Eosinophilic granulomatosis with polyangiitis: A review

An update on risk factors for relapse in antineutrophil cytoplasmic antibody-associated vasculitis

Ongoing therapeutic advances in antineutrophil cytoplasmic antibody-associated vasculitis (AAV) have significantly reduced the risk of death in AAV, but 30%-50% of patients still relapse. Relapse is a major problem in these diseases, leading to increased morbidity and mortality. It is, therefore, necessary to find predictors of relapse at the end of the remission induction and maintenance phases in order to personalize treatment.

Efficacy and safety of benralizumab in eosinophilic granulomatosis with polyangiitis: A meta-analysis of eight studies

OBJECTIVE

Eosinophilic granulomatous polyangiitis (EGPA) is a rare autoimmune disease characterized by multisystemic inflammation, with eosinophils playing a central role in its pathogenesis. Traditional management relies heavily on corticosteroids and immunosuppressants, which are associated with significant side effects. The emergence of biologic agents, such as benralizumab, offers targeted therapeutic options by inhibiting the interleukin-5 receptor α, thereby reducing eosinophilic inflammation.

METHODS

This systematic review and meta-analysis comprehensively evaluate the efficacy and safety of benralizumab in EGPA patients, focusing on its ability to reduce oral corticosteroid (OCS) use, facilitate remission and spare immunosuppressants. We searched MEDLINE, LILACS and ISI Web of Science databases for relevant studies up to July 2024.

RESULTS

Eight studies, including both randomized controlled trials (RCTs) and observational studies, were included in the meta-analysis, involving a total of 396 EGPA patients. The pooled analysis demonstrated a significant reduction in OCS dose, with an overall estimated effect of -8.25 mg/day (95% CI, -9.39 to -7.10). Complete remission was achieved in 56.8% of patients, and immunosuppressants were reduced or discontinued in 28.1% of cases. Adverse events (AEs) were reported in 21.9% of patients, with only one discontinuation due to an AE.

CONCLUSION

These findings provide robust evidence supporting the use of benralizumab as an effective and well-tolerated treatment option for EGPA, significantly reducing OCS requirements and offering promising remission rates. Future research should focus on larger, multicentre RCTs to confirm these findings and further elucidate the long-term benefits and safety profile of benralizumab in EGPA.

Long-term efficacy of mepolizumab in patients with eosinophilic granulomatosis with polyangiitis: a propensity score matching analysis in the multicenter REVEAL cohort study

Background

Mepolizumab (MPZ) has demonstrated efficacy in clinical trials for eosinophilic granulomatosis with polyangiitis (EGPA); however, few studies compare the disease course between patients treated with MPZ (MPZ group) and those who were not treated with MPZ (non-MPZ group) in real-world settings.

Objectives

This study aimed to compare the disease course and outcomes between the two groups and assess the long-term efficacy of MPZ in a multicenter cohort in Japan. Methods: We enrolled 113 EGPA patients registered in the cohort until June 2023. Data on clinical characteristics, disease activity, organ damage, treatments, and outcomes were retrospectively collected. To minimize potential confounding factors, we conducted propensity score matching (PSM).

Results

After PSM, 37 pairs of matched patients were identified. Clinical characteristics, including age at disease onset, sex, disease duration at last observation, antineutrophil cytoplasmic antibody positivity at disease onset, Birmingham Vasculitis Activity Score (BVAS) at disease onset, and Five-factor score at disease onset, were comparable between the groups. The median BVAS at the last observation was 0 in both groups; however, more cases in the non-MPZ group exhibited elevated BVAS, resulting in a significantly higher BVAS in the non-MPZ group at the last observation (median; MPZ group: 0, non-MPZ group: 0, p=0.028). The MPZ group had significantly lower glucocorticoid (GC) doses at the last observation (median; MPZ group: 4 mg/day, non-MPZ group: 5 mg/day, p=0.011), with a higher proportion achieving a GC dose ≤ 4 mg/day at the last observation (MPZ group: 51.4%, non-MPZ group: 24.2%, p=0.027). Three models of multivariable logistic regression analyses were performed to identify factors associated with GC doses ≤ 4 mg/day at the last observation. In all models, achieving a GC dose ≤ 4 mg/day was positively associated with MPZ administration and inversely associated with asthma at disease onset. Finally, we evaluated the survival rates between the groups, and the 5-year survival rates were significantly higher in the MPZ group compared to the non-MPZ group (MPZ group: 100%, non-MPZ group: 81.3%, p=0.012).

