connect multimodal genomics data with a commonly used clinical marker of cardiovascular disease.

Predictors of coronary collaterals in patients with non ST-elevated acute coronary syndrome: the paradox of the leukocytes

Aim of the study

Atherosclerosis represents active inflammation in which leukocytes play significant role. Coronary collateral development is a response to myocardial ischaemia. In this study we aimed to investigate the association of the leukocytes with coronary collateral development in patients with non ST-elevated acute coronary syndromes (NST-ACS).

Material and methods

A total of 251 consecutive patients were hospitalized in our hospital with a diagnosis of NST-ACS. The blood samples were collected 1-hour after admission to the hospital and peripheral leukocytes (neutrophils, monocytes and lymphocytes) were examined. All patients underwent coronary angiography. The coronary collateral vessels (CCV) are graded according to the Rentrop scoring system.

Results

Group 1 consisted of 146 patients with Rentrop 0 and Group 2 consisted of 105 patients with Rentrop 1, 2 and 3. The presence of CCV was significantly associated with neutrophil count, lymphocyte count, monocyte count and neutrophil-lymphocyte ratio (NLR). In subgroup analyses, higher NLR was significantly associated with good CCV development in patients with NST-ACS.

Conclusions

Higher neutrophil count, monocyte count and NLR and lower lymphocyte count on admission, were associated with the presence of CCV in patients with NST-ACS. High NLR may predict good collateral development in patients with NST-ACS.

Impact of nonculprit vessel myocardial perfusion on outcomes of patients undergoing percutaneous coronary intervention for acute coronary syndromes: analysis from the ACUITY trial (Acute Catheterization and Urgent Intervention Triage Strategy)

OBJECTIVES

This study evaluated the impact of nonculprit vessel myocardial perfusion on outcomes of non-ST-segment elevation acute coronary syndromes (NSTE-ACS) patients.

BACKGROUND

ST-segment elevation myocardial infarction patients have decreased perfusion in areas remote from the infarct-related vessel. The impact of myocardial hypoperfusion of regions supplied by nonculprit vessels in NSTE-ACS patients treated with percutaneous coronary intervention (PCI) is unknown.

METHODS

The angiographic substudy of the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial included 6,921 NSTE-ACS patients. Complete 3-vessel assessments of baseline coronary TIMI (Thrombolysis In Myocardial Infarction) flow grade and myocardial blush grade (MBG) were performed. We examined the outcomes of PCI-treated patients according to the worst nonculprit vessel MBG identified per patient.

RESULTS

Among the 3,826 patients treated with PCI, the worst nonculprit MBG was determined in 3,426 (89.5%) patients, including 375 (10.9%) MBG 0/1 patients, 475 (13.9%) MBG 2 patients, and 2,576 (75.2%) MBG 3 patients. Nonculprit MBG 0/1 was associated with worse baseline clinical characteristics. Patients with nonculprit MBG 0/1 versus MBG 3 had increased rates of 30-day (3.0% vs. 0.7%, p < 0.0001) and 1-year (4.4% vs. 1.0%, p < 0.0001) death. Similar results were found among patients with pre-procedural TIMI flow grade 3 in the culprit vessel, where nonculprit vessel MBG 0/1 (hazard ratio: 2.81 [95% confidence interval: 1.63 to 4.84], p = 0.0002) was the strongest predictor of 1-year mortality.

CONCLUSIONS

Reduced myocardial perfusion in an area supplied by a nonculprit vessel is associated with increased short- and long-term mortality rates in NSTE-ACS patients undergoing PCI. Furthermore, worst nonculprit MBG is able to risk-stratify patients with normal baseline flow of the culprit vessel.

White Blood Cell Subtypes and Neutrophil-Lymphocyte Ratio in Prediction of Coronary Thrombus Formation in Non-ST-Segment Elevated Acute Coronary Syndrome

Leukocytes are reported as crucial not only for plaque activation but also in thrombus formation in acute coronary syndromes (ACSs). Among the markers of inflammation, in coronary artery disease neutrophil-lymphocyte ratio (NLR) has been reported to have the greatest predictive power of poor outcomes. Our aim was to evaluate the association of NLR with coronary thrombus in patients with non-ST-segment elevated ACSs (NST-ACSs). A total of 251 patients were hospitalized with a diagnosis of NST-ACS including non-ST-segment elevated myocardial infarction and unstable angina pectoris. Coronary angiographies were performed. In 167 patients, coronary thrombus was detected. Between the patient groups with and without coronary thrombus, neutrophil count, platelet count, and NLR are significantly increased, and lymphocyte count is significantly decreased in the group with coronary thrombus as compared to patient group without coronary thrombus. Leukocyte count and NLR may give an indication about the presence of coronary thrombus. In NST-ACS, blood parameters may give valuable information about the status of the coronary arteries.

