Acute Effects of Interleukin-1 Blockade Using Anakinra in Patients With Acute Pericarditis

Recurrent pericarditis and interleukin (IL)-1 inhibitors

Recurrent pericarditis (RP) is defined by the European Society of Cardiology (ESC) as an instance of acute pericarditis (AP) that occurs at least 4-6 weeks after the resolution of a previous episode of the same ailment. To mitigate the risk of RP, it is advised to administer accurate and prolonged pharmacological treatment for both the initial AP and subsequent RP. ESC guidelines recommend commencing treatment for any single episode of AP, including those that contribute to RP, with non-steroidal anti-inflammatory drugs (NSAIDs) in conjunction with colchicine for several months, often followed by gradual tapering. If there is an inadequate response, corticosteroids (CS) may be introduced cautiously. However, in a minority of cases, even when NSAIDs, colchicine, and CS are administered together at the highest recommended dosages, they may prove ineffective. In such instances, treatment with immunosuppressive drugs or biologics is advised. Among biologics, interleukin (IL)-1 inhibitors have been extensively studied, although certain gaps remain. This narrative review delves into the rationale for employing IL-1 inhibitors and presents findings from existing studies regarding their efficacy, tolerability, and safety. Analysis of the literature indicates that there is currently insufficient data to ascertain the true therapeutic role of IL-1 inhibitors in managing and preventing RP. However, theoretically, drugs targeting both IL-1α and IL-1β may offer superior efficacy compared to those solely targeting IL-1β due to the significant involvement of both cytokines in inflammation. Further research is warranted to determine the comparative effectiveness of IL-1α and IL-1β inhibitors.

Efficacy and safety of anakinra in radiation-induced acute pericarditis: a case report

Background

Acute pericarditis represents an inflammatory disease affecting the pericardial layers. In developed countries more than 80% of pericarditis are defined as idiopathic, less frequently they are secondary to other conditions such as infections, rheumatic or systemic inflammatory diseases, cancer, post-cardiac injury syndromes and radiation therapy (RT).

Case presentation

We reported a case of a patient with acute pericarditis that occurred a few hours after chest radiation therapy, performed for breast cancer. After the failure of first-line therapy, we introduced anakinra, an anti- interleukin-1 (IL-1) agent, observing an immediate clinical and instrumental response.

Conclusions

Our experience highlights the efficacy and safety profile of anakinra in early stages of acute pericarditis with an inflammatory phenotype. To the best of our knowledge, there is no data supporting the use of anakinra in the treatment of RT induced acute pericarditis.

Interleukin-1 Blockers for the Treatment of Recurrent Pericarditis: Pathophysiology, Patient-Reported Outcomes, and Perspectives

ABSTRACT

Recurrent pericarditis (RP) is the most troublesome complication of acute pericarditis reflecting an unresolving inflammation of the pericardial sac around the heart and associated with significant morbidity. Recent studies have shown interleukin-1 (IL-1) signaling to be central to the pathophysiology of cases of RP with evidence of activation of systemic inflammation. We herein review the literature and clinical trials discussing the utility of IL-1 blockade for RP. The early experience of IL-1 blockade with anakinra (Kineret) and its favorable safety profile paved the way for the clinical development of rilonacept (Arcalyst) and subsequent approval by the US FDA for RP. In patients with RP who have become colchicine-resistant and glucocorticoid-dependent, IL-1 blockade with rilonacept or anakinra effectively treats recurrences and prevents future flares and significantly improves quality of life.

Novel Therapeutic Insights Into the Treatment of Pericarditis: Targeting the Innate Immune System

ABSTRACT

Acute pericarditis is characterized by pericardial inflammation that can be treated with anti-inflammatory drugs. A considerable percentage of patients develops recurrent pericarditis with several relapses. In developed countries, the idiopathic form is the most frequent and has a high risk of recurrences. Two pathophysiological mechanisms have been described for idiopathic recurrent pericarditis: autoimmune and autoinflammatory. The autoimmune mechanism is more frequently encountered in patients with rheumatologic disorders, especially systemic lupus erythematosus. The innate immune system plays a central role in the pathophysiology of pericarditis, especially in the autoinflammatory phenotype. Current evidence highlights the central role played by interleukin 1 and NLRP3 (NACHT, leucine-rich repeat, and pyrin domain-containing protein 3) in idiopathic recurrent pericarditis. Accordingly, interleukin 1 blockers have been approved for the treatment of this condition. Neutrophils are likely to be important in such setting; however, their role has only been partially investigated. In the present review, we have collected the current knowledge on the role of innate immune system in pericarditis pathophysiology and how this can be used to provide targeted treatments for patients with recurrent pericarditis.

The role of the NLRP3 inflammasome and pyroptosis in cardiovascular diseases

An intense, stereotyped inflammatory response occurs in response to ischaemic and non-ischaemic injury to the myocardium. The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome is a finely regulated macromolecular protein complex that senses the injury and triggers and amplifies the inflammatory response by activation of caspase 1; cleavage of pro-inflammatory cytokines, such as pro-IL-1β and pro-IL-18, to their mature forms; and induction of inflammatory cell death (pyroptosis). Inhibitors of the NLRP3 inflammasome and blockers of IL-1β and IL-18 activity have been shown to reduce injury to the myocardium and pericardium, favour resolution of the inflammation and preserve cardiac function. In this Review, we discuss the components of the NLRP3 inflammasome and how it is formed and activated in various ischaemic and non-ischaemic cardiac pathologies (acute myocardial infarction, cardiac dysfunction and remodelling, atherothrombosis, myocarditis and pericarditis, cardiotoxicity and cardiac sarcoidosis). We also summarize current preclinical and clinical evidence from studies of agents that target the NLRP3 inflammasome and related cytokines.

Pathogenic pathways and therapeutic targets of inflammation in heart diseases: A focus on Interleukin-1

BACKGROUND

An exuberant and dysregulated inflammatory response contributes to the development and progression of cardiovascular diseases (CVDs).

METHODS

This narrative review includes original articles and reviews published over the past 20 years and found through PubMed. The following search terms (or combination of terms) were considered: "acute pericarditis," "recurrent pericarditis," "myocarditis," "cardiac sarcoidosis," "atherosclerosis," "acute myocardial infarction," "inflammation," "NLRP3 inflammasome," "Interleukin-1" and "treatment."

RESULTS

Recent evidence supports the role of inflammation across a wide spectrum of CVDs including myocarditis, pericarditis, inflammatory cardiomyopathies (i.e. cardiac sarcoidosis) as well as atherosclerotic CVD and heart failure. Interleukins (ILs) are the signalling mediators of the inflammatory response. The NACHT, leucine-rich repeat and pyrin-domain containing protein 3 (NLRP3) inflammasome play a key role in producing IL-1β, the prototypical pro-inflammatory cytokine involved in CVDs. Other pro-inflammatory cytokines (e.g. tumour necrosis factor) have been implicated in cardiac sarcoidosis. As a proof of this, IL-1 blockade has been proven efficacious in pericarditis and chronic coronary syndrome.

CONCLUSION

Tailored strategies aiming at quenching the inflammatory response have emerged as promising to treat CVDs. In this review article, we summarize recent evidence regarding the role of inflammation across a broad spectrum of CVDs. We also review novel evidence regarding targeted therapeutic strategies.

Interleukin-1 Blockers in Recurrent and Acute Pericarditis: State of the Art and Future Directions

Diseases of the pericardium encompass a spectrum of conditions, including acute and recurrent pericarditis, where inflammation plays a pivotal role in the pathogenesis and clinical manifestations. Anti-inflammatory therapy indeed forms the cornerstone of treating these conditions: NSAIDs, colchicine, and corticosteroids (as a second-line treatment) are recommended by current guidelines. However, these medications come with several contraindications and are not devoid of adverse effects. In recent years, there has been an increased focus on the role of the inflammasome and potential therapeutic targets. Recurrent pericarditis also shares numerous characteristics with other autoinflammatory diseases, in which interleukin-1 antagonists have already been employed with good efficacy and safety. The objective of this review is to summarize the available studies on the use of anti-IL-1 drugs both in acute and recurrent pericarditis.

Rilonacept and Other Interleukin-1 Inhibitors in the Treatment of Recurrent Pericarditis

Pericarditis is the commonest form of pericardial disease. Unfortunately, despite optimal treatment, approximately 15-30% of patients with acute pericarditis have recurrence. Many of these patients are refractory to colchicine, and become corticosteroid-dependent. Recurrent pericarditis severely impairs quality of life, and is associated with significant morbidity. Inflammasome formation and overproduction of interleukin (IL)-1 have been found to drive the systemic inflammatory response in recurrent autoinflammatory pericarditis. Several IL-1 inhibitors have been evaluated for their usefulness as therapeutic options. Rilonacept is a dimeric fusion protein that functions as a soluble decoy receptor that binds to both IL-1α and IL-1β, thereby inhibiting the IL-1 pathway. It is safe and efficacious in the treatment of recurrent pericarditis in the RHAPSODY II and III trials. Anakinra is a recombinant IL-1 receptor antagonist that blocks the action of circulating IL-1α and IL-1β. It has also been shown to be safe and efficacious in the AIRTRIP and IRAP studies. Canakinumab is a selective human monoclonal antibody against IL-1β, and data on its use in recurrent pericarditis is scarce. Several questions regarding IL-1 inhibitor therapy, such as the duration of treatment and the recommended tapering protocols, as well as their use in special populations like pregnant or lactating women, remain unanswered and need to be addressed in future studies.

NLRP3-mediated inflammation in cardio-oncology: sterile yet harmful

Despite significant advances and the continuous development of novel, effective therapies to treat a variety of malignancies, cancer therapy-induced cardiotoxicity has been identified as a prominent cause of morbidity and mortality, closely competing with secondary malignancies. This unfortunate limitation has prompted the inception of the field of cardio-oncology with its purpose to provide the necessary knowledge and key information on mechanisms that support the use of the most efficacious cancer therapy with minimal or no interruption while paying close attention to preventing cardiovascular related morbidity and mortality. Several mechanisms that contribute to cancer therapy-induced cardiotoxicity have been proposed and studied. These mainly involve mitochondrial dysfunction and reactive oxygen species-induced oxidative stress, lysosomal damage, impaired autophagy, cell senescence, DNA damage, and sterile inflammation with the formation and activation of the NLRP3 inflammasome. In this review, we focus on describing the principal mechanisms for different classes of cancer therapies that lead to cardiotoxicity involving the NLRP3 inflammasome. We also summarize current evidence of cardio-protection with inflammasome inhibitors in the context of heart disease in general, and further highlight the potential application of this evidence for clinical translation in at risk patients for the purpose of preventing cancer therapy associated cardiovascular morbidity and mortality.

NLRP3 inflammasome: The rising star in cardiovascular diseases

Cardiovascular diseases (CVDs) are the prevalent cause of mortality around the world. Activation of inflammasome contributes to the pathological progression of cardiovascular diseases, including atherosclerosis, abdominal aortic aneurysm, myocardial infarction, dilated cardiomyopathy, diabetic cardiomyopathy, heart failure, and calcific aortic valve disease. The nucleotide oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) inflammasome plays a critical role in the innate immune response, requiring priming and activation signals to provoke the inflammation. Evidence shows that NLRP3 inflammasome not only boosts the cleavage and release of IL-1 family cytokines, but also leads to a distinct cell programmed death: pyroptosis. The significance of NLRP3 inflammasome in the CVDs-related inflammation has been extensively explored. In this review, we summarized current understandings of the function of NLRP3 inflammasome in CVDs and discussed possible therapeutic options targeting the NLRP3 inflammasome.

Recent advances in pericarditis

Pericardial diseases are an heterogeneous group of entities, ranging from acute pericarditis to asymptomatic pericardial effusions. New advances in understanding the processes underlying them have been made. In 2020 a prospective study defined the reference intervals of the component of normal pericardial fluid, that was found to be rich in nucleated cells, proteins, albumin and LDH, at levels compatible with the inflammatory exudates of other biological fluids such as pleural or peritoneal fluid; Light's criteria should not be used to evaluate it. Recently we also analyzed systematically large chronic idiopathic non-inflammatory pericardial effusions, observing that a non-invasive wait-and-see approach may be the best choice in clinical practice in oligosymptomatic cases. Concerning acute recurrent pericarditis (RP), an innovative interaction between cardiologists, internists and pediatric rheumatologists led to the intuition of a pivotal role of IL-1 in recurrent pericarditis characterized by an evident inflammatory recurrent phenotype, and recent data have shown the striking efficacy of anakinra and rilonacept in these patients. The proper selection of the patient is important; the ideal candidate for anti-IL-1 therapy is the patient with RP with high levels of serum C-reactive protein, high fever, neutrophil leukocitosis, pleuropulmonary involvement, frequent exacerbations and resistant to conventional therapy. On the contrary, anti-IL-1 drugs are not indicated in patients with pericardial effusion whose cause is not attributable to inflammatory phenomena. Finally, many patients with RP are women of childbearing age, and the possibility for these women to become pregnant must be addressed by multidisciplinary teams.

Targeting the NLRP3 inflammasome in cardiovascular diseases

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that plays a major role in innate immunity. Following tissue injury, activation of the NLRP3 inflammasome results in cytokine production, primarily interleukin(IL)-1β and IL-18, and, eventually, inflammatory cell death - pyroptosis. While a balanced inflammatory response favors damage resolution and tissue healing, excessive NLRP3 activation causes detrimental effects. A key involvement of the NLRP3 inflammasome has been reported across a wide range of cardiovascular diseases (CVDs). Several pharmacological agents selectively targeting the NLRP3 inflammasome system have been developed and tested in animals and early phase human studies with overall promising results. While the NLRP3 inhibitors are in clinical development, multiple randomized trials have demonstrated the safety and efficacy of IL-1 blockade in atherothrombosis, heart failure and recurrent pericarditis. Furthermore, the non-selective NLRP3 inhibitor colchicine has been recently shown to significantly reduce cardiovascular events in patients with chronic coronary disease. In this review, we will outline the mechanisms driving NLRP3 assembly and activation, and discuss the pathogenetic role of the NLRP3 inflammasome in CVDs, providing an overview of the current and future therapeutic approaches targeting the NLRP3 inflammasome.

Current pharmacotherapy management of children and adults with pericarditis: Prospectus for improved outcomes

Pericarditis is the most common inflammatory pericardial disease in both children and adults. Since the 2015 European Society of Cardiology Guidelines for the diagnosis and management of pericardial disease were published, there have been significant updates to management. Pharmacotherapy has been historically reserved for idiopathic pericarditis (IP). However, there has been increasing use of pharmacotherapies, such as anti-inflammatory therapies, colchicine, and immunotherapies for other causes of pericarditis, such as post-cardiac injury syndromes (PCIS). Nevertheless, the quality of data varies depending on PCIS or idiopathic etiologies, as well as the adult and pediatric population. High-dose anti-inflammatory therapies should be used to manage symptoms associated with either etiology of pericarditis in both adults and children, but do not ameliorate the inflammatory disease process. Choice of anti-inflammatory should be guided by drug-drug/disease interactions, cost, tolerability, patient age, and should be tapered accordingly over several weeks to months. Colchicine should be added as adjuvant therapy to anti-inflammatory therapies in adults and children with IP, as it has been shown to lower the risk of recurrence, reduce pericarditis symptoms, and improve morbidity. Colchicine is also reasonable to add to adults and children with pericarditis secondary to PCIS. Systemic glucocorticoids increase risk of recurrence in adults and children with IP and are reserved for second-line treatment in acute and recurrent IP; they are generally avoided in PCIS. Immunotherapies are regarded as third-line for recurrent IP in adults and children. Limited evidence exists to support their use in patients with pericarditis from PCIS. Pharmacovigilance strategies, such as C-reactive protein and adverse drug event monitoring, are also important toward balancing efficacy and safety of the various strategies used to manage pericarditis in adults and children.

Interleukin-1 and the NLRP3 Inflammasome in Pericardial Disease

Purpose of Review

Pericarditis is a generally benign disease, although complications and/or recurrences may occur in up to 30% of cases. New evidence on the pathophysiology of the disease has accumulated in recent years.

Recent Findings

Recently, it has been shown that the activation of the NLRP3 (NACHT, leucine-rich repeat, and pyrin domain-containing protein 3) inflammasome is central in the pathophysiology of pericarditis. These findings derive from clinical data, an experimental animal model of acute pericarditis supporting a role for the NLRP3 inflammasome in pericarditis, and from indirect evidence of inhibitors of NLRP3 inflammasome in clinical trials.

Summary

Pericarditis is regarded as a stereotypical response to an acute damage of the mesothelial cells of the pericardial layers. NLRP3 inflammasome, a macromolecular structure sensing damage and releasing pro-inflammatory cytokines, is centrally involved as it releases interleukin (IL)-1β, whose auto-induction feeds an autoinflammatory disease, mostly responsible for recurrences. Colchicine, an inhibitor of NLRP3 inflammasome formation, and IL-1-targeted therapies, such as anakinra and rilonacept, were found to effectively blunt the acute inflammation and reduce the risk for recurrences.

Early introduction of anakinra improves acute pericarditis and prevents tamponade in Staphylococcal sepsis

The clinical response to anakinra observed by this patient concurrently treated with antibiotics indirectly confirms the potentially pathogenic role of IL-1 in maintaining the pericardial disease and shows how IL-1 blockade might allow avoiding the pericardiocentesis procedure. The report supports the hypothesis that anakinra is an effective and safe tool in the early treatment of acute pericarditis of presumed bacterial origin nonresponding to targeted antibiotic therapy.

Recurrent pericarditis: an update on diagnosis and management

Acute pericarditis is a disease of the pericardium characterized by inflammation. Around 16-38% of patients develop recurrent events after the first episode. Recurrent pericarditis (RP) seems to be caused by a pathologic immune response. An inadequate treatment in terms of drug choice, dose, duration of therapy or tapering, has been shown to increase the risk of recurrences. Symptoms, physical signs and electrocardiographic signs are usually less severe during a recurrent event as compared to the first episode, thus favoring imaging as a tool to confirm the diagnosis of RP. Cardiac magnetic resonance is becoming the technique of choice because of its ability to detect active pericardial inflammation. Inflammatory biomarkers can be used to assess the risk of recurrences and to guide the tapering of treatments. First-line treatment is based on non-steroidal anti-inflammatory drugs (NSAIDs) and colchicine. NSAIDs are useful for pain control, and colchicine has shown to reduce the risk of further recurrences. Glucocorticoids are often used as second-line drugs, but they are associated with a high rate of recurrent events. Interleukin-1 inhibitors, such as anakinra and rilonacept, significantly reduce the risk of recurrences in patients with RP while on treatment.

The Role of NLRP3 Inflammasome in Pericarditis: Potential for Therapeutic Approaches

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Acute pericarditis is characterized by an intense inflammatory response involving the pericardium. Although mostly benign in its clinical course, 30% of patients may experience complications (recurrence, treatment failure, cardiac tamponade).

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The pathogenesis of pericarditis is poorly understood. The scarcity of animal models might justify the limited understanding of this syndrome and the lack of targeted therapies.

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Acute pericarditis is believed to represent a stereotypical response to an acute injury of the pericardium. The NLRP3 inflammasome, through its main product, IL-1β, could play a central role in the clinical manifestations.

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A mouse model of acute pericarditis was developed through the intrapericardial injection of zymosan A, leading to the classical features of the inflamed pericardium: pericardial effusion, pericardial thickening, and increased expression of the NLRP3 inflammasome. By inhibiting the NLRP3 inflammasome or IL-1β, the pericardial effusion and thickening and the NLRP3 inflammasome expression were greatly reduced compared with vehicle.

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Treatment with IL-1 trap, neutralizing both IL-1β and IL-1α, produced a powerful effect on pericardial inflammation in the experimental pericarditis model.

Human samples of patients with chronic pericarditis and appropriate control subjects were stained for the inflammasome components. A mouse model of pericarditis was developed through the intrapericardial injection of zymosan A. Different inflammasome blockers were tested in the mouse model. Patients with pericarditis presented an intensification of the inflammasome activation compared with control subjects. The experimental model showed the pathological features of pericarditis. Among inflammasome blockers, NLRP3 inflammasome inhibitor, anakinra, and interleukin-1 trap were found to significantly improve pericardial alterations. Colchicine partially improved the pericardial inflammation. An intense activation of the inflammasome in pericarditis was demonstrated both in humans and in mice.

Biologic and advanced immunomodulating therapeutic options for sarcoidosis: a clinical update

Introduction: Sarcoidosis is a multi-organ disease with a wide range of clinical manifestations and outcomes. A quarter of sarcoidosis patients require long-term treatment for chronic disease. In this group, corticosteroids and cytotoxic agents be insufficient to control diseaseAreas covered: Several biologic agents have been studied for treatment of chronic pulmonary and extra-pulmonary disease. A review of the available literature was performed searching PubMed and an expert opinion regarding specific therapy was developed.Expert opinion: These agents have the potential of treating patients who have progressive disease. Many of these agents have different mechanisms of action, response rates, and toxicity profiles.

An update on the pathophysiology of acute and recurrent pericarditis

Pericarditis is an inflammatory disease of the pericardium. Progress has been done in recent years in the understanding of its pathophysiology. In particular, pre-clinical and clinical studies have contributed to increasing our knowledge on the role of interleukin (IL)-1 and NLRP3 (NACHT, leucine- rich repeat, and pyrin domain- containing protein 3) inflammasome. Based on current evidence, pericarditis should be considered as an inflammatory reaction to various stimuli, including chemical/physical, infectious, or ischemic ones, with a viral infection being a common etiology. Interaction of pathogens or irritants with toll-like receptor (TLRs) and stimulation of IL-1 receptor by IL-1α and IL-1β lead to an increased transcription of pro-inflammatory genes, including those needed for NLRP3 inflammasome assembly. This pathway is confirmed indirectly by the beneficial effect of colchicine (an indirect NLRP3 inflammasome inhibitor) and IL-1 blockers in patients with recurrent pericarditis. More recently, a direct evidence of the NLRP3 inflammasome within the inflamed pericardium has been provided as well. It may, however, occur that selfantigens on the surface of mesothelial cells or microbial peptides may stimulate autoreactive T cells along with B cells producing anti-heart antibodies, although less evidence is available on this. Some uncertainties still remain about the role of neutrophils, neutrophil extracellular traps (NETs), and pericardial interstitial cells in recurrent and constrictive pericarditis. Unraveling these aspects might have a direct impact on the development of novel targeted therapies, especially considering the increasing number of drugs targeting NETs.