Conclusion

Mepolizumab not only contributes to disease activity control but also reduces the GC dose, which may lead to improved survival in EGPA patients.

Red flags for clinical suspicion of eosinophilic granulomatosis with polyangiitis (EGPA)

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA), is a rare ANCA-associated systemic vasculitis. Its overlapping features with other vasculitic or eosinophilic diseases, and the wide and heterogeneous range of clinical manifestations, often result in a delay to diagnosis.

OBJECTIVE

To identify red flags that raise a suspicion of EGPA to prompt diagnostic testing and to present an evidence-based clinical checklist tool for use in routine clinical practice.

METHODS

Systematic literature review and expert consensus to identify a list of red flags based on clinical judgement. GRADE applied to generate a strength of recommendation for each red flag and to develop a checklist tool.

RESULTS

86 studies were included. 40 red flags were identified as relevant to raise a suspicion of EGPA and assessed by the experts as being clinically significant. Experts agreed that a diagnosis of EGPA should be considered in a patient aged ≥6 years with a blood eosinophil level >1000 cells/µL if untreated and >500 cells/µL if previously treated with any medication likely to have altered the blood eosinophil count. The presence of asthma and/or nasal polyposis should reinforce a suspicion of EGPA. Red flags of asthma, lung infiltrates, pericarditis, cardiomyopathy, polyneuropathy, biopsy with inflammatory eosinophilic infiltrates, palpable purpura, digital ischaemia and ANCA positivity, usually anti-myeloperoxidase, among others, were identified.

CONCLUSION

The identification of a comprehensive set of red flags could be used to raise a suspicion of EGPA in patients with eosinophilia, providing clinicians with an evidence-based checklist tool that can be integrated into their practice.

Interleukin-5 as a pleiotropic cytokine orchestrating airway type 2 inflammation: Effects on and beyond eosinophils

Interleukin (IL)-5 is the key cytokine in the maturation, activation, proliferation, migration and survival of eosinophils, which are key effector cells in many upper and lower airway diseases. Through its effects on eosinophils, IL-5 indirectly contributes to various pathophysiological processes including tissue damage, repair and remodelling. Understanding the importance of IL-5 in eosinophil-associated diseases led to the development of anti-IL-5 therapies, which provide clinical benefits across a range of conditions. However, recent evidence suggests that eosinophil-depletion alone may not account for all of the therapeutic effects of anti-IL-5 therapy and that IL-5 may also contribute to disease independently of its effects on eosinophils. Indeed, evidence from ex vivo studies and targeted therapy in vivo demonstrates that IL-5 and its inhibition affects a much broader range of cells beyond eosinophils, including epithelial cells, plasma cells, mast cells, basophils, neutrophils, type 2 innate lymphoid cells, T regulatory cells and fibroblasts. This review will provide an update on the evidence supporting the breadth of IL-5 biology relevant to disease pathogenesis beyond eosinophil-associated inflammation, where there is a need for additional insight, and the clinical implications of a more central role of IL-5 in type 2 inflammation.

A case of eosinophilic granulomatosis with polyangiitis combined with pulmonary tuberculosis: A case report

RATIONALE

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare autoimmune disease that can affect multiple organ systems. The standard treatment mainly relies on glucocorticoids and immunosuppressive agents. In our study, we present an EGPA patient who had pulmonary tuberculous mycobacteria infection, such cases are rarely reported.