Trans-vessel gradient of myeloperoxidase in coronary artery disease

BACKGROUND

Coronary artery disease (CAD) may reflect generalized inflammation. We evaluated leucocyte activation in subjects with and without CAD in different vascular compartments.

MATERIALS AND METHODS

Patients were divided in two groups; subjects without CAD (controls; n = 25) and with stable CAD (n = 52) based on coronary angiography. After blood sampling from vessels, cardiovascular risk factors and leucocyte activation markers CD11b, CD66b and cytoplasmatic myeloperoxidase (MPO) were determined by flow cytometry.

RESULTS

Myeloperoxidase (MPO) was higher in patients with CAD at all sites compared with controls (188 ± 7 vs. 210 ± 12 au for venous (P < 0.05), 178 ± 7 vs. 212 ± 12 au for femoral artery (P = 0.08), 166 ± 7 vs. 195 ± 12 au for abdominal artery (P < 0.05), 166 ± 6 vs. 189 ± 14 au for left coronary (P = 0.08) and 163 ± 6 vs. 193 ± 12 au for the right coronary artery (P < 0.05)). Other markers did not differ between the groups. A gradient of inflammation from peripheral vessels to the coronaries was found by differences in MPO in both groups; from 210 ± 12 au in the venous compartments towards 189 ± 14 and 193 ± 12 au, in the left and right coronaries, respectively, for the controls (P = 0.001), and from 188 ± 7 au in the venous compartment towards 166 ± 6 and 163 ± 6 au in the left and right coronaries, respectively, for the patients (P = 0.007). Other leucocyte activation markers did not show such a gradient.

CONCLUSIONS

There is a generalized inflammatory neutrophil gradient for MPO from peripheral vessels towards the coronaries in both patients with CAD and controls. However, patients with CAD show a higher degree of inflammation, mostly in the coronaries. These data strengthen the role of activated neutrophils in CAD.

Pathophysiological role of neutrophils in acute myocardial infarction

The pathogenesis of acute myocardial infarction is known to be mediated by systemic, intraplaque and myocardial inflammatory processes. Among different immune cell subsets, compelling evidence now indicates a pivotal role for neutrophils in acute coronary syndromes. Neutrophils infiltrate coronary plaques and the infarcted myocardium and mediate tissue damage by releasing matrix-degrading enzymes and reactive oxygen species. In addition, neutrophils are also involved in post-infarction adverse cardiac remodelling and neointima formation after angioplasty. The promising results obtained in preclinical modelswith pharmacological approaches interfering with neutrophil recruitment or function have confirmed the pathophysiological relevance of these immune cells in acute coronary syndromes and prompted further studies of these therapeutic interventions. This narrative review will provide an update on the role of neutrophils in acute myocardial infarction and on the pharmacological means that were devised to prevent neutrophil-mediated tissue damage and to reduce post-ischaemic outcomes.

Cholesterol efflux in megakaryocyte progenitors suppresses platelet production and thrombocytosis

Platelets play a key role in atherogenesis and its complications. Both hypercholesterolemia and increased platelet production promote athero-thrombosis; however, a potential link between altered cholesterol homeostasis and platelet production has not been explored. Transplantation of bone marrow (BM) deficient in ABCG4, a transporter of unknown function, into Ldlr^−/− mice resulted in thrombocytosis, accelerated thrombosis and atherosclerosis. While not detected in lesions, Abcg4 was highly expressed in BM megakaryocyte progenitors (MkP). Abcg4^−/− MkPs displayed defective cholesterol efflux to HDL, increased cell surface levels of thrombopoietin (TPO) receptor (c-MPL) and enhanced proliferation. This appeared to reflect disruption of the negative feedback regulation of c-MPL levels and signaling by E3 ligase c-CBL and cholesterol-sensing LYN kinase. HDL infusions reduced platelet counts in Ldlr^−/− mice and in a mouse model of myeloproliferative neoplasm, in a completely ABCG4-dependent fashion. HDL infusions may offer a novel approach to reducing athero-thrombotic events associated with increased platelet production.

