Churg-Strauss Syndrome: an evolving paradigm

Mesenchymal stem cell therapy in eosinophilic granulomatosis with polyangiitis-related lower limb gangrene: a case report

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA), a rare but life-threatening systemic vasculitis, is distinguished by marked eosinophilia and presents with diverse symptoms, including asthma, cutaneous purpura, ecchymosis, skin necrosis, cardiac lesions, peripheral neuropathy, and necrotizing vasculitis. The etiology of EGPA involves a complex interaction among humoral, adaptive, innate, and allergic immune responses. Standard treatment employs prolonged high-dose glucocorticoid therapy, which is critical for survival; however, some patients' symptoms cannot be relieved.

CASE REPORT

This case report details the medical management of an 11-year-old patient with EGPA, who was at risk of bilateral lower limb amputation due to differential arterial occlusion and severe, necrotizing vasculitis-induced gangrene in both feet. Treatment modalities administered included systemic infusion of Umbilical Cord Mesenchymal Stem Cells (UC-MSCs), targeted gastrocnemius muscle injections, and application of a Placenta-Derived Mesenchymal Stem Cells (PD-MSCs) hydrogel.

RESULTS

After receiving a four-month regimen of allogeneic mesenchymal stem cell therapy via intravenous and local administration, the patient showed normalized eosinophil counts, reestablished blood flow in the dorsal arteries, and marked improvement in foot ulcerations.

CONCLUSION

Mesenchymal stem cell therapy is a promising option for severe EGPA cases refractory to glucocorticoids.

Successful treatment with benralizumab in a patient with eosinophilic granulomatosis with polyangiitis refractory to mepolizumab

Introduction

Eosinophilic granulomatosis with polyangiitis (EGPA) is characterized by necrotizing eosinophilic granulomatous inflammation that frequently involves the respiratory tract (90% of cases). Asthma in EGPA is systematically severe and often refractory to common treatment, it is corticosteroid resistant and can often anticipate the onset of systemic vasculitis by many years. A release of cytokines necessary for the activation, maturation and survival of eosinophils, such as IL-4, IL-5 and IL-13 occurs in the activated Th-2 phenotype. In particular, IL-5 level is high in active EGPA and its inhibition has become a key therapeutic target. Oral glucocorticoids (OCS) are effective treatment options but unfortunately, frequent relapses occur in many patients and they lead to frequent side effects. As for now, there are currently no official recommendations on doses and treatment schedules in the management of EGPA.

Case presentation

In this article, we describe the case of a man with EGPA, severe asthma and chronic rhinosinusitis with nasal polyps (CRSwNP), with poor asthma and CRSwNP control despite OCS and mepolizumab treatment. Respiratory and vasculitis symptoms improved markedly after therapeutic switch to benralizumab. During the treatment, in addition to clinical effects, we witnessed a depletion of blood eosinophils, as well as an improvement in both pulmonary function tests, CT scan and skin lesions present initially.

Conclusions

While there are many studies confirming the efficacy of benralizumab in EGPA, the most interesting aspect of our report is that efficacy was confirmed in a patient previously unresponsive to mepolizumab, known to be effective in EGPA.

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)

Churg-Strauss syndrome, Eosinophilic granulomatosis with polyangiitis (EGPA), is a systemic vasculitis that affects small- to medium-sized vessels. It is rare and part of the Anti-neutrophil cytoplasm antibody-associated vasculitis (ANCA) group. We present a 37-year-old man, with a previous history of asthma, that was sent to the ED due to 2 weeks of productive cough, occasional dyspnea on exertion, fever (one week), asthenia, and anorexia. Upon physical examination, he was subfebrile and tachycardic. He had leukocytosis (17.00 x10^9/L) and eosinophilia of 20.0 % (3.4 X10^9/L), creatinine level of 1.5 mg/dL, subtle elevation on liver function tests and CRP of 10.82mg/dL. On Chest X-Ray, there was infiltrate on the right pulmonary base. Due to a strong suspicion of EGPA, he was started on 80mg of prednisolone from admission. ANCA MPO was positive, with the remaining auto-immune study negative. He underwent Thorax CT (under corticotherapy) without relevant changes, as well as bronchoalveolar lavage, without macroscopic signs of alveolar hemorrhage. Because of active urinary sediment, nephrotic proteinuria (6.5g/24h), and acute renal failure he underwent a renal biopsy, which revealed pauci-immune crescentic glomerulonephritis, with predominantly acute findings (in the context of ANCA-MPO Vasculitis - EGPA). After the biopsy, he received three 1g methylprednisolone pulses and was started on Cyclophosphamide. He remained asymptomatic and renal function was restored. This case highlights the importance of integrating all findings in one clinical scenario to prevent a more complex disease diagnosis, with a specific treatment, from being missed.

Eosinophilic Granulomatosis with Polyangiitis: Clinical Pathology Conference and Review

Eosinophilic granulomatosis with polyangiitis (EGPA) (formerly Churg-Strauss syndrome) is a small vessel vasculitis associated with asthma and eosinophilia. Despite its rarity, continuous gains are being made in understanding the disease with knowledge advancements regarding its epidemiology, heterogeneous clinical manifestations, management, and outcomes. Large knowledge gaps remain, however, particularly surrounding pathophysiologic and diagnostic uncertainties. There is still an incomplete understanding of the interplay between the eosinophilic and vasculitic processes that are features of disease pathogenesis. EGPA is also a conceptually difficult disorder given its dual categorization with hypereosinophilic syndromes and systemic vasculitides and the absence of a biomarker that can reliably distinguish between the two. In addition, recent evidence points to distinct, but partly overlapping, disease phenotypes, yet there is insufficient understanding to inform phenotype-tailored therapies. EGPA also remains a diagnostic challenge in part because asthma may be the primary or predominant manifestation for years, and the chronic corticosteroid requirement may mask other disease features. Efforts are ongoing to better elucidate pathophysiologic mechanisms, resolve classification issues, better characterize disease manifestations, and further clarify disease subcategorization, all of which will translate into better diagnosis and treatment with the possibility of specifically adapted therapies.

Mepolizumab for the treatment of eosinophilic granulomatosis with polyangiitis

INTRODUCTION

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis characterized by asthma, hypereosinophilia, and progressive multiorgan involvement. Although not fully elucidated, advancement in our understanding of the pathophysiology of EGPA has led to the development of multiple new treatment targets.

AREAS COVERED

Herein we review the epidemiology, clinical manifestations, pathophysiology, treatments, and ongoing research in the management of EGPA. The central role of Interleukin-5 (IL-5) in the development and maintenance of hypereosinophilia will be discussed. The value of mepolizumab, an anti-IL-5 monoclonal antibody, in the treatment of EGPA is reviewed in detail.

EXPERT OPINION

The available literature supports the use of mepolizumab for the induction and maintenance of remission of refractory, relapsing, or glucocorticoid-dependent EGPA with potentially greater benefit in those who are ANCA-positive or those with greater eosinophilia ( ≥ 150 cells/ μ L). Despite these positive results, relapses remain frequent, and the need for both short- and long-term glucocorticoid use remains common. More research is needed to address these needs and determine the precise role of mepolizumab.

Mepolizumab as the first targeted treatment for eosinophilic granulomatosis with polyangiitis: a review of current evidence and potential place in therapy

Mepolizumab is an anti-interleukin-5 (IL-5) humanized monoclonal antibody that binds to free IL-5. It induces bone marrow eosinophil maturation arrest and decreases eosinophil progenitors and subsequent maturation in the blood and bronchial mucosa. Its use has been extensively studied in severe eosinophilic asthma at a dose of 100 mg subcutaneously (SC) every 4 weeks and, more recently, in other hypereosinophilic syndromes. Eosinophilic granulomatosis with polyangiitis (EGPA) is an eosinophilic vasculitis that may involve multiple organs. Characteristic clinical manifestations are asthma, sinusitis, transient pulmonary infiltrates and neuropathy. Among the numerous pathways involved in the pathogenesis of EGPA, the Th-2 phenotype has a main role, as suggested by the prominence of the asthmatic component, in triggering the release of key cytokines for the activation, maturation and survival of eosinophils. In particular, IL-5 is highly increased in active EGPA and its inhibition can represent a potential therapeutic target. In this scenario, mepolizumab may play a therapeutic role. After some positive preliminary observations on the use of mepolizumab in small case series of EGPA patients with refractory or relapsing disease despite standard of care treatment, a randomized controlled trial was published in 2017. Mepolizumab at a dose of 300 mg administered by SC injection every 4 weeks proved effective in prolonging the period of remission of the disease, allowing for reduced steroid use. The positive results of this study, which met both of the primary endpoints, led to the approval in the USA of mepolizumab in adult patients with EGPA by the Food and Drug Administration in 2017. Therefore, mepolizumab can be officially considered as an add-on therapy with steroid-sparing effect in cases of relapsing or refractory EGPA. However, the most appropriate dose and duration of therapy still need to be determined. Future studies on larger multinational populations with prolonged follow-up are warranted.

[Hyper-IgE in internal medicine]

Hyper-IgE may be found under many pathological conditions. The role of IgE is essentially associated with the occurrence of allergic manifestations, which may be accompanied by an increase of their serum levels. Elevation of total IgE has also been reported in association with certain rare genetic immune deficiencies called hyper-IgE syndromes. Other circumstances such as infectious diseases, tumors or autoimmune diseases may also be accompanied by an excessive synthesis of IgE. Considering the diversity of these situations, discussion of the prognostic value of total IgE is useful to the internist.

Development of a Certified Reference Material for myeloperoxidase-anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA)

A serum Certified Reference Material (CRM) for supporting reliable autoimmune diagnostics was recently released by the Institute for Reference Materials and Measurements (IRMM) of the Joint Research Centre of the European Commission. It was produced in collaboration with a Working Group on the Harmonisation of Autoimmune Tests of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC WG-HAT). This material is aimed at facilitating the standardisation of measurements of anti-myeloperoxidase immunoglobulin G antibodies. The CRM could be used as a common calibrant by clinicians and manufacturers thereby significantly improving the comparability of results from commercial immunoassays used for IgG anti-MPO measurements. This paper provides information on the new CRM and its intended use.

Pulmonary vasculature and critical asthma syndromes: a comprehensive review

One of the important factors and consequences in persistent asthma is the change in the vasculature of the airways and lung parenchyma. These changes could contribute to worsening asthma control and predispose asthmatics to critical asthma syndromes. For many years, the contribution of vasculature to severe asthma was limited to discussion of small and medium vessel vasculitis commonly referred to as Churg − Strauss syndrome. This comprehensive review will explore the known mechanisms that are associated with remodeling of the vasculature in a variety of critical asthma presentations. Inflammation of pulmonary and bronchial small blood vessels may contribute significantly but silently to asthma pathobiology. Inflammation in the vasculature of the lung parenchyma can decrease lung capacity while inflammation in airway vasculature can decrease airflow. This review will provide a modern perspective on Churg–Strauss syndromes with a focus on phenotyping, mechanism, and ultimately modern therapeutic approaches. Vascular remodeling and airway remodeling are not mutually exclusive concepts in understanding the progression of asthma and frequency of acute exacerbations. Furthermore, the contribution of vascular leak, particularly in the parenchymal vasculature, has become an increasingly recognized component of certain presentations of poorly controlled, severe persistent asthmatic and during exacerbations. We highlight how these mechanisms can contribute to some the severe presentations of influenza infection in patients with a history of asthma. The ultimate aim of this review is to summarize the current literature concerning vasculitis and the contribution of airway and parenchymal vascular remodeling to presentation of persistent asthma and its consequences during acute exacerbations and critical asthma syndromes.

Churg-Strauss syndrome

Churg-Strauss syndrome (CSS), alternatively known as eosinophilic granulomatosis with polyangiitis (EGPA), was first described in 1951 by Churg and Strauss as a rare disease characterized by disseminated necrotizing vasculitis with extravascular granulomas occurring exclusively among patients with asthma and tissue eosinophilia. EGPA is classified as a small-vessel vasculitis associated with antineutrophil cytoplasmic antibodies (ANCAs) and the hypereosinophilic syndromes (HESs) in which vessel inflammation and eosinophilic proliferation are thought to contribute to organ damage. Although still considered an idiopathic condition, EGPA is classically considered a Th2-mediated disease. Emerging clinical observations provide compelling evidence that ANCAs are primarily and directly involved in the pathogenesis of AASVs, although recent evidence implicates B cells and the humoral response as further contributors to EGPA pathogenesis. EGPA has traditionally been described as evolving through a prodromic phase characterized by asthma and rhino-sinusitis, an eosinophilic phase marked by peripheral eosinophilia and organ involvement, and a vasculitic phase with clinical manifestations due to small-vessel vasculitis. The American College of Rheumatology defined the classification criteria to distinguish the different types of vasculitides and identified six criteria for EGPA. When four or more of these criteria are met, vasculitis can be classified as EGPA. The French Vasculitis Study Group has identified five prognostic factors that make up the so-called five-factor score (FFS). Patients without poor prognosis factors (FFS=0) have better survival rates than patients with poor prognosis factors (FFS≥1). The treatment of patients with CSS must be tailored to individual patients according to the presence of poor prognostic factors. A combination of high-dose corticosteroids and cyclophosphamide is still the gold standard for the treatment of severe cases, but the use of biological agents such as rituximab or mepolizumab seems to be a promising therapeutic alternative.