PATIENT CONCERNS

A 71-year-old male patient was diagnosed with EGPA (systemic type) and pulmonary tuberculosis simultaneously.

DIAGNOSES

The Five-Factor score indicated that the patient required glucocorticoids combined with immunosuppressive agents for induction therapy, however, the use of immunosuppressive agents would significantly inhibit antituberculosis treatment. Nowadays, treating active autoimmune disease in patients with infections remains a clinical challenge.

INTERVENTIONS

Considering the patient did not show life-threatening or severe organ involvement and reduced the effect of antituberculosis immunity, we used glucocorticoids alone.

OUTCOMES

Finally, the patient had no adverse events, the eosinophil counts were markedly decreased and symptoms of EGPA were relieved.

LESSONS

The patient of EGPA combined with pulmonary tuberculosis successfully treated with glucocorticoids alone may provide significant support in selecting the appropriate treatments for similar cases in the future.

A case of eosinophilic granulomatosis with polyangiitis preceded by allergic bullous lesions

A 62-year-old man with a history of diabetes mellitus was hospitalised with numbness of lower limbs, bullous lesions of the whole body, kidney dysfunction, presence of eosinophils, and elevated antineutrophil cytoplasmic antibodies to myeloperoxidase and anti-bullous pemphigoid 180 antibodies and was diagnosed with mononeuritis multiplex. Kidney and muscle biopsies showed vasculitis with fibrinoid necrosis, whereas skin biopsies showed only blister formation between the epidermis and dermis; a high eosinophilic infiltrate was present in all three tissues. These findings led to a diagnosis of eosinophilic granulomatosis with polyangiitis combined with allergic bullous lesions. Immunohistological examination indicated cytolytic eosinophils and extracellular traps, suggesting the presence of eosinophil extracellular trap cell death (eosinophil ETosis) in diseased tissue.

Causal relationship between immune cells and the risk of myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis: A Mendelian randomization study

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare inflammatory disease categorized as antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. The majority of patients are ANCA-positive, predominantly against myeloperoxidase (MPO). Previous studies have predominantly concentrated on the association between EGPA and neutrophils, but recent research has emphasized the role of lymphocytes in the development of EGPA. The objective of our research was to examine the causal association between immune cells and MPO + ANCA EGPA. A two-sample bidirectional Mendelian randomization (MR) analysis was performed, which included 159 MPO + ANCA EGPA cases and 6688 controls and utilized Genome-Wind Associaton Studies (GWAS) summary statistics of immune traits from approximately 3757 individuals, encompassing around 22 million single nucleotide polymorphisms (SNPs). Our findings revealed that 23 immunophenotypes were associated with MPO + ANCA EGPA. Furthermore, the reverse MR analysis showed that MPO + ANCA EGPA had significant causal effects on three immunophenotypes within the Treg panel. By integrating existing research, our study unveiled the contributions of Tregs, B cells, and monocytes to the development of EGPA. Subgroup analysis specifically examined the roles of lymphocyte subtypes, cytokines, and their surface molecules in the pathogenic mechanisms of the disease. This comprehensive approach provides a novel perspective on the biological mechanisms and early intervention strategies for MPO + ANCA EGPA by focusing on immune cells.

Genetic and Non-Genetic Contributions to Eosinophilic Granulomatosis with Polyangiitis: Current Knowledge and Future Perspectives