Sex differences in endothelial function of aged hypertriglyceridemic rats - effect of atorvastatin treatment

The aim of the study was to test the hypothesis that the effect of atorvastatin on endothelium-dependent relaxation of the superior mesenteric artery (SMA) may differ in male vs. female aged hypertriglyceridemic rats (HTGs). Experiments were performed on 11-month-old male and female Prague hereditary HTGs. Atorvastatin (ATO) was administered p.o. in the dose of 0.30 mg/100g/day. Controls received vehiculum. After two months of ATO administration blood pressure, serum triglycerides (TG) and total cholesterol (CHOL) were determined. Endothelial function of SMA was studied in vitro using evaluation of relaxant responses of precontracted SMA to acetylcholine. The serum TG of control male HTGs were found to be statistically higher than those of female controls, while CHOL and blood pressure did not share gender differences. Responses of SMA of female control HTGs were statistically decreased compared to their male counterparts. ATO treatment induced decrease in blood pressure and TG of both males and females, yet CHOL values were reduced only in females. The protective effect of ATO on SMA endothelial function was much more pronounced in females compared to males. We conclude that vascular endothelial dysfunction of aged HTG rats is more severe and more attenuated by ATO in females compared to males. The protective effect of ATO on vascular endothelial function does not seem to depend solely on its lipid lowering action.

Toll-Like Receptor induced CD11b and L-selectin response in patients with coronary artery disease

Toll-Like Receptor (TLR) -2 and -4 expression and TLR-induced cytokine response of inflammatory cells are related to atherogenesis and atherosclerotic plaque progression. We examined whether immediate TLR induced changes in CD11b and L-selectin (CD62L) expression are able to discriminate the presence and severity of atherosclerotic disease by exploring single dose whole blood TLR stimulation and detailed dose-response curves. Blood samples were obtained from 125 coronary artery disease (CAD) patients and 28 controls. CD11b and L-selectin expression on CD14+ monocytes was measured after whole blood stimulation with multiple concentrations of the TLR4 ligand LPS (0.01–10 ng/ml) and the TLR2 ligand P3C (0.5–500 ng/ml). Subsequently, dose-response curves were created and the following parameters were calculated: hillslope, EC50, area under the curve (AUC) and delta. These parameters provide information about the maximum response following activation, as well as the minimum trigger required to induce activation and the intensity of the response. CAD patients showed a significantly higher L-selectin, but not CD11b response to TLR ligation than controls after single dose stimulations as well as significant differences in the hillslope and EC50 of the dose-response curves. Within the CAD patient group, dose-response curves of L-selectin showed significant differences in the presence of hypertension, dyslipidemia, coronary occlusion and degree of stenosis, whereas CD11b expression had the strongest discriminating power after single dose stimulation. In conclusion, single dose stimulations and dose-response curves of CD11b and L-selectin expression after TLR stimulation provide diverse but limited information about atherosclerotic disease severity in stable angina patients. However, both single dose stimulation and dose-response curves of LPS-induced L-selectin expression can discriminate between controls and CAD patients.

Do we know enough about the immune pathogenesis of acute coronary syndromes to improve clinical practice?

Morbidities related to atherosclerosis, such as acute coronary syndromes (ACS) including unstable angina and myocardial infarction, remain leading causes of mortality. Unstable plaques are inflamed and infiltrated with macrophages and T lymphocytes. Activated dendritic cells interact with T cells, yielding predominantly Th1 responses involving interferon-gamma (IFN-γ) and tumour necrosis factor-alpha (TNF-α), while the role of interleukin 17 (IL-17) is questionable. The expansion of CD28nullCD4 or CD8 T cells as well as pattern recognition receptors activation (especially Toll-like receptors; TLR2 and TLR4) is characteristic for unstable plaque. Inflammation modifies platelet and fibrin clot characteristics, which are critical for ACS. Understanding of the inflammatory mechanisms of atherothrombosis, bridging inflammation, oxidative stress and immune regulation, will allow for the detection of subjects at risk, through the use of novel biomarkers and imaging techniques including intravascular ultrasound, molecular targeting, magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). Moreover, understanding the specific inflammatory pathways of plaque rupture and atherothrombosis may allow for immunomodulation of ACS. Statins and anti-platelet drugs are anti-inflammatory, but importance of immune events in ACS warrants the introduction of novel, specific treatments directed either on cytokines, TLRs or inflammasomes. While the prime time for the introduction of immunologically inspired diagnostic tests and treatments for atherosclerosis have not come yet, we are closer than ever before to finally being able to benefit from this vast body of experimental and clinical evidence. This paper provides a comprehensive review of the role of the immune system and inflammation in ACS.

Interference of IP-10 expression inhibits vascular smooth muscle cell proliferation and intimal hyperplasia in carotid artery: a new insight in the prevention of restenosis

After vascular angioplasty, vascular smooth muscle cell (VSMC) proliferation causes atherosclerosis and intimal hyperplasia leading to restenosis. Interferon-γ-inducible protein (IP)-10 plays a role in atherogenesis, but the mechanism remains unclear. We evaluated the role of IP-10 in intimal hyperplasia and restenosis. IP-10 expression was determined in arterial specimens from 20 arteriosclerotic obliteration patients and 6 healthy individuals. VSMCs were stimulated in vitro with IFN-γ and transfected with IP-10 siRNA. Silencing was verified with RT-PCR/Western blot; cell proliferation rate was detected by methyl-thiazol-tetrazolium. The carotid artery model of atherosclerosis injury was established with IP-10 siRNA. IP-10 expression was detected at 1 and 4 weeks using RT-PCR and immunohistochemistry. Artery morphology was assessed with hematoxylin-and-eosin staining, and intimal hyperplasia was evaluated by electron microscopy. IP-10 was overexpressed in arteriosclerotic obliteration group compared with control group (P < 0.05). IP-10 expression in transfected group was significantly lower than in untransfected group. The intima-to-media ratio of transfected group at 4 weeks was lower than that of untransfected group (P < 0.01). The transfected group exhibited more regular intimal structure and less hyperplasia under electron microscopy. We, therefore, concluded that IP-10 played an important role in intimal hyperplasia as siRNA-mediated IP-10 silencing inhibited aberrant VSMCs hyperplasia and reduced restenosis.

High levels of systemic myeloperoxidase are associated with coronary plaque erosion in patients with acute coronary syndromes: a clinicopathological study

BACKGROUND

Systemic levels of myeloperoxidase predict prognosis in patients with acute coronary syndromes and are considered a marker of plaque vulnerability. It is not known whether myeloperoxidase is associated with different coronary morphologies (ie, rupture or erosion of the culprit lesion) in patients with acute coronary syndrome.

METHODS AND RESULTS

Twenty-five consecutive patients (aged 67±11 years; 15 men [60%]; 13 [52%] with non-ST-segment elevation acute coronary syndrome and 12 [48%] with acute ST-segment elevation myocardial infarction) were enrolled. Optical coherence tomography classified the culprit lesion as ruptured in 18 (72%) or eroded in 7 patients (28%) and detected intraluminal thrombus in 89% of ruptured plaques and 100% of eroded plaques. Baseline systemic levels of serum myeloperoxidase were significantly higher in patients with an eroded plaque than in those with a ruptured plaque (median, 2500 ng/mL; 25th to 75th percentile, 1415 to 2920 versus median, 707 ng/mL; 25th to 75th percentile, 312 to 943; P=0.001), whereas C-reactive protein levels did not differ significantly (median, 11.3 mg/L; 25th to 75th percentile, 1.3 to 28.5 versus median, 3.9 mg/L; 25th to 75th percentile, 1.3 to 17.8; P=0.76, respectively). In addition, the density of myeloperoxidase-positive cells within thrombi overlying plaques in postmortem coronary specimens retrieved from sudden coronary death victims was significantly higher in lesions with erosion (n=11) than ruptures (n=11) (median, 1584; 25th to 75th percentile, 1,088 to 2,135 cells/mm(2) versus median, 579; 25th to 75th percentile, 442 to 760 cells/mm(2); P=0.0012).

CONCLUSIONS

Systemic myeloperoxidase levels are significantly elevated in patients with acute coronary syndrome presenting with eroded culprit plaque compared with patients presenting with ruptured culprit plaque. Consistently, in postmortem coronary specimens, luminal thrombi superimposed on eroded plaques contain a higher density of myeloperoxidase-positive cells than thrombi superimposed on ruptured plaques. This study supports the concept that elevations in selective inflammatory biomarkers reflect specific acute complications of coronary atherosclerosis.

Relation of elevated levels of plasma myeloperoxidase to impaired myocardial microcirculation after reperfusion in patients with acute myocardial infarction

Previous studies have shown that oxidative stress and endothelial dysfunction are related to impaired myocardial microcirculation after reperfusion. Moreover, elevated myeloperoxidase (MPO) levels are associated with endothelial dysfunction. Plasma MPO levels were measured in patients with ST-segment elevation acute myocardial infarction (n = 160) who had undergone percutaneous coronary stenting within 12 hours of symptom onset. We investigated whether the plasma MPO level at admission was associated with impaired myocardial microcirculation, as indicated by ST-segment resolution and myocardial blush grade after reperfusion, and left ventricular ejection fraction and remodeling at 6 months. The patients were divided into 2 groups according to the median MPO value for the entire cohort (low-MPO group < or =50 ng/ml, n = 80; high-MPO group >50 ng/ml, n = 80). ST-segment resolution and the myocardial blush grade were significantly lower in the high-MPO than in the low-MPO group (48 +/- 27% vs 61 +/- 24%, p <0.005; and 2.1 +/- 0.8 vs 2.4 +/- 0.7, p <0.01; respectively). Moreover, the percentage of increase in the left ventricular end-diastolic volume index was significantly greater and the left ventricular ejection fraction at 6 months was significantly lower in the high-MPO group than in the low-MPO group (8.2 +/- 24.7% vs -1.9 +/- 23.5%, p <0.05; and 46 +/- 9% vs 54 +/- 9%, p <0.0001, respectively). Multiple regression analysis showed that the plasma MPO level was an independent predictor of incomplete ST-segment resolution (odds ratio 6.94, 95% confidence interval 2.10 to 22.9, p = 0.0015). In conclusion, elevated plasma MPO levels at admission were associated with impaired myocardial microcirculation after reperfusion in patients with acute myocardial infarction.

Role of polymorphonuclear neutrophils in atherosclerosis: current state and future perspectives

Contrary to the long-standing and widely accepted belief that polymorphonuclear neutrophils (PMN) are of marginal relevance in atherosclerosis, evidence revealing a previously unappreciated role of PMN in the process of atherosclerosis is being accumulating. Systemic inflammation involving activated PMN is clearly associated with unstable conditions of coronary artery disease and an increased number of circulating neutrophils is a well-known risk indicator of future cardiovascular outcomes. Furthermore, PMN are activated in a number of clinical conditions associated with high risk of developing atherosclerosis and are detectable into culprit lesions of patients with coronary artery disease. At present, pharmacological interventions aimed at blocking neutrophil emigration from the blood into the arterial wall and/or inhibiting neutrophil-mediated inflammatory functions are not an option for treating atherosclerosis. Nevertheless, several lines of evidence suggest that part of the atheroprotective effects of statins as well as HDL and HDL apolipoproteins may be related to their ability to modulate neutrophilic inflammation in the arterial wall. These hypotheses are not definitely established and warrant for further study. This Review describes the evidence suggesting that PMN may have a causative role in atherogenesis and atheroprogression and discusses the potential importance of modulating neutrophilic inflammation as part of a novel, improved strategy for preventing and treating atherosclerosis.

Coronary stenting is associated with an acute increase in plasma myeloperoxidase in stable angina patients but not in patients with acute myocardial infarction

BACKGROUND

Myeloperoxidase (MPO) has emerged as a critical mediator in the physiopathology of atherosclerosis from plaque formation and growth until destabilization and rupture leading to acute coronary syndrome (ACS). Using coronary stenting as a model of plaque injury, we aimed to determine the evolution of systemic MPO levels following coronary stenting in stable angina patients and in patients with acute myocardial infarction (AMI).

METHODS

Plasma levels of MPO, lactoferrin, interleukin (IL)-6, C-reactive protein and PMN counts were assessed in 13 patients with Non-ST-elevation myocardial infarction (NSTEMI) (Group A) and in 29 patients with stable angina pectoris (Group B), undergoing coronary stenting. Serial blood samples were taken before angioplasty (baseline) and at 1, 6 and 24 h following initial balloon inflation.

RESULTS

Following angioplasty, the overall plasma MPO levels significantly increased at 1 h in group B (120.5+/-79.0 to 166+/-79.5, p=0.003) but not in group A (121+/-63.4 to 124.7+/-76.9, p=0.753). In Group B, the increase in MPO levels at 1 h were significantly higher in the presence of complex lesions compared to patients with simple lesions (p=0.023). Lactoferrin levels showed no change over time except for a significant decrease at 6 h in group B.

CONCLUSIONS

In stable angina patients, coronary stenting is associated with an acute and transient increase in plasma MPO levels, but not in lactoferrin levels, with an enhanced response in the presence of complex lesions. In contrast, we observed no changes in plasma MPO and lactoferrin levels following stenting in patients with AMI. Given its pro-inflammatory properties, the potential implication of MPO release on clinical outcome in stable patients undergoing stenting needs further investigation.

Monocyte-endothelial cell interaction in atherogenesis and thrombosis

Cellular interactions between leukocytes and the endothelium are critical events in vascular biology, such as atherosclerosis and acute coronary syndrome. When monocytes and endothelial cells are activated via direct cell-cell interaction, both types of cells express several biologically active molecules such as adhesion molecules, cytokines, coagulation and fibrinolytic factors, metalloproteinases, and vasoactive substances. All of these molecules could contribute to atherogenesis and thrombosis.

TNF-alpha/IL-10 ratio and C-reactive protein as markers of the inflammatory response in CAD-prone North Indian patients with acute myocardial infarction

BACKGROUND

Cytokines are responsible for the modulation of immunological and inflammatory processes and play a significant role in the pathogenesis of coronary artery disease (CAD). Tumor necrosis factor (TNF)-alpha is the major pro-inflammatory cytokine while interleukin-10 (IL-10) is the major anti-inflammatory cytokine in patients with CAD. We determined the significance of the TNF/IL-10 ratio and C-reactive protein (CRP) in patients of acute myocardial infarction as a marker for CAD in the atherosclerosis-prone North Indian population.

METHODS

The study group comprised of 100 patients of acute myocardial infarction (AMI) and 100 age and sex matched healthy controls. Lipid profile, apolipoprotein-A (Apo-A), apolipoprotein-B (Apo-B) and CRP concentrations were estimated using commercially available kits in all patients and control subjects. TNF-alpha, lipoprotein (a) (Lp(a)) and IL-10 concentrations were assayed by using commercially available ELISA kits.

RESULTS

The TNF-alpha concentrations were significantly higher in patients with acute myocardial infarction (86.9+/-4.7 pg/ml), as compared to control subjects (7.1+/-0.67 g/ml). AMI patients also exhibited higher serum concentrations of IL-10 (5.74+/-0.82 pg/ml), in comparison to the controls (1.22+/-0.06 pg/ml). The ratio of TNF-alpha to IL-10 was significantly increased in cases (15.2+/-1.13), in comparison to healthy subjects (5.8+/-0.64).

CONCLUSIONS

These cytokines underline the role of the immune processes during unstable atherosclerosis and in the pathogenesis of coronary artery disease in the Indian context.

Delayed neutrophil apoptosis in patients with unstable angina: relation to C-reactive protein and recurrence of instability

AIMS

To investigate spontaneous polymorphonuclear neutrophils (PMNs) apoptosis in unstable angina (UA) and its association with recurrence of instability.

METHODS AND RESULTS

We compared PMNs apoptotic rate at 4 and 24 h in patients with UA, stable angina (SA), and controls (H) with two different protocols by flow cytometry. We measured apoptotic rate of isolated PMNs (Protocol 1) in 30 UA patients, 13 SA patients, and 34 H; and apoptosis of PMNs in whole blood culture (Protocol 2) in further 10 UA patients, 7 SA patients, and 6 H. Serum high-sensitivity C-reactive protein was also measured. Polymorphonuclear neutrophils of UA patients showed a decreased apoptotic rate compared with SA patients and H at 4 h in Protocol 1 (both P < 0.01), and at 24 h in Protocol 2 (P < 0.05 and <0.01, respectively). In overall population, a negative correlation was found between apoptotic rate at 4 h and high-sensitivity C-reactive protein levels (P < 0.01). Six among 40 patients with UA had early recurrence of symptoms and their apoptotic rate was significantly reduced compared with UA patients without recurrence of symptoms (P = 0.024).

CONCLUSIONS

Our study demonstrates delayed PMN apoptosis in UA. This alteration might be involved in the persistence of inflammatory activation and affects recurrence of instability.