Cardiovascular manifestations of hypereosinophilic syndromes

Loeffler's Endocarditis: An Integrated Multimodality Approach

Loeffler's endocarditis (LE) is the cardiac manifestation of hypereosinophilic syndrome, a rare systemic disease characterized by the sustained production of eosinophils leading to organ damage. Few data, principally by case reports, are available regarding the diagnostic workup in patients with suspected LE. Thus, we have performed a systematic search of the literature dealing with imaging in LE and propose an integrated multimodality imaging approach in the cardiac diagnostics of LE patients. The aim is to provide an updated state-of-the-art review focused on noninvasive and invasive imaging modalities for this rare and underdiagnosed disease. Standard and advanced echocardiography are typically the first cardiac imaging examinations when LE is suspected and they are also used later in follow-up for prognostic stratification and assessing response to treatment. Cardiac magnetic resonance provides a more detailed anatomical and functional evaluation of cardiac chambers, tissue characterization for the presence and extension of myocardial edema and fibrosis, and ventricular thrombi identification. Computed tomography scan and [18F]-fluoro-deoxy-glucose positron emission tomography may be helpful in selected cases to evaluate the cardiac involvement of LE as well as the other noncardiac manifestations of hypereosinophilic syndrome. Endomyocardial biopsy may be considered in patients with high clinical suspicion of LE if noninvasive imaging findings are confusing or not conclusive. The appropriate use of invasive and noninvasive imaging modalities, combining the available techniques with the patients' clinical features, will hopefully lead to early diagnosis, more accurate staging of disease, and timely treatment of LE that may prevent the irreversible myocardial damage of LE and adverse cardiovascular events.

Late-Stage Löffler's Endocarditis Mimicking Cardiac Tumor: A Case Report

Löffler's endocarditis (cardiac involvement in hypereosinophilic syndrome) is rare yet life-threatening if left untreated. We describe a case of hypereosinophilic syndrome presenting as a cardiac mass with an abnormal electrocardiogram. Diagnostic studies of the cardiac mass strongly suggested a malignant cardiac tumor invading the papillary muscle. Thus, excision of the cardiac mass and endomyocardial resection with mitral valve replacement were successfully performed. Pathology revealed various stages of thrombosis and irreversible myocardial damage caused by eosinophilic infiltration with no malignancy, leading to the correct diagnosis of late-stage Löffler's endocarditis. The subsequent combination of anticoagulation and corticosteroids was effective with a favorable outcome. This case highlights pitfalls in multimodality imaging of cardiac thrombus and the clinical significance of considering Löffler's endocarditis in the diagnostic work-up of a cardiac mass.

Contrast echocardiography: current status and future directions

Contrast echocardiography is a family of ultrasound-based procedures, whereby acoustic enhancing agents, usually microbubbles, are administered by intravenous route and detected in order to improve diagnostic performance. This review describes: (1) the agents that have been designed for diagnostic imaging, (2) current clinical applications where either left ventricular opacification or microvascular perfusion imaging with myocardial contrast echocardiography have been demonstrated to provide incremental information to non-contrast echocardiography and (3) future diagnostic and therapeutic applications of contrast ultrasound that rely on unique compositional design of ultrasound-enhancing agents.

Allergy and the Heart: Eosinophilic Myocarditis With Biventricular Thrombi

A 40-year-old woman with history of atopy and peripheral eosinophilia presented with clinical signs of heart failure. Echocardiography revealed a restrictive cardiomyopathy with biventricular thrombi. Hypereosinophilic syndrome resulting in eosinophilic myocarditis (Loeffler’s syndrome) was diagnosed. This case highlights the workup, diagnosis, and management of hypereosinophilic syndrome with eosinophilic myocarditis. (Level of Difficulty: Advanced.)

Eosinophil percentage as a new prognostic marker in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background

In addition to proinflammatory properties, eosinophils can stimulate platelet activation and enhance prothrombotic pathways. In this study, we aimed to investigate the association between the eosinophil percentage (EOS%) and major adverse cardiac events (MACE) in patients with ST-segment elevation myocardial infarction (STEMI).

Methods

This study enrolled a total of 1,909 patients who were diagnosed with STEMI. Ventricular arrhythmia, reinfarction, the need for cardiopulmonary resuscitation, target vessel revascularization, congestive heart failure, and cardiovascular mortality during index hospitalization were defined as MACE.

Results

Three hundred and eighty patients (19.7%) reached the combined endpoint with MACE. The rates of inhospital mortality and MACE were significantly higher in low EOS% group as compared to high EOS% group (4% vs. 1.1%, p < 0.01 and 32.8% vs. 11.3%, p < 0.01, respectively). On multivariate logistic regression analyses, EOS% (OR = 0.44, p < 0.01) was found to be one of the independent predictors of MACE. The EOS% lower than 0.60 on admission predicted inhospital MACE with a sensitivity of 68% and a specificity of 72% (AUC: 0.684, p < 0.01).

Conclusions

Low EOS% on admission may be associated with high inhospital MACE in STEMI patients. EOS% may be used as a novel biomarker for risk stratification of these patients.

Loeffler's Endocarditis and the Diagnostic Utility of Multimodality Imaging

Loeffler’s endocarditis is a rare form of restrictive cardiomyopathy associated with eosinophilia and endomyocardial fibrosis. It manifests most commonly as diastolic dysfunction or valvular abnormalities due to eosinophilic infiltration and degranulation. Herein, we chronicle a case of left ventricular involvement with Loeffler’s endocarditis. We emphasize the utility of multimodality imaging including two-dimensional echocardiography and cardiac magnetic resonance imaging in providing diagnostic information, as there is no standardized diagnostic criteria to date.

Loeffler's Endocarditis and Hypereosinophilic Syndrome

Loeffler's endocarditis and hypereosinophilic syndromes are a unique group of infiltrative disorders characterized by hypereosinophilia, inflammatory thrombotic, and ultimately, fibrotic involvement of the heart leading to multiple complications including valve involvement, thromboembolic phenomena, heart failure. Clinical recognition, comprehensive laboratory and multimodality imaging diagnostic workup, and early initiation of treatment have been shown to slow down the progression and promote remission. This review addresses a detailed analysis of Loeffler's endocarditis and hypereosinophilic syndromes.

Hypereosinophilia with Concurrent Venous Thromboembolism: Clinical Features, Potential Risk Factors, and Short-term Outcomes in a Chinese Cohort

Idiopathic hypereosinophilia (IHE) and hypereosinophilic syndrome (HES) are benign haematological disorders. Studies have suggested that venous thromboembolism (VTE) is a rare but sometimes fatal complication of hypereosinophilia; however, data are limited. We retrospectively analysed clinical features and short-term outcomes of 63 consecutive patients (82.5% men; mean age, 40.92 ± 10.89 years) with IHE or HES with concurrent VTE from January 1998 through December 2018. Risk factors for pulmonary embolism (PE) were explored by multivariate logistic analysis. DVT and/or PE was detected by imaging in all patients. Independent risk factors for PE were a body mass index of >24.1 kg/m² (odds ratio [OR]: 5.62, 95% confidence interval [CI]: 1.21–26.13, P = 0.028), peak absolute eosinophil count of >6.3 × 10⁹/L (OR: 5.55, 95% CI: 1.292–23.875, P = 0.021), and >13.9-month duration of hypereosinophilia (OR: 4.51, 95% CI: 1.123–18.09, P = 0.034). All patients were treated with corticosteroids and anticoagulants. The short-term hypereosinophilia remission rate was 100%; no recurrent VTE or major bleeding was observed. Hypereosinophilia is a potential risk factor for VTE. PE in patients with IHE/HES and DVT is associated with a higher body mass index, higher peak absolute eosinophil count, and longer duration of hypereosinophilia. Corticosteroids and anticoagulants provided effective short-term control of hypereosinophilia and VTE.

Case Report: Two Cases of Strongyloidiasis Presenting with Thrombotic Events

We report two unusual cases of clinical strongyloidiasis that present as extensive thrombosis: a case of hyperinfection with concurrent eosinophilia and a case of disseminated infection as a complication of immunosuppression. We discuss risk factors for the development of Strongyloides stercoralis infection and thromboembolism, and the recommended management.

A systems biology approach for defining the potential molecular framework of idiopathic hypereosinophilic syndrome with cutaneous involvement

Hypereosinophilic syndrome (HES) is a rare multisystem disease that predominantly includes skin with severe and persistent itching. A lack of understanding about the pathological condition and mechanism of dermatosis caused by HES hinders its treatment. In the present study, we applied a quantitative proteomics approach to characterize the cellular responses of skin tissue to idiopathic HES (IHES) at the proteome level. We identified hundreds of skin tissue proteins that were differentially expressed between IHES patients and healthy individuals. IHES patients display severely damaged microenvironment, including extracellular matrix (ECM) organization and disassembly, immune disorders, decreased metabolic capacity, and susceptibility to microbial infection. Moreover, there was abnormal proliferation of basal epidermal stem cells, which was closely related to high expression of the epigenetic regulator, histone deacetylase 2, providing mechanistic insight into the abnormal epidermal thickening of IHES skin tissues. Overall, our study provides a comprehensive framework for a system-level understanding of IHES-induced dermatosis (IHESiD) tissues at the protein and cell pathway levels. Our findings may facilitate a new approach to diagnosis and treatment to alleviate skin clinical symptoms, monitor the activity of IHES, and determine therapeutic effects.

When multimodality cardiac imaging saves the day: rare cause of embolic strokes

Hypereosinophilic syndrome (HES) is a rare disorder characterised by eosinophilic infiltration of tissues. Myocardial infiltration occurs in 50%–60% of HES and leads to a condition called Loeffler’s endocarditis. This can lead to endomyocardial injury with resultant superimposed thrombus formation and embolic stroke. We describe the case of a 57-year-old female patient presenting with neurological symptoms who was found to have multiple embolic strokes on a background of long-standing eosinophilia. Following a series of investigations, including transthoracic and transoesophageal echocardiographies and cardiovascular MRI, she was confirmed to have Loeffler’s endocarditis with left ventricular thrombus. She was treated successfully with steroids and anticoagulation. We describe the pathophysiology of HES and Loeffler’s endocarditis and stress the crucial role of multimodality cardiac imaging in establishing its diagnosis and treatment monitoring.

A case report of a 40-year-old woman with endomyocardial fibrosis in a non-tropical area: from initial presentation to high urgent heart transplantation

Background

Endomyocardial fibrosis (EMF) represents the most common cause of restrictive cardiomyopathy worldwide. Despite a high prevalence in tropical regions, it occasionally occurs in patients who have never visited these areas. While researches have proposed various possible triggers for EMF, etiology and pathogenesis remain largely unknown. Diagnosis is based on patient history, heart failure symptoms, and echocardiographic signs of restrictive ventricular filling, atrioventricular valve regurgitation and frequently apical thrombus. Following is a case report of an Austrian patient with EMF who eventually had to undergo a heart transplant. This case report strives to promote awareness for this in non-tropical areas uncommon but nevertheless detrimental disease.

Case presentation

A 40-year-old woman was presented at our emergency department with chest pain and fever up to 38.1° Celsius. Plasma troponin-T levels and inflammatory markers were slightly elevated, but the echocardiogram was without pathological findings. The patient was hospitalized on the suspicion of acute myocarditis and discharged soon after improvement. Eight months later, she was presented again with chest pain and symptoms of heart failure. The echocardiogram showed normal systolic left ventricular (LV) function with LV wall thickening and severe restrictive mitral regurgitation as well as aortic and tricuspid regurgitation. Coronary angiogram was normal but right heart catheterization showed pulmonary hypertension due to left heart disease. Further diagnostic workup with cardiac magnetic resonance imaging revealed subendocardial late enhancement and apical thrombus formation in the left ventricle compatible with the diagnosis of EMF. A comprehensive diagnostic workup showed no evidence of infection, systemic immunologic or hematological disease, in particular hypereosinophilic syndrome. After a multidisciplinary consideration of several therapeutic options, the patient was listed for heart transplantation. On the waiting list, she deteriorated rapidly due to progressive heart failure and finally underwent a heart transplantation. Histological examination confirmed the diagnosis of EMF. Six years after her heart transplantation, the patient was presented in an excellent clinical condition.

Conclusions

Even in non-tropical regions, the diagnosis of EMF should always be considered in restrictive cardiomyopathy. Knowledge of the distinct phenotype of EMF facilitates diagnosis, but comprehensive workup and therapeutic management remain challenging and require a multidisciplinary approach.

Endomyocardial Fibrosis: an Update After 70 Years

PURPOSE OF REVIEW

This review aims at highlighting the need to better understand the pathogenesis and natural history of endomyocardial fibrosis when set against its changing endemicity and disease burden, improvements in diagnosis, and new options for clinical management.

RECENT FINDINGS

Progress in imaging diagnostic techniques and availability of new targets for drug and surgical treatment of heart failure are contributing to earlier diagnosis and may lead to improvement in patient survival. Endomyocardial fibrosis was first described in Uganda by Davies more than 70 years ago (1948). Despite its poor prognosis, the etiology of this neglected tropical restrictive cardiomyopathy still remains enigmatic nowadays. Our review reflects on the journey of scientific discovery and construction of the current guiding concepts on this mysterious and fascinating condition, bringing to light the contemporary knowledge acquired over these years. Here we describe novel tools for diagnosis, give an overview of the improvement in clinical management, and finally, suggest research themes that can help improve patient outcomes focusing (whenever possible) on novel players coming into action.

Multiple cerebral infarction diagnosed as Eosinophilic Granulomatosis with Polyangiitis by autopsy

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis of unknown cause involving the brain and accompanied by prominent eosinophilia. Intracardiac thrombosis is a major cardiac complication of EGPA that may cause thromboembolism.

CASE PRESENTATION

A 53-year-old man presenting with abulia (consciousness disturbance) and left upper limb paralysis was admitted to our hospital. His case was complicated by penetrating branches, small vessel infarcts, and endocardial thrombosis in the right and left ventricle. Cardiomyopathy was also observed. Sixteen days after admission, the patient died from intracranial hemorrhage. Brain autopsy revealed two major findings: 1) large hemorrhagic infarction caused by cardiac embolism; and 2) granuloma and eosinophil infiltration. Vasculitis was accompanied by eosinophil infiltration in the cortical blood vessels and granuloma.

CONCLUSIONS

In this case study, we report autopsy findings of brain infarction in a patient with EGPA and endocardial thrombosis. The brain infarction was caused by the cardiac embolisms and vasculitis.

Eosinophillic Myocarditis Secondary to Metastatic Melanoma

Eosinophilic myocarditis is a rare form of myocarditis that may manifest from cancer-mediated inflammation. A case of eosinophilic myocarditis secondary to metastatic melanoma is described; metastatic melanoma can cause a T helper type 2 lymphocyte-mediated increase in circulating levels of interleukin-5, which is known to stimulate eosinophil proliferation resulting in myocardial inflammation and fibrosis. Cardiac imaging with transesophageal echocardiography revealed a large immobile left ventricular apical thrombus. Cardiac MRI was then performed and revealed enhancing fibrosis along the endocardial surface. © RSNA, 2019 Supplemental material is available for this article.

Eosinophillic Myocarditis Secondary to Metastatic Melanoma

Eosinophilic myocarditis is a rare form of myocarditis that may manifest from cancer-mediated inflammation. A case of eosinophilic myocarditis secondary to metastatic melanoma is described; metastatic melanoma can cause a T helper type 2 lymphocyte-mediated increase in circulating levels of interleukin-5, which is known to stimulate eosinophil proliferation resulting in myocardial inflammation and fibrosis. Cardiac imaging with transesophageal echocardiography revealed a large immobile left ventricular apical thrombus. Cardiac MRI was then performed and revealed enhancing fibrosis along the endocardial surface. © RSNA, 2019 Supplemental material is available for this article.

Polyarteritis Nodosa with Marked Eosinophilia, Associated with Severe Gastrointestinal Tract Involvement and Recurrent Venous Thrombosis

A 45-year-old man was admitted with acute abdominal pain and eosinophilia. Abdominal computed tomography revealed thickness of the ascending and transverse colon with decreased contrast enhancement and a small amount of ascites. In an emergency operation, the necrotic colon was resected. Histopathology showed subserous medium-sized arteritis with abundant eosinophil infiltrates and thrombosis in the portal vein branches. He was diagnosed with polyarteritis nodosa (PAN), and immunosuppressive therapy improved his condition. Two years later, the disease recurred with ischemic cutaneous lesions and marked eosinophilia. Our experience suggests that marked eosinophilia in PAN may imply severe organ involvement, including gastrointestinal necrosis, as well as the association of venous thrombosis.

Heart disease in a mutant mouse model of spontaneous eosinophilic myocarditis maps to three loci

Background

Heart disease (HD) is the major cause of morbidity and mortality in patients with hypereosinophilic diseases. Due to a lack of adequate animal models, our understanding of the pathophysiology of eosinophil-mediated diseases with heart complications is limited. We have discovered a mouse mutant, now maintained on an A/J inbred background, that spontaneously develops hypereosinophilia in multiple organs. Cellular infiltration into the heart causes an eosinophilic myocarditis, with affected mice of the mutant line (i.e., A/J^HD) demonstrating extensive myocardial damage and remodeling that leads to HD and premature death, usually by 15-weeks old.

Results

Maintaining the A/J^HD line for many generations established that the HD trait was heritable and implied the mode of inheritance was not too complex. Backcross and intercross populations generated from mating A/J^HD males with females from four different inbred strains produced recombinant populations with highly variable rates of affected offspring, ranging from none in C57BL/6 J intercrosses, to a few mice with HD using 129S1/SvImJ intercrosses and C57BL/6 J backcrosses, but nearly 8% of intercrosses and > 17% of backcrosses from SJL/J related populations developed HD. Linkage analyses of these SJL/J derived recombinants identified three highly significant loci: a recessive locus mapping to distal chromosome 5 (LOD = 4.88; named Emhd1 for eosinophilic myocarditis to heart disease-1); and two dominant variants mapping to chromosome 17, one (Emhd2; LOD = 7.51) proximal to the major histocompatibility complex, and a second (Emhd3; LOD = 6.89) that includes the major histocompatibility region. Haplotype analysis identified the specific crossovers that defined the Emhd1 (2.65 Mb), Emhd2 (8.46 Mb) and Emhd3 (14.59 Mb) intervals.

Conclusions

These results indicate the HD trait in this mutant mouse model of eosinophilic myocarditis is oligogenic with variable penetrance, due to multiple segregating variants and possibly additional genetic or nongenetic factors. The A/J^HD mouse model represents a unique and valuable resource to understand the interplay of causal factors that underlie the pathology of this newly discovered eosinophil-associated disease with cardiac complications.

Role of Inflammatory Cell Subtypes in Heart Failure

Inflammation is a well-known feature of heart failure. Studies have shown that while some inflammation is required for repair during injury and is protective, prolonged inflammation leads to myocardial remodeling and apoptosis of cardiac myocytes. Various types of immune cells are implicated in myocardial inflammation and include neutrophils, macrophages, eosinophils, mast cells, natural killer cells, T cells, and B cells. Recent clinical trials have targeted inflammatory cascades as therapy for heart failure with limited success. A better understanding of the temporal course of the infiltration of the different immune cells and their contribution to the inflammatory process may improve the success for therapy. This brief review outlines the major cell types involved in heart failure, and some of their actions are summarized in the supplementary figure.

Eosinophilic disorders: evaluation of current classification and diagnostic criteria, proposal of a practical diagnostic algorithm

Eosinophilic disorders represent a group of pathologic conditions with highly heterogeneous pathophysiology and clinical presentation and variable prognosis, ranging from asymptomatic or mild, to severe and complex cases, with fatal outcome. Interest in this group of disorders has increased during the last two decades, with consistent progress made regarding understanding of molecular mechanisms, refining of diagnostic criteria, classification and evaluation of therapeutic options. There are still many gaps and difficulties in evaluating eosinophilic syndromes and diseases in medical practice. The disease prognosis depends mainly on the cause and mechanism of eosinophilia, on severity of organ dysfunction and on accurate diagnosis and response to treatment. Besides primary hypereosinophilic syndromes and secondary (reactive) eosinophilias, many associated or idiopathic forms have been described, making this topic a complex and difficult medical entity. An important aim of the experts in the field is to agree upon a more clear and practically useful classification, a better characterization of various phenotypes and endotypes of eosinophilic diseases and to identify novel biomarkers and more effective therapies. The aim of this paper is to review recent data from the literature regarding definition, classification and diagnosis criteria of eosinophilic diseases and to propose a revised and updated diagnostic algorithm useful in clinical practice.

Mitral and tricuspid valve repair in hypereosinophilic syndrome

Hypereosinophilic syndrome (HES) is a rare systemic condition, defined as a persistently elevated eosinophil count associated with end organ damage and the absence of a primary cause. Cardiac involvement occurs in about 50% of patients with HES. Myocardial infiltration results in endomyocardial fibrosis, valve dysfunction and mural thrombus. The atrioventricular valves are almost always involved, resulting in regurgitation due to leaflet restriction, most commonly affecting the posterior mitral valve leaflet. Surgical management remains challenging in patients with HES with limited data on the choice of valve surgery. We describe the case of a 17-year-old woman with HES complicated by congestive cardiac failure secondary to severe mitral and tricuspid regurgitation. Because of refractory heart failure despite medical therapy, surgical mitral and tricuspid valve repair was performed, and an excellent 24-month outcome was achieved. We believe this is the first report of double valve repair in this rare condition.

Characterization of a mouse model of hypereosinophilia-associated heart disease

Hypereosinophilic syndrome is characterized by sustained and marked eosinophilia leading to tissue damage and organ dysfunction. Morbidity and mortality occur primarily due to cardiac and thromboembolic complications. Understanding the cause and mechanism of disease would aid in the development of targeted therapies with greater efficacy and fewer side effects. We discovered a spontaneous mouse mutant in our colony with a hypereosinophilic phenotype. Mice develop peripheral blood eosinophilia; infiltration of lungs, spleen, and heart by eosinophils; and extensive myocardial damage and remodeling. This ultimately leads to heart failure and premature death. Histopathological assessment of the hearts revealed a robust inflammatory infiltrate composed primarily of eosinophils and B-lymphocytes, associated with myocardial damage and replacement fibrosis, consistent with eosinophilic myocarditis. In many cases, hearts showed dilatation and thinning of the right ventricular wall, suggestive of an inflammatory dilated cardiomyopathy. Most mice showed atrial thrombi, which often filled the chamber. Protein expression analysis revealed overexpression of chemokines and cytokines involved in innate and adaptive immunity including IL-4, eotaxin, and RANTES. Disease could be transferred to wild-type mice by adoptive transfer of splenocytes from affected mice, suggesting a role for the immune system. In summary, the pathologies observed in the mutant lines are reminiscent of those seen in patients with hypereosinophilia, where cardiac-related morbidities, like congestive heart failure and thrombi, are the most common causes of death. As such, our model provides an opportunity to test mechanistic hypotheses and develop targeted therapies.NEW & NOTEWORTHY This article describes a new model of heart disease in hypereosinophilia. The model developed as a spontaneous mouse mutant in the colony and is characterized by peripheral blood eosinophilia and infiltration of lungs, spleen, and heart by eosinophils. In the heart, there is extensive myocardial damage, remodeling, fibrosis, and thrombosis, leading to heart failure and death. The immune microenvironment is one of increased innate and adaptive immunity, including Th1 and Th2 cytokines/chemokines. Finally, adoptive transfer of splenocytes transfers disease to recipient mice. In summary, this model provides an opportunity to test mechanistic hypotheses and develop targeted therapies for this rare but devastating disease.

Synergy of Interleukin (IL)-5 and IL-18 in eosinophil mediated pathogenesis of allergic diseases

Eosinophils are circulating granulocytes that have pleiotropic effects in response to inflammatory signals in the body. In response to allergens or pathogens, exposure eosinophils are recruited in various organs that execute pathological immune responses. IL-5 plays a key role in the differentiation, development, and survival of eosinophils. Eosinophils are involved in a variety of allergic diseases including asthma, dermatitis and various gastrointestinal disorders (EGID). IL-5 signal transduction involves JAK-STAT-p38MAPK-NFκB activation and executes extracellular matrix remodeling, EMT transition and immune responses in allergic diseases. IL-18 is a classical cytokine also involved in immune responses and has a critical role in inflammasome pathway. We recently identified the IL-18 role in the generation, transformation, and maturation of (CD101+CD274+) pathogenic eosinophils. In, addition, several other cytokines like IL-2, IL-4, IL-13, IL-21, and IL-33 also contribute in advancing eosinophils associated immune responses in innate and adaptive immunity. This review discusses with a major focus (1) Eosinophils and its constituents, (2) Role of IL-5 and IL-18 in eosinophils development, transformation, maturation, signal transduction of IL-5 and IL-18, (3) The role of eosinophils in allergic disorders and (4) The role of several other associated cytokines in promoting eosinophils mediated allergic diseases.

Non-infectious aortic and mitral valve vegetations in a patient with eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare form of vasculitis characterised by atopic manifestations, inflammation of small-sized to medium-sized arteries and veins, hypereosinophilia and tissue infiltration with eosinophils. Cardiac complications occur most commonly in the absence of antineutrophil cytoplasmic antibodies. Cardiac complications include coronary arteritis (rare), pericarditis, myocarditis, endocardial fibrosis (Loeffler's endocarditis) and intracavitary thrombosis of the left or right ventricle. This is the first reported case of large non-infectious valvular vegetations associated with EGPA.

Idiopathic hypereosinophilic syndrome presenting with multiple organ damage: A case report

RATIONALE

Idiopathic hypereosinophilic syndrome (IHES) is a rare disease in which patients which present with eosinophilia-associated damage. Previous studies focused on organ damage from increased eosinophilic granulocytosis. We report IHES in a patient who presented with multiple organ damage (MOD).

PATIENT CONCERNS

A 52-year-old male presented with MOD, including myocardial damage suggestive of myocardial infarction, cardiac tamponade, respiratory failure, skin damage, and gastrointestinal damage.

DIAGNOSES

The absolute eosinophil count was 12,920/mm, much higher than occurs in other diseases associated with eosinophilia (1500/mm), and suggesting a diagnosis of IHES.

INTERVENTIONS

Prednisone combined with hydroxyurea.

OUTCOMES

At 6 months after completion of drug treatment, the patient had no chest pain or dyspnea, and the results of a blood panel, chest computed tomography, and gastroscopy were normal.

LESSONS

MOD is very rare in patients with IHES. Patients receiving prompt diagnosis and treatment have very good prognoses.

Myocarditis and Eosinophilia: Three Cases of Hypereosinophilic Syndrome and Myocarditis

Eosinophilic infiltration is a rare and underrecognized cause of myocarditis associated with prolonged eosinophilia. Before advanced imaging and routine biopsy, patients were diagnosed with an idiopathic cardiomyopathy with subsequent diagnosis made on autopsy. We present 3 cases of eosinophilic myocarditis diagnosed by cardiac biopsy classified as hypereosinophilic syndrome. Two patients presented with severe left ventricular dysfunction, and 1 patient presented with cardioembolic stroke. All patients were successfully treated with glucocorticoid therapy. Our cases highlight the importance of early diagnosis with endomyocardial biopsy and prompt immunosuppressive treatment.

The Clinicopathological Profile of Eosinophilic Myocarditis

Eosinophilic myocarditis (EM) is a rare form of myocarditis. As there is extreme diversity in its manifestations, the true incidence is difficult to assess and no proper epidemiological criteria are present. It generally presents with a wide array of clinical manifestations. Clinical presentation tends to differ in cases and not all the patients show the same signs and symptoms. The etiology of EM often remains obscure but potential causes have been identified which may include hypersensitivity to drugs, exposure to certain viruses and parasites, and hyper-eosinophilic syndromes. Endomyocardial biopsy is considered to be a gold standard for the diagnosis of EM. Echocardiography, cardiac magnetic resonance, and bio markers particularly serum eosinophilic cationic protein concentrations are also known to aid in diagnosis. EM may lead to progressive, irreversible, and fatal myocardial damage if prompt diagnosis is not made and therapy is not initiated. The current treatment regimens include corticosteroids, cytotoxic agents, and immunosuppressive therapy. However, a proper treatment criterion is yet to be established.

Arterial thrombosis in unusual sites: A practical review

While cardiovascular disease is common, occasionally hematologists and other practitioners will encounter patients with arterial thrombosis/infarction in unusual sites, without clear cause or obvious diagnostic and treatment paradigms. Contrary to the more commonly encountered cerebrovascular accident and cardiovascular disorders, the various infarctions outlined in this review have unique presentations, pathophysiology, workup, and treatments that all hematologists should be aware of. This review outlines the current literature on arterial thrombosis, with consideration given to anatomic sources and hypercoagulable associations, while focusing on the epidemiology, pathophysiology, provoking factors, and current recommended treatments for intracardiac thrombus, primary aortic mural thrombus, visceral infarctions, and cryptogenic limb ischemia to provide a useful and practical review for the practitioner.

Intracardiac Thrombus in Leukemia: Role of Cardiac Magnetic Resonance Imaging in Eosinophilic Myocarditis

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EM involves acute necrotic, intermediate thrombotic, and late fibrotic stages.

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Echocardiography is the initial modality for the diagnosis of EM.

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EMB could miss the diagnosis if the area involved is not biopsied.

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CMR reliably detects all three stages of EM.

Idiopathic hypereosinophilic syndrome with pulmonary hypertension

Hypereosinophilic syndrome is a myeloproliferative disorder characterized by persistent eosinophilia with involvement of multiple organs. The occurrence of severe pulmonary hypertension (PH) in the setting of hypereosinophilic syndrome is very uncommon. A 43-year-old man with documented idiopathic hypereosinophlic syndrome presented to the hospital with symptoms of paroxysmal chest discomfort and progressive exertional dyspnea. Physical examination showed distended jugular veins, cyanosed lips, increased P2 sound, and moderate pitting edema of the lower extremities. Echocardiography revealed enlarged right atrium, enlarged right ventricle, increased pulmonary artery systolic pressure, and decreased right ventricular systolic function. Venous ultrasound of the lower extremities, computed tomography pulmonary angiography, and right heart catheterization (RHC) were negative for thrombus. The pulmonary artery systolic pressure was found severely increased during the RHC. Treatment included prednisolone, ambrisentan, diuretics, and digoxin. The involvement of the pulmonary artery in patients with idiopathic hypereosinophilic syndrome is an uncommon finding. The patient presents with clinical manifestations of right ventricular systolic dysfunction resulted from severely increased PH.

Cardiac involvement in hypereosinophilic syndrome

A 9-year-old boy with hypereosinophilic syndrome (HES) was referred for cardiac magnetic resonance (CMR) imaging following an abnormal echocardiogram that showed a large mass layered on the inferolateral wall of the left ventricle, causing secondary severe mitral regurgitation. Cardiac involvement in HES usually affects the ventricular apex. In our case, CMR confirmed the presence of a large mural thrombus of 0.9 cm × 4.2 cm. This unusual cardiac involvement in HES was diagnosed in its intermediate thrombotic stage. CMR is very sensitive and specific in staging the disease. It explained the etiology of mitral regurgitation and guided therapy, especially when echocardiography was nonconclusive.

Loeffler endocarditis as a rare cause of heart failure with preserved ejection fraction: A case report and review of literature

RATIONALE

Hypereosinophilic syndrome (HES) is a rare disease characterized by hypereosinophilia and its ensuing organ damage. Cardiac involvement is divided into 3 chronological stages: an acute necrotic stage; a thrombus formation stage; and a fibrotic stage. Infiltration of the myocardium by eosinophilic cells followed by endomyocardial fibrosis is known as "Loeffler endocarditis."

PATIENT CONCERNS

We report a case of a 60-year-old man diagnosed with left-sided restrictive cardiomyopathy.

DIAGNOSIS

The patient experienced heart failure with preserved ejection fraction. The cardiac MRI showed intense, linear, delayed gadolinium enhancement of the endocardium of the lateral wall of the left ventricle, and obliteration of the LV apex. He was ultimately identified as Loeffler endocarditis.

INTERVENTION

A bone marrow smear and biopsy revealed the FIP1L1-PDGFRA fusion gene was positive in 82% of segmented nucleated cells.

OUTCOME

Our patient responded well to prednisone at 1 mg/kg/d.

LESSONS

HES is a rare disease that often afflicts the heart. Cardiac involvement in hypereosinophilia, especially Loeffler endocarditis, carries a poor prognosis and significant mortality. Early detection and treatment of the disease is therefore essential. Further studies are needed to ascertain therapeutic corticosteroid dosages and develop targeted gene therapies, both important steps to ameliorate the effects of Loeffler endocarditis and improve patient outcomes.

Reversible bioprosthetic valve thrombosis from eosinophilia

A 31-year-old man with a mitral bioprosthetic valve presented with recent worsening of exertional dyspnoea 7 years after the mitral valve replacement. Evaluation revealed an increased gradient across the thickened mitral bioprosthetic valve leaflets. Marked eosinophilia was present and was considered as a putative cause for bioprosthetic valve thrombosis. The treatment with systemic corticosteroids and oral anticoagulation led to complete resolution of symptoms with significant decrease in mitral bioprosthetic valve gradient and leaflet thinning. The case is reported to highlight the fact that eosinophilia may cause reversible bioprosthetic valve thrombosis.

Eosinophil Development, Disease Involvement, and Therapeutic Suppression

Human eosinophils have characteristic morphologic features, including a bilobed nucleus and cytoplasmic granules filled with cytotoxic and immunoregulatory proteins that are packaged in a specific manner. Eosinophil production in the bone marrow is exquisitely regulated by timely expression of a repertoire of transcription factors that work together via collaborative and hierarchical interactions to direct eosinophil development. In addition, proper granule formation, which occurs in a spatially organized manner, is an intrinsic checkpoint that must be passed for proper eosinophil production to occur. In eosinophil-associated disorders, eosinophils and their progenitors can be recruited in large numbers into tissues where they can induce proinflammatory organ damage in response to local signals. Eosinophils are terminally differentiated and do not proliferate once they leave the bone marrow. The cytokine IL-5 specifically enhances eosinophil production and, along with other mediators, promotes eosinophil activation. Indeed, eosinophil depletion with anti-IL-5 or anti-IL-5Rα is now proven to be clinically beneficial for several eosinophilic disorders, most notably severe asthma, and several therapeutics targeting eosinophil viability and production are now in development. Significant progress has been made in our understanding of eosinophil development and the consequences of tissue eosinophilia. Future research efforts focused on basic eosinophil immunobiology and translational efforts to assist in the diagnosis, treatment selection, and resolution of eosinophil-associated disorders will likely be informative and clinically helpful.

Hypereosinophilic Syndrome Presented as Acute Ischaemic Stroke and Raised Cardiac Enzymes

The hypereosinophilic syndromes (HES) are a group of disorders marked by the sustained overproduction of eosinophils, resulting in multiple organ damage. We report a 55-year-old lady presented with sudden onset of left-sided limb weakness and hypereosinophilia. Cerebral computerised tomography scan showed multiple small infarctions in bilateral corona radiata and right thalamus. A transesophageal echocardiogram revealed endomyocardial damage with mural thrombus suggesting Loeffler endocarditis. The multiple cerebral infarctions were probably due to cardiac thromboembolism. Treatment with prednisolone led to significant clinical improvement. This case illustrates hypereosinophilia should be considered in patients with multiple cerebral infarctions.

Loeffler Endocarditis: A Unique Presentation of Right-Sided Heart Failure Due to Eosinophil-Induced Endomyocardial Fibrosis

Loeffler endocarditis is a rare restrictive cardiomyopathy caused by abnormal endomyocardial infiltration of eosinophils, with subsequent tissue damage from degranulation, eventually leading to fibrosis. Although an uncommon entity, it is still a disease with significant morbidity and mortality. Often identified only at late stages, treatment options are limited once fibrosis occurs, usually requiring heart failure medications or surgical intervention. We present a unique case of a woman with remote history of hypereosinophilic syndrome, attributed to treatment of rheumatoid arthritis with infliximab, who presented with symptoms of heart failure refractory to medical management and was found to have Loeffler endocarditis. The severe progression of the disease required surgical intervention with endocardial stripping to treat the right-sided diastolic heart failure.

Sudden death in a pediatric heart transplant recipient with peripheral eosinophilia and eosinophilic myocardial infiltrates

Eosinophilia has been rarely reported in pediatric heart transplant recipients and has been suggested to play a role in graft rejection. We report a case of a young female patient with peripheral blood eosinophilia who died suddenly 2 years following ABO-incompatible heart transplantation. She was found at autopsy to have myocardial infiltration of not only T-lymphocytes and macrophages expected in acute cellular rejection but also of eosinophils, B-lymphocytes, and plasma cells indicating myocarditis.

Usefulness of three-dimensional echocardiography in the assessment of valvular involvement in Loeffler endocarditis

Loeffler endocarditis is a complication of hypereosinophilic syndrome resulting from eosinophilic infiltration of heart tissue. We report a case of Loeffler endocarditis in which three-dimensional transthoracic and transesophageal echocardiography provided additional information to what was found by two-dimensional transthoracic echocardiography alone. Our case illustrates the usefulness of combined two- and three-dimensional echocardiography in the assessment of Loeffler endocarditis. In addition, a summary of the features of hypereosinophilic syndrome and Loeffler endocarditis is provided in tabular form.

Eosinophils in Autoimmune Diseases

Eosinophils are multifunctional granulocytes that contribute to initiation and modulation of inflammation. Their role in asthma and parasitic infections has long been recognized. Growing evidence now reveals a role for eosinophils in autoimmune diseases. In this review, we summarize the function of eosinophils in inflammatory bowel diseases, neuromyelitis optica, bullous pemphigoid, autoimmune myocarditis, primary biliary cirrhosis, eosinophilic granulomatosis with polyangiitis, and other autoimmune diseases. Clinical studies, eosinophil-targeted therapies, and experimental models have contributed to our understanding of the regulation and function of eosinophils in these diseases. By examining the role of eosinophils in autoimmune diseases of different organs, we can identify common pathogenic mechanisms. These include degranulation of cytotoxic granule proteins, induction of antibody-dependent cell-mediated cytotoxicity, release of proteases degrading extracellular matrix, immune modulation through cytokines, antigen presentation, and prothrombotic functions. The association of eosinophilic diseases with autoimmune diseases is also examined, showing a possible increase in autoimmune diseases in patients with eosinophilic esophagitis, hypereosinophilic syndrome, and non-allergic asthma. Finally, we summarize key future research needs.

Eosinophils Promote Antiviral Immunity in Mice Infected with Influenza A Virus

Eosinophils are multifunctional cells of the innate immune system linked to allergic inflammation. Asthmatics were more likely to be hospitalized but less likely to suffer severe morbidity and mortality during the 2009 influenza pandemic. These epidemiologic findings were recapitulated in a mouse model of fungal asthma wherein infection during heightened allergic inflammation was protective against influenza A virus (IAV) infection and disease. Our goal was to delineate a mechanism(s) by which allergic asthma may alleviate influenza disease outcome, focused on the hypothesis that pulmonary eosinophilia linked with allergic respiratory disease is able to promote antiviral host defenses against the influenza virus. The transfer of eosinophils from the lungs of allergen-sensitized and challenged mice into influenza virus-infected mice resulted in reduced morbidity and viral burden, improved lung compliance, and increased CD8+ T cell numbers in the airways. In vitro assays with primary or bone marrow-derived eosinophils were used to determine eosinophil responses to the virus using the laboratory strain (A/PR/08/1934) or the pandemic strain (A/CA/04/2009) of IAV. Eosinophils were susceptible to IAV infection and responded by activation, piecemeal degranulation, and upregulation of Ag presentation markers. Virus- or viral peptide-exposed eosinophils induced CD8+ T cell proliferation, activation, and effector functions. Our data suggest that eosinophils promote host cellular immunity to reduce influenza virus replication in lungs, thereby providing a novel mechanism by which hosts with allergic asthma may be protected from influenza morbidity.