Cardiotoxicity of human recombinant interleukin-2 in rats. A morphological study

Acute and Chronic Cardiopulmonary Effects of High Dose Interleukin-2 Therapy: An Observational Magnetic Resonance Imaging Study

High dose interleukin-2 (IL-2) is known to be associated with cardiopulmonary toxicity. The goal of this study was to evaluate the effects of high dose IL-2 therapy on cardiopulmonary structure and function. Combined cardiopulmonary magnetic resonance imaging (MRI) was performed in 7 patients in the acute period following IL-2 therapy and repeated in 4 patients in the chronic period. Comparison was made to 10 healthy volunteers. IL-2 therapy was associated with myocardial and pulmonary capillary leak, tissue oedema and cardiomyocyte injury, which resulted in acute significant left ventricular (LV) dilatation, a reduction in LV ejection fraction (EF), an increase in LV mass and a prolongation of QT interval. The acute effects occurred irrespective of symptoms. In the chronic period many of the effects resolved, but LV hypertrophy ensued, driven by focal replacement and diffuse interstitial myocardial fibrosis and increased cardiomyocyte mass. In conclusion, IL-2 therapy is ubiquitously associated with acute cardiopulmonary inflammation, irrespective of symptoms, which leads to acute LV dilatation and dysfunction, increased LV mass and QT interval prolongation. Most of these effects are reversible but IL-2 therapy is associated with chronic LV hypertrophy, driven by interstitial myocardial fibrosis and increased cardiomyocyte mass. The findings have important implications for the monitoring and long term impact of newer immunotherapies. Future studies are needed to improve risk stratification and develop cardiopulmonary-protective strategies.

Cancer Treatment-Associated Pericardial Disease: Epidemiology, Clinical Presentation, Diagnosis, and Management

PURPOSE OF REVIEW

Cancer therapeutics have seen tremendous growth in the last decade and have been effective in the treatment of several cancer types. However, with advanced therapies like kinase inhibitors and immunotherapies, there have been unintended consequences of cardiotoxicities. While traditional chemotherapy and radiation-induced cardiotoxicity have been well studied, further research is needed to understand the adverse effects of newer regimens.

RECENT FINDINGS

Both immune-mediated and non-immune-medicated cytotoxicity have been noted with targeted therapies such as tyrosine kinase inhibitors and immune checkpoint inhibitors. In this manuscript, we describe the pericardial syndromes associated with cancer therapies and propose management strategies. Pericardial effusion and pericarditis are common presentations in cancer patients and often difficult to diagnose. Concomitant myocarditis may also present with pericardial toxicity, especially with immunotherapies. In addition to proper history and physical, additional testing such as cardiovascular imaging and tissue histology need to be obtained as appropriate. Holding the offending oncology drug, and institution of anti-inflammatory medications, and immunosuppressants such as steroids are indicated. A high index of suspicion, use of standardized definitions, and comprehensive evaluation are needed for early identification, appropriate treatment, and better outcomes for patients with cancer treatment-associated pericardial disease. Further research is needed to understand the pathophysiology and to evaluate how the management of pericardial conditions in these patients differ from traditional management and also evaluate new therapies.

Adaptive Immune Responses Contribute to Post-ischemic Cardiac Remodeling

Myocardial infarction (MI) is a common condition responsible for mortality and morbidity related to ischemic heart failure. Accumulating experimental and translational evidence support a crucial role for innate immunity in heart failure and adverse heart remodeling following MI. More recently, the role of adaptive immunity in myocardial ischemia has been identified, mainly in rodents models of both transient and permanent heart ischemia. The present review summarizes the experimental evidence regarding the role of lymphocytes and dendritic cells in myocardial remodeling following coronary artery occlusion. Th1 and potentially Th17 CD4⁺ T cell responses promote adverse heart remodeling, whereas regulatory T cells appear to be protective, modulating macrophage activity, cardiomyocyte survival, and fibroblast phenotype. The role of CD8⁺ T cells in this setting remains unknown. B cells contribute to adverse cardiac remodeling through the modulation of monocyte trafficking, and potentially the production of tissue-specific antibodies. Yet, further substantial efforts are still required to confirm experimental data in human MI before developing new therapeutic strategies targeting the adaptive immune system in ischemic cardiac diseases.

Cardiovascular Toxicities Associated with Cancer Immunotherapies

PURPOSE OF REVIEW

We review the cardiovascular toxicities associated with cancer immune therapies and discuss the cardiac manifestations, potential mechanisms, and management strategies.

RECENT FINDINGS

The recent advances in cancer immune therapy with immune checkpoint inhibitors and adoptive cell transfer have improved clinical outcomes in numerous cancers. The rising use of cancer immune therapy will lead to a higher incidence in immune-related adverse events. Recent studies have highlighted several reports of severe cases of acute cardiotoxic events with immune therapy including fulminant myocarditis. We believe that immune-mediated myocarditis is a driving mechanism behind these cardiovascular toxicities and requires vigilant screening and prompt management with corticosteroids and immune-modulating drugs, especially with combination immune therapies. While the incidence of serious cardiovascular toxicities with immune therapy appears low, these can be life-threatening especially when manifesting as acute immune-mediated myocarditis. Further collaborative studies are needed to effectively identify, characterize, and manage these events.

Fulminant myocarditis owing to high-dose interleukin-2 therapy for metastatic melanoma

High-dose interleukin-2 (IL-2) therapy may cause acute myocarditis characterised by diffuse myocardial involvement and occasionally fulminant heart failure. Cardiac MRI (CMRI) provides a comprehensive assessment of myocardial function, inflammation and injury in a single examination and has shown value in the diagnosis of myocarditis. We report a case of a 54-year-old male with metastatic melanoma who developed acute severe myocarditis with fulminant heart failure after high-dose IL-2 therapy. CMRI using a combination of T(2) weighted imaging and T(1) weighted late post-gadolinium enhancement techniques played a key role in establishing the diagnosis. To our knowledge we present the first case report of the combined use of T(1) and T(2) weighted CMRI techniques to diagnose IL-2 induced myocarditis.

Cardiac and cardiovascular toxicity of nonanthracycline anticancer drugs

Anthracyclines are a well-known cause of cardiotoxicity, but a number of other drugs used to treat cancer can also result in cardiac and cardiovascular adverse effects. Cardiotoxicity can result in the alteration of cardiac rhythm, changes in blood pressure and ischemia, and can also alter the ability of the heart to contract and/or relax. The clinical spectrum of these toxicities can range from subclinical abnormalities to catastrophic life-threatening, and sometimes fatal, sequelae. These events may occur acutely or may only become apparent months or years following completion of oncological treatment. Ischemia and rhythm abnormalities are treated symptomatically in most cases. Knowledge of these toxicities can aid clinicians to choose the optimal and least toxic regimen suitable for an individual patient.

Heart failure induced by non-cardiac drugs

Although heart failure is predominantly caused by cardiovascular conditions such as hypertension, coronary heart disease and valvular heart disease, it can also be an adverse reaction induced by drug therapy. In addition, some drugs have the propensity to adversely affect haemodynamic mechanisms in patients with an already existing heart condition. In this article, non-cardiac drugs known to be associated with the development or worsening of heart failure are reviewed. Moreover, drugs that may adversely affect the heart as a pump without causing symptoms or signs of heart failure are also included. The drugs discussed include anticancer agents such as anthracyclines, mitoxantrone, cyclophosphamide, fluorouracil, capecitabine and trastuzumab; immunomodulating drugs such as interferon-alpha-2, interleukin-2, infliximab and etanercept; antidiabetic drugs such as rosiglitazone, pioglitazone and troglitazone; antimigraine drugs such as ergotamine and methysergide; appetite suppressants such as fenfulramine, dexfenfluramine and phentermine; tricyclic antidepressants; antipsychotic drugs such as clozapine; antiparkinsonian drugs such as pergolide and cabergoline; glucocorticoids; and antifungal drugs such as itraconazole and amphotericin B. NSAIDs, including selective cyclo-oxygenase (COX)-2 inhibitors, are included as a result of their ability to cause heart disease, particularly in patients with an already existing cardiorenal dysfunction. Two drug groups are of particular concern. Anthracyclines and their derivatives may cause cardiomyopathy in a disturbingly high number of exposed individuals, who may develop symptoms of insidious onset several years after drug therapy. The risk seems to encompass all exposed individuals, but data suggest that children are particularly vulnerable. Thus, a high degree of awareness towards this particular problem is warranted in cancer survivors subjected to anthracycline-based chemotherapy. A second group of problematic drugs are the NSAIDs, including the selective COX-2 inhibitors. These drugs may cause renal dysfunction and elevated blood pressure, which in turn may precipitate heart failure in vulnerable individuals. Although NSAID-related cardiotoxicity is relatively rare and most commonly seen in elderly individuals with concomitant disease, the widespread long-term use of these drugs in risk groups is potentially hazardous. Pending comprehensive safety analyses, the use of NSAIDs in high-risk patients should be discouraged. In addition, there is an urgent need to resolve the safety issues related to the use of COX-2 inhibitors. As numerous drugs from various drug classes may precipitate or worsen heart failure, a detailed history of drug exposure in patients with signs or symptoms of heart failure is mandatory.

Cardiac manifestations of graft-versus-host disease

Graft-versus-host disease (GVHD) is a major cause of morbidity and mortality after bone marrow transplantation. Well-documented manifestations of GVHD include dermatologic, gastrointestinal, hepatic, pulmonary, musculoskeletal, and hematologic manifestations and sicca syndrome. To date, the heart has only rarely been reported to be a target of GVHD. We report a series of patients who developed bradycardia, coronary artery disease, or cardiomyolysis in association with acute or chronic GVHD. The severity of these manifestations ranged from asymptomatic to fatal. The bradycardias were responsive to increased immunosuppression. Although they are uncommon, it is important to recognize these cardiac manifestations, because they may reflect GVHD activity and may be reversible by increasing immunosuppression.

Myocardial remodeling in viral heart disease: possible interactions between inflammatory mediators and MMP-TIMP system

Matrix metalloproteinases (MMP), a family of proteases, are involved in the degradation of extracellular matrix proteins and hence in the determination of interstitial architecture. In the heart, MMPs have been found to play a significant role in the development of myocardial remodeling and congestive heart failure. Tissue inhibitors of matrix metalloproteinases (TIMPs) represent a family of proteins which are known to regulate the expression and activity of MMPs. TIMPs are endogenous physiological inhibitors of MMPs and their concomitant downregulation in heart failure suggests the existence of a critical balance between MMPs and TIMPs in the normal maintenance of myocardial interstitial homeostasis. In addition, cytokines regulate expression of both MMPs and TIMPs besides eliciting a direct effect on myocardial cell function. Therefore, myocardial inflammation may also contribute to the development of cardiac remodeling along with other stimuli like mechanical stress and humoral factors. Viral myocarditis, a predisposing factor for dilated cardiomyopathy, is a condition in which extent of intramyocardial inflammation is thought to determine the progression of disease. Inflammatory events in the heart following viral infection are speculated to be responsible for the transition of myocarditis to dilated cardiomyopathy. In viral myocarditis and other inflammatory heart diseases, the inflammatory cells and their battery of cytokines may also alter the myocardial MMP-TIMP system and eventually lead to dilation of the heart and ventricular dysfunction. The objective of this review is to present an overall picture of the inflammatory phase in viral myocarditis and discuss the possible interactions between inflammation and myocardial MMP profiles which may lead to the evolution of dilated cardiomyopathy.

Propagation of lewis rat encephalitogenic T cell lines: T-cell-growth-factor is superior to recombinant IL-2

This study was designed to test the process of selecting encephalitogenic T cell lines in the Lewis rat using recombinant human IL-2 (rhIL-2) in comparison to TCGF. The lines were tested for growth, antigen induced proliferation, cytokine production, V-beta 8.2 expression and pathogenicity. We now report that rhIL-2 and TCGF were equally effective in supporting short-term pathogenic T-cell lines with similar proportion of V-beta 8.2 usage. For the maintenance of long term lines, however, TCGF was superior to IL-2. The concentration of rhIL-2 influenced the cultures: 10 units/ml led to more T-cell proliferation than either 2 or 50 units/ml. However, 50 units/ml of IL-2 led to enhanced Th1 polarization. Thus, the type and concentration of growth factors can influence both the propagation of T cells and their phenotype.

Protection against murine coxsackievirus B3 myocarditis by T cell vaccination

T cell vaccination regulates autoimmunity by the modification of helper and suppressor T cells. The present study was performed to examine whether T cell vaccination can prevent viral myocarditis in vivo. We used coxsackievirus B3 myocarditis in mice as an animal model with the analysis of lymphokine-activated killer cell activity. Vaccination of the mice with T lymphocytes significantly prolonged survival and improved cardiac histology of murine myocarditis. The effects of T cell vaccination were most evident when T cells sensitized with the same virus were used. Vaccination of the mice with T cells from other strains of mice showed lesser protective effects. Clearance of myocardial virus was not affected by this treatment. The efficacy of T cell vaccination was confirmed in vitro by the decrease of the lymphokine-activated killer cell activity against EL-4 tumor cells and cultured myocytes. T cell vaccination of mice prolonged survival and improved myocardial lesions of animals inoculated with coxsackievirus B3.

Immunopathology of Chagas disease

The main clinical forms of Chagas disease (acute, indeterminate and chronic cardiac) present strong evidences for the participation of the immune system on pathogenesis. Although parasite multiplication is evident during acute infection, the intense acute myocarditis of this phase exhibits clear ultrastructural signs of cell-mediated immune damage, inflicted to parasitized and non-parasitized myocardiocytes and to the endothelium of myocardial capillaries (microangiopathy). Inflammation subsides almost completely when immunity decreases parasite load and suppressor factors modulate host reaction, but inflammation does not disappear when the disease enters the indeterminate phase. Inflammation becomes mild and focal and undergoes cyclic changes leading to complete resolution. However, the process is maintained because the disappearance of old focal lesions is balanced by the upsurge of new ones. This equilibrium allows for prolonged host survival in the absence of symptoms or signs of disease. The chronic cardiac form is represented by a delayed-type, cell-mediated diffuse myocarditis, that probably ensues when the suppressive mechanisms, operative during the indeterminate phase, become defaulted. The mechanism responsible for the transition from the indeterminate to the cardiac form, is poorly understood.

Sustained ventricular tachycardia and its successful prophylaxis during high-dose bolus interleukin-2 therapy for metastatic renal cell carcinoma

In the setting of interleukin-2 (IL-2) administration, tachycardias of ventricular origin are classified as serious, grade IV toxicities, necessitating the discontinuation of therapy. In this report, we describe a patient with renal cell carcinoma who experienced ventricular tachycardia while undergoing treatment with high-dose bolus IL-2. Prophylaxis with sotalol permitted the successful completion of his first cycle of treatment, without any recurrent rhythm disturbances.

Idiopathic giant cell myocarditis after autologous hematopoietic stem cell transplantation and interleukin-2 immunotherapy: a case report

BACKGROUND

Interleukin-2 (IL-2) is used in the treatment of solid tumors and hematologic malignancies. Sudden death is a rare complication of IL-2 treatment.

METHODS

A patient with lymphoma underwent chemoradiotherapy myeloablation and autologous stem cell transplantation. The stem cells were cultured in IL-2 (6000 IU/mL) for 24 hours prior to infusion. After engraftment, treatment with IL-2 (1.8 x 10(6) IU/m2/day administered subcutaneously) was begun. After 4 days of treatment, the patient suddenly died. An autopsy was performed.

RESULTS

Histologic examination of the myocardium revealed a diffuse, lymphocytic infiltrate with scattered, multinucleated giant cells and foci of myocardial degeneration consistent with giant cell myocarditis. The lymphocytes were predominantly CD4 positive T cells, and the majority of these cells stained with antibodies for perforin, suggesting an unusual cytolytic role for these lymphocytes. DNA end-labeling of myocardial tissue sections revealed numerous apoptotic myocytes within the lymphocytic infiltrate.

CONCLUSIONS

To the authors' knowledge, this is the first report of giant cell myocarditis in association with high dose chemotherapy, transplantation, and IL-2 immunomodulation. The authors suggest that the cytokine imbalance produced by IL-2 may have initiated a preferential activation of T helper cells and an autoimmune phenomenon manifesting as giant cell myocarditis.

Characterization of the pulmonary lesions induced in rats by human recombinant interleukin-2

Histologic, electron microscopic, and immunohistochemical studies were made to analyze the structural features and the cellular composition of the pulmonary lesions produced in rats by the administration of interleukin-2 (IL-2). This agent induced pulmonary edema; thickening of alveolar septa; damage to endothelial cells in capillaries and venules, marked interstitial infiltration by cytotoxic T lymphocytes, lymphokine-activated killer (LAK) cells, macrophages, and dendritic cells (as demonstrated by cell counting in preparations stained immunohistochemically with peroxidase- and fluorochrome-labeled antibodies); and injury to bronchiolar and alveolar epithelial cells. Granular and agranular lymphocytes often were closely apposed to endothelial cells in capillaries and venules. Contacts between lymphocytes and type II alveolar epithelial cells also were observed. Damaged type II alveolar epithelial cells showed nuclear and cytoplasmic features that are considered indicative of apoptosis (confirmed by nick end labeling). Phagocytosis of apoptotic bodies by macrophages was occasionally found. These results support the concept that IL-2 induces cytotoxic vascular and parenchymal cell damage that is mediated by LAK cells and cytotoxic T lymphocytes, which make contacts with endothelial cells and type II alveolar epithelial cells. This damage appears to be exacerbated by the secondary release of a variety of vasoactive agents and inflammatory mediators.

Ultrastructural aspect of myocarditis: its relevance for the diagnosis

The Dallas consensus was used to reveal active or borderline inflammatory loci by light microscopy (LM). When lymphocyte-cardiocyte interaction was observed by electron microscopy (EM), the deleterious or dormant pattern of inflammatory process was recognized. The first was determined by lymphocytes that adhered to cardiocytes, next to necrotic cardiocytes or admixed with debris. The second was marked by scattered lymphocytes between preserved cardiocytes and the absence of lymphocytes adhered to cardiocytes and necrotic cardiocytes. The deleterious pattern of the inflammatory process (EM) commonly supplemented the active appearance of inflammatory loci (LM). In contrast, the borderline outlook of the LM completed either the deleterious or dormant pattern of the EM. This discrepancy was related to the restricted resolution of LM, which might hide the actual stage of the disease. The diagnosis of myocarditis was founded on mutual LM and EM observations. The active or borderline appearance of LM of the deleterious pattern (EM) was considered indicative for the active stage of myocarditis. The borderline outlook of the LM of the dormant pattern of the EM was admitted to indicate either the healing phase of the disease with lymphocytes still lagging behind, or a latent phase of the ongoing myocarditis, according to the patient's hemodynamic status.

Experimental rat model representing both acute and chronic heart failure related to autoimmune myocarditis

The most important clinical manifestation of myocarditis is congestive heart failure. The precise mechanisms of heart failure during myocarditis have not been elucidated because no animal model that would permit in vivo study of hemodynamics in severe active myocarditis has been available. We monitored hemodynamics and left ventricular function in a rat model of experimental autoimmune myocarditis to determine if this model could be useful for the study of in vivo hemodynamics in severe active myocarditis. Lewis rats were immunized with human cardiac myosin suspended in complete Freund's adjuvant. Baseline hemodynamics were measured using an ultraminiature catheter pressure transducer via the right internal carotid artery, 4 weeks after immunization in one group of rats (acute phase) and 3 months after immunization in another group (chronic phase). Untreated rats served as the control group. Hemodynamic measurements were also obtained after infusion of dobutamine in the acute-phase and chronic-phase groups. The heart weight-to-body weight ratios were significantly higher in both the acute-phase group and the chronic-phase group compared with normal control rats. The baseline left ventricular systolic pressure was significantly lower in the chronic phase group than in the control group. Peak dP/dt and peak -dP/dt were significantly lower in both the acute-phase group and the chronic-phase group compared with the control group. Dobutamine significantly increased left ventricular systolic pressure, peak dP/dt, and peak -dP/dt in the chronic-phase group but caused only minor changes in hemodynamic variables in the acute-phase group. In vivo measurements of hemodynamic variables indicated the presence of left ventricular dysfunction in rats with experimental autoimmune myocarditis. This animal model may be useful for the study of both acute heart failure related to acute myocarditis and chronic heart failure due to diffuse myocardial fibrosis.

Interleukin-1 alpha reduces the severity of the vascular leak syndrome produced by interleukin-2 and interleukin-2 plus interferon-alpha

Histological and ultrastructural changes were investigated in lung, liver, and heart of mice given interleukin-2 (IL-2), either alone or in combination with other cytokines. IL-2 induced a vascular leak syndrome (VLS) of a moderate degree with infiltration of lymphoid cells, moderate endothelial damage, mild hepatic parenchymal damage, and minimal myocardial alterations. Interferon-alpha (IFN-alpha) produced infiltration mainly of monocytes/macrophages in liver and heart; endothelial cell damage was absent in lung and heart and minimal in liver. Interleukin-1 alpha (IL-1 alpha) caused an increased number of neutrophils in liver and lung; VLS and parenchymal cell and endothelial damage were not found. The VLS and the cellular damage caused by the combination of IL-2 and IFN were much more severe than those produced by IL-2 alone. In animals treated with IL-2, IFN-alpha, and IL-1 alpha, VLS was minimal and parenchymal and endothelial cell damage were less severe than after IL-2 alone or IL-2 plus IFN-alpha. Taken together, these observations show that IL-1 alpha reduces ultrastructural changes produced by IL-2 and IFN-alpha. This reduction may be clinically useful in the treatment of neoplasms.