An increase of interleukin-33 serum levels after coronary stent implantation is associated with coronary in-stent restenosis

Catlet scoring system as a new predictor for in-stent restenosis in patients with chronic coronary artery disease undergoing percutaneous coronary intervention with drug-eluting stent

BACKGROUND

He's team have recently developed a new Coronary Artery Tree description and Lesion EvaluaTion (CatLet) angiographic scoring system, which is capable of accounting for the variability in coronary anatomy, and risk-stratifying patients with coronary artery disease. Preliminary studies have demonstrated its superiority over the the Synergy between percutaneous coronary intervention with Taxus and Cardiac Surgery (SYNTAX) score with respect to outcome predictions for acute myocardial infarction (AMI) patients. However, there are fewer studies on the prognostic in chronic coronary artery disease(CAD). This study aimed to clarify whether the CatLet score had a predictive value for in-stent restenosis(ISR) in patients with chronic coronary artery disease undergoing percutaneous coronary intervention with drug-eluting stent(DES).

METHODS

A total of 260 patients who were diagnosed with chronic CAD and underwent coronary DES implantation at the second affiliated Hospital of Wannan medical college in China were consecutively enrolled from January 2020 to June 2021.Finally, 164 patients underwent the second angiography after 2 years.According to whether ISR was detected at follow-up angiography, patients were divided into the ISR group (n = 26) and the non-ISR group (n = 139).

RESULTS

A total of 165 patients (46 women and 119 men) with a mean ages of 66.19 ± 10.54 years were finally enrolled in this study. Of these, ISR occurred in 26/165 chronic CAD patients (15.76%) by follow-up angiography. Univariate analysis showed that most baseline characteristics of the ISR and non-ISR group were similar. Patients in the ISR group had significantly the history of chronic obstructive pulmonary disease(COPD), adverse lesion characteristic, higher Catlet score compared with patients in the non-ISR group.The CatLet score was capable of predicting in-stent restenosis after adjustment for risk factors; The Multivariable-adjusted model showed good calibration and good discrimination (area under ROC curve = 0.7164) for ISR.

CONCLUDE

CatLet score is a new predictor of ISR in patients with chronic CAD after coronary DES implantation.

IL-33/sST2 signaling pathway in pulmonary thromboembolism: A clinical observational study

BACKGROUND

Pulmonary thromboembolism (PTE) is a cardiovascular emergency that can result in mortality. In the interleukin-33 (IL-33) /soluble suppression of tumorigenicity 2 (sST2) signaling pathway, increased sST2 is a cardiovascular risk factor. This study aimed to investigate the effectiveness of biomarkers in the IL-33/sST2 signaling pathway in determining PTE diagnosis, clinical severity, and mortality.

METHOD

This study was conducted as a single-center, prospective, observational study. Patients admitted to the emergency department and diagnosed with PTE constituted the patient group (n = 112), and healthy volunteers with similar sociodemographic characteristics constituted the control group (n = 62). Biomarkers in the IL-33/sST2 signaling pathway were evaluated for diagnosis, clinical severity, and prognosis.

RESULTS

IL-33 was lower in the patient group than in the control group (275.89 versus 403.35 pg/mL), while sST2 levels were higher in the patient group than in the control group (53.16 versus 11.78 ng/mL) (p < 0.001 and p = 0.001; respectively). The AUC of IL-33 to diagnose PTE was 0.656 (95 % CI: 0.580-0.726). The optimal IL-33 cut-off point to diagnose PTE was ≤304.11 pg/mL (56.2 % sensitivity, 79 % specificity). The AUC of sST2 to diagnose PTE was 0.818 (95 % CI: 0.752-0.872). The optimal sST2 cut-off point to diagnose PTE was >14.48 ng/mL (83 % sensitivity, 71 % specificity). IL-33 levels were lower in patients with mortality (169.85 versus 332.04 pg/mL) compared to patients without mortality, whereas sST2 levels were higher in patients with mortality (118.32 versus 28.07 ng/mL) compared to patients without mortality (p > 0.001 for both). The AUC of IL-33 to predict the mortality of PTE was 0.801 (95 % CI: 0.715-0.870). The optimal IL-33 cut-off point to predict the mortality of PTE was ≤212.05 pg/mL (75 % sensitivity, 79.5 % specificity). The AUC of sST2 to predict the mortality of PTE was 0.824 (95 % CI: 0.740-0.889). The optimal sST2 cut-off point to predict the mortality of PTE was >81 ng/mL (95.8 % sensitivity, 78.4 % specificity).

CONCLUSION

In the IL-33/ST2 signaling pathway, decreased IL-33 and increased sST2 are valuable biomarkers for diagnosis and prediction of mortality in patients with PTE.

Risk prediction model for in-stent restenosis following PCI: a systematic review

Introduction

The morbidity and mortality rates of coronary heart disease are significant, with PCI being the primary treatment. The high incidence of ISR following PCI poses a challenge to its effectiveness. Currently, there are numerous studies on ISR risk prediction models after PCI, but the quality varies and there is still a lack of systematic evaluation and analysis.

Methods

To systematically retrieve and evaluate the risk prediction models for ISR after PCI. A comprehensive search was conducted across 9 databases from inception to March 1, 2024. The screening of literature and extraction of data were independently carried out by two investigators, utilizing the checklist for critical appraisal and data extraction for systematic reviews of prediction modeling studies (CHARMS). Additionally, the risk of bias and applicability were evaluated using the Prediction Model Risk of Bias Assessment Tool (PROBAST).

Results

A total of 17 studies with 29 models were included, with a sample size of 175-10,004 cases, and the incidence of outcome events was 5.79%-58.86%. The area under the receiver operating characteristic curve was 0.530-0.953. The top 5 predictors with high frequency were diabetes, number of diseased vessels, age, LDL-C and stent diameter. Bias risk assessment into the research of the risk of higher bias the applicability of the four study better.

Discussion

The overall risk of bias in the current ISR risk prediction model post-PCI is deemed high. Moving forward, it is imperative to enhance study design and specify the reporting process, optimize and validate the model, and enhance its performance.

