Investigation of the effect of Interleukin-1 receptor antagonist (IL-1ra) on markers of inflammation in non-ST elevation acute coronary syndromes (The MRC-ILA-HEART Study)

Interleukin-receptor antagonist and tumour necrosis factor inhibitors for the primary and secondary prevention of atherosclerotic cardiovascular diseases

BACKGROUND

Atherosclerotic cardiovascular disease (ACVD) is worsened by chronic inflammatory diseases. Interleukin receptor antagonists (IL-RAs) and tumour necrosis factor-alpha (TNF) inhibitors have been studied to see if they can prevent cardiovascular events.

OBJECTIVES

The purpose of this study was to assess the clinical benefits and harms of IL-RAs and TNF inhibitors in the primary and secondary prevention of ACVD.

SEARCH METHODS

The Cochrane Heart Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, EBSCO CINAHL plus, and clinical trial registries for ongoing and unpublished studies were searched in February 2024. The reference lists of relevant studies, reviews, meta-analyses and health technology reports were searched to identify additional studies. No limitations on language, date of publication or study type were set.

SELECTION CRITERIA

RCTs that recruited people with and without pre-existing ACVD, comparing IL-RAs or TNF inhibitors versus placebo or usual care, were selected. The primary outcomes considered were all-cause mortality, myocardial infarction, unstable angina, and adverse events.

DATA COLLECTION AND ANALYSIS

Two or more review authors, working independently at each step, selected studies, extracted data, assessed the risk of bias and used GRADE to judge the certainty of evidence.

MAIN RESULTS

We included 58 RCTs (22,053 participants; 21,308 analysed), comparing medication efficacy with placebo or usual care. Thirty-four trials focused on primary prevention and 24 on secondary prevention. The interventions included IL-1 RAs (anakinra, canakinumab), IL-6 RA (tocilizumab), TNF-inhibitors (etanercept, infliximab) compared with placebo or usual care. The certainty of evidence was low to very low due to biases and imprecision; all trials had a high risk of bias. Primary prevention: IL-1 RAs The evidence is very uncertain about the effects of the intervention on all-cause mortality(RR 0.33, 95% CI 0.01 to 7.58, 1 trial), myocardial infarction (RR 0.71, 95% CI 0.04 to 12.48, I² = 39%, 2 trials), unstable angina (RR 0.24, 95% CI 0.03 to 2.11, I² = 0%, 2 trials), stroke (RR 2.42, 95% CI 0.12 to 50.15; 1 trial), adverse events (RR 0.85, 95% CI 0.59 to 1.22, I² = 54%, 3 trials), or infection (rate ratio 0.84, 95% 0.55 to 1.29, I² = 0%, 4 trials). Evidence is very uncertain about whether anakinra and cankinumab may reduce heart failure (RR 0.21, 95% CI 0.05 to 0.94, I² = 0%, 3 trials). Peripheral vascular disease (PVD) was not reported as an outcome. IL-6 RAs The evidence is very uncertain about the effects of the intervention on all-cause mortality (RR 0.68, 95% CI 0.12 to 3.74, I² = 30%, 3 trials), myocardial infarction (RR 0.27, 95% CI 0.04 to1.68, I² = 0%, 3 trials), heart failure (RR 1.02, 95% CI 0.11 to 9.63, I² = 0%, 2 trials), PVD (RR 2.94, 95% CI 0.12 to 71.47, 1 trial), stroke (RR 0.34, 95% CI 0.01 to 8.14, 1 trial), or any infection (rate ratio 1.10, 95% CI: 0.88 to 1.37, I2 = 18%, 5 trials). Adverse events may increase (RR 1.13, 95% CI 1.04 to 1.23, I² = 33%, 5 trials). No trial assessed unstable angina. TNF inhibitors The evidence is very uncertain about the effects of the intervention on all-cause mortality (RR 1.78, 95% CI 0.63 to 4.99, I² = 10%, 3 trials), myocardial infarction (RR 2.61, 95% CI 0.11 to 62.26, 1 trial), stroke (RR 0.46, 95% CI 0.08 to 2.80, I² = 0%; 3 trials), heart failure (RR 0.85, 95% CI 0.06 to 12.76, 1 trial). Adverse events may increase (RR 1.13, 95% CI 1.01 to 1.25, I² = 51%, 13 trials). No trial assessed unstable angina or PVD. Secondary prevention: IL-1 RAs The evidence is very uncertain about the effects of the intervention on all-cause mortality (RR 0.94, 95% CI 0.84 to 1.06, I² = 0%, 8 trials), unstable angina (RR 0.88, 95% CI 0.65 to 1.19, I² = 0%, 3 trials), PVD (RR 0.85, 95% CI 0.19 to 3.73, I² = 38%, 3 trials), stroke (RR 0.94, 95% CI 0.74 to 1.2, I² = 0%; 7 trials), heart failure (RR 0.91, 95% 0.5 to 1.65, I² = 0%; 7 trials), or adverse events (RR 0.92, 95% CI 0.78 to 1.09, I² = 3%, 4 trials). There may be little to no difference between the groups in myocardial infarction (RR 0.88, 95% CI 0.0.75 to 1.04, I² = 0%, 6 trials). IL6-RAs The evidence is very uncertain about the effects of the intervention on all-cause mortality (RR 1.09, 95% CI 0.61 to 1.96, I² = 0%, 2 trials), myocardial infarction (RR 0.46, 95% CI 0.07 to 3.04, I² = 45%, 3 trials), unstable angina (RR 0.33, 95% CI 0.01 to 8.02, 1 trial), stroke (RR 1.03, 95% CI 0.07 to 16.25, 1 trial), adverse events (RR 0.89, 95% CI 0.76 to 1.05, I² = 0%, 2 trials), or any infection (rate ratio 0.66, 95% CI 0.32 to 1.36, I² = 0%, 4 trials). No trial assessed PVD or heart failure. TNF inhibitors The evidence is very uncertain about the effect of the intervention on all-cause mortality (RR 1.16, 95% CI 0.69 to 1.95, I² = 47%, 5 trials), heart failure (RR 0.92, 95% 0.75 to 1.14, I² = 0%, 4 trials), or adverse events (RR 1.15, 95% CI 0.84 to 1.56, I² = 32%, 2 trials). No trial assessed myocardial infarction, unstable angina, PVD or stroke. Adverse events may be underestimated and benefits inflated due to inadequate reporting.

AUTHORS' CONCLUSIONS

This Cochrane review assessed the benefits and harms of using interleukin-receptor antagonists and tumour necrosis factor inhibitors for primary and secondary prevention of atherosclerotic diseases compared with placebo or usual care. However, the evidence for the predetermined outcomes was deemed low or very low certainty, so there is still a need to determine whether these interventions provide clinical benefits or cause harm from this perspective. In summary, the different biases and imprecision in the included studies limit their external validity and represent a limitation to determining the effectiveness of the intervention for both primary and secondary prevention of ACVD.

Reduced C-reactive protein levels after root canal treatment in clinically healthy young apical periodontitis individuals at cardiovascular risk. A prospective study

AIM

To determine the systemic inflammatory burden, including hsCRP and its monomeric forms, in patients with apical lesions of endodontic origin treated with root canal treatment (RCT).

METHODOLOGY

Prospective pre-/post-study. Apical periodontitis (AP) individuals aged 16-40 were included (N = 29). Individuals received RCT and were followed at 1 and 6 months. Fasting blood samples were obtained. Apical lesions of endodontic origin (ALEO) diameter (mm), and periapical index (PAI), were recorded. The serum concentrations of total hsCRP were determined by turbidimetry. Tumour necrosis factor (TNF)-α, interleukin (IL)-6, IL-10, IL-1β, and soluble (s) E-selectin were assessed by Multiplex assay. Additionally, mCRP forms were determined in the serum of AP patients with a baseline moderate to high cardiovascular risk based on hsCRP stratification (hsCRP ≥1 mg/L) by immunowestern blot (n = 15). Also, CRP isoforms were explored in ALEOs from AP individuals (n = 4). Data were analysed with StataV16.

RESULTS

Periapical index and ALEO sizes were reduced at both follow-up visits after RCT (p < .05). Serum levels of TNF-α, IL-6, IL-10, IL-1β, and sE-selectin did not show significant differences. CRP was borderline reduced at 1 month (p = .04); however, in AP individuals at cardiovascular risk (hsCRP ≥ 1 mg/L), hsCRP and its monomeric isoform significantly decreased at 1 and 6 months (p < .05).

CONCLUSIONS

High-sensitivity CRP and mCRP are reduced after RCT in AP individuals at cardiovascular risk.

Ceramides and pro-inflammatory cytokines for the prediction of acute coronary syndrome: a multi-marker approach

BACKGROUND

There is a growing body of evidence supporting the significant involvement of both ceramides and pro-inflammatory cytokines in the occurrence and progression of acute coronary syndrome (ACS).

METHODS

This study encompassed 216 participants whose laboratory variables were analysed using standardised procedures. Parameters included baseline serum lipid markers, comprising total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, triglycerides (TGs), lipoprotein(a) (LPa), fasting blood glucose, B-natriuretic peptide and hypersensitive C-reactive protein. Liquid chromatography-tandem mass spectrometry measured the concentrations of plasma ceramides. Enzyme-linked immunosorbent assay quantified tumour necrosis factor-α (TNF-α), interleukin 6 (IL6) and IL8. The correlation between ceramides and inflammatory factors was determined through Pearson's correlation coefficient. Receiver operating characteristic (ROC) curve analysis and multivariate logistic regression evaluated the diagnostic potential of models incorporating traditional risk factors, ceramides and pro-inflammatory cytokines in ACS detection.

RESULTS

Among the 216 participants, 138 (63.89%) were diagnosed with ACS. Univariate logistic regression analysis identified significant independent predictors of ACS, including age, gender, history of diabetes, smoking history, TGs, TNF-α, IL-6, ceramide (d18:1/16:0), ceramide (d18:1/18:0), ceramide (d18:1/24:0), ceramide (d18:1/20:0) and ceramide (d18:1/22:0). Multivariate logistic regression analysis revealed significant associations between gender, diabetes mellitus history, smoking history, LPa, IL-6, ceramide (d18:1/16:0) and ACS. Receiver operating characteristic analysis indicated that model 4, which integrated traditional risk factors, IL-6 and ceramide (d18:1/16:0), achieved the highest area under the curve (AUC) of 0.827 (95% CI 0.770-0.884), compared with model 3 (traditional risk factors and ceramide [d18:1/16:0]) with an AUC of 0.782 (95% CI 0.720-0.845) and model 2 (traditional risk factors and IL-6), with an AUC of 0.785 (95% CI 0.723-0.846) in ACS detection.

CONCLUSIONS

In summary, incorporating the simultaneous measurement of traditional risk factors, pro-inflammatory cytokine IL-6 and ceramide (d18:1/16:0) can improve the diagnostic accuracy of ACS.

Inflammation in acute myocardial infarction: the good, the bad and the ugly

Convergent experimental and clinical evidence have established the pathophysiological importance of pro-inflammatory pathways in coronary artery disease. Notably, the interest in treating inflammation in patients suffering acute myocardial infarction (AMI) is now expanding from its chronic aspects to the acute setting. Few large outcome trials have proven the benefits of anti-inflammatory therapies on cardiovascular outcomes by targeting the residual inflammatory risk (RIR), i.e. the smouldering ember of low-grade inflammation persisting in the late phase after AMI. However, these studies have also taught us about potential risks of anti-inflammatory therapy after AMI, particularly related to impaired host defence. Recently, numerous smaller-scale trials have addressed the concept of targeting a deleterious flare of excessive inflammation in the early phase after AMI. Targeting different pathways and implementing various treatment regimens, those trials have met with varied degrees of success. Promising results have come from those studies intervening early on the interleukin-1 and -6 pathways. Taking lessons from such past research may inform an optimized approach to target post-AMI inflammation, tailored to spare 'The Good' (repair and defence) while treating 'The Bad' (smouldering RIR) and capturing 'The Ugly' (flaming early burst of excess inflammation in the acute phase). Key constituents of such a strategy may read as follows: select patients with large pro-inflammatory burden (i.e. large AMI); initiate treatment early (e.g. ≤12 h post-AMI); implement a precisely targeted anti-inflammatory agent; follow through with a tapering treatment regimen. This approach warrants testing in rigorous clinical trials.

IL-1β in atherosclerotic vascular calcification: From bench to bedside

Atherosclerotic vascular calcification contributes to increased risk of death in patients with cardiovascular diseases. Assessing the type and severity of inflammation is crucial in the treatment of numerous cardiovascular conditions. IL-1β, a potent proinflammatory cytokine, plays diverse roles in the pathogenesis of atherosclerotic vascular calcification. Several large-scale, population cohort trials have shown that the incidence of cardiovascular events is clinically reduced by the administration of anti-IL-1β therapy. Anti-IL-1β therapy might reduce the incidence of cardiovascular events by affecting atherosclerotic vascular calcification, but the mechanism underlying this effect remains unclear. In this review, we summarize current knowledge on the role of IL-1β in atherosclerotic vascular calcification, and describe the latest results reported in clinical trials evaluating anti-IL-1β therapies for the treatment of cardiovascular diseases. This review will aid in improving current understanding of the pathophysiological roles of IL-1β and mechanisms underlying its activity.

Immune-Inflammation in Atherosclerosis: A New Twist in an Old Tale

Background and Objective:

Atherosclerosis, a chronic and progressive inflammatory disease, is triggered by the activation of endothelial cells followed by infiltration of innate and adaptive immune cells including monocytes and T cells in arterial walls. Major populations of T cells found in human atherosclerotic lesions are antigen-specific activated CD4+ effectors and/or memory T cells from Th1, Th17, Th2 and Treg subsets. In this review, we will discuss the significance of T cell orchestrated immune inflammation in the development and progression of atherosclerosis.

Discussion:

Pathogen/oxidative stress/lipid induced primary endothelial wound cannot develop to a full-blown atherosclerotic lesion in the absence of chronically induced inflammation. While the primary inflammatory response might be viewed as a lone innate response, the persistence of such a profound response over time must be (and is) associated with diverse local and systemic T cell responses. The interplay between T cells and innate cells contributes to a phenomenon called immuneinflammation and has an impact on the progression and outcome of the lesion. In recent years immuneinflammation, an old term, has had a comeback in connecting the puzzle pieces of chronic inflammatory diseases.

Conclusion:

Taking one-step back and looking from afar at the players of immune-inflammation may help us provide a broader perspective of these complicated interactions. This may lead to the identification of new drug targets and the development of new therapies as well as preventative measures.

The Multiple Faces of C-Reactive Protein-Physiological and Pathophysiological Implications in Cardiovascular Disease

C-reactive protein (CRP) is an intriguing protein which plays a variety of roles in either physiological or pathophysiological states. For years it has been regarded merely as a useful biomarker of infection, tissue injury and inflammation, and it was only in the early 80s that the modified isoforms (mCRP) of native CRP (nCRP) appeared. It soon became clear that the roles of native CRP should be clearly discriminated from those of the modified form and so the impacts of both isoforms were divided to a certain degree between physiological and pathophysiological states. For decades, CRP has been regarded only as a hallmark of inflammation; however, it has since been recognised as a significant predictor of future episodes of cardiovascular disease, independent of other risk factors. The existence of modified CRP isoforms and their possible relevance to various pathophysiological conditions, suggested over thirty years ago, has prompted the search for structural and functional dissimilarities between the pentameric nCRP and monomeric mCRP isoforms. New attempts to identify the possible relevance between the diversity of structures and their opposing functions have initiated a new era of research on C-reactive protein. This review discusses the biochemical aspects of CRP physiology, emphasizing the supposed relevance between the structural biology of CRP isoforms and their differentiated physiological and pathophysiological roles.

Microparticles Locally Deliver Active Interleukin-1 Receptor Antagonist In Vivo

Despite significant research in therapeutic protein delivery, localized and sustained delivery of active therapeutic proteins remains a challenge. Delivery is a particular challenge for therapeutic proteins with a short half-life. Herein, localized delivery of interleukin-1 receptor antagonist (IL-1Ra) by mineral coated microparticles (MPs) is assessed in a healing rat medial collateral ligament (MCL). The local tissue concentration and systemic serum concentration of IL-1Ra, the anti-inflammatory activity of IL-1Ra delivered with MPs, and whether IL-1Ra loaded MPs (IL-1Ra MPs) are immunogenic in a healing ligament are also examined. IL-1Ra MPs significantly increase the local concentration of IL-1Ra compared to soluble IL-1Ra at 7 and 14 days after treatment but do not elevate the systemic concentration of IL-1Ra at these time points, indicating localized delivery of IL-1Ra. IL-1Ra MPs significantly reduce inflammation caused by the MPs themselves, indicating the IL-1Ra is active. Finally, IL-1Ra MPs do not induce a foreign body response and decrease the immunogenicity of human IL-1Ra in a healing rat MCL. Overall, mineral coated microparticles have the ability to locally deliver active therapeutic proteins for an extended period of time.

Inflammation: A Novel Therapeutic Target/Direction in Atherosclerosis

Over the past two decades, the viewpoint of atherosclerosis has been replaced gradually by a lipid-driven, chronic, low-grade inflammatory disease of the arterial wall. Current treatment of atherosclerosis is focused on limiting its risk factors, such as hyperlipidemia or hypertension. However, treatment targeting the inflammatory nature of atherosclerosis is still very limited and deserves further attention to fight atherosclerosis successfully. Here, we review the current development of inflammation and atherosclerosis to discuss novel insights and potential targets in atherosclerosis, and to address drug discovery based on anti-inflammatory strategy in atherosclerotic disease.

Potential of anti-inflammatory agents for treatment of atherosclerosis

Chronic inflammation is a central pathogenic mechanism of atherosclerosis induction and progression. Vascular inflammation is associated with accelerated onset of late atherosclerosis complications. Atherosclerosis-related inflammation is mediated by a complex cocktail of pro-inflammatory cytokines, chemokines, bioactive lipids, and adhesion molecules, and blocking the key pro-atherogenic inflammatory mechanisms can be beneficial for treatment of atherosclerosis. Therapeutic agents that specifically target some of the atherosclerosis-related inflammatory mechanisms have been evaluated in preclinical and clinical studies. The most promising anti-inflammatory compounds for treatment of atherosclerosis include non-specific anti-inflammatory drugs, phospholipase inhibitors, blockers of major inflammatory cytokines, leukotrienes, adhesion molecules, and pro-inflammatory signaling pathways, such as CCL2-CCR2 axis or p38 MAPK pathway. Ongoing studies attempt evaluating therapeutic utility of these anti-inflammatory drugs for treatment of atherosclerosis. The obtained results are important for our understanding of atherosclerosis-related inflammatory mechanisms and for designing randomized controlled studies assessing the effect of specific anti-inflammatory strategies on cardiovascular outcomes.

Targeting Interleukin-1β Reduces Leukocyte Production After Acute Myocardial Infarction

BACKGROUND

Myocardial infarction (MI) is an ischemic wound that recruits millions of leukocytes. MI-associated blood leukocytosis correlates inversely with patient survival, yet the signals driving heightened leukocyte production after MI remain incompletely understood.

METHODS AND RESULTS

With the use of parabiosis surgery, this study shows that soluble danger signals, among them interleukin-1β, increase bone marrow hematopoietic stem cell proliferation after MI. Data obtained in bone marrow reconstitution experiments reveal that interleukin-1β enhances hematopoietic stem cell proliferation by both direct actions on hematopoietic cells and through modulation of the bone marrow's hematopoietic microenvironment. An antibody that neutralizes interleukin-1β suppresses these effects. Anti-interleukin-1β treatment dampens the post-MI increase in hematopoietic stem cell proliferation. Consequently, decreased leukocyte numbers in the blood and infarct reduce inflammation and diminish post-MI heart failure in ApoE(-/-) mice with atherosclerosis.

CONCLUSIONS

The presented insight into post-MI bone marrow activation identifies a mechanistic target for muting inflammation in the ischemically damaged heart.

Inflammation, oxidative stress and renin angiotensin system in atherosclerosis

Atherosclerosis is a chronic inflammatory disease associated with cardiovascular dysfunction including myocardial infarction, unstable angina, sudden cardiac death, stroke and peripheral thromboses. It has been predicted that atherosclerosis will be the primary cause of death in the world by 2020. Atherogenesis is initiated by endothelial injury due to oxidative stress associated with cardiovascular risk factors including diabetes mellitus, hypertension, cigarette smoking, dyslipidemia, obesity, and metabolic syndrome. The impairment of the endothelium associated with cardiovascular risk factors creates an imbalance between vasodilating and vasoconstricting factors, in particular, an increase in angiotensin II (Ang II) and a decrease in nitric oxide. The renin-angiotensin system (RAS), and its primary mediator Ang II, also have a direct influence on the progression of the atherosclerotic process via effects on endothelial function, inflammation, fibrinolytic balance, and plaque stability. Anti-inflammatory agents [statins, secretory phospholipase A2 inhibitor, lipoprotein-associated phospholipase A2 inhibitor, 5-lipoxygenase activating protein, chemokine motif ligand-2, C-C chemokine motif receptor 2 pathway inhibitors, methotrexate, IL-1 pathway inhibitor and RAS inhibitors (angiotensin-converting enzyme inhibitors)], Ang II receptor blockers and ranin inhibitors may slow inflammatory processes and disease progression. Several studies in human using anti-inflammatory agents and RAS inhibitors revealed vascular benefits and reduced progression of coronary atherosclerosis in patients with stable angina pectoris; decreased vascular inflammatory markers, improved common carotid intima-media thickness and plaque volume in patients with diagnosed atherosclerosis. Recent preclinical studies have demonstrated therapeutic efficacy of vitamin D analogs paricalcitol in ApoE-deficient atherosclerotic mice.

The effect of interleukin-1 receptor antagonist therapy on markers of inflammation in non-ST elevation acute coronary syndromes: the MRC-ILA Heart Study

AIMS

Acute coronary syndromes (ACSs) are driven by inflammation within coronary plaque. Interleukin-1 (IL-1) has an established role in atherogenesis and the vessel-response to injury. ACS patients have raised serum markers of inflammation. We hypothesized that if IL-1 is a driving influence of inflammation in non-ST elevation ACS (NSTE-ACS), IL-1 inhibition would reduce the inflammatory response at the time of ACS.

METHODS AND RESULTS

A phase II, double-blinded, randomized, placebo-controlled, study recruited 182 patients with NSTE-ACS, presenting <48 h from onset of chest pain. Treatment was 1:1 allocation to daily, subcutaneous IL-1receptor antagonist (IL-1ra) or placebo for 14 days. Baseline characteristics were well matched. Treatment compliance was 85% at 7 days. The primary endpoint (area-under-the-curve for C-reactive protein over the first 7 days) was: IL-1ra group, 21.98 mg day/L (95%CI 16.31-29.64); placebo group, 43.5 mg day/L (31.15-60.75) (geometric mean ratio = 0.51 mg/L; 95%CI 0.32-0.79; P = 0.0028). In the IL-1ra group, 14-day achieved high-sensitive C-reactive protein (P < 0.0001) and IL-6 levels (P = 0.02) were lower than Day 1. Sixteen days after discontinuation of treatment (Day 30) high-sensitive C-reactive protein levels had risen again in the IL-1ra group [IL-1ra; 3.50 mg/L (2.65-4.62): placebo; 2.21 mg/L (1.67-2.92), P = 0.022]. MACE at Day 30 and 3 months was similar but at 1 year there was a significant excess of events in the IL-1ra group.

CONCLUSION

IL-1 drives C-reactive protein elevation at the time of NSTE-ACS. Following 14 days IL-1ra treatment inflammatory markers were reduced. These results show the importance of IL-1 as a target in ACS, but also indicate the need for additional studies with anti-IL-1 therapy in ACS to assess duration and safety.

CLINICAL TRIAL REGISTRATION EUCTR

2006-001767-31-GB: www.clinicaltrialsregister.eu/ctr-search/trial/2006-001767-31/GB.

Comparative safety of interleukin-1 blockade with anakinra in patients with ST-segment elevation acute myocardial infarction (from the VCU-ART and VCU-ART2 pilot studies)

Two pilot studies of interleukin-1 (IL-1) blockade in ST-segment elevation myocardial infarction (STEMI) showed blunted acute inflammatory response and overall favorable outcomes at 3 months follow-up. We hereby present a patient-level pooled analysis with extended follow-up of 40 patients with clinically stable STEMI randomized to anakinra, a recombinant IL-1 receptor antagonist, 100 mg/day for 14 days or placebo in a double-blinded fashion. End points included death, cardiac death, recurrent acute myocardial infarction (AMI), stroke, unstable angina, and symptomatic heart failure. Median follow-up was 28 (interquartile range 3 to 38) months. Sixteen patients (40%) had a total of 22 adverse cardiovascular events: 1 cardiac death, 4 recurrent AMI, 5 episodes of unstable angina pectoris requiring hospitalization and/or urgent revascularization, and 11 new diagnoses of heart failure. Treatment with anakinra was associated with a hazard ratio of 1.08 (95% confidence interval 0.31 to 3.74, p = 0.90) for the combined end point of death, recurrent AMI, unstable angina pectoris, or stroke and a hazard ratio of 0.16 (95% confidence interval 0.03 to 0.76, p = 0.008) for death or heart failure. In conclusion, IL-1 blockade with anakinra for 2 weeks appears, therefore, to have a neutral effect on recurrent ischemic events, whereas it may prevent new-onset heart failure long term after STEMI.

Cytokines and Immune Responses in Murine Atherosclerosis

Atherosclerosis is an inflammatory disease of the vessel wall characterized by activation of the innate immune system, with macrophages as the main players, as well as the adaptive immune system, characterized by a Th1-dominant immune response. Cytokines play a major role in the initiation and regulation of inflammation. In recent years, many studies have investigated the role of these molecules in experimental models of atherosclerosis. While some cytokines such as TNF or IFNγ clearly had atherogenic effects, others such as IL-10 were found to be atheroprotective. However, studies investigating the different cytokines in experimental atherosclerosis revealed that the cytokine system is complex with both disease stage-dependent and site-specific effects. In this review, we strive to provide an overview of the main cytokines involved in atherosclerosis and to shed light on their individual role during atherogenesis.

Anti-inflammatory therapies for cardiovascular disease

Atherothrombosis is no longer considered solely a disorder of lipoprotein accumulation in the arterial wall. Rather, the initiation and progression of atherosclerotic lesions is currently understood to have major inflammatory influences that encompass components of both the innate and acquired immune systems. Promising clinical data for 'upstream' biomarkers of inflammation such as interleukin-6 (IL-6) as well as 'downstream' biomarkers such as C-reactive protein, observations regarding cholesterol crystals as an activator of the IL-1β generating inflammasome, and recent Mendelian randomization data for the IL-6 receptor support the hypothesis that inflammatory mediators of atherosclerosis may converge on the central IL-1, tumour necrosis factor (TNF-α), IL-6 signalling pathway. On this basis, emerging anti-inflammatory approaches to vascular protection can be categorized into two broad groups, those that target the central IL-6 inflammatory signalling pathway and those that do not. Large-scale Phase III trials are now underway with agents that lead to marked reductions in IL-6 and C-reactive protein (such as canakinumab and methotrexate) as well as with agents that impact on diverse non-IL-6-dependent pathways (such as varespladib and darapladib). Both approaches have the potential to benefit patients and reduce vascular events. However, care should be taken when interpreting these trials as outcomes for agents that target IL-6 signalling are unlikely to be informative for therapies that target alternative pathways, and vice versa. As the inflammatory system is redundant, compensatory, and crucial for survival, evaluation of risks as well as benefits must drive the development of agents in this class.

Interleukin-18 as a therapeutic target in acute myocardial infarction and heart failure

Interleukin 18 (IL-18) is a proinflammatory cytokine in the IL-1 family that has been implicated in a number of disease states. In animal models of acute myocardial infarction (AMI), pressure overload, and LPS-induced dysfunction, IL-18 regulates cardiomyocyte hypertrophy and induces cardiac contractile dysfunction and extracellular matrix remodeling. In patients, high IL-18 levels correlate with increased risk of developing cardiovascular disease (CVD) and with a worse prognosis in patients with established CVD. Two strategies have been used to counter the effects of IL-18:IL-18 binding protein (IL-18BP), a naturally occurring protein, and a neutralizing IL-18 antibody. Recombinant human IL-18BP (r-hIL-18BP) has been investigated in animal studies and in phase I/II clinical trials for psoriasis and rheumatoid arthritis. A phase II clinical trial using a humanized monoclonal IL-18 antibody for type 2 diabetes is ongoing. Here we review the literature regarding the role of IL-18 in AMI and heart failure and the evidence and challenges of using IL-18BP and blocking IL-18 antibodies as a therapeutic strategy in patients with heart disease.

Genetic experimental preparations for studying atherosclerosis

Atherosclerosis is a pathological process with several inputs (biological, chemical, physiological, and others) interacting slowly over a lifetime leading to coronary artery disease, significant morbidity, and a limited lifespan. Over the past two decades, biologists have used experimental preparations from cells, animals, and man to understand the biology of atherosclerosis. Much has been discovered but our use of the standard gene-targeted experimental preparations is now nearing its limit. Better preparations to answer the remaining questions in the field of atherosclerosis biology are needed.

The role of the inflammasome in cardiovascular diseases

Inflammasome is a very important signaling platform sensing a variety of triggers of the innate immune system. Inflammasome promotes the production of important pro-inflammatory cytokines such as IL-1β and IL-18. Tight control of inflammasome activity is, therefore, essential and occurs at multiple levels. The activation of inflammasome pathways is linked to the pathogenesis of various prevalent disorders including cardiovascular disease such as atherosclerosis, ischemic injury, cardiomyopathy, and Kawasaki disease. The study of the inflammasome in the cardiovascular system has led to the identification of important triggers and endogenous modulators, and to the exploration of new treatment strategies based on the inhibition of inflammasome activation or its end products, i.e., IL-1β and IL-18. In summary, the discovery of the inflammasome has greatly advanced our understanding of how the innate immune system interferes with cardiovascular disease development and progression, and targeting inflammasome provides new avenues for the treatment and management of cardiovascular diseases.

Targeting the unstable plaque in acute coronary syndromes

BACKGROUND

Rupture or erosion of an unstable atherosclerotic plaque is the typical pathology and usual cause of acute coronary syndromes. Despite detailed understanding of the processes of lipid accumulation, thinning of the fibrous cap, and inflammation leading to plaque instability, there are no strategies in clinical use that uniquely target the unstable plaque.

OBJECTIVE

A critical review of recent publications on potential therapies that could be used to stabilize unstable plaque.

METHODS

We searched PubMed, other literature databases, drug development sites, and clinical trial registries to retrieve clinical studies on anti-inflammatory and lipid-modulating therapies that could be used to stabilize unstable atherosclerotic plaque.

RESULTS

Multiple experimental targets involving lipid and inflammatory pathways have the potential to stabilize the plaque and expand the armamentarium against coronary artery disease. Randomized clinical trials of darapladib, methotrexate, canakinumab, and colchicine are well advanced to establish if plaque stabilization is feasible and effective in patients with acute coronary syndromes.

CONCLUSIONS

Although there are still no agents in clinical use for plaque stabilization, there are important advances in understanding plaque instability and several encouraging approaches are being evaluated in Phase III clinical trials.

Effects of interleukin-1 on cardiac fibroblast function: relevance to post-myocardial infarction remodelling

The cardiac fibroblast (CF) is a multifunctional and heterogeneous cell type that plays an essential role in regulating cardiac development, structure and function. Following myocardial infarction (MI), the myocardium undergoes complex structural remodelling in an attempt to repair the damaged tissue and overcome the loss of function induced by ischemia/reperfusion injury. Evidence is emerging that CF play critical roles in all stages of post-MI remodelling, including the initial inflammatory phase that is triggered in response to myocardial damage. CF are particularly responsive to the proinflammatory cytokine interleukin-1 (IL-1) whose levels are rapidly induced in the myocardium after MI. Studies from our laboratory in recent years have sought to evaluate the functional effects of IL-1 on human CF function and to determine the underlying molecular mechanisms. This review summarises these data and sets it in the context of post-MI cardiac remodelling, identifying the fibroblast as a potential therapeutic target for reducing adverse cardiac remodelling and its devastating consequences.

Effects of interleukin-1 blockade with anakinra on adverse cardiac remodeling and heart failure after acute myocardial infarction [from the Virginia Commonwealth University-Anakinra Remodeling Trial (2) (VCU-ART2) pilot study]

A first pilot study of interleukin-1 blockade in ST-segment elevation acute myocardial infarction showed improved remodeling. In the present second pilot study, we enrolled 30 patients with clinically stable ST-segment elevation acute myocardial infarction randomized to anakinra, recombinant interleukin-1 receptor antagonist, 100 mg/day for 14 days or placebo in a double-blind fashion. The primary end point was the difference in the interval change in left ventricular (LV) end-systolic volume index between the 2 groups within 10 to 14 weeks. The secondary end points included changes in the LV end-diastolic volume index, LV ejection fraction, and C-reactive protein levels. No significant changes in end-systolic volume index, LV end-diastolic volume index, or LV ejection fraction were seen in the placebo group. Compared to placebo, treatment with anakinra led to no measurable differences in these parameters. Anakinra significantly blunted the increase in C-reactive protein between admission and 72 hours (+0.8 mg/dl, interquartile range -6.4 to +4.2, vs +21.1 mg/dl, interquartile range +8.7 to +36.6, p = 0.002), which correlated with the changes in LV end-diastolic volume index and LV end-systolic volume index at 10 to 14 weeks (R = +0.83, p = 0.002, and R = +0.55, p = 0.077, respectively). One patient in the placebo group (7%) died. One patient (7%) in the anakinra group developed recurrent acute myocardial infarction. More patients were diagnosed with new-onset heart failure in the placebo group (4, 27%) than in the anakinra group (1, 7%; p = 0.13). When the data were pooled with those from the first Virginia Commonwealth University-Anakinra Remodeling Trial (n = 40), this difference reached statistical significance (30% vs 5%, p = 0.035). In conclusion, interleukin-1 blockade with anakinra blunted the acute inflammatory response associated with ST-segment elevation acute myocardial infarction. Although it failed to show a statistically significant effect on LV end-systolic volume index, LV end-diastolic volume index, or LV ejection fraction in this cohort of clinically stable patients with near-normal LV dimensions and function, anakinra led to a numerically lower incidence of heart failure.

SPIRIT 2013 explanation and elaboration: guidance for protocols of clinical trials

High quality protocols facilitate proper conduct, reporting, and external review of clinical trials. However, the completeness of trial protocols is often inadequate. To help improve the content and quality of protocols, an international group of stakeholders developed the SPIRIT 2013 Statement (Standard Protocol Items: Recommendations for Interventional Trials). The SPIRIT Statement provides guidance in the form of a checklist of recommended items to include in a clinical trial protocol. This SPIRIT 2013 Explanation and Elaboration paper provides important information to promote full understanding of the checklist recommendations. For each checklist item, we provide a rationale and detailed description; a model example from an actual protocol; and relevant references supporting its importance. We strongly recommend that this explanatory paper be used in conjunction with the SPIRIT Statement. A website of resources is also available (www.spirit-statement.org). The SPIRIT 2013 Explanation and Elaboration paper, together with the Statement, should help with the drafting of trial protocols. Complete documentation of key trial elements can facilitate transparency and protocol review for the benefit of all stakeholders.

Inflammation in atherosclerosis: a cause or a result of vascular disorders?

Sound data support the concept that in atherosclerosis, inflammation and dyslipidemia intersect each other and that irrespective of the initiator, both participate from the early stages to the ultimate fate of the atheromatous plaque. The two partakers manoeuvre a vicious circle in atheroma formation: dyslipidaemia triggers an inflammatory process and inflammation elicits dyslipidaemia. Independent of the initial cause, the atherosclerotic lesions occur focally, in particular arterial-susceptible sites, by a process that, although continuous, can be arbitrarily divided into a sequence of consecutive stages that lead from fatty streak to the fibro-lipid plaque and ultimately to plaque rupture and thrombosis. In the process, the initial event is a change in endothelial cells (EC) constitutive properties. Then, the molecular alarm signals send by dysfunctional EC are decoded by specific blood immune cells (monocytes, T lymphocytes, neutrophils, mast cells) and by the resident vascular cells, that respond by initiating a robust inflammatory process, in which the cells and the factors they secrete hasten the atheroma development. Direct and indirect crosstalk between the cells housed within the nascent plaque, complemented by the increase in risk factors of atherosclerosis lead to atheroma development and outcome. The initial inflammatory response can be regarded as a defense/protective reaction mechanism, but its further amplification, speeds up atherosclerosis. In this review, we provide an overview on the role of inflammation and dyslipidaemia and their intersection in atherogenesis. The data may add to the foundation of a novel attitude in the diagnosis and treatment of atherosclerosis.

Blocking interleukin-1 as a novel therapeutic strategy for secondary prevention of cardiovascular events

The inflammatory hypothesis of atherosclerosis postulates that inflammation within the plaque promotes plaque progression and complications. Interleukin-1 (IL-1) is a key pro-inflammatory cytokine responsible for the amplification of the inflammatory response following injury. Animal studies show that IL-1 blockade is effective in limiting atherosclerosis and atherothrombosis and improving outcomes in acute myocardial infarction and ischemic stroke. Preliminary data in patients with acute myocardial infarction, ischemic stroke, and heart failure are promising. A large secondary prevention trial with canakinumab in patients with prior acute myocardial infarction is currently ongoing. Many unanswered questions remain regarding the optimal use of IL-1 blockade and the preferred agent.

Effect of interleukin 1β inhibition in cardiovascular disease

PURPOSE OF REVIEW

Atherosclerosis is greatly influenced by inflammatory mediators at all phases. Recent studies have suggested a causal role of one such mediator, interleukin 1β (IL-1β), in the development of atherosclerotic vascular disease. This review highlights recent investigation of the role of IL-1β in atherosclerosis and the potential of its inhibition as a promising therapeutic strategy for the treatment of atherosclerotic vascular disease.

RECENT FINDINGS

Studies in animals have generally shown decreased atherosclerotic plaque burden in atherosclerosis-prone mice deficient in IL-1β and increased plaque in mice exposed to excess IL-1β. In humans, IL-1β was found in greater concentrations in atherosclerotic human coronary arteries compared with normal coronary arteries. Preclinical and clinical studies of IL-1β inhibition have shown efficacy in the treatment of several inflammatory disorders, suggesting that IL-1β may be a novel therapeutic target for anti-inflammatory therapy in atherosclerosis, such as coronary artery disease (CAD).

SUMMARY

IL-1β inhibition offers an interesting and biology-based opportunity to test the potential beneficial effects of an anti-inflammatory therapeutic strategy in patients with CAD. A large clinical trial evaluating the impact of IL-1β inhibition in CAD is ongoing and will be an important test of the inflammation hypothesis in CAD.

Novel anti-inflammatory strategies in atherosclerosis

PURPOSE OF REVIEW

Inflammation has been widely acknowledged to contribute throughout all stages of atherogenesis. However, these recent advances in our understanding have not been translated into clinical practice in which the mainstay of treatment is still lipid-targeted therapy. This review provides an overview of promising anti-inflammatory therapies in atherosclerosis, and discusses potential drawbacks and clinical benefits.

RECENT FINDINGS

Immunosuppressive drugs are likely to beneficially affect atherogenesis. Several novel anti-inflammatory targets have been scrutinized, of which some have reached clinical development stage, such as cytokine targets interleukin-1 and interleukin-6, CCR2 antagonist, selective phospholipase, and leukotriene inhibitors. Novel imaging modalities such as MRI and PET-computed tomography provide valuable surrogate inflammatory endpoints for risk stratification and testing anti-inflammatory agents in cardiovascular randomized trials.

SUMMARY

Anti-inflammatory therapies hold great promise in cardiovascular prevention regimens; however, atherosclerosis is a chronic disease, and systemic long-term use of anti-inflammatory agents carries the risk of complications arising from immunosuppression. In order to successfully add immunosuppressive drugs to our routine armament, we need to identify high-risk patients who benefit from anti-inflammatory treatment, increase our insight into the inflammatory pathogenesis of atherogenesis, and find safe and effective compounds capable of directly suppressing plaque inflammation.

Sustained response and prevention of damage progression in patients with neonatal-onset multisystem inflammatory disease treated with anakinra: a cohort study to determine three- and five-year outcomes

OBJECTIVE

Blocking interleukin-1 with anakinra in patients with the autoinflammatory syndrome neonatal-onset multisystem inflammatory disease (NOMID) reduces systemic and organ-specific inflammation. However, the impact of long-term treatment has not been established. This study was undertaken to evaluate the long-term effect of anakinra on clinical and laboratory outcomes and safety in patients with NOMID.

METHODS

We conducted a cohort study of 26 NOMID patients ages 0.80-42.17 years who were followed up at the NIH and treated with anakinra 1-5 mg/kg/day for at least 36 months. Disease activity was assessed using daily diaries, questionnaires, and C-reactive protein level. Central nervous system (CNS) inflammation, hearing, vision, and safety were evaluated.

RESULTS

Sustained improvements in diary scores, parent's/patient's and physician's global scores of disease activity, parent's/patient's pain scores, and inflammatory markers were observed (all P<0.001 at 36 and 60 months). At 36 and 60 months, CNS inflammation was suppressed, with decreased cerebrospinal fluid white blood cell counts (P=0.0026 and P=0.0076, respectively), albumin levels, and opening pressures (P=0.0012 and P<0.001, respectively). Most patients showed stable or improved hearing. Cochlear enhancement on magnetic resonance imaging correlated with continued hearing loss. Visual acuity and peripheral vision were stable. Low optic nerve size correlated with poor visual field. Bony lesions progressed. Adverse events other than viral infections were rare, and all patients continued to receive the medication.

CONCLUSION

These findings indicate that anakinra provides sustained efficacy in the treatment of NOMID for up to 5 years, with the requirement of dose escalation. Damage progression in the CNS, ear, and eye, but not bone, is preventable. Anakinra is well tolerated overall.

Pharmacological modulation of cell death in atherosclerosis: a promising approach towards plaque stabilization?

Despite tremendous advances over the last 15 years in identifying vulnerable atherosclerotic plaques, the incidence of death and disability caused by such lesions still remains the number one health threat in developed countries. Therefore, new systemic or focal therapies aimed at decreasing the overall burden of disease, and a change to a more benign phenotype, are needed. Because cell death is a prominent feature of advanced atherosclerotic plaques with a major impact on plaque destabilization, an increasing number of compounds targeting the apoptotic or autophagic machinery in atherosclerosis are being explored, predominantly at the preclinical level. This review will provide an overview of these compounds, with a focus on both inhibition and stimulation of cell death, to prevent acute coronary syndromes and sudden cardiac death.

Interleukin-1β inhibition and the prevention of recurrent cardiovascular events: rationale and design of the Canakinumab Anti-inflammatory Thrombosis Outcomes Study (CANTOS)

BACKGROUND

Inflammation contributes to all phases of the atherothrombotic process, and patients with elevated inflammatory biomarkers such as high-sensitivity C-reactive protein (hsCRP) have increased vascular risk. Yet, it remains unknown whether direct inhibition of inflammation will reduce cardiovascular event rates.

DESIGN

The CANTOS will evaluate whether interleukin-1β (IL-1β) inhibition as compared with placebo can reduce rates of recurrent myocardial infarction, stroke, and cardiovascular death among stable patients with coronary artery disease who remain at high vascular risk due to persistent elevations of hsCRP (>2 mg/L) despite contemporary secondary prevention strategies. Canakinumab is a human monoclonal antibody that selectively neutralizes IL-1β, a proinflammatory cytokine that plays multiple roles in the atherothrombotic process and that undergoes activation by the nucleotide-binding leucine-rich repeat-containing pyrin receptor 3 inflammasome, a process promoted by cholesterol crystals. Canakinumab significantly reduces systemic C-reactive protein and other inflammatory biomarker levels, is generally well tolerated, and is currently indicated for the treatment of inherited IL-1β driven inflammatory diseases such as the Muckle-Wells syndrome. In a multinational collaborative effort using an event-driven intention-to-treat protocol, CANTOS will randomly allocate 17,200 stable postmyocardial infarction patients with persistent elevation of hsCRP to either placebo or to canakinumab at doses of 50, 150, or 300 mg every 3 months, administered subcutaneously. All participants will be followed up over an estimated period of up to 4 years for the trial primary end point (nonfatal myocardial infarction, nonfatal stroke, cardiovascular death) as well as for other vascular events, total mortality, adverse events, and specific clinical end points associated with inflammation including new onset diabetes, venous thrombosis, and atrial fibrillation.

SUMMARY

If positive, CANTOS would confirm the inflammatory hypothesis of atherothrombosis and provide a novel cytokine-based therapy for the secondary prevention of cardiovascular disease and new-onset diabetes.

The puzzle of depression and acute coronary syndrome: reviewing the role of acute inflammation

The relationship between depression and coronary heart disease is well-established, but causal mechanisms are poorly understood. The aim of this review is to stimulate different ways of viewing the relationship between depression and adverse outcomes following acute coronary syndrome (ACS) and coronary artery bypass graft (CABG) surgery patients. We present an argument for depression in ACS and CABG patients being a qualitatively distinct form from that observed in psychiatric populations. This is based on three features: (1) depression developing after cardiac events has been linked in many studies to poorer outcomes than recurrent depression; (2) somatic symptoms of depression following cardiac events are particularly cardiotoxic; (3) depression following an ACS does not respond well to antidepressant treatments. We propose that inflammation is a common causal process responsible in part both for the development of depressive symptoms and for adverse cardiac outcomes, and we draw parallels with inflammation-induced sickness behaviour. Clinical implications of our observations are discussed along with suggestions for further work to advance the field.

Anti-inflammatory therapeutics for the treatment of atherosclerosis

Atherosclerosis is the primary cause of heart disease and stroke and is thus the underlying pathology of the leading causes of death in the western world. Although risk can be reduced by lowering lipid levels, the equally important contribution of inflammation to the development of cardiovascular disease is not adequately addressed by existing therapies. Here, we summarize the evidence supporting a role for inflammation in the pathogenesis of atherosclerosis, discuss agents that are currently in the clinic and provide a perspective on the challenges faced in the development of drugs that target vascular inflammation.

Assessment of tissue edema in patients with acute myocardial infarction by computer-assisted quantification of triple inversion recovery prepared MRI of the myocardium

The aim of this study was to design a computer algorithm to assess the extent of cardiac edema from triple inversion recovery MR images of the human left ventricular myocardium. Twenty-one patients presenting with acute myocardial infarction were scanned within 48 h of the onset of symptoms. Eight patients were scanned a second time, 4 weeks after the initial event. Myocardial edema was detected in 27 of 29 studies using visual contour-based manual segmentation. A reference standard, created from the segmentations of three raters by voxel-wise majority voting, was compared to the edema mass estimates obtained using a newly developed computer algorithm. At baseline (n=20), the reference standard yielded an edema mass of 16.4±15.0 g (mean±SD) and the computer algorithm edema mass was 16.4±12.6 g. At follow-up (n=7), the reference standard edema mass was 7.1±4.4 g compared to 16.3±7.7 g at baseline. Computer algorithm estimates showed the same pattern of change with 5.7±5.7 g at follow-up compared to 20.8±13.8 g at baseline. Although there was a significant degree of discrepancy between reference standard and computer algorithm estimates of edema mass in individual patients, their overall agreement was good, with intraclass correlation coefficient ICC(3, 1)=0.753.

Association between C reactive protein and coronary heart disease: mendelian randomisation analysis based on individual participant data

OBJECTIVE

To use genetic variants as unconfounded proxies of C reactive protein concentration to study its causal role in coronary heart disease.

DESIGN

Mendelian randomisation meta-analysis of individual participant data from 47 epidemiological studies in 15 countries.

PARTICIPANTS

194 418 participants, including 46 557 patients with prevalent or incident coronary heart disease. Information was available on four CRP gene tagging single nucleotide polymorphisms (rs3093077, rs1205, rs1130864, rs1800947), concentration of C reactive protein, and levels of other risk factors.

MAIN OUTCOME MEASURES

Risk ratios for coronary heart disease associated with genetically raised C reactive protein versus risk ratios with equivalent differences in C reactive protein concentration itself, adjusted for conventional risk factors and variability in risk factor levels within individuals.

RESULTS

CRP variants were each associated with up to 30% per allele difference in concentration of C reactive protein (P<10(-34)) and were unrelated to other risk factors. Risk ratios for coronary heart disease per additional copy of an allele associated with raised C reactive protein were 0.93 (95% confidence interval 0.87 to 1.00) for rs3093077; 1.00 (0.98 to 1.02) for rs1205; 0.98 (0.96 to 1.00) for rs1130864; and 0.99 (0.94 to 1.03) for rs1800947. In a combined analysis, the risk ratio for coronary heart disease was 1.00 (0.90 to 1.13) per 1 SD higher genetically raised natural log (ln) concentration of C reactive protein. The genetic findings were discordant with the risk ratio observed for coronary heart disease of 1.33 (1.23 to 1.43) per 1 SD higher circulating ln concentration of C reactive protein in prospective studies (P=0.001 for difference).

CONCLUSION

Human genetic data indicate that C reactive protein concentration itself is unlikely to be even a modest causal factor in coronary heart disease.

Pharmacological modulation of vascular inflammation in atherothrombosis

Vascular inflammation, especially at the level of endothelial cells, has been shown to play a pivotal role in the inception, progression, and clinical complications of atherosclerosis. The common denominators for the activation of inflammatory genes appear to be a small subset of transcription factors--among which include nuclear factor-κB, activator protein-1 (AP-1), and GATA--that function as the central hub of vascular inflammation. Strategies directed to inhibit both the secondary mediators and the primary triggers (atherosclerosis risk factors) appear viable to inhibit atherosclerosis. However, attempts have now been made to address the central hub of vascular inflammation. "Old" drugs, such as dipyridamole, can also now be revisited for properties related to inhibition of vascular inflammation, probably by acting on the common hub of inflammation.

Monogenic autoinflammatory diseases: new insights into clinical aspects and pathogenesis

PURPOSE OF REVIEW

The genetic and clinical characterizations of monogenic autoinflammatory syndromes have led to ground breaking insights into the regulation of inflammatory responses to endogenous and exogenous inducers or triggers of inflammation and continue to uncover key inflammatory pathways of the innate immune system. This article summarizes recent progress in the clinical aspects and understanding of the pathogenesis of this growing spectrum of diseases.

RECENT FINDINGS

The understanding of the spectrum of organ manifestations in autoinflammation was expanded by the discovery of two novel monogenic diseases both caused by the absence of an anti-inflammatory signal and added evidence that increased IL-1 signaling can cause aseptic osteolytic bone lesions and that the absence of IL-10 signaling causes inflammatory enterocolitis in neonates. New knock in animal models for TNF-receptor-associated periodic syndrome, and familial Mediterranean fever and cryopyrin-associated periodic syndromes allow insights into the complexity of the dysregulated immune pathways. Exploring 'triggers' of the NLRP3 inflammasome spurred studies of tissue inflammation in diseases including gout and those that previously have not been considered inflammatory in nature such as diabetes, fibrosing lung disease and possibly coronary artery disease.

SUMMARY

The genetic characterization of a growing number of monogenic autoinflammatory diseases has provided important insights into the phenotypic expression of single gene disorders and the complexity of the dysregulated inflammatory pathways leading to clinical disease. Knowledge obtained from these disorders is pertinent to a number of common disorders and provides new targets for drug development.

Interleukin-1 blockade with anakinra to prevent adverse cardiac remodeling after acute myocardial infarction (Virginia Commonwealth University Anakinra Remodeling Trial [VCU-ART] Pilot study)

Acute myocardial infarction (AMI) initiates an intense inflammatory response in which interleukin-1 (IL-1) plays a central role. The IL-1 receptor antagonist is a naturally occurring antagonist, and anakinra is the recombinant form used to treat inflammatory diseases. The aim of the present pilot study was to test the safety and effects of IL-1 blockade with anakinra on left ventricular (LV) remodeling after AMI. Ten patients with ST-segment elevation AMI were randomized to either anakinra 100 mg/day subcutaneously for 14 days or placebo in a double-blind fashion. Two cardiac magnetic resonance (CMR) imaging and echocardiographic studies were performed during a 10- to 14-week period. The primary end point was the difference in the interval change in the LV end-systolic volume index (LVESVi) between the 2 groups on CMR imaging. The secondary end points included differences in the interval changes in the LV end-diastolic volume index, and C-reactive protein levels. A +2.0 ml/m(2) median increase (interquartile range +1.0, +11.5) in the LVESVi on CMR imaging was seen in the placebo group and a -3.2 ml/m(2) median decrease (interquartile range -4.5, -1.6) was seen in the anakinra group (p = 0.033). The median difference was 5.2 ml/m(2). On echocardiography, the median difference in the LVESVi change was 13.4 ml/m(2) (p = 0.006). Similar differences were observed in the LV end-diastolic volume index on CMR imaging (7.6 ml/m(2), p = 0.033) and echocardiography (9.4 ml/m(2), p = 0.008). The change in C-reactive protein levels between admission and 72 hours after admission correlated with the change in the LVESVi (R = +0.71, p = 0.022). In conclusion, in the present pilot study of patients with ST-segment elevation AMI, IL-1 blockade with anakinra was safe and favorably affected by LV remodeling. If confirmed in larger trials, IL-1 blockade might represent a novel therapeutic strategy to prevent heart failure after AMI.

Monogenic IL-1 mediated autoinflammatory and immunodeficiency syndromes: finding the right balance in response to danger signals

INTRODUCTION

Interleukin-1 was the first cytokine identified and is a powerful inducer of fever and inflammation. The biologically active receptor for IL-1, shares signaling pathways with some pathogen recognition receptors, the Toll-like receptors (TLRs) which early on suggested an important role in innate immune function.

DISCUSSION

The discovery that some intracellular "danger receptors", the NOD like receptors (NLRs) can assemble to form multimolecular platforms, the inflammasomes, that not only sense intracellular danger but also activate IL-1beta, has provided the molecular basis for the integration of IL-1 as an early response mediator in danger recognition. The critical role of balancing IL-1 production and signaling in human disease has recently been demonstrated in rare human monogenic diseases with mutations that affect the meticulous control of IL-1 production, release and signaling by leading to decreased or increased TLR/IL-1 signaling. In diseases of decreased TLR/IL-1 signaling (IRAK-4 and MyD88 deficiencies) patients are at risk for infections with gram positive organisms; and in diseases of increased signaling, patients develop systemic autoinflammatory diseases (cryopyrin-associated periodic syndromes (CAPS), and deficiency of the IL-1 receptor antagonist (DIRA)).

CONCLUSION

Monogenic defects in a number of rare diseases that affect the balance of TLR/IL-1 signaling have provided us with opportunities to study the systemic effects of IL-1 in human diseases. The molecular defects in CAPS and DIRA provided a therapeutic rationale for targeting IL-1 and the impressive clinical results from IL-1 blocking therapies have undoubtedly confirmed the pivotal role of IL-1 in human disease and spurred the exploration of modifying IL-1 signaling in a number of genetically complex common human diseases.

The IL-1 family: regulators of immunity

Over recent years it has become increasingly clear that innate immune responses can shape the adaptive immune response. Among the most potent molecules of the innate immune system are the interleukin-1 (IL-1) family members. These evolutionarily ancient cytokines are made by and act on innate immune cells to influence their survival and function. In addition, they act directly on lymphocytes to reinforce certain adaptive immune responses. This Review provides an overview of both the long-established and more recently characterized members of the IL-1 family. In addition to their effects on immune cells, their involvement in human disease and disease models is discussed.