Asthma drug use and the development of Churg-Strauss syndrome (CSS)

Eosinophilic granulomatosis with polyangiitis - Advances in pathogenesis, diagnosis, and treatment

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare disease characterized by eosinophil-rich granulomatous inflammation and necrotizing vasculitis, pre-dominantly affecting small-to-medium-sized vessels. It is categorized as a primary antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) but also shares features of hypereosinophilic syndrome (HES); therefore, both vessel inflammation and eosinophilic infiltration are suggested to cause organ damage. This dual nature of the disease causes variable clinical presentation. As a result, careful differentiation from mimicking conditions is needed, especially from HES, given the overlapping clinical, radiologic, and histologic features, and biomarker profile. EGPA also remains a diagnostic challenge, in part because of asthma, which may pre-dominate for years, and often requires chronic corticosteroids (CS), which can mask other disease features. The pathogenesis is still not fully understood, however, the interaction between eosinophils and lymphocytes B and T seems to play an important role. Furthermore, the role of ANCA is not clear, and only up to 40% of patients are ANCA-positive. Moreover, two ANCA-dependent clinically and genetically distinct subgroups have been identified. However, a gold standard test for establishing a diagnosis is not available. In practice, the disease is mainly diagnosed based on the clinical symptoms and results of non-invasive tests. The unmet needs include uniform diagnostic criteria and biomarkers to help distinguish EGPA from HESs. Despite its rarity, notable progress has been made in understanding the disease and in its management. A better understanding of the pathophysiology has provided new insights into the pathogenesis and therapeutic targets, which are reflected in novel biological agents. However, there remains an ongoing reliance on corticosteroid therapy. Therefore, there is a significant need for more effective and better-tolerated steroid-sparing treatment schemes.

Advances in the pharmacotherapeutic management of eosinophilic granulomatosis with polyangiitis

INTRODUCTION

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare but potentially lethal systemic vasculitis. Only a few prospective therapeutic trials had been conducted in EGPA, and its treatment was mostly adapted from other vasculitides. Monoclonal antibodies inhibiting various pathways (e.g. interleukin-5 [IL5] or B cells) have been investigated.

AREAS COVERED

Published studies on treatments for EGPA using glucocorticoids, conventional immunosuppressants (such as cyclophosphamide or azathioprine), antiIL5 pathway agents (mepolizumab, approved by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) for EGPA; benralizumab and reslizumab), other and future possible treatments [PubMed search, 01/1990-02/2023] are reviewed.

EXPERT OPINION

With advances made in the pharmacotherapeutic management of EGPA, the prognosis has gradually shifted from a potentially fatal to a more chronic course, for which more targeted and safer treatments can be used. However, glucocorticoids remain central. Rituximab is now a possible alternative to cyclophosphamide for induction, although data are still limited. AntiIL5 pathway therapies have been shown to be safe and effective in relapsing patients with EGPA, who often experience asthma and/or ears, nose, and throat (ENT) manifestations, but long-term data are needed. Treatment strategies need to be optimized based on individual patient characteristics, likely with sequential, combination-based approaches, while topical airway treatments should not be forgotten.

Eosinophilic Lung Diseases

The eosinophilic lung diseases may manifest as chronic eosinophilic pneumonia, acute eosinophilic pneumonia, or as the Löffler syndrome (generally of parasitic etiology). The diagnosis of eosinophilic pneumonia is made when both characteristic clinical-imaging features and alveolar eosinophilia are present. Peripheral blood eosinophils are generally markedly elevated; however, eosinophilia may be absent at presentation. Lung biopsy is not indicated except in atypical cases after multidisciplinary discussion. The inquiry to possible causes (medications, toxic drugs, exposures, and infections especially parasitic) must be meticulous. Idiopathic acute eosinophilic pneumonia may be misdiagnosed as infectious pneumonia. Extrathoracic manifestations raise the suspicion of a systemic disease especially eosinophilic granulomatosis with polyangiitis. Airflow obstruction is frequent in allergic bronchopulmonary aspergillosis, idiopathic chronic eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis, and hypereosinophilic obliterative bronchiolitis. Corticosteroids are the cornerstone of therapy, but relapses are common. Therapies targeting interleukin 5/interleukin-5 are increasingly used in eosinophilic lung diseases.

Eosinophilic granulomatosis with polyangiitis: A review

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, multi-system, inflammatory disease, belonging to the group of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV). Previously known as Churg-Strauss syndrome, EGPA is characterised by late-onset asthma, eosinophilia and vasculitis affecting small-to-medium vessels. This disease behaves differently in many aspects to the other AAV and is often excluded from AAV studies. The disease is poorly understood and, due to it rarity and unique manifestations, there has been limited research progress to optimise our understanding of its complex pathogenesis and ability to develop management options - although the success of interleukin-5 inhibitors such as Mepolizumab has been a welcome development. The pathophysiology also appears to be different to other forms of AAV and hence management strategies that work for AAV may not fully apply to this condition. There is no current standard therapy for EGPA although corticosteroids are almost universally used for treatment alongside other agents and encouraging modes of treatment continue to evolve beyond glucocorticoid immunosuppression (including interleukin-5 inhibition). There is therefore a significant ongoing unmet need for efficacious steroid-sparing immunosuppressing agents. The prognosis also diverges from other forms of AAV, and we discuss the pathophysiology, clinical features and diagnosis, management and prognosis in this article.

Real-life evidence of low-dose mepolizumab efficacy in EGPA: a case series

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, small vessel, necrotizing vasculitis. The disease is mainly characterized by hypereosinophilia and asthma with frequent sinonasal involvement, although multiple organs can be affected, including the heart, lungs, skin, gastrointestinal tract, kidneys, and nervous system. IL-5 production is pathogenetically central for the development of the disease by promoting proliferation, transvascular migration and functional activation of eosinophils. The degree of blood and tissue eosinophilia appears to be associated with disease pathogenesis and eosinophil depletion represents a promising treatment approach for EGPA. We prospectively evaluated the efficacy and safety of a low dose (100 mg q4w), 12-month course of mepolizumab, an anti-IL-5 monoclonal antibody, in eight patients with severe asthma and active EGPA. Patients were recruited by the tertiary care center of Clinical Immunology and Allergy, University of Naples Federico II. The following outcomes were assessed before (T0), and after 6 (T6) and 12 months (T12) of mepolizumab treatment: Birmingham Vasculitis Activity Score (BVAS), prednisone intake, Sino-Nasal Outcome Test (SNOT-22), Total Endoscopic Polyp Score (TENPS), Asthma Control Test (ACT), Forced Expiratory Volume one second (FEV1)%, blood eosinophilia. BVAS score significantly decreased showing a sharp reduction in disease activity score. Clinical improvements in terms of sinonasal scores and asthma symptoms were observed, in parallel with a drastic drop in eosinophil blood count. Prednisone intake was significantly reduced. In two patients, asthma exacerbations led to discontinuation in mepolizumab therapy after 6 and 12 months despite BVAS reduction. Mepolizumab treatment was well tolerated, and no severe adverse drug effects were registered. In conclusion, our 12-month real-life study suggests that mepolizumab may be beneficial and safe in active EGPA patients by improving disease activity score, sinonasal and asthma outcomes while reducing the burden of prednisone intake.

Eosinophilic granulomatosis with polyangiitis: understanding the disease and its management

Eosinophilic granulomatosis with polyangiitis is characterized by asthma, blood and tissue eosinophilia and small-vessel vasculitis. The clinical presentation is variable, but two main clinic-pathologic subsets can be distinguished: one hallmarked by positive ANCA and predominant 'vasculitic' manifestations (e.g. glomerulonephritis, purpura and mononeuritis multiplex) and the other by negative ANCA and prominent 'eosinophilic' manifestations (e.g. lung infiltrates and cardiomyopathy). The pathogenesis is not fully understood but probably results from the interplay between T and B cells and eosinophils. Eosinophilic granulomatosis with polyangiitis must be differentiated from several conditions, including hypereosinophilic syndromes and other small-vessel vasculitides. The overall survival is good; however, patients frequently relapse and have persistent symptoms. The recently developed monoclonal antibodies targeting B cells and eosinophilopoietic cytokines such as IL-5 are emerging as valid alternatives to conventional immunosuppressive therapies. In this review, we discuss the essential features of eosinophilic granulomatosis with polyangiitis, with particular respect to the most relevant issues concerning clinical presentation and management.

Eosinophilic Granulomatosis with Polyangiitis: A Systematic Review and Meta-Analysis of Test Accuracy and Benefits and Harms of Common Treatments

Objective

Eosinophilic granulomatosis with polyangiitis (EGPA) is part of a group of vasculitides commonly referred to as antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV), in addition to granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and renal‐limited vasculitis. Patients with EGPA characteristically have asthma and marked peripheral eosinophilia with only approximately 30% to 35% of patients being myeloperoxidase (MPO)‐ANCA positive, distinguishing it from other forms of AAV (1,2). The aim of this systematic review is to support the development of the American College of Rheumatology/Vasculitis Foundation guideline for the management of EGPA.

Methods

A systematic review was conducted of the literature for seven forms of primary systemic vasculitis (GPA, MPA, EGPA, polyarteritis nodosa, Kawasaki disease, giant cell arteritis, and Takayasu arteritis). The search was done for articles in English using Ovid Medline, PubMed, Embase, and the Cochrane Library. Articles were screened for suitability in addressing population/patients, intervention, comparator, and outcomes (PICO) questions, with studies presenting the highest level of evidence given preference. Two independent reviewers conducted a title/abstract screen and full‐text review for each eligible study.

Results

The initial search, conducted in August 2019, included 13 800 articles, of which 2596 full‐text articles were reviewed. There were 190 articles (addressing 34 PICO questions) reporting on the diagnosis and management of EGPA.

Conclusion

This comprehensive systematic review synthesizes and evaluates the accuracy of commonly used tests for EGPA as well as benefits and toxicities of different treatment options.

Environmental risk factors associated with ANCA associated vasculitis: A systematic mapping review

BACKGROUND

Anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) is a rare multi-system autoimmune disease, characterised by a pauci-immune necrotising small-vessel vasculitis, with a relapsing and remitting course. Like many autoimmune diseases, the exact aetiology of AAV, and the factors that influence relapse are unknown. Evidence suggests a complex interaction of polygenic genetic susceptibility, epigenetic influences and environmental triggers. This systematic mapping review focuses on the environmental risk factors associated with AAV. The aim was to identify gaps in the literature, thus informing further research.

METHODS

Articles that examined any environmental risk factor in AAV disease activity (new onset disease or relapse) were included. Studies had to make explicit reference to AAV, which includes the 3 clinico-pathological phenotypes (GPA, MPA and EGPA), rather than isolated ANCA-positivity. All articles identified were English-language, full manuscripts involving adult humans (>16 years). There was no restriction on publication date and all study designs, except single case reports, were included. The systematic search was performed on 9th December 2019, using the following databases: EMBASE, Medline (Ovid), Cochrane Library, CINAHL and Web of Science.

RESULTS

The search yielded a total of 2375 articles. 307 duplicates were removed, resulting in the title and abstract of 2068 articles for screening. Of these, 1809 were excluded. Thus, 259 remained for full-text review, of which 181 were excluded. 78 articles were included in this review. The most notable findings support the role of various pollutants - primarily silica and other environmental antigens released during natural disasters and through farming. Assorted geoepidemiological triggers were also identified including seasonality and latitude-dependent factors such as UV radiation. Finally, infection was tightly associated, but the exact microorganism(s) is not clear - Staphylococcus aureus is the most presently convincing.

CONCLUSION

The precise aetiology of AAV has yet to be elucidated. It is likely that different triggers, and the degree to which they influence disease activity, vary by subgroup (e.g. ANCA subtype, geographic region). There is a need for more interoperable disease registries to facilitate international collaboration and hence large-scale epidemiological studies, with novel analytical techniques.

The importance and implications of comparator selection in pharmacoepidemiologic research

PURPOSE OF REVIEW

Pharmacoepidemiologic studies employing large databases are critical to evaluating the effectiveness and safety of drug exposures in large and diverse populations. Because treatment is not randomized, researchers must select a relevant comparison group for the treatment of interest. The comparator group can consist of individuals initiating: (1) a similarly indicated treatment (active comparator), (2) a treatment used for a different indication (inactive comparator) or (3) no particular treatment (non-initiators). Herein we review recent literature and describe considerations and implications of comparator selection in pharmacoepidemiologic studies.

RECENT FINDINGS

Comparator selection depends on the scientific question and feasibility constraints. Because pharmacoepidemiologic studies rely on the choice to initiate or not initiate a specific treatment, rather than randomization, they are at-risk for confounding related to the comparator choice including: by indication, disease severity and frailty. We describe forms of confounding specific to pharmacoepidemiologic studies and discuss each comparator along with informative examples and a case study. We provide commentary on potential issues relevant to comparator selection in each study, highlighting the importance of understanding the population in whom the treatment is given and how patient characteristics are associated with the outcome.

SUMMARY

Advanced statistical techniques may be insufficient for reducing confounding in observational studies. Evaluating the extent to which comparator selection may mitigate or induce systematic bias is a critical component of pharmacoepidemiologic studies.

A case report and literature review of Churg-Strauss syndrome presenting with myocarditis

BACKGROUND

Churg-Strauss syndrome (CSS) is a multisystem disorder characterized by asthma, prominent peripheral blood eosinophilia, and vasculitis signs.

CASE SUMMARY

Here we report a case of CSS presenting with acute myocarditis and heart failure and review the literature on CSS with cardiac involvement. A 59-year-old man with general fatigue, numbness of limbs, and a 2-year history of asthma was admitted to the department of orthopedics. Eosinophilia, history of asthma, lung infiltrates, peripheral neurological damage, and myocarditis suggested the diagnosis of CSS. Transthoracic echocardiography revealed a dilated hypokinetic left ventricle (left ventricular ejection fraction ∼40%) with mild segmental abnormalities in the septal and apical segments.

CONCLUSION

By reviewing the present case reports, we concluded that (1) the younger age of CSS, the greater occurrence rate of complicating myocarditis and the poorer prognosis; (2) female CSS patients are older than male patients; (3) patients with cardiac involvement usually have a history of severe asthma; (4) markedly increased eosinophil count suggests a potential diagnosis of CSS (when the count increases to 20% of white blood cell counts or 8.1 × 109/L, eosinophils start to infiltrate into myocardium); and (5) negative ANCA status is associated with heart disease in CSS.

Eosinophilic Lung Diseases

Eosinophilic lung diseases especially comprise eosinophilic pneumonia or as the more transient Löffler syndrome, which is most often due to parasitic infections. The diagnosis of eosinophilic pneumonia is based on characteristic clinical-imaging features and the demonstration of alveolar eosinophilia, defined as at least 25% eosinophils at BAL. Peripheral blood eosinophilia is common but may be absent at presentation in idiopathic acute eosinophilic pneumonia, which may be misdiagnosed as severe infectious pneumonia. All possible causes of eosinophilia, including drug, toxin, fungus related etiologies, must be thoroughly investigated. Extrathoracic manifestations should raise the suspicion of eosinophilic granulomatosis with polyangiitis.

The lag-time approach improved drug-outcome association estimates in presence of protopathic bias

OBJECTIVES

Protopathic bias is a systematic error which occurs when measured exposure status may be affected by the latent onset of the target outcome. In this article, we aimed to discuss the benefits and drawbacks of the lag-time approach to address this type of bias.

STUDY DESIGN AND SETTING

The lag-time approach consists in excluding from exposure assessment the period immediately preceding the outcome detection date. With the help of simple causal diagrams, we illustrate the rationale and limitations of such strategy. The lag-time approach was illustrated in a case-crossover study, based on the health care utilization databases of the Italian Lombardy Region, on the real-world effectiveness of some respiratory drugs (exposure) in preventing asthma exacerbations (outcome).

RESULTS

A total of 7,300 of patients who were admitted to an emergency department (ED) for asthma during 2010-2012 (cases) were included. Use (vs. nonuse) of short-acting beta-agonists (SABAs, an asthma reliever medication) during the 90 days before the ED admission date was associated with an increased risk of the outcome [odds ratio (OR): 1.95; 95% confidence interval (CI): 1.72, 2.22]. This paradoxical finding may be explained by protopathic bias, as SABA use prior the ED admission may be affected by preceding respiratory distress. Indeed, when a 120-day period preceding the ED admission was ignored from drug exposure assessment (lag time), SABAs were found to be associated with a reduced risk of the outcome (OR: 0.81; 95% CI: 0.84, 0.92), as expected.

CONCLUSIONS

The lag-time approach can be a useful strategy to circumvent protopathic bias in observational studies.

Eosinophilic Lung Disease: Accompanied with 12 Cases

OBJECTIVES

Eosinophilic lung diseases are a rare group of heterogeneous diseases characterized by the increase of the eosinophil ratio in airways and lung parenchyma. In our clinic, patients diagnosed with eosinophilic lung disease were evaluated with their clinical features and prognoses.

MATERIAL AND METHODS

In our clinic, 12 cases that were diagnosed and followed up for eosinophilic lung disease [eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss syndrome) (n=4), chronic eosinophilic pneumonia (CEP) (n=7), and simple pulmonary eosinophilia (Löffler's syndrome) (n=1)] were retrospectively evaluated.

RESULTS

Of the 12 cases, 8 were females, and the average age was 43 (28-72) years. All cases were undergoing bronchodilator therapy with asthma diagnosis (2 months-40 years). Additionally, 4 of the cases had sinusitis, and 1 had allergic rhinitis. The most common complaints of the patients were difficulty in breathing and coughing, and the duration of complaints was a median of 2 months. Peripheral eosinophilia and total IgE elevation were present during the admission of all cases; additionally, leucocyte elevation was recorded in 10 of them, anemia in 4 of them, and thrombocytosis in 4 of them. Moreover, 43% of the recorded DLCO values were lower than normal. Of the 10 cases that underwent bronchoalveolar lavage (BAL), the eosinophil ratio was above 25% in 7 subjects. Of the 8 cases that underwent transbronchial biopsy, eosinophil-involving infiltration was detected in 6 subjects. Additional findings in cases diagnosed with EGPA were nasal polyposis (n=1), sinusitis (n=2), polyneuropathy (n=1), cardiac involvement (n=2), and skin involvement in biopsy (n=1). Spontaneous recovery was observed in the patient diagnosed with simple pulmonary eosinophilia during the follow-up that was performed based on the history and laboratory and BAL results of the patient. Prednisolone treatment was started for all cases, except for simple pulmonary eosinophilia, and their controls were performed. Relapse was observed in eight cases (EGPA: 4, CEP: 4); during the relapse treatment of one case diagnosed with EGPA, exitus occurred. One case rejected treatment despite the presence of peripheral eosinophilia, and the other cases are being followed-up without medication.

CONCLUSION

Given that the clinical pictures in pulmonary eosinophilia syndromes are on a wide spectrum, a specific diagnosis is important. Progression may differ in each patient, and a close follow-up is necessary during and after the treatment.

Omalizumab in patients with eosinophilic granulomatosis with polyangiitis: a 36-month follow-up study

OBJECTIVE

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis characterized by asthma and blood eosinophilia, with the lung being the organ most frequently affected. Oral glucocorticoids and/or immunosuppressive drugs are the mainstay therapy of EGPA. Occasional reports suggest that EGPA patients can be treated with omalizumab in addition to conventional therapy to achieve asthma control. To investigate the long-term effects of omalizumab in patients with EGPA and asthma (2 females, 3 males, age 41-64 years), we carried out a 36-month follow-up observational study. At the time of enrollment, the patients were on maintenance therapy and had moderate to severe allergic asthma, eosinophilia and rhinosinusitis. Mononeuropathy/polyneuropathy and/or histological evidence of tissue eosinophilic infiltration were also present.

METHODS

Patients were treated with omalizumab (300-600 mg s.c. every 2-4 weeks) as add-on therapy to prednisone, inhaled steroids and bronchodilators. During omalizumab treatment, spirometry, the asthma control test (ACT) score and eosinophilia were evaluated, and prednisone dosage was recorded.

RESULTS

During the 36 months of omalizumab treatment asthma progressively improved as indicated by spirometry and the ACT score. Eosinophilia progressively decreased. The oral prednisone dose was reduced or withdrawn during treatment. No adverse events were recorded.

CONCLUSIONS

In patients with EGPA and moderate to severe allergic asthma, omalizumab can be beneficial and safe. It enables corticosteroid tapering while decreasing eosinophilia and improving asthma symptoms over 36 months.

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss) (EGPA) Consensus Task Force recommendations for evaluation and management

OBJECTIVE

To develop disease-specific recommendations for the diagnosis and management of eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) (EGPA).

METHODS

The EGPA Consensus Task Force experts comprised 8 pulmonologists, 6 internists, 4 rheumatologists, 3 nephrologists, 1 pathologist and 1 allergist from 5 European countries and the USA. Using a modified Delphi process, a list of 40 questions was elaborated by 2 members and sent to all participants prior to the meeting. Concurrently, an extensive literature search was undertaken with publications assigned with a level of evidence according to accepted criteria. Drafts of the recommendations were circulated for review to all members until final consensus was reached.

RESULTS

Twenty-two recommendations concerning the diagnosis, initial evaluation, treatment and monitoring of EGPA patients were established. The relevant published information on EGPA, antineutrophil-cytoplasm antibody-associated vasculitides, hypereosinophilic syndromes and eosinophilic asthma supporting these recommendations was also reviewed.

DISCUSSION

These recommendations aim to give physicians tools for effective and individual management of EGPA patients, and to provide guidance for further targeted research.

Eosinophilic Pneumonia

Eosinophilic pneumonia may manifest as chronic or transient infiltrates with mild symptoms, chronic idiopathic eosinophilic pneumonia, or the frequently severe acute eosinophilic pneumonia that may be secondary to a variety of causes (drug intake, new onset of tobacco smoking, infection) and that may necessitate mechanical ventilation. When present, blood eosinophilia greater than 1 × 10⁹ eosinophils/L (and preferably greater than 1.5 × 10⁹/L) is of considerable help for suggesting the diagnosis, however it may be absent, as in the early phase of idiopathic acute eosinophilic pneumonia or when patients are already taking corticosteroids. On bronchoalveolar lavage, high eosinophilia (>25 %, and preferably >40 % of differential cell count) is considered diagnostic of eosinophilic pneumonia in a compatible setting, obviating the need of video-assisted thoracic surgical lung biopsy, which is now performed only on very rare occasions with inconsistency between clinical, biological, and imaging features. Inquiry as to drug intake must be meticulous (www.pneumotox.com) and any suspected drug should be withdrawn. Laboratory investigations for parasitic causes must take into account the travel history or residence and the epidemiology of parasites. In patients with associated extrathoracic manifestations, the diagnosis of eosinophilic granulomatosis with polyangiitis or of the hypereosinophilic syndromes should be raised. Presence of airflow obstruction can be found in hypereosinophilic asthma, allergic bronchopulmonary aspergillosis, idiopathic chronic eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis, or in the recently identified syndrome of hyperosinophilic obliterative bronchiolitis. Corticosteroids remain the cornerstone of symptomatic treatment for eosinophilic pneumonias, with a generally dramatic response. Relapses are common when tapering the doses or after stopping treatment especially in idiopathic chronic eosinophilic pneumonia. Cyclophosphamide is necessary only in patients with eosinophilic granulomatosis with polyangiitis and poor-prognostic factors. Imatinib is very effective in the treatment of the myeloproliferative variant of hypereosinophilic syndromes. Anti-interleukin-5 monoclonal antibodies are promising in the spectrum of eosinophilic disorders.

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss): evolutions in classification, etiopathogenesis, assessment and management

PURPOSE OF REVIEW

Eosinophilic granulomatosis with polyangiitis (EGPA) (Churg-Strauss syndrome) is a peculiar hybrid condition of a systemic antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and a hypereosinophilic disorder with frequent lung involvement that occurs in people with asthma. This review focuses on areas of evidence or persistent uncertainty in the classification, epidemiology, clinical presentation, diagnosis, prognosis and management of EGPA and attempts to identify clues to the mechanisms in the development or course of the disease.

RECENT FINDINGS

The 2013 revision of the EGPA definition formally placed the disease in the subset of ANCA-associated vasculitides. Recently published large case series underlined that the presence of ANCAs, found in 30-40% of EGPA, determines distinct but partly overlapping disease expression and the major detrimental effect of heart involvement on survival. There is some evidence that asthma in EGPA resembles a nonallergic eosinophilic asthma phenotype. Encouraging results have been reported for the treatment of EGPA with rituximab or with the eosinophil-targeted antiinterleukin-5 agent mepolizumab.

SUMMARY

The understanding of EGPA continues to advance, but many gaps in knowledge remain. The nomenclature remains a source of conceptual variance in terms of demonstrated presence or not of vessel inflammation or ANCAs in the diagnosis of EGPA. Distinguishing EGPA from hypereosinophilic syndromes can be problematic, and an understanding of the mechanistic relation between the vasculitis and the eosinophilic proliferation is profoundly lacking. Some evidence suggests distinct disease phenotypes, but this concept has not yet been translated to phenotype-adapted therapy.

Cerebral vasculitis

The noninfectious, inflammatory vasculitides include giant cell arteritis, Takayasu disease, Churg-Strauss angiitis, Wegener disease, polyarteritis nodosa, microscopic polyangiitis, Buerger disease, amyloid-β-related angiitis, and isolated vasculitis of the central nervous system. While these disorders are relatively uncommon, they produce a variety of neurologic diseases including muscle disease, mononeuropathy multiplex, polyneuropathy, cranial nerve palsies, visual loss, seizures, an encephalopathy, venous thrombosis, ischemic stroke, and intracranial hemorrhage. The multisystem vasculitides often have stereotypical clinical findings that reflect disease of the kidney, sinuses, lungs, skin, joints, or cardiovascular system. These disorders also usually have abnormalities found on serologic testing. Isolated vasculitis of the central nervous system is more difficult to diagnose because the clinical and brain imaging findings are relatively nonspecific. Examination of the cerebrospinal fluid will demonstrate changes consistent with an inflammatory process. Arteriography often shows areas of segmental narrowing affecting multiple intracranial vessels and brain/meningeal biopsy may be required to establish the diagnosis. Management of patients with a multisystem vasculitis or isolated vasculitis of the central nervous system is centered on the administration of immunosuppressive agents. In many cases, corticosteroids remain the mainstay of medical treatment.

Novel therapies in asthma: leukotriene antagonists, biologic agents, and beyond

Asthma is one of the most common conditions seen in clinical practice and carries both a significant disease burden in terms of patient morbidity and a high economic burden in both direct and indirect costs. Despite this, it remains a comparatively poorly understood disease, with only modest advances in treatment over the past decade. Corticosteroids remain the cornerstone of therapy. Both patient compliance with medications and physician adherence to evidence-based guidelines are often poor, and a high percentage of patients continue to have inadequately controlled disease even with optimal therapy. Following a contextual overview of the current treatment guidelines, this review focuses on novel asthma therapies, beginning with the introduction of the leukotriene receptor antagonist zafirlukast in the 1990s, continuing through advanced endoscopic therapy and into cytokine-directed biologic agents currently in development. Along with clinically relevant biochemistry and pharmacology, the evidence supporting the place of these therapies in current guidelines will be highlighted along with data comparing these agents with more conventional treatment. A brief discussion of other drugs, such as those developed for unrelated conditions and subsequently examined as potential asthma therapies, is included.

Successful multidrug treatment of a pediatric patient with severe Churg-Strauss syndrome refractory to prednisolone

Churg-Strauss syndrome (CSS), which is characterized by systemic small-vessel vasculitis of unknown etiology, is associated with a history of asthma. Although reports of CSS occurring in children are limited, effective treatment of pediatric patients with severe CSS remains challenging. A 10-year-old Japanese boy with a 6-month history of asthma treated with a leukotriene modifier, pranlukast, developed high fever, pleural infiltration, and pericarditis that were associated with marked hypereosinophilia (10,350 eosinophils/µl). Owing to his persistent high fever, mononeuritis multiplex, and severe abdominal pain that was refractory to prednisolone, his general condition progressively deteriorated thereafter. Although intravenous high-dose immunoglobulin administration was transiently effective for mononeuritis multiplex, the recurrent high fever and severe abdominal pain remained refractory. An endoscopic study revealed ulcerative lesions of the total colon. In this context, we treated the patient with an aggressive multidrug immunosuppressive regimen consisting of a high-dose methylprednisolone pulse plus short-course intravenous cyclophosphamide pulse therapy, followed by oral tacrolimus combined with prednisolone. After the rescue multidrug treatment, his severe clinical signs dramatically subsided within a short time, and the concomitantly administered prednisolone was successfully tapered without flare. At present, 12 months after the presentation, he is free from CSS signs or therapy-related toxicity except for an occasional mild asthma attack. Although further close observation should be needed to draw a long-term outcome in this patient, we believe that aggressive multidrug immunosuppressive treatment should be considered as an alternative rescue treatment in selected patients with severe CSS, even with pediatric-onset disease, that is refractory to prednisolone.

Drug allergy: an updated practice parameter

Adverse drug reactions (ADRs) result in major health problems in the United States in both the inpatient and outpatient setting. ADRs are broadly categorized into predictable (type A and unpredictable (type B) reactions. Predictable reactions are usually dose dependent, are related to the known pharmacologic actions of the drug, and occur in otherwise healthy individuals, They are estimated to comprise approximately 80% of all ADRs. Unpredictable are generally dose independent, are unrelated to the pharmacologic actions of the drug, and occur only in susceptible individuals. Unpredictable reactions are subdivided into drug intolerance, drug idiosyncrasy, drug allergy, and pseudoallergic reactions. Both type A and B reactions may be influenced by genetic predisposition of the patient

Mepolizumab as a steroid-sparing treatment option in patients with Churg-Strauss syndrome

BACKGROUND

Treatments for Churg-Strauss syndrome (CSS), a rare eosinophilic vasculitis characterized by asthma, sinusitis, peripheral eosinophilia, pulmonary infiltrates, and tissue infiltration, are limited by toxicity or poor efficacy. Levels of IL-5, a cytokine regulating eosinophils, can be increased in patients with CSS. Mepolizumab, a humanized monoclonal anti-IL-5 antibody, decreases steroid requirements in patients with non-CSS hypereosinophilic syndromes.

OBJECTIVE

The purpose of this study was to assess whether mepolizumab would safely allow corticosteroid tapering in patients with steroid-dependent CSS while decreasing serum markers of disease activity.

METHODS

This open-label pilot study treated 7 patients with 4 monthly doses of mepolizumab to assess whether it safely decreased CSS disease activity and permitted tapering of systemic corticosteroids.

RESULTS

Mepolizumab was safe and well tolerated in patients with CSS. Mepolizumab reduced eosinophil counts and allowed for safe corticosteroid reduction in all 7 subjects. On cessation of mepolizumab, CSS manifestations recurred, necessitating corticosteroid bursts.

CONCLUSION

Mepolizumab is a safe and well-tolerated therapy in patients with CSS, offering clinical benefit by enabling corticosteroid tapering while maintaining clinical stability.

Epidemiology of ANCA-associated vasculitis

The epidemiology of the antineutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV), comprising Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome, poses considerable challenges to epidemiologists. These challenges include the difficulty of defining a case with a lack of clear distinction between the different disorders, case capture, and case ascertainment. The AAV are rare and therefore a large population is required to determine the incidence and prevalence, and this poses questions of feasibility. Despite these difficulties a considerable body of data on the epidemiology of the AAV has been built in the past 20 years with an interesting age, geographic, and ethnic tropism gradually being revealed. Most of the data come from White populations of European descent, and the overall annual incidence is estimated at approximately 10-20/million with a peak age of onset in those aged 65 to 74 years.

Clinical and immunological features of drug-induced and infection-induced proteinase 3-antineutrophil cytoplasmic antibodies and myeloperoxidase-antineutrophil cytoplasmic antibodies and vasculitis

PURPOSE OF REVIEW

Drugs and infections may induce antineutrophil cytoplasmic antibodies (ANCA) and vasculitic manifestations mimicking ANCA-associated vasculitides (AAV) and mechanisms relevant in their pathogenesis. This review summarizes the most recent findings in this field.

RECENT FINDINGS

Drug-induced and infection-induced proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA may be associated with a vasculitis clinically resembling AAV. Mechanisms relevant for the break of tolerance and induction of ANCA (e.g. danger signals, superantigens, neutrophil extracellular traps, protease-activated receptor-2, IL-17 cells) may be shared to some extent between drug-induced and infection-induced ANCA-positive vasculitis and AAV, especially with regard to the potential role of infection in Wegener's granulomatosis. Differences in immunopathology, clinical presentation, and functional aspects of ANCA help to distinguish drug-induced and infection-induced ANCA-positive vasculitis from AAV, and present new avenues for future research in this field.

SUMMARY

Medications and infections, which induce PR3-ANCA and MPO-ANCA, have to be considered in the differential diagnosis of primary AAV. Moreover, there is clinical and experimental evidence for an association between certain drugs and infections with ANCA-production. Analysis of ANCA-induction in such conditions also sheds new light on our understanding of immune mechanisms relevant in the break of tolerance and ANCA-production in AAV.

Progress in pediatric vasculitis

PURPOSE OF REVIEW

To examine recent advances in the pathophysiology and therapy of pediatric vasculitis.

RECENT FINDINGS

The past 2 years have been marked by significant progress in extending novel techniques to the investigation of the two most common pediatric vasculitis syndromes, Henoch-Schonlein purpura and Kawasaki disease. Study of other vasculitides, such as Wegener granulomatosis, Churg-Strauss syndrome, and microscopic polyangiitis, is impeded by the small number of pediatric patients. Nonetheless, national and international registries are beginning to provide the foundation for generation of testable hypotheses regarding pathogenesis and optimal treatment. Thus, recent data from the study of children suggest that disorders in the control of inflammation, such as those that underlie familial Mediterranean fever and other autoinflammatory diseases, may predispose to vasculitis. Improved knowledge of mechanisms of disease, in turn, should pave the way for more targeted, effective, and tolerable therapies for children with systemic vasculitis.

SUMMARY

International collaboration to study rare disorders such as pediatric vasculitis are demonstrating disorders of inflammatory regulation that predispose to these diseases and may point toward new treatment approaches.

Churg-strauss syndrome in patients treated with omalizumab

BACKGROUND

Churg-Strauss syndrome (CSS) is a rare systemic vasculitis associated with asthma, eosinophilia, sinusitis, and pulmonary infiltrates. CSS has been reported in association with asthma therapies.

MATERIALS AND METHODS

The objective is to describe the characteristics of CSS in patients treated with the anti-IgE antibody omalizumab (Xolair; Genentech Inc; South San Francisco, CA). A retrospective review of available data to identify cases of CSS was performed using the Novartis Argus global drug safety database for omalizumab in asthma patients.

RESULTS

We identified 34 potential cases of CSS. Of these, 13 cases fulfilled at least four of the six criteria identified in the American College of Rheumatology classification criteria. Eight of the patients in these 13 definite or probable cases (62%) had CSS symptoms prior to receiving omalizumab or described symptom onset just after corticosteroid weaning. Six of the 13 patients (46%) were confirmed as having been treated with corticosteroids for what was perceived to be severe asthma; when corticosteroids were tapered in conjunction with omalizumab treatment, CSS symptoms appeared just after the tapering. There were 4 other cases of possible CSS, and the remaining 17 patients were judged to not have CSS.

CONCLUSIONS

CSS may develop in patients receiving asthma medications who have an underlying eosinophilic disorder that is unmasked by the withdrawal of therapy with corticosteroids, or in patients who delay therapy in favor of other medications. Omalizumab treatment may unmask CSS due to the weaning of corticosteroids in some asthma patients or may delay corticosteroid treatment allowing for CSS to manifest.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00252135.

Churg-Strauss syndrome: 2005-2008 update

Churg-Strauss syndrome (CSS) is a rare necrotizing small-vessel vasculitis associated with eosinophil-rich granulomatous inflammation of tissues and vessels and is also associated with asthma and eosinophilia. Epidemiologic studies continue to show that CSS is the rarest of the necrotizing small-vessel vasculitides. However, it is not possible to know with any certainty if there has been an increase in incidence. There has been an attempt to divide the patients with CSS into an antineutrophil cytoplasmic antibody-positive and cytoplasmic antibody-negative group. The former group has an increased frequency of renal involvement, parenchymal pulmonary disease, constitutional symptoms, and peripheral and central nervous system involvement, whereas the latter group has more frequent cardiac disease. The role of eosinophils and antineutrophil cytoplasmic antibodies remains poorly defined but provocative. Leukotriene receptor antagonists do not appear to induce CSS but facilitate the tapering of glucocorticoids, which unmasks the condition. Glucocorticoids and cyclophosphamide remain the foundation of treatment for vasculitis, but there are other promising and less toxic alternatives on the horizon.

Leukotriene receptor antagonists and Churg-Strauss syndrome: cause, trigger or merely an association?

Concern has been raised in the medical literature that the use of leukotriene receptor antagonists for the treatment of asthma may be associated with an increased incidence of Churg-Strauss syndrome, a rare small-vessel vasculitic syndrome. This review provides a critical appraisal of the literature to address this question. The incidence of Churg-Strauss syndrome in the general population is one to four cases per million. In patients with asthma it is 20-60 cases per million patient-years, which is similar to that seen in a population receiving leukotriene receptor antagonists. There is no evidence for a direct causative role of leukotriene receptor antagonists in the development of Churg-Strauss syndrome. There may be multiple other non-causative reasons for an association, including the fact that these agents may be initiated in patients who are already in the process of developing Churg-Strauss syndrome, or that the use of leukotriene receptor antagonists leads to a reduction in corticosteroid use, which in turn allows the Churg-Strauss syndrome to be 'unmasked'.

A comparison of pioglitazone and rosiglitazone for hospitalization for acute myocardial infarction in type 2 diabetes

BACKGROUND

Recent studies have raised concerns about potential increased cardiovascular (CV) risk in type 2 diabetes patients treated with some peroxisome proliferator-activated receptor gamma (PPAR-gamma) agonists.

OBJECTIVE

To ascertain the risk of hospitalization for acute myocardial infarction (AMI) in type 2 diabetes patients treated with pioglitazone relative to rosiglitazone.

METHODOLOGY

Using data covering 2003-2006 from a large health care insurer in the US, a retrospective cohort study was conducted in patients who initiated treatment with pioglitazone or rosiglitazone. The hazard ratio (HR) of incident hospitalization for AMI after initiation of treatment with these drugs was estimated from multivariate Cox's proportional hazards survival analysis; similarly, the HR was ascertained for hospitalization for the composite endpoint of AMI or coronary revascularization (CR).

RESULTS

A total of 29 911 eligible patients were identified in the database; 14 807 in the pioglitazone and 15 104 in the rosiglitazone group. Baseline demographics, medical history, and dispensed medications were generally well balanced between groups. The unadjusted HR for hospitalization for AMI was 0.82, 95%CI: 0.67-1.01. After adjustment for baseline covariates the HR was 0.78, 95%CI: 0.63-0.96. The adjusted HR for the composite of AMI or CR was 0.85, 95%CI: 0.75-0.98.

CONCLUSION

This retrospective cohort study showed that pioglitazone, in comparison with rosiglitazone, is associated with a 22% relative risk reduction of hospitalization for AMI in patients with type 2 diabetes.