Investigating the Prognostic Potential of Plasma ST2 in Patients with Peripheral Artery Disease: Identification and Evaluation

Soluble interleukin 1 receptor-like 1 (ST2) is a circulating protein demonstrated to be associated with cardiovascular diseases; however, it has not been studied as a biomarker for peripheral artery disease (PAD). Using a prospectively recruited cohort of 476 patients (312 with PAD and 164 without PAD), we conducted a prognostic study of PAD using clinical/biomarker data. Plasma concentrations of three circulating proteins [ST2, cytokine-responsive gene-2 (CRG-2), vascular endothelial growth factor (VEGF)] were measured at baseline and the cohort was followed for 2 years. The outcome of interest was a 2-year major adverse limb event (MALE; composite of major amputation, vascular intervention, or acute limb ischemia). Using 10-fold cross-validation, a random forest model was trained using clinical characteristics and plasma ST2 levels. The primary model evaluation metric was the F1 score. Out of the three circulating proteins analyzed, ST2 was the only one that was statistically significantly higher in individuals with PAD compared to patients without PAD (mean concentration in plasma of 9.57 [SD 5.86] vs. 11.39 [SD 6.43] pg/mL, p < 0.001). Over a 2-year period, 28 (9%) patients with PAD experienced MALE. Our predictive model, incorporating clinical features and plasma ST2 levels, achieved an F1 score of 0.713 for forecasting 2-year MALE outcomes. Patients identified as high-risk by this model showed a significantly increased likelihood of developing MALE (HR 1.06, 95% CI 1.02-1.13, p = 0.003). By combining clinical characteristics and plasma ST2 levels, our proposed predictive model offers accurate risk assessment for 2-year MALE in PAD patients. This algorithm supports risk stratification in PAD, guiding clinical decisions regarding further vascular evaluation, specialist referrals, and appropriate medical or surgical interventions, thereby potentially enhancing patient outcomes.

A systematic review and bioinformatic study on clinical, paraclinical, and genetic factors predisposing to stent restenosis following percutaneous coronary intervention

BACKGROUND

Stent restenosis is a relatively common phenomenon among patients with coronary heart disease undergoing percutaneous coronary intervention (PCI). It seems that a set of clinical, laboratory, and even genetic factors make people susceptible to such a phenomenon and in fact, this is multi-factorial. We aimed to first determine the underlying clinical and laboratory risk factors for the occurrence of stent re-stenosis after PCI based on a systematic review study, and after that, through a bioinformatics study, to evaluate the related genes and microRNAs with the occurrence of stent re-stenosis.

MAIN TEXT

In the first step, the manuscript databases including Medline, Web of Knowledge, Google Scholar, Scopus, and Cochrane were deeply searched by the two blinded investigators for all eligible studies based on the considered keywords to introduce clinical and laboratory determinants of stent re-stenosis. In the bioinformatic phase, and following a review of the literature to identify genes and microRNAs involved in restenosis, the interaction of each gene with other genes associated with stent re-stenosis was determined by GeneMANIA network analysis and Cytoscape software. Overall, 67 articles (including 40,789 patients) on clinical and biochemical predictors for stent restenosis and 25 articles on genetic determinants of this event were eligible for the final analysis. The predictors for this event were categorized into four subgroups patient-based parameters including traditional cardiovascular risk profiles, stent-based parameters including type and diametric characteristics of the stents used, coronary lesion-based parameters including several two target lesions and coronary involvement severity and laboratory-based parameters particularly related to activation of inflammatory processes. In the bioinformatic phase, we uncovered 42 genes that have been described to be involved in such a phenomenon considering a special position for genes encoding inflammatory cytokines. Also, 12 microRNAs have been pointed to be involved in targeting genes involved in stent re-stenosis.

CONCLUSIONS

The incidence of stent re-stenosis will be the result of a complex interaction of clinical risk factors, laboratory factors mostly related to the activation of inflammatory processes, and a complex network of gene-to-gene interactions.

The role of inflammation in percutaneous coronary intervention, from balloon angioplasty to drug eluting stents

The role of inflammation in percutaneous coronary intervention (PCI) has been investigated in numerous studies. Both pre-PCI and post-PCI inflammatory status have been demonstrated to be linked with patient outcomes. C-reactive protein continues to be the most studied inflammatory biomarker, while a growing number of additional biomarkers, including cytokines and immune cells, are being assessed. As insights are gained into the complexities of the inflammatory response to PCI, it becomes evident that a targeted approach is necessary to ensure optimal patient outcomes. Here, we review the biomarkers that can predict patient outcomes following PCI and specifically how they differ for balloon angioplasty, bare metal stents and drug eluting stents. A specific focus is given to human studies and periprocedural inflammation rather than inflammation associated with myocardial infarction.

Roles of IL-33 in the Pathogenesis of Cardiac Disorders

Interleukin-33 (IL-33) is a member of the IL-1 cytokine family and is believed to play important roles in different diseases by binding to its specific receptor suppression of tumorigenicity 2 (ST2). In the heart, IL-33 is expressed in different cells including cardiomyocytes, fibroblasts, endothelium, and epithelium. Although many studies have been devoted to investigating the effects of IL-33 on heart diseases, its roles in myocardial injuries remain obscure, and thus further studies are mandatory to unravel the underlying molecular mechanisms. We highlighted the current knowledge of the molecular and cellular characteristics of IL-33 and then summarized its major roles in different myocardial injuries, mainly focusing on infection, heart transplantation, coronary atherosclerosis, myocardial infarction, and diabetic cardiomyopathy. This narrative review will summarize current understanding and insights regarding the implications of IL-33 in cardiac diseases and its diagnostic and therapeutic potential for cardiac disease management.

Interleukin-33/sST2: Dynamic assessment in patients with acute coronary syndrome

PURPOSE

Interleukin (IL)-33 and its soluble receptor ST2 (sST2) play a crucial role in the immune response. sST2 has been approved by the Food and Drug Administration as a prognostic biomarker of mortality in chronic heart failure patients, however, the role of IL-33 and sST2 in atherosclerotic cardiovascular disease remains unclear. The aim of this study was to measure serum level of IL-33 and sST2 of patients at the onset of acute coronary syndrome (ACS) and 3 months after primary percutaneous revascularization.

PATIENTS AND METHODS

Forty patients were divided into ST segment elevation myocardial infarction (STEMI) group, non-ST segment elevation myocardial infarction (NSTEMI) and unstable angina (UA) group. IL-33 and sST2 level were measured with ELISA. Additionally, IL-33 expression in peripheral blood mononuclear cells (PBMCs), was evaluated.

RESULTS

All ACS patients had a significantly lower level of sST2 3 months after ACS as compared to the baseline (p ​< ​0.039). The STEMI patients had higher serum levels of IL-33 at the moment of ACS as compared to 3 months after the event, with an average decrease of 17.87 ​pg/ml (p ​< ​0.007). Conversely, sST2 serum levels were still high after 3 months following an ACS in STEMI patients. ROC curve demonstrated that increased IL-33 serum level could be STEMI predictor.

CONCLUSIONS

The assessment of the baseline and dynamics of changes in IL-33 and sST2 concentrations in patients with ACS may be important for the diagnostic process and may help in understanding of how the immune mechanisms work at the moment of an ACS event.

Markers of Restenosis after Percutaneous Transluminal Balloon Angioplasty in Patients with Critical Limb Ischemia

Among cardiovascular diseases, chronic obliterating lesions of the arteries of lower extremities, which are one of the important problems of modern healthcare, are distinguished. In most cases, the cause of damage to the arteries of lower extremities is atherosclerosis. The most severe form is chronic ischemia, characterized by pain at rest and ischemic ulcers, ultimately increasing the risk of limb loss and cardiovascular mortality. Therefore, patients with critical limb ischemia need limb revascularization. Percutaneous transluminal balloon angioplasty is one of the least invasive and safe approaches, with advantages for patients with comorbidities. However, after this procedure, restenosis is still possible. Early detection of changes in the composition of some molecules as markers of restenosis will help screen patients at the risk of restenosis, as well as find ways to apply efforts for further directions of inhibition of this process. The purpose of this review is to provide the most important and up-to-date information on the mechanisms of restenosis development, as well as possible predictors of their occurrence. The information collected in this publication may be useful in predicting outcomes after surgical treatment and will also find new ways for the target implication to the mechanisms of development of restenosis and atherosclerosis.

Effect and significance of hyperlipoproteinemia on stent thrombosis in patients with implanted drug-eluting stents: The 5-year follow up study

BACKGROUND

Elevated blood lipid level, also known as hyperlipoproteinemia (HLP), is the most common metabolic disorder in the general population. According to US National Heart Institute data, about 36% of adults and 10% of children aged 9 to 12 have elevated cholesterol levels. The risk of ischemic heart disease increases by 2-3% with every 1% increase in total cholesterol levels. Therefore, men aged 55-65 with a 10% increase in total cholesterol have about 38% increased ischemic heart disease mortality. The study's main objective is to determine the occurrence of thrombotic complications in patients in whom first-generation drug-eluting stents are implanted and how these events are influenced by the presence of HLP.

METHODS

The study is retrospective, clinical, and non-interventional with a five-year follow-up period for each patient. Initially, 800 patients undergoing index percutaneous coronary angioplasty with sirolimus-eluting and paclitaxel-eluting stent implantation were enrolled. Clinical data collected included cardiac disorders, the presence of diabetes mellitus, hyperlipoproteinemia, and smoking as a risk factor. In the examined group of patients, stent thrombosis was monitored according to Academic Research Consortium (ARC) criteria.

RESULTS

The study included 800 patients who underwent percutaneous coronary angioplasty index. At the end of the follow-up period, 701 patients (87.6%) completed the clinical trial and were included in the statistical analysis. Stent thrombosis, determined according to ARC criteria, was reported as 'definitive stent thrombosis' in 22 patients (3.06%), 'probable stent thrombosis' in 1 patient (0.14%), and 'possible stent thrombosis' in 1 patient (0.14%). Of the 404 patients with HLP, 120 patients had a total cholesterol value >300 mg/dL. Twenty patients with definitive stent thrombosis had cholesterol >300 mg/dL. Patients with probable and possible stent thrombosis did not have HLP. A comparison of patients with stent thrombosis, with HLP and without HLP, revealed a statistically significant difference (16.67% vs. 1.35%, p <0.001). Comparing patients with unstable angina pectoris, with cholesterol value >300 mg/dL and without HLP, a statistically significant difference was observed (71.7% vs. 17.2%, p <0.001).

CONCLUSIONS

We report on the long-term follow up of patients with stent thrombosis after drug-eluting stent insertion with and without HLP. The results suggest that HLP influences the development of coronary disease, with a significant influence on complications following percutaneous coronary intervention.

IL-33 and the Cytokine Storm in COVID-19: From a Potential Immunological Relationship towards Precision Medicine

Coronavirus SARS-CoV-2 has represented, and still represents, a real challenge from a clinical, diagnostic and therapeutic point of view. During acute infection, the increased levels of pro-inflammatory cytokines, which are involved in the pathology of disease and the development of SARS-CoV-2-induced acute respiratory disease syndrome, the life-threatening form of this infection, are correlated with patient survival and disease severity. IL-33, a key cytokine involved in both innate and adaptive immune responses in mucosal organs, can increase airway inflammation, mucus secretion and Th2 cytokine synthesis in the lungs, following respiratory infections. Similar to cases of exposure to known respiratory virus infections, exposure to SARS-CoV-2 induces the expression of IL-33, correlating with T-cell activation and lung disease severity. In this work, we analyse current evidence regarding the immunological role of IL-33 in patients affected by COVID-19, to evaluate not only the clinical impact correlated to its production but also to identify possible future immunological therapies that can block the most expressed inflammatory molecules, preventing worsening of the disease and saving patient lives.

IL-33/ST2 immunobiology in coronary artery disease: A systematic review and meta-analysis

The IL-33/ST2 axis is reported to be controversially associated with coronary artery disease (CAD). A systematic review of the association between the IL-33/ST2 axis and CAD revealed that IL-33/ST2 plays a protective role in CAD and serum sST2 and IL-33 levels are increased in patients with cardiovascular disease. Therefore, the association of IL-33/ST2 single nucleotide polymorphisms (SNPs) with CAD prevalence, prognosis, and risk factors was assessed by performing a meta-analysis. Through a literature search of relevant articles in various databases using the relevant keywords, seven studies were included in the analysis. The meta-analysis showed that the IL-33/ST2 axis was associated with increased CAD risk [pooled odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.13–1.20]. Gene subgroup analysis showed a close association of IL1RL1 (OR = 1.25, 95% CI: 1.20–1.30; I² = 85.9%; p = 0.000) and IL1RAcP (OR = 1.42, 95% CI: 1.26–1.60; I² = 27.1%; p = 0.203) with increased CAD risk. However, the association for the IL-33 gene was not statistically significant. SNPs rs7044343 (T), rs10435816 (G), rs11792633 (C) in IL-33 gene were associated with a protective effect in CAD. However, rs7025417 (T) in IL-33, rs11685424 (G) in IL1RL1, rs950880 (A) in sST2, and rs4624606 (A) in IL1RAcP were related to increased CAD risk. Overall, polymorphisms in IL-33/ST2 axis components were associated with increased CAD risk. These results may help identify key features of IL-33/ST2 immunobiology in CAD along with potential treatment strategies to lower disease burden.

Serum glycated albumin is associated with in-stent restenosis in patients with acute coronary syndrome after percutaneous coronary intervention with drug-eluting stents: An observational study

Background

Previous studies have confirmed the predicted value of serum glycated albumin (GA) in atherosclerotic cardiovascular disease. However, the relationship between GA and the development of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation has not been verified in patients with acute coronary syndrome (ACS).

Materials and methods

In this study, 797 patients diagnosed with ACS who underwent re-coronary angiography more than 6 months after the first successful DES-based percutaneous coronary intervention (PCI) were eventually included. Patients were categorized into two groups based on the median GA levels of 14.94%. Moreover, multivariate logistic regression analysis models and the net reclassification improvement and integrated differentiation improvement risk models were constructed to assess the relationship between the GA and DES-ISR in patients with ACS.

Results

The GA was significantly associated with an increased risk of DES-ISR, upon adjusting for confounding factors (as nominal variate: OR 1.868, 95% CI 1.191-2.932, P = 0.007; as continuous variate: OR 1.109, 95% CI 1.040-1.183, P = 0.002). The addition of GA to a baseline risk model had an incremental effect on the predictive value for DES-ISR (AUC: GA vs. baseline model, 0.714 vs. 0.692, comparison P = 0.017; category-free net reclassification improvement (NRI) 0.080, P = 0.035; integrated discrimination improvement (IDI) 0.023, P < 0.001).

Conclusion

GA level was significantly associated with a high risk of DES-ISR in patients with ACS treated with PCI. Moreover, the addition of the GA to a baseline risk model has an incremental effect on the predictive potential for DES-ISR.

Soluble ST2 and All-Cause Mortality in Patients with Chronic Obstructive Pulmonary Disease—A 10-Year Cohort Study

Chronic obstructive pulmonary disease (COPD) is an inflammatory condition with constantly increasing mortality rates. Interleukin (IL)-33 and its decoy receptor, soluble suppression of tumorigenicity 2 (sST2), play a central role in the inflammatory response during infection. sST2 was suggested as a factor in the pathogenesis of COPD and emerged as a predictor of mortality in other non-communicable diseases. The role of sST2 as a predictor of mortality remains unclear in COPD yet. In this cohort study, we measured circulating concentrations of IL-33 and sST2 in the serum of patients with stable COPD (n = 59), patients with acute exacerbation of COPD (n = 29) and smoking (n = 20) and non-smoking controls (n = 20), using commercially available ELISAs, and investigated the prognostic role of sST2 in stable COPD. sST2 levels were significantly higher in COPD patients and smokers compared with non-smoking controls. We identified systolic blood pressure, forced expiratory volume in 1 s (FEV1% predicted), neutrophil count, lactate dehydrogenase and pack-years index as independent predictors of sST2 levels. During a median follow-up time of 10.6 years, 28 patients (47.5%) died. sST2 was an independent predictor of all-cause mortality in patients with COPD with a hazard ratio of 2.9 (95% CI 1.1–8.4, p = 0.035) per one standard deviation after adjustment for age, sex, pack-years, FEV1% predicted and C-reactive protein (CRP). sST2 concentrations are associated with severity of disease and long-term outcome in patients with COPD.

Treg cells in atherosclerosis

Atherosclerosis involves both innate and adaptive immunity. Here, we provide an overview of the role of regulatory T (Treg) cells in atherosclerotic diseases. Treg cells and their inhibitory cytokines, IL-10 and TGF-β, have been identified in atherosclerotic lesions and to inhibit progression through lipoprotein metabolism modulation. Treg cells have also been found to convert to T follicular helper (Tfh) cells and promote atherosclerosis progression. Treg cell involvement in different stages of atherosclerotic progression and Treg cell-mediated modulation of plaque development occurs via inflammation suppression and atheroma formation has been focused. Moreover, existing knowledge suggests that Treg cells are likely involved in the pathology of other specific circumstances including in-stent restenosis, neointimal hyperplasia, vessel graft failure, and ischemic arterial injury; however, there remain gaps regarding their specific contribution. Hence, advancements in the knowledge regarding Treg cells in diverse aspects of atherosclerosis offer translational significance for the management of atherosclerosis and associated diseases.

Association of metabolic and inflammatory markers with polycystic ovarian syndrome (PCOS): an update

BACKGROUND

Polycystic ovarian syndrome (PCOS) is the most prevalent metabolic disorder in reproductive-age women. It is indeed a multifactorial condition evidenced by ovarian dysfunction, hyperandrogenaemia, infertility, hormonal imbalance and chronic anovulation. Experimental evidence infers that PCOS women are prone to cardiovascular problems and insulin resistance.

PURPOSE

To furnish the details about the association of inflammatory markers in PCOS.

DESIGN

An extensive literature search on PubMed, science direct and google scholar has been performed for articles about PCOS and inflammation in PCOS. A comprehensive analysis using original articles, reviews, systemic and meta-analysis was conducted for better understanding the relationship between inflammatory cytokines and PCOS.

RESULTS

The inflammatory markers perform a substantial part in managing the functions of the ovary. Any disturbances in their levels can lead to ovarian dysfunction. Inflammatory markers are associated with PCOS pathogenesis. The interplay between inflammatory cytokines in the PCOS ovary strongly implies that inflammation is one of the most potent risk factors of PCOS.

CONCLUSION

Inflammatory markers have a significant role in regulating the ovary. This manuscript highlights the significance of metabolic and inflammatory markers with PCOS. Since PCOS is always considered as a metabolic disorder, researchers can also consider focusing on the relationship between the inflammatory markers in PCOS to establish a new treatment or management of the disease and to improve women's health.

Association of Soluble Suppression of Tumorigenesis 2 (sST2) With Platelet Activation, Monocyte Tissue Factor and Ischemic Outcomes Following Angioplasty and Stenting

Background: Peripheral artery disease (PAD) patients undergoing infrainguinal angioplasty with stenting suffer high rates of target lesion restenosis and ischemic events. Blood-based prognostic markers in these patients are currently limited. The IL-33/ST2-system is involved in atherothrombosis. Soluble ST2 has been proposed as a biomarker in patients with cardiovascular disease. Aim: To investigate the association of sST2 with platelet activation and monocyte tissue factor (TF) in 316 patients undergoing elective angioplasty and stenting for cardiovascular disease, and its predictive value for ischemic outcomes following infrainguinal angioplasty with stent implantation in 104 PAD patients within this cohort. Methods and Results: Circulating levels of sST2, platelet surface P-selectin, monocyte TF expression as well as soluble P-selectin were determined in 316 consecutive patients on dual antiplatelet therapy following angioplasty and stenting. sST2 was independently associated with soluble P-selectin (B = 6.4, 95% CI 2.0-10.7, p = 0.004) and TF expression (B = 0.56, 95% CI 0.02-1.1, p = 0.041) but not with platelet surface P-selectin (B = 0.1, 95% CI -0.1-0.3, p = 0.307) after adjustment for age, sex, clinical risk factors and inflammatory parameters. During the follow-up of 24 months, the primary endpoint occurred in 41 of 104 PAD patients (39.4%). However, circulating levels of sST2 did not predict the primary endpoint in PAD patients (HR 1.1, 95% CI 0.76-1.71, p = 0.527). Conclusion: sST2 is associated with soluble P-selectin and monocyte TF expression in atherosclerosis but not with ischemic outcomes following infrainguinal angioplasty with stent implantation for PAD.

IL-33 promotes the progression of vascular restenosis after carotid artery balloon injury by promoting carotid artery intimal hyperplasia and inflammatory response

Interleukin (IL)-33 is associated with vascular restenosis after carotid artery balloon injury. This work aims to investigate the involvement of IL-33 in carotid artery balloon injury. We first constructed carotid artery balloon injury model in male Wistar rats. Then, we found that IL-33 was highly expressed in the rats with carotid artery balloon injury 3, 14 and 21 days after surgery. Furthermore, IL-33 treatment promoted inflammatory response and carotid artery intimal hyperplasia in the rats with carotid artery balloon injury, which was effectively improved by anti-IL-33 treatment. In addition, IL-33 treatment enhanced proliferation, migration, inflammatory response and tube formation of human umbilical vein endothelial cells in a concentration-dependent way. In summary, our study demonstrates that IL-33 treatment promotes the progression of vascular restenosis after carotid artery balloon injury by enhancing carotid artery intimal hyperplasia and inflammatory response. Thus, our findings suggest that IL-33 maybe a valuable target for carotid artery balloon injury therapies.

Pro-inflammatory Cytokines in Acute Coronary Syndromes

BACKGROUND

Over the last decades, the role of inflammation and immune system activation in the initiation and progression of coronary artery disease (CAD) has been established.

OBJECTIVES

The study aimed to present the interplay between cytokines and their actions preceding and shortly after ACS.

METHODS

We searched in a systemic manner the most relevant articles to the topic of inflammation, cytokines, vulnerable plaque and myocardial infarction in MEDLINE, COCHRANE and EMBASE databases.

RESULTS

Different classes of cytokines (intereleukin [IL]-1 family, Tumor necrosis factor-alpha (TNF-α) family, chemokines, adipokines, interferons) are implicated in the entire process leading to destabilization of the atherosclerotic plaque, and consequently, to the incidence of myocardial infarction. Especially IL-1 and TNF-α family are involved in inflammatory cell accumulation, vulnerable plaque formation, platelet aggregation, cardiomyocyte apoptosis and adverse remodeling following the myocardial infarction. Several cytokines such as IL-6, adiponectin, interferon-γ, appear with significant prognostic value in ACS patients. Thus, research interest focuses on the modulation of inflammation in ACS to improve clinical outcomes.

CONCLUSION

Understanding the unique characteristics that accompany each cytokine-cytokine receptor interaction could illuminate the signaling pathways involved in plaque destabilization and indicate future treatment strategies to improve cardiovascular prognosis in ACS patients.

The pro-inflammatory marker soluble suppression of tumorigenicity-2 (ST2) is reduced especially in diabetic morbidly obese patients undergoing bariatric surgery

BACKGROUND

High soluble suppression of tumorigenicity-2 (sST2) is a marker of poor prognosis in chronic inflammatory conditions. ST2 and its ligand interleukin (IL)-33 are elevated in adipose tissue of obese individuals. We aimed to evaluate circulating sST2 and IL-33 as possible markers of metabolic benefit in morbidly overweight patients after Roux-en-Y gastric bypass (RYGB) bariatric surgery.

METHODS

sST2, IL-33, high sensitive IL-6, high sensitive C-reactive protein (hsCRP), leptin, cholesterol metabolism and liver parameters were measured in 80 morbidly obese individuals before and 1 year after bariatric surgery.

RESULTS

sST2 was higher (P = 0.03) in diabetics as compared to individuals without diabetes. Baseline sST2 was also higher in males than in females (P= 0.0002). One year after bariatric surgery, sST2 levels were decreased (median 120, IQR 59-176 pg/mL) as compared to sST2 before surgery (median 141, IQR 111-181, P = 0.0024), and the diabetic group showed most pronounced reduction in sST2 (P = 0.0016). An association was found between sST2 and liver function parameters before and after bariatric surgery, and between baseline sST2 and total cholesterol, triglyceride, total low density lipoprotein (LDL), small dense LDL, Apolipoprotein B as well as with small dense high density lipoproteins (HDL). In the subgroup of diabetic patients positive correlation between IL-33 and sST2 (r = 0.44, P = 0.05) was noticed.

CONCLUSIONS

Circulating sST2 is associated with markers of liver functions and lipid metabolism in severely obese patients and a reduction of sST2 was shown after successful bariatric surgery, most prominently in diabetic patients.

NFATc1-E2F1-LMCD1-Mediated IL-33 Expression by Thrombin Is Required for Injury-Induced Neointima Formation

Objective- IL (interleukin)-33 has been shown to play a role in endothelial dysfunction, but its role in atherosclerosis is controversial. Therefore, the purpose of this study is to examine its role in vascular wall remodeling following injury. Approach and Results- Thrombin induced IL-33 expression in a time-dependent manner in human aortic smooth muscle cells and inhibition of its activity by its neutralizing antibody suppressed thrombin induced human aortic smooth muscle cell migration but not DNA synthesis. In exploring the mechanisms, we found that Par1 (protease-activated receptor 1), Gαq/11 (Gα protein q/11), PLCβ3 (phospholipase Cβ3), NFATc1 (nuclear factor of activated T cells), E2F1 (E2F transcription factor 1), and LMCD1 (LIM and cysteine-rich domains protein 1) are involved in thrombin-induced IL-33 expression and migration. Furthermore, we identified an NFAT-binding site at -100 nt that mediates thrombin-induced IL-33 promoter activity. Interestingly, we observed that NFATc1, E2F1, and LMCD1 bind to NFAT site in response to thrombin and found that LMCD1, while alone has no significant effect, enhanced either NFATc1 or E2F1-dependent IL-33 promoter activity. In addition, we found that guidewire injury induces IL-33 expression in SMC and its neutralizing antibodies substantially reduce SMC migration and neointimal growth in vivo. Increased expression of IL-33 was also observed in human atherosclerotic lesions as compared to arteries without any lesions. Conclusions- The above findings reveal for the first time that thrombin-induced human aortic smooth muscle cell migration and injury-induced neointimal growth require IL-33 expression. In addition, thrombin-induced IL-33 expression requires LMCD1 enhanced combinatorial activation of NFATc1 and E2F1.

IL-33/IL-33R in various types of carotid artery atherosclerotic lesions

OBJECTIVE

Inflammation plays a crucial role in the progression of atherosclerotic plaques. The aim of the study was to investigate serum levels and expression of Interleukin-33 (IL-33) and ST2 receptor in atherosclerotic plaques and to analyze correlation with the type of the carotid plaques in patients with carotid disease.

METHODS

This study included 191 consecutive patients submitted for carotid endarterectomy (CEA). Preoperative serum levels of IL-33 and soluble ST2 (sST2) were measured. Atherosclerotic plaques obtained during surgery were initially histologically classified and immunohistochemical analyzes of IL-33, IL-33R, CD68 and alpha-SMA expression was performed. Ultrasound assessment of the level of carotid stenosis in each patient was performed prior to carotid surgery. Demographic and clinical data such as gender, age, smoking status, blood pressure, glycaemia, hemoglobin and creatinine levels, and comorbidities were collected and the comparisons between variables were statistically evaluated.

RESULTS

Serum levels of IL-33 (35.86 ± 7.93 pg/ml vs.12.29 ± 1.8 pg/ml, p < 0.05) and sST2 (183 ± 8.03 pg/ml vs. 122.31 ± 15.89 pg/ml, p < 0.05) were significantly higher in the group of CEA patients vs. healthy subjects. We demonstrated abundant tissue expression of IL-33 and ST2 in atherosclerotic carotid artery lesions. The levels of IL-33 and IL-33R expression were significantly higher in vulnerable plaques and significantly correlated with the degree of inflammatory cells infiltration in these plaques (R = 0.579, p = 0.049). Immunohistochemical analysis also revealed that cells responsible for IL-33 expression are not only mononuclear cells confined to inflammatory atherosclerotic lesions, but also smooth muscle cells which gained phenotypic characteristics of foam cells and were loaded with lipid droplets.

CONCLUSION

The obtained results confirm the importance of IL-33/ST2 axis in the process of atherosclerosis, and indicate its ambiguous function in immune response, whether as proinflammatory cytokine in advanced atherosclerotic lesions, or as profibrotic, in early lesions.

Dysregulation of IL-33/ST2 signaling and myocardial periarteriolar fibrosis

Microvascular dysfunction in the heart and its association with periarteriolar fibrosis may contribute to the diastolic dysfunction seen in heart failure with preserved ejection fraction. Interleukin-33 (IL-33) prevents global myocardial fibrosis in a pressure overloaded left ventricle by acting via its receptor, ST2 (encoded by the gene, Il1rl1); however, whether this cytokine can also modulate periarteriolar fibrosis remains unclear. We utilized two approaches to explore the role of IL-33/ST2 in periarteriolar fibrosis. First, we studied young and old wild type mice to test the hypothesis that IL-33 and ST2 expression change with age. Second, we produced pressure overload in mice deficient in IL-33 or ST2 by transverse aortic constriction (TAC). With age, IL-33 expression increased and ST2 expression decreased. These alterations accompanied increased periarteriolar fibrosis in aged mice. Mice deficient in ST2 but not IL-33 had a significant increase in periarteriolar fibrosis following TAC compared to wild type mice. Thus, loss of ST2 signaling rather than changes in IL-33 expression may contribute to periarteriolar fibrosis during aging or pressure overload, but manipulating this pathway alone may not prevent or reverse fibrosis.

Plasma levels of interleukin-33 and soluble suppression of tumorigenicity 2 in patients with advanced pancreatic ductal adenocarcinoma undergoing systemic chemotherapy

Interleukin-33 (IL-33) and its "decoy" receptor soluble ST2 (sST2) are involved in the development of chronic inflammation and cancer. We explored IL-33 and sST2 as a potential prognostic marker in patients with metastatic and locally advanced pancreatic ductal adenocarcinoma (PDAC). IL-33 and sST2 plasma levels were assessed in 20 patients with advanced PDAC before start of systemic chemotherapy and were analyzed in relation to clinical outcome. Kaplan Meier and multivariable Cox proportional hazards model analysis revealed a significant association between sST2 plasma levels and survival (HR 2.10, 95% CI 1.33-3.41, p = 0.002) and link high sST2 plasma levels to inferior survival in patients with advanced PDAC undergoing chemotherapy.

Conflicting vascular and metabolic impact of the IL-33/sST2 axis

Interleukin 33 (IL-33), which is expressed by several immune cell types, endothelial and epithelial cells, and fibroblasts, is a cytokine of the IL-1 family that acts both intra- and extracellularly to either enhance or resolve the inflammatory response. Intracellular IL-33 acts in the nucleus as a regulator of transcription. Once released from cells by mechanical stress, inflammatory cytokines, or necrosis, extracellular IL-33 is proteolytically processed to act in an autocrine/paracrine manner as an 'alarmin' on neighbouring or various immune cells expressing the ST2 receptor. Thus, IL-33 may serve an important role in tissue preservation and repair in response to injury; however, the actions of IL-33 are dampened by a soluble form of ST2 (sST2) that acts as a decoy receptor and is produced by endothelial and certain immune cells. Accumulating evidence supports the conclusion that sST2 is a biomarker of vascular health with diagnostic and/or prognostic value in various cardiovascular diseases, including coronary artery disease, myocardial infarction, atherosclerosis, giant-cell arteritis, acute aortic dissection, and ischaemic stroke, as well as obesity and diabetes. Although sST2 levels are positively associated with cardiovascular disease severity, the assumption that IL-33 is always beneficial is naïve. It is increasingly appreciated that the pathophysiological importance of IL-33 is highly dependent on cellular and temporal expression. Although IL-33 is atheroprotective and may prevent obesity and type 2 diabetes by regulating lipid metabolism, IL-33 appears to drive endothelial inflammation. Here, we review the current knowledge of the IL-33/ST2/sST2 signalling network and discuss its pathophysiological and translational implications in cardiovascular diseases.

Elevated Levels of Very Low-density Lipoprotein Cholesterol Independently Associated with In-stent Restenosis in Diabetic Patients after Drug-eluting Stent Implantation

Background:

High rate of in-stent restenosis (ISR) remained an unsolved clinical problem in clinical practice, especially among patients with diabetes mellitus (DM). Diabetic patients often had hypertriglyceridemia with elevated levels of very low-density lipoprotein cholesterol (VLDL-C). Increasing evidence suggested that VLDL-C was known as a significant risk factor for atherosclerosis and had been recommended as a treatment target by current dyslipidemia guidelines. However, the role of VLDL-C in the occurrence and development of ISR in coronary artery disease (CAD) patients with DM had not been studied. The aim of this study was to evaluate the association between the elevated levels of VLDL-C and the risk of ISR in CAD patients with DM.

Methods:

A total of 1390 diabetic patients, who underwent coronary drug-eluting stent (DES) implantation at Beijing Anzhen Hospital and followed up by angiography within 6–24 months, were consecutively enrolled. Patients’ demographic and clinical characteristics, including age, gender, CAD risk factors, family history, life style, medical history, and coronary angiographic information, were collected carefully at baseline percutaneous coronary intervention and follow-up angiography. Multivariate Cox's proportional hazards regression modeling using the step-wise method (entry, 0.05; removal, 0.05) was used to determine the independent risk associated with ISR in diabetic patients.

Results:

Finally, 1206 of patients were included in this study. ISR occurred in 132/1206 diabetic patients (10.9%) by follow-up angiography. Patients with ISR had elevated median serum VLDL-C levels compared with those without ISR (0.65 mmol/L vs. 0.52 mmol/L, P = 0.030). The multivariate regression analysis showed that VLDL-C was significantly associated with the risk of ISR in diabetic CAD patients (hazard ratio [HR] = 1.15, 95% confidence interval [CI]: 1.03–1.29, P = 0.017). The HR for the risk of ISR associated with VLDL-C level ≥0.52 mmol/L was 3.01 (95% CI: 1.24–7.34, P = 0.015).

Conclusion:

The elevated level of serum VLDL-C was a significant and independent risk factor for ISR in diabetic CAD patients after coronary DES implantation.

Understanding the role of non-coding RNA (ncRNA) in stent restenosis

Coronary heart disease (CHD) is one of the leading disorders with the highest mortality rate. Percutaneous angioplasty and stent implantation are the currently available standard methods for the treatment of obstructive coronary artery disease. However, the stent being an exogenous substance causes several complications by promoting the proliferation of vascular smooth muscle cells, immune responses and neointima formation after implantation, leading to post-stent restenosis (ISR) and late thrombosis. The prevention of these adverse vascular events is important to achieve long-term proper functioning of the heart after stent implantation. Non-coding ribonucleic acids (ncRNAs) are RNA molecules not translated into proteins, theyhave a great potential in regulating endothelial cell and vascular smooth muscle function as well as inflammatory reactions. In this review, we outline the regulatory functions of different classes of ncRNA in cardiovascular disease and propose ncRNAs as new targets for stent restonosis treatment.

Predictive value of low interleukin-33 in critically ill patients

Patients admitted to a medical intensive care unit (ICU) are characterized by an activated immune system and exhibit a high mortality rate irrespective of the underlying cause of admission. Interleukin (IL)-33 has been shown to be protective in experimental sepsis models and it has been demonstrated that circulating levels of its "decoy" receptor soluble ST2 (sST2) are associated with outcome in critically ill patients. The aim of the present study was to investigate whether circulating IL-33 is associated with 30-day mortality in patients admitted to a medical ICU. In this prospective, observational study, both IL-33 and sST2 levels were assessed in 223 consecutive patients at ICU admission using specific enzyme-linked immunosorbent assays (ELISAs). During the 30-day follow-up, 58 patients (26%) died. Circulating IL-33 was detectable in 166 patients and in 57 patients, serum IL-33 was below the detection limit. Both detectable IL-33 and sST2 below the median were strong predictors of survival in critically ill patients independent of acute physiology and chronic health evaluation II (APACHE II) score. IL-33 and sST2 predicted risk independent from each other. Patients with both, non-detectable levels of IL-33 and sST2 levels above the median, showed a dramatically increased mortality risk (HR 6.9 95% CI 3.0-16.2; p<0.001). Low levels of IL-33 and increased levels of sST2 predict mortality risk in critically ill patients independent from each other and APACHE II score. Both together showed additive predictive value suggesting a pathogenic role of the IL-33/ST2 system in critically ill patients.

HUCMNCs protect vascular endothelium and prevent ISR after endovascular interventional therapy for vascular diseases in T2DM rabbits

The therapeutic effect of transplantation of human umbilical cord blood cell-derived mononuclear cells (HUCMNCs) on treating in-stent restenosis (ISR) after endovascular interventional therapy (EIT) was evaluated in preclinical rabbit model of type 2 diabetes mellitus (T2DM)-related peripheral artery disease (PAD). HUCMNCs were transplanted to T2DM rabbits subjected to femoral artery occlusion surgery and received EIT. Serum concentration of soluble vascular endothelial cadherin (VE-cad) and plasma concentration of lipoprotein-associated phospholipase A2 (Lp-PLA2) were determined with enzyme-linked immunosorbent assay before and after the transplantation. The injury and the recovery of right femoral artery at stenting site were evaluated with Hematoxylin and Eosin (HE) staining. HUCMNCs purified from umbilical cord blood were 100% CD45⁺ and 96.5% CD34^- with round or oval morphology and adherent growth pattern. The soluble VE-cad and Lp-PLA2 were significantly attenuated after HUCMNC transplantation. The intimal area and the ratio between intimal area and medium film area in the dilated occlusion site were also dramatically decreased 4 weeks after receiving HUCMNCs. HUCMNC transplantation is effective in protecting vascular endothelial function and preventing ISR after EIT in T2DM rabbits suffering from PAD.

Clinical significance of ADAMTS1, ADAMTS5, ADAMTS9 aggrecanases and IL-17A, IL-23, IL-33 cytokines in polycystic ovary syndrome

PURPOSE

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders among women of reproductive age. A disintegrin and metalloproteinase with thrombospondin-like motifs (ADAMTS) are involved in inflammation and fertility. The aim of this investigation was to evaluate the serum levels of ADAMTS1, ADAMTS5, ADAMTS9, IL-17, IL-23, IL-33 and to find out the relationship between these inflammatory cytokines and ADAMTSs in PCOS patients.

METHODS

A case-control study was performed in a training and research hospital. Eighty patients with PCOS and seventy-eight healthy female volunteers were recruited in the present study. Serum ADAMTS and IL levels were determined by a human enzyme-linked immunoassay (ELISA) in all subjects.

RESULTS

The IL-17A, IL-23 and IL-33 levels were significantly higher in the PCOS patients compared to the controls (p < 0.05). We could not find significant difference between the groups in terms of ADAMTS1, ADAMTS5 and ADAMTS9 levels. IL-17A had positive correlations with LDL cholesterol and IL-33 and negative correlations with ADAMTS1, ADAMTS5, and ADAMTS9. IL-33 had positive correlation with LDL cholesterol and IL-17A. In ROC curve analysis, PCOS can be predicted by the use of IL-17A, IL-23 and IL-33 which at a cut-off value of 8.37 pg/mL (44 % sensitivity, 83 % specificity), 26.75 pg/mL (36 % sensitivity, 64 % specificity) and 14.28 pg/mL (83 % sensitivity, 39 % specificity), respectively.

CONCLUSIONS

The results of the study might suggest that ADAMTS and IL molecules have a role in the pathogenesis of the PCOS. Further efforts are needed to establish causality for ADAMTS-IL axis.

Tissue factor is induced by interleukin-33 in human endothelial cells: a new link between coagulation and inflammation

Tissue factor (TF) is the primary trigger of coagulation. Elevated levels of TF are found in atherosclerotic plaques, and TF leads to thrombus formation when released upon plaque rupture. Interleukin (IL)-33 was previously shown to induce angiogenesis and inflammatory activation of endothelial cells (ECs). Here, we investigated the impact of IL-33 on TF in human ECs, as a possible new link between inflammation and coagulation. IL-33 induced TF mRNA and protein in human umbilical vein ECs and coronary artery ECs. IL-33-induced TF expression was ST2- and NF-κB-dependent, but IL-1-independent. IL-33 also increased cell surface TF activity in ECs and TF activity in ECs-derived microparticles. IL-33-treated ECs reduced coagulation time of whole blood and plasma but not of factor VII-deficient plasma. In human carotid atherosclerotic plaques (n = 57), TF mRNA positively correlated with IL-33 mRNA expression (r = 0.691, p < 0.001). In this tissue, IL-33 and TF protein was detected in ECs and smooth muscle cells by immunofluorescence. Furthermore, IL-33 and TF protein co-localized at the site of clot formation within microvessels in plaques of patients with symptomatic carotid stenosis. Through induction of TF in ECs, IL-33 could enhance their thrombotic capacity and thereby might impact on thrombus formation in the setting of atherosclerosis.

The Protective Role of Interleukin-33 in Myocardial Ischemia and Reperfusion Is Associated with Decreased HMGB1 Expression and Up-Regulation of the P38 MAPK Signaling Pathway

Interleukin-33 (IL-33) plays a protective role in myocardial ischemia and reperfusion (I/R) injury, but the underlying mechanism was not fully elucidated. The present study was designed to investigate whether IL-33 protects against myocardial I/R injury by regulating both P38 mitogen-activated-protein kinase (P38 MAPK), which is involved in one of the downstream signaling pathways of IL-33, and high mobility group box protein 1 (HMGB1), a late pro-inflammatory cytokine. Myocardial I/R injury increased the level of IL-33 and its induced receptor (sST) in myocardial tissue. Compared with the I/R group, the IL-33 group had significantly lower cardiac injury (lower serum creatine kinase (CK), lactate dehydrogenase (LDH), and cTnI levels and myocardial infarct size), a suppressed inflammatory response in myocardial tissue (lower expression of HMGB1, IL-6, TNF-α and INF-γ) and less myocardial apoptosis (much higher Bcl-2/Bax ratio and lower cleaved caspase-3 expression). Moreover, IL-33 activated the P38 MAPK signaling pathway (up-regulating P-P38 expression) in myocardial tissue, and SB230580 partially attenuated the anti-inflammatory and anti-apoptosis effects of IL-33. These findings indicated that IL-33 protects against myocardial I/R injury by inhibiting inflammatory responses and myocardial apoptosis, which may be associated with the HMGB1 and P38 MAPK signaling pathways.

Associations between variants in IL-33/ST2 signaling pathway genes and coronary heart disease risk

The IL-33/ST2 signaling pathway plays an important role in coronary artery disease (CHD); however, few studies have explored how variants in IL-33/ST2 genes influence CHD risk. Here, we examined the association between genetic variants in IL-33, ST2, and IL-1RAcP of the IL-33/ST2 axis and the risk of CHD. We conducted a case-controlled study with 1146 CHD cases and 1146 age- and sex-frequency-matched controls. Twenty-eight single nucleotide polymorphisms (SNPs) in IL-33, ST2, and IL-1RAcP were genotyped by Sequenom MassArray and TaqMan assay. Logistic regression was used to analyze these associations. The SNP rs4624606 in IL-1RAcP was nominally associated with CHD risk. The AA genotype was associated with a 1.85-fold increased risk of CHD (95% confidence interval (CI) = 1.01-3.36; p = 0.045) compared to the TT genotype. Further analysis showed that AA carriers also had a higher risk of CHD than TT + TA carriers (odds ratio (OR) = 1.85; 95% CI = 1.85-3.35; p = 0.043). However, no significant association was observed between variants in IL-33/ST2 genes and CHD risk. Further studies are needed to replicate our results in other ethnic groups with larger sample size.

Soluble ST2 and interleukin-33 levels in coronary artery disease: relation to disease activity and adverse outcome

Objectives

ST2 is a receptor for interleukin (IL)-33. We investigated an association of soluble ST2 (sST2) and IL-33 serum levels with different clinical stages of coronary artery disease. We assessed the predictive value of sST2 and IL-33 in patients with stable angina, non-ST elevation myocardial infarction (NSTEMI) and ST elevation myocardial infarction (STEMI).

Methods

We included 373 patients of whom 178 had stable angina, 97 had NSTEMI, and 98 had STEMI. Patients were followed for a mean of 43 months. The control group consisted of 65 individuals without significant stenosis on coronary angiography. Serum levels of sST2 and IL-33 were measured by ELISAs.

Results

sST2 levels were significantly increased in patients with STEMI as compared to patients with NSTEMI and stable angina as well as with controls. IL-33 levels did not differ between the four groups. During follow-up, 37 (10%) patients died and the combined endpoint (all cause death, MI and rehospitalisation for cardiac causes) occurred in 66 (17.6%) patients. sST2 serum levels significantly predicted mortality in the total cohort. When patients were stratified according to their clinical presentation, the highest quintile of sST2 significantly predicted mortality in patients with STEMI, but not with NSTEMI or stable coronary artery disease. sST2 was a significant predictor for the combined endpoint in STEMI patients and in patients with stable angina. Serum levels of IL-33 were not associated with clinical outcome in the total cohort, but the highest quintile of IL-33 predicted mortality in patients with STEMI.

Conclusions

Serum levels of sST2 are increased in patients with acute coronary syndromes as compared to levels in patients with stable coronary artery disease and in individuals without coronary artery disease. sST2 and IL-33 were associated with mortality in patients with STEMI but not in patients with NSTEMI or stable angina.