In this work, we present a comprehensive overview of the genetic and non-genetic complexity of eosinophilic granulomatosis with polyangiitis (EGPA). EGPA is a rare complex systemic disease that occurs in people presenting with severe asthma and high eosinophilia. After briefly introducing EGPA and its relationship with the anti-neutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis (AAVs), we delve into the complexity of this disease. At first, the two main biological actors, ANCA and eosinophils, are presented. Biological and clinical phenotypes related to ANCA positivity or negativity are explained, as well as the role of eosinophils and their pathological subtypes, pointing out their intricate relations with EGPA. Then, the genetics of EGPA are described, providing an overview of the research effort to unravel them. Candidate gene studies have investigated biologically relevant candidate genes; the more recent genome-wide association studies and meta-analyses, able to analyze the whole genome, have confirmed previous associations and discovered novel risk loci; in the end, family-based studies have dissected the contribution of rare variants and the heritability of EGPA. Then, we briefly present the environmental contribution to EGPA, reporting seasonal events and pollutants as triggering factors. In the end, the latest omic research is discussed and the most recent epigenomic, transcriptomic and microbiome studies are presented, highlighting the current challenges, open questions and suggesting approaches to unraveling this complex disease.

[Bronchial asthma and allergic rhinitis-The skin sample reveals a severe systemic disease]

This article reports the case of a 30-year-old female patient who suffered for many years from initially unspecific symptoms, such as recurrent, nonallergic and noninfectious sinusitis, late-onset bronchial asthma and pronounced lymphadenopathy; however, the correct diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA) could only be made by histological investigations after the appearance of skin symptoms. The EGPA is a severe systemic disease which, if left untreated, can cause multiple organ damage and even be fatal. With adequate treatment the disease is mild in more than 90% of cases and patients can even completely recover. By making the correct diagnosis, the patient could be successfully treated and the risk of late manifestations and subsequent damage with a potentially fatal outcome was reduced.

Monocentric study of IL-5 monoclonal antibody induction therapy for eosinophilic granulomatosis with polyangiitis

OBJECTIVE

Although sporadic case reports have demonstrated successful management of eosinophilic granulomatosis with polyangiitis (EGPA) by anti-IL-5 therapy, larger-scale monocentric studies for the efficacy of mepolizumab (MEP), an IL-5 monoclonal antibody, are still lacking in Taiwan.

METHODS

Hospitalized EGPA patients aged at least 18 years were enrolled from November 1998 to October 2023, and analyzed for demographic, clinical, laboratory, medication and outcome data, focusing on the efficacy and safety of biologics use, particularly induction therapy with MEP.

RESULTS

Twenty-seven EGPA patients aged 10-70 years (43 ± 15) at disease diagnosis were recruited with 21 under combined corticosteroids/cyclophosphamide induction therapy. Seventeen patients received biologics with 13 under MEP therapy. Ten patients aged 19-71 years (48 ± 15) completed 12-month induction therapy with a 100 mg quadri-weekly subcutaneous injection regimen indicated for active or relapse disease. There were reduced BVAS with complete remission in 6 and partial remission in 4 patients, lower CRP levels, decreased eosinophil counts with an inhibition of 92∼96 %, and tapered prednisolone dosages from 5 to 25 (13.0 ± 6.3) to 0-10 (3.3 ± 3.1) mg/day. Only one patient had an adverse event of injection site reactions. Nine patients received the same regimen for annual maintenance therapy. All had a persistent clinical remission. In these patients, 13-56 injections (41 ± 15) were prescribed with a follow-up period of 12∼52 months (38 ± 14).

CONCLUSION

In this retrospective study, induction therapy with a 12-month 100 mg MEP quadri-weekly subcutaneous injection regimen demonstrates the efficacy and safety for active and relapsing EGPA patients.

The Evaluation of Changing the Eponym Churg-Strauss Syndrome Due to the 2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides

Background: Eponyms do not describe any pathogenesis of a disease. So, there is no other way than to memorize the disease or anatomical area. Over the years, new nomenclatures have been suggested for some diseases due to a better understanding of the pathogenesis. In this article, the changes in the use of Churg-Strauss syndrome were investigated. Methods: In the study, a computerized search was performed using the PubMed database. Books and documents, clinical trials, editorials, meta-analyses, reviews, and case reports were included in the study. Data were obtained from the title of the database, and the variations or distribution by year for the nomenclature of the most related studies were evaluated. Results: Overall, 68.3% of the articles included CSS, 25.7% included eosinophilic granulomatous polyangiitis (EGPA), and 6.0% included both nomenclatures. When evaluated in terms of the distribution according to years, it was determined that there was a statistically significant increase in use in terms of EGPA. When evaluated among specific section journals, the highest rate was in Rheumatology (29.4%). The highest rate of using CSS was in the Rheumatology (25.1%) journals, followed by Pulmonary/Respiratory (17%), Cardiovascular (12%), and Allergy/Immunology/Biology (9.8%). The use of EGPA combined with CSS decreased in all the specific journals from 2012 to the present. Conclusions: The findings of the study revealed that the number of articles with the eponym of EGPA showed an increased frequency in contrast to a decreasing frequency for those with CSS during recent years. Today, with the elaboration of the disease pathogenesis and the increase in knowledge, the trend has shifted in this direction.

Pleural Diseases in Connective Tissue Diseases

Connective tissue diseases (CTD) are heterogeneous, immune-mediated inflammatory disorders often presenting with multiorgan involvement. With the advent of high-resolution computed tomography, CTD-related pleuritis-pleural thickening and effusion-is now increasingly recognized early in the disease trajectory. The natural history of CTD-related pleural effusions varies from spontaneous resolution to progressive fibrothorax with ventilatory impairment. Treatment of the underlying CTD is necessary to manage the pleural disease. Depending on the degree of symptom burden and physiological insult, specific treatment of pleural disease can include monitoring, repeated aspirations, systemic anti-inflammatory medication, and surgical decortication.

Performance of the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for antineutrophil cytoplasmic antibody-associated vasculitis in previously diagnosed adult patients from Türkiye

Objectives: This study aimed to evaluate the applicability of the new 2022 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) criteria in Turkish adult patients previously diagnosed with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Patients and methods: One hundred sixty-four patients (96 males, 68 females; mean age: 49.6±14.4 years; range, 18 to 87 years) diagnosed with AAV by experienced rheumatologists between July 2016 and May 2022 were included in this retrospective cross-sectional study and reclassified based on the 1990 ACR criteria, the European Medicines Agency (EMEA) algorithm, and the 2022 ACR/EULAR criteria. For external validation, 83 patients (48 males, 35 females; mean age: 47.3±17.5 years; range, 19 to 81 years) diagnosed with immunoglobulin (Ig)A vasculitis were included. Results: One hundred twenty-six (76.8%) patients had granulomatosis with polyangiitis (GPA), 13 (7.9%) patients had eosinophilic granulomatosis with polyangiitis (EGPA), and 25 (15.2%) patients had microscopic polyangiitis (MPA). According to the criteria, the number of unclassified patients was nine (5.5%) for both the 2022 ACR/EULAR AAV classification criteria and the EMEA algorithm. The new criteria had an almost perfect agreement with the clinician's diagnosis (Cohen's kappa coefficient [κ]=0.858 for GPA, κ=0.820 for EGPA, and κ=0.847 for MPA). The kappa statistics for agreement of 2022 ACR/EULAR classification criteria with the EMEA algorithm were found 0.794 for GPA, 0.820 for EGPA, and 0.700 for MPA. None of the 83 patients diagnosed with IgA vasculitis could be classified as GPA, EGPA, or MPA using the new ACR/EULAR AAV classification criteria. Conclusion: The 2022 ACR/EULAR classification criteria for AAV showed substantial or perfect agreement with the clinical diagnosis and the EMEA algorithm.

