Markers of inflammation associated with plaque progression and instability in patients with carotid atherosclerosis

[Stenosis of the carotid artery in women with ischemic stroke and markers of inflammation]

AIM

To assess the relationship between the severity of stenosis of the carotid arteries, the level of female sex hormones and markers of subclinical inflammation in women with ischemic stroke (IS).

MATERIAL AND METHODS

Two hundred and eleven women (mean age 68.9±9.23 years) were examined. A history of cardiovascular disease, previous cardiovascular events, type and subtype of stroke were recorded. Neurological status was assessed using neurological scales. Atherosclerosis was diagnosed by color duplex scanning of brachiocephalic arteries and laboratory testing (estradiol, markers of subclinical inflammation).

RESULTS

Carotid artery stenosis of ≥50% was found in 13.3% of patients, less severe stenosis in 36.0%. Stenosis of ≥50% was positively correlated with the level of IL-18, TNF-alpha, and negatively correlated with the level of IL-6, IL-4, and MMSE score. In dynamics, there was a decrease in the level of TNF-alpha in all groups of patients, and an increase in the IL-4 level in women with carotid artery stenosis of ≥50%.

CONCLUSION

Study of the influence of markers of subclinical inflammation on the atherosclerosis progression and recurrent disorders of cerebral circulation in women with IS should be continued.

C-reactive protein in atherosclerosis - A risk marker but not a causal factor? A 13-year population-based longitudinal study: The Tromsø study

BACKGROUND AND AIMS

CRP predicts cardiovascular disease (CVD) in large epidemiologic studies. The aim of the present study was to elucidate the role of CRP in atherosclerosis formation and progression in a prospective population-based study.

METHODS

6503 middle-aged subjects from The Tromsø study had serum CRP, carotid ultrasound and complete covariate data collected at baseline in 1994. Of these, 4730 and 2917 attended follow-up surveys with repeated assessments in 2001 and 2007, respectively. The cross-sectional associations between CRP and subclinical carotid atherosclerosis, and the longitudinal associations between baseline CRP and novel plaque formation and plaque progression were assessed in generalized estimating equations and linear mixed models stratified by sex.

RESULTS

At baseline, traditional risk factors and plaque prevalence increased by CRP risk categories (<1 mg/L, 1-3 mg/L, and >3 mg/L) in both sexes. In cross-sectional analyses, multivariable-adjusted CRP was associated with plaque prevalence and total plaque area (TPA) in men and women. Age-adjusted baseline CRP >3 mg/L compared to CRP <1 mg/L predicted novel plaque formation (OR 1.44, CI 1.08-1.92) and TPA progression (β = 0.0.029 (CI, 0.003-0.056)) in men, but not in women. In neither men nor women was baseline CRP a predictor of TPA-progression or novel plaque formation when adjusted for traditional risk factors.

CONCLUSIONS

CRP was associated with plaque presence and TPA in cross-sectional analyses, but was not an independent predictor of novel plaque formation or plaque progression. Our findings suggest that CRP may link to CVD by other mechanisms than promoting formation and progression of atherosclerotic plaques.

Identification of neovascularization by contrast-enhanced ultrasound to detect unstable carotid stenosis

Background

Plaque neovascularization accompanies local inflammation and critically contributes to plaque instability. Correct identification of intraplaque neovascularization by contrast–enhanced ultrasound (CEUS) may provide an additional risk marker in carotid stenosis. This pilot study investigates the correlation between histological evaluation of carotid plaque specimens and pre-surgery CEUS to identify neovascularization.

Methods

17 patients with high-grade internal carotid artery (ICA) stenosis were studied. CEUS was performed in all patients shortly before carotid endarterectomy. Neovascularization, infiltration of T cells and macrophages along with intraplaque hemorrhage were studied in excised plaques by immunohistochemistry. Ultrasound-based four-level and two-level classification systems for neovascularization were used. CEUS findings were compared with histological findings.

Results

Scores on the CEUS-based four-level and two-level classifications were robustly correlated with the density of intraplaque vessels (r = 0.635, p = 0.006 and r = 0.578, p = 0.015, respectively). Histological evaluation of regions with strong and prolonged intraplaque enhancement typically showed strong intraplaque neovascularization in conjunction with acute intraplaque hemorrhage. Moreover, higher grades of intraplaque neovascularization as determined by ultrasound were associated with a higher percentage of macrophage-rich areas.

Conclusion

CEUS is a technique well suited to gauge the degree of neovascularization of carotid plaques. Future research will have to define the reliability and validity of CEUS in everyday clinical practice. Further, our study suggests that CEUS may also be useful to pick up features of vulnerable plaques such as acute intraplaque hemorrhages.

Monocyte/lymphocyte ratio predicts the severity of coronary artery disease: a syntax score assessment

Background

We aimed to explore whether monocyte to lymphocyte ratio (MLR) provides predictive value of the lesion severity in patients with coronary artery disease (CAD).

Methods

Five hundred forty-three patients undergoing coronary angiography were analyzed in this retrospective study. Patients with coronary stenosis were divided into three groups on the basis of Syntax score. The control group consisted of patients with normal coronary arteries. MLR was calculated by dividing monocytes count by lymphocytes count obtained from routine blood examination. Multivariate logistic analysis was used to assess risk factors of CAD. Ordinal logistic regression analysis was used to assess the relationship between MLR and the lesion severity of coronary arteries.

Results

MLR was found to be an independent risk factor of the presence of CAD (OR: 3.94, 95% CI: 1.20–12.95) and a predictor of the lesion severity (OR: 2.05, 95% CI: 1.15–3.66). Besides, MLR was positively correlated with Syntax score(r = 0.437, p < 0.001). In the receiver-operating characteristic (ROC) curve analysis, MLR, with an optimal cut-off value of 0.25, predicted the severe coronary lesion with a sensitivity of 60.26% and specificity of 78.49%.

Conclusions

MLR was an independent risk factor of the presence of CAD, and a predictor of the lesion severity. Compared to neutrophil to lymphocyte ratio (NLR), MLR has better performance to reflect the severity of coronary lesion.

CCR5+ CD8 T-cell levels and monocyte activation precede the onset of acute coronary syndrome in HIV-infected patients on antiretroviral therapy

Acute coronary syndrome (ACS) is nowadays one of the leading causes of morbid-mortality in HIV-infected population, but innate and adaptive immune mechanisms preceding this event are unknown. In this work we comprehensively and longitudinally observed, by multiparametric flow cytometry and following a case-control design, increased CCR5⁺CD8⁺ T-cells levels and monocytes expressing activation and adhesion markers in HIV-infected patients who are going to suffer ACS. In addition, we found direct associations between activated CD8⁺ T-cells and myeloid cells that were only statistically significant in the group of patients with ACS and in the follow up time point just before the ACS. Our data highlight the important role of CCR5 in the onset of ACS and suggest this receptor as a marker of cardiovascular risk and potential therapeutic target to prevent the development of such non-AIDS-related event in HIV-infected patients.

The Relationship between Neutrophil-to-Lymphocyte Ratio and Aortic Arch Calcification in Ischemic Stroke Patients

BACKGROUND

Inflammation plays a central role in atherogenesis and artery calcification. Although neutrophil-to-lymphocyte ratio (NLR) has been introduced as an inflammatory marker for atherosclerosis, the relationship between NLR and aortic arch calcification (AAC) has not been studied. This study aimed to determine the association between NLR and AAC.

METHODS

A total of 749 participants were enrolled. Demographic and clinical data were collected. Degree of AAC in each enrolled patient was determined with Agatston method based on a neck computed tomography angiography. NLR was divided into 4 groups according to quartile values. Generalized linear model (ordinal probit) was performed to assess the association between NLR quartiles and severity of AAC.

RESULTS

There were 151 (20.2%), 153 (20.4%), and 445 (59.4%) patients classified as without AAC, with mild AAC, and with severe AAC, respectively. Patients with severe AAC had the highest NLR values (2.37[1.79-3.42] versus 2.29[1.55-2.96] versus 2.17[1.64-2.91], P = .025) compared to patients without AAC and with mild AAC. In age- and sex-adjusted models, patients with the highest NLR (quartile 4) were correlated with severer AAC (β = .348 ± .128, P = .006) compared to those with the lowest levels (quartile 1). The correlation between NLR quartile 4 and severer AAC still existed (β = .335 ± .129, P = .009) in multivariable-adjusted model.

CONCLUSIONS

This study suggested that NLR may reflect the severity of AAC. NLR may be considered as a valuable predictor of the degree of artery calcification.

Increased levels of legumain in plasma and plaques from patients with carotid atherosclerosis

BACKGROUND AND AIMS

The cysteine protease legumain has been shown to be up-regulated in unstable atherosclerotic plaques. This study aims to further elucidate legumain in atherosclerosis, by examining legumain in plasma and carotid plaques from patients with carotid stenosis. Furthermore, legumain secretion from monocyte-derived macrophages treated with atherogenic lipids during macrophage polarization was studied.

METHODS

Plasma levels of legumain from patients with carotid stenosis (n = 254), healthy controls (n = 91), and secreted from monocyte-derived macrophages were assessed by enzyme-linked-immunosorbent assay. Quantitative PCR and immunoblotting of legumain were performed on isolated plaques and legumain localization was visualized by immunohistochemistry and fluorescence microscopy. Monocyte-derived macrophages polarized to M1 or M2 macrophages were treated with VLDL, oxLDL or cholesterol crystals (CC) and the level of legumain analysed.

RESULTS

Patients with carotid stenosis had significantly higher levels of plasma legumain compared with healthy controls (median 2.0 versus 1.5 ng/ml, respectively; p = 0.003), although there was no correlation between the level of legumain and the degree of stenosis, and legumain was not an independent factor to identify patients with carotid plaques. Moreover, patients with symptoms the last 2 months had higher expressions of mature legumain, cystatin C and E/M, and the macrophage markers CD80 (M1) and CD163 (M2). Legumain co-localized with both M1 and M2 macrophages within plaques, whereas legumain mRNA expression was significantly higher (p < 0.0001) in plaques compared to non-atherosclerotic arteries (controls). Furthermore, in vitro studies showed significantly increased secretion of legumain from pro-inflammatory M1 compared to pro-resolving M2 macrophages (p = 0.014), and particularly in M1 treated with CC. In plaques, legumain was localized to structures resembling foam cells.

CONCLUSIONS

Legumain is increased in both plasma and plaques of patients with carotid stenosis and might be a new and early biomarker of atherosclerosis.

Impact of Ivabradine on Inflammatory Markers in Chronic Heart Failure

Background. Inflammation plays a crucial role in the progression of chronic heart failure (CHF). Ivabradine is known to reduce the morbidity and mortality of patients with CHF under certain conditions. Beyond the reduction of heart rate, only limited knowledge exists about potential anti-inflammatory effects of ivabradine that might contribute to its benefit in CHF. Thus, the present study aimed to investigate the effect of ivabradine on systemic inflammation. Methods. In the present study, 33 patients with CHF due to dilated, ischemic, and hypertensive cardiomyopathy were treated with ivabradine according to the guidelines of the European Society of Cardiology (ESC). A number of circulating dendritic cells as well as inflammatory mediators were investigated using FACS analysis and ELISA, respectively, before and during ivabradine therapy. Results. Treatment with ivabradine resulted in a significant improvement of CHF symptoms as well as an increase in left ventricular ejection fraction. Moreover, ivabradine treatment led to a significant reduction of TNF-alpha (TNF-α) serum levels and a reconstitution of circulating dendritic cells which are known to be reduced in patients with CHF. Conclusion. We show that treatment with ivabradine in patients with CHF resulted in an improvement of HF symptoms and ejection fraction as well as a normalization of inflammatory mediators.

Anti-cytokine therapy for prevention of atherosclerosis

BACKGROUND

Currently a chronic inflammation is considered to be the one of the most important reasons of the atherosclerosis progression. A huge amount of researches over the past few decades are devoted to study the various mechanisms of inflammation in the development of atherosclerotic lesions.

PURPOSE

To review current capabilities of anti-inflammatory therapy for the prevention and treatment of atherosclerosis and its clinical manifestations.

METHODS

Appropriate articles on inflammatory cytokines in atherosclerosis and anti-inflammatory prevention of atherosclerosis were searched in PubMed Database from their respective inceptions until October 2015.

SECTIONS

"The role of inflammatory cytokines in the development of atherosclerotic lesions" describes available data on the possible inflammatory mechanisms of the atherogenesis with a special attention to the role of cytokines. "Modern experience of anti-inflammatory therapy for the treatment of atherosclerosis" describes modern anti-inflammatory preparations with anti-atherosclerotic effect including natural preparations. In "the development of anti-inflammatory herbal preparation for atherosclerosis prevention" an algorithm is demonstrated that includes screening of anti-cytokine activity of different natural products, the development of the most effective combination and estimation of its effect in cell culture model, in animal model of the acute aseptic inflammation and in a pilot clinical trial. A natural preparation "Inflaminat" based on black elder berries (Sambucus nigra L.), violet tricolor herb (Viola tricolor L.) and calendula flowers (Calendula officinalis L.) possessing anti-cytokine activity was developed using the designed algorithm. The results of the following 2-year double blind placebo-controlled clinical study show that "Inflaminat" reduces carotid IMT progression, i.e. has anti-atherosclerotic effect.

CONCLUSION

Anti-cytokine therapy may be a promising direction in moderation of atherogenesis, especially when it begins on the early stages of subclinical atherosclerosis. The use of herbal preparations with anti-cytokine mechanism of action is the most perspective for timely prevention of atherosclerosis, as they have no significant side effects and can be prescribed for long-term administration.

Circulating CD14+ and CD14highCD16- classical monocytes are reduced in patients with signs of plaque neovascularization in the carotid artery

BACKGROUND AND AIMS

Monocytes are known to play a key role in the initiation and progression of atherosclerosis and contribute to plaque destabilization through the generation of signals that promote inflammation and neoangiogenesis. In humans, studies investigating the features of circulating monocytes in advanced atherosclerotic lesions are lacking.

METHODS

Patients (mean age 69 years, 56% males) with intermediate asymptomatic carotid stenosis (40-70% in diameter) were evaluated for maximal stenosis in common carotid artery, carotid bulb and internal carotid artery, overall disease burden as estimated with total plaque area (TPA), greyscale and neovascularization in 244 advanced carotid plaques. Absolute counts of circulating CD14+ monocytes, of classical (CD14^highCD16-), intermediate (CD14^highCD16+) and non-classical (CD14^lowCD16+) monocytes and HLA-DR+ median fluorescence intensity for each subset were evaluated with flow cytometry.

RESULTS

No correlation was found between monocytes and overall atherosclerotic burden, nor with high sensitivity C-reactive protein (hsCRP) or interleukin-6 (IL-6). In contrast, plaque signs of neovascularization were associated with significantly lower counts of circulating CD14+ monocytes (297 versus 350 cells/mm³, p = 0.039) and of classical monocytes (255 versus 310 cells/mm³, p = 0.029).

CONCLUSIONS

Neovascularized atherosclerotic lesions selectively associate with lower blood levels of CD14+ and CD14^highCD16- monocytes independently of systemic inflammatory activity, as indicated by normal hsCRP levels. Whether the reduction of circulating CD14+ and CD14^highCD16- monocytes is due to a potential redistribution of these cell types into active lesions remains to be explored.

Circulating Chemerin Is Associated With Carotid Plaque Instability, Whereas Resistin Is Related to Cerebrovascular Symptomatology

OBJECTIVE

The rupture of unstable carotid atherosclerotic plaques is one of the main causes of cerebrovascular ischemic events. There is need for circulating markers that can predict plaque instability and risk of stroke. Proinflammatory chemerin, leptin, and resistin, along with anti-inflammatory adiponectin, are adipokines with direct influence on vascular function. We investigated the association of circulating adipokines with carotid plaque instability and cerebrovascular symptomatology.

APPROACH AND RESULTS

Neurologically symptomatic and asymptomatic patients (n=165) scheduled for carotid endarterectomy were recruited. Fasting blood samples were collected preoperatively; adiponectin and leptin levels were determined by radioimmunoassay; and chemerin and resistin levels were measured by enzyme-linked immunosorbent assays. The instability of plaque specimens was assessed using gold-standard histological classifications. Chemerin was significantly associated with plaque instability. The fully adjusted model, accounting for age, sex, body mass index, high-sensitivity C-reactive protein, type 2 diabetes mellitus, and circulating adiponectin, leptin, and resistin, yielded an odds ratio of 0.991 (95% confidence interval 0.985-0.998) for plaque instability per unit increase in chemerin. High leptin levels were significantly associated with presence of specific features of plaque instability. In subjects with type 2 diabetes mellitus, resistin levels were significantly elevated in symptomatic when compared with asymptomatic subjects (P=0.001) and increased the risk of cerebrovascular symptomatology (adjusted odds ratio 1.264, 95% confidence interval 1.004-1.594).

CONCLUSIONS

Low chemerin and high resistin levels were associated with carotid disease severity, suggesting that these adipokines may act as potential markers for plaque instability and stroke risk. Future studies are needed to assess causation between circulating adipokines and plaque instability.

Linking CD11b (+) Dendritic Cells and Natural Killer T Cells to Plaque Inflammation in Atherosclerosis

Atherosclerosis remains the leading cause of death and disability in our Western society. To investigate whether the dynamics of leukocyte (sub)populations could be predictive for plaque inflammation during atherosclerosis, we analyzed innate and adaptive immune cell distributions in blood, plaques, and lymphoid tissue reservoirs in apolipoprotein E-deficient (ApoE^−/−) mice and in blood and plaques from patients undergoing endarterectomy. Firstly, there was predominance of the CD11b⁺ conventional dendritic cell (cDC) subset in the plaque. Secondly, a strong inverse correlation was observed between CD11b⁺ cDC or natural killer T (NKT) cells in blood and markers of inflammation in the plaque (including CD3, T-bet, CCR5, and CCR7). This indicates that circulating CD11b⁺ cDC and NKT cells show great potential to reflect the inflammatory status in the atherosclerotic plaque. Our results suggest that distinct changes in inflammatory cell dynamics may carry biomarker potential reflecting atherosclerotic lesion progression. This not only is crucial for a better understanding of the immunopathogenesis but also bares therapeutic potential, since immune cell-based therapies are emerging as a promising novel strategy in the battle against atherosclerosis and its associated comorbidities. The cDC-NKT cell interaction in atherosclerosis serves as a good candidate for future investigations.

A focus on inflammation as a major risk factor for atherosclerotic cardiovascular diseases

Atherosclerosis is a dynamic, pathogenic process in the artery wall, with potential adverse outcome for the host. Acute events such as myocardial infarction and ischemic stroke often result from rupture of unstable atherosclerotic lesions. Understanding the underlying pathology of such lesions and why and when they rupture, is therefore of great interest for the development of new diagnostics and treatment. Inflammation is one of the key drivers of atherosclerotic plaque development and the interplay between inflammation and lipids constitutes the hallmark of atherosclerotic disease. This review summarizes the role of inflammation in atherosclerosis and presents some of the latest discoveries as well as unmet needs regarding the role of inflammation as major risk factor in atherosclerotic disease.

Smooth muscle immaturity in the carotid arterial neointima as a prognostic marker for systemic atherogenic cardiovascular events in the Asian male

Although immaturity of neointimal smooth muscle cells (SMCs) in coronary arteries has recently been demonstrated to be associated with acute coronary syndrome, the carotid arterial counterpart has not been investigated. We hypothesized that the same investigation of carotid endarterectomy specimens might contribute to living patients. Carotid endarterectomy specimens from 33 Asian males who underwent a 5-year follow-up were examined. Age, atherosclerotic risk factors, and percentage stenosis were investigated. Histologically, the fibrous cap/lipid core ratio was measured. Maturation of SMCs was assessed by the h-caldesmon/smooth muscle actin (SMA) ratio by immunohistochemistry in 3 different regions (luminal, medial, and opposite side of lipid core) in the neointima. Associations of these factors with preoperative symptoms along with postoperative systemic atherogenic cardiovascular events were analyzed. It was revealed that fibrous cap/lipid core ratio was significantly lower in symptomatic than in asymptomatic patients, while the h-caldesmon/SMA ratio was significantly lower in patients with than without postoperative systemic atherogenic cardiovascular events by the Student's t-test (P<0.05). Logistic regression model demonstrated that younger age and a lower h-caldesmon/SMA ratio were associated with postoperative systemic atherogenic cardiovascular events (P<0.05). This result was not different when 3 different regions were each analyzed instead. Immaturity of neointimal SMCs shown by a lower h-caldesmon/SMA ratio by immunohistochemistry was associated with systemic atherogenic cardiovascular events. Thus, this finding may be predictive of these events after carotid endarterectomy. Uniform results among different neointimal regions suggest that immaturity of neointimal SMCs causes plaque instability and does not occur secondarily to plaque instability.

Apple Polyphenols Decrease Atherosclerosis and Hepatic Steatosis in ApoE-/- Mice through the ROS/MAPK/NF-κB Pathway

In this study, we examined the effects of apple polyphenols (APs) on hyperlipidemia, atherosclerosis, hepatic steatosis and endothelial function and investigated the potential mechanisms. ApoE^−/− mice were fed a western-type diet and orally treated with APs (100 mg/kg) or atorvastatin (10 mg/kg) for 12 weeks. Hyperlipidemia and atherosclerosis in the aortic sinuses and, and hepatic lipidosis were measured. The treatment with APs or atorvastatin induced a remarkable reduction in the atherosclerotic lesions and hepatic steatosis and decreased the levels of low-density lipoprotein, triglyceride, CCL-2 and VCAM-1 levels in the plasma. Conversely, the APs significantly increased the plasma levels of high-density lipoprotein (HDL) cholesterol and markedly up-regulated the glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) levels in liver tissues. Moreover, the APs treatment modulated lipid metabolism by up-regulating the transcription of associated hepatic genes including PPARα, while down-regulating the transcription of SCAP and its downstream genes associated with lipid synthesis in the liver. Histological assessment showed that the APs treatment also reduced the macrophage infiltration in the aortic root plaque and the inflammatory cells infiltrations to the liver tissues. Moreover, we confirmed that the APs treatment greatly reduced the ox-LDL-induced endothelial dysfunction and monocyte adhesion to rat aortic endothelial cells (RAECs). Mechanistically, the APs treatment suppressed the ROS/MAPK/NF-κB signaling pathway, and consequently, reduced CCL-2, ICAM-1 and VCAM-1 expression. Our results suggest that the APs are a beneficial nutritional supplement for the attenuation of atherosclerosis.