Anti-IL-5 Pathway Agents in Eosinophilic-Associated Disorders Across the Lifespan

Monoclonal antibodies targeting interleukin (IL)-5 pathways have revolutionized the treatment expectations for eosinophilic-associated conditions, particularly in patients with respiratory involvement. Mepolizumab (IL-5 antagonist monoclonal antibody), benralizumab (IL-5 receptor blocker monoclonal antibody), and reslizumab (IL-5 antagonist monoclonal antibody) have collectively contributed to the overall improvement of the disease burden in various conditions. Eosinophilic asthma currently boasts the most robust evidence across all age groups: all three biologics are approved for adults (aged ≥18 years); mepolizumab is approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) also in children (aged ≥ 6 years), while bernalizumab was recently approved by the FDA for patients aged ≥6 years in the USA. In chronic rhinosinusitis with nasal polyps, subcutaneous mepolizumab is the only anti-IL-5 therapy approved so far and can be used in adult patients (aged ≥18 years). For eosinophilic esophagitis, conflicting evidence surrounds both mepolizumab, reslizumab, and benralizumab, leading to non-approval of these agents by the FDA/EMA. Recently, mepolizumab was approved for eosinophilic granulomatosis with polyangiitis patients aged ≥6 years or older and for hypereosinophilic syndrome adult patients. A phase III trial proving noninferiority of benralizumab versus mepolizumab in eosinophilic granulomatosis with polyangiitis has been recently published, while evidence on reslizumab is scant. Overall, current evidence on anti-IL-5 biologics for eosinophilic-associated disorders is mostly focused on adults, whereas data for individuals aged under 18 years and over 65 years are scarce, resulting in a lack of evidence, particularly regarding efficacy, for the use of anti-IL-5 agents in these specific patient populations. This review addresses high-quality evidence from randomized controlled trials and real-world post-marketing studies regarding the use of anti-IL-5 therapies for eosinophilic-associated disorders across all age groups, spanning childhood, adulthood, and older age.

Pathogenesis of Pulmonary Manifestations in ANCA-Associated Vasculitis and Goodpasture Syndrome

Pulmonary manifestations of vasculitis are associated with significant morbidity and mortality in affected individuals. They result from a complex interplay between immune dysregulation, which leads to vascular inflammation and tissue damage. This review explored the underlying pathogenesis of pulmonary involvement in vasculitis, encompassing various forms such as granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), and anti-GBM disease. Mechanisms involving ANCA and anti-GBM autoantibodies, neutrophil activation, and neutrophil extracellular trap (NETs) formation are discussed, along with the role of the complement system in inducing pulmonary injury. Furthermore, the impact of genetic predisposition and environmental factors on disease susceptibility and severity was considered, and the current treatment options were presented. Understanding the mechanisms involved in the pathogenesis of pulmonary vasculitis is crucial for developing targeted therapies and improving clinical outcomes in affected individuals.

Severe heart failure and intracardiac thrombosis: going beyond the appearance for diagnosis and treatments

We describe the case of a 45-year-old female affected by asthma and nasal polyposis who presented to the emergency department because of worsening dyspnea and paresthesia of the left lower limb. Comprehensive instrumental examinations revealed the presence of severe left ventricle dysfunction, intra-cardiac thrombus, deep vein thrombosis, pulmonary embolism, lung infiltrates, polyserositis, and neurological involvements. Finally, the patient was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA), formerly Churg-Strauss syndrome, a rare vasculitis of small-medium blood vessels with several organ involvements. Treatment with anticoagulants, corticosteroids, and cyclophosphamide led to a significant clinical improvement. However, a subcutaneous cardiac defibrillator was implanted because of the persistence of severe left ventricular dysfunction and the high cardiovascular risk phenotype. Indeed, several cardiac manifestations may occur in EGPA, particularly in patients with anti-neutrophil cytoplasmic antibody-negative disease. Therefore, clinicians should have high clinical suspicion because cardiac involvement in EGPA results in a poor prognosis if not diagnosed and adequately treated.

Clinical Characteristics of EGPA Patients in Comparison to GPA Subgroup with Increased Blood Eosinophilia from POLVAS Registry

Objective

To characterize the eosinophilic granulomatosis with polyangiitis (EGPA) population from the POLVAS registry depending on ANCA status and diagnosis onset, including their comparison with the granulomatosis with polyangiitis (GPA) subset with elevated blood eosinophilia (min. 400/μl) (GPA HE) to develop a differentiating strategy.

Methods

A retrospective analysis of the POLVAS registry.

Results

The EGPA group comprised 111 patients. The ANCA-positive subset (n = 45 [40.54%]) did not differ from the ANCA-negative one in clinics. Nevertheless, cardiovascular manifestations were more common in ANCA-negative patients than in those with anti-myeloperoxidase (MPO) antibodies (46.97% vs. 26.92%, p = 0.045). Patients diagnosed before 2012 (n = 70 [63.06%]) were younger (median 41 vs. 49 years, p  < 0.01), had higher blood eosinophilia at diagnosis (median 4,946 vs. 3,200/μl, p  < 0.01), and more often ear/nose/throat (ENT) and cardiovascular involvement. GPA HE comprised 42 (13.00%) out of 323 GPA cases with reported blood eosinophil count. Both GPA subsets had a lower prevalence of respiratory, cardiovascular, and neurologic manifestations but more often renal and ocular involvement than EGPA. EGPA also had cutaneous and gastrointestinal signs more often than GPA with normal blood eosinophilia (GPA NE) but not GPA HE. The model differentiating EGPA from GPA HE, using ANCA status and clinical manifestations, had an AUC of 0.92, sensitivity of 96%, and specificity of 95%.

Conclusion

Cardiovascular symptoms were more prevalent in the ANCA-negative subset than in the MPO-ANCA-positive one. Since EGPA and GPE HE share similarities in clinics, diagnostic misleading may result in an inappropriate therapeutic approach. Further studies are needed to optimize their differentiation and tailored therapy, including biologics.

Multi-Modality Imaging in Vasculitis

Systemic vasculitides are a rare and complex group of diseases that can affect multiple organ systems. Clinically, presentation may be vague and non-specific and as such, diagnosis and subsequent management are challenging. These entities are typically classified by the size of vessel involved, including large-vessel vasculitis (giant cell arteritis, Takayasu's arteritis, and clinically isolated aortitis), medium-vessel vasculitis (including polyarteritis nodosa and Kawasaki disease), and small-vessel vasculitis (granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis). There are also other systemic vasculitides that do not fit in to these categories, such as Behcet's disease, Cogan syndrome, and IgG4-related disease. Advances in medical imaging modalities have revolutionized the approach to diagnosis of these diseases. Specifically, color Doppler ultrasound, computed tomography and angiography, magnetic resonance imaging, positron emission tomography, or invasive catheterization as indicated have become fundamental in the work up of any patient with suspected systemic or localized vasculitis. This review presents the key diagnostic imaging modalities and their clinical utility in the evaluation of systemic vasculitis.

Eosinophils in Oral Disease: A Narrative Review

The prevalence of diseases characterised by eosinophilia is on the rise, emphasising the importance of understanding the role of eosinophils in these conditions. Eosinophils are a subset of granulocytes that contribute to the body's defence against bacterial, viral, and parasitic infections, but they are also implicated in haemostatic processes, including immunoregulation and allergic reactions. They contain cytoplasmic granules which can be selectively mobilised and secrete specific proteins, including chemokines, cytokines, enzymes, extracellular matrix, and growth factors. There are multiple biological and emerging functions of these specialised immune cells, including cancer surveillance, tissue remodelling and development. Several oral diseases, including oral cancer, are associated with either tissue or blood eosinophilia; however, their exact mechanism of action in the pathogenesis of these diseases remains unclear. This review presents a comprehensive synopsis of the most recent literature for both clinicians and scientists in relation to eosinophils and oral diseases and reveals a significant knowledge gap in this area of research.

Exploring novel perspectives on eosinophilic inflammation in severe asthma

Two recent articles by the same research group documented that patients with severe eosinophilic asthma exhibit an increased proportion of a subtype of eosinophils, namely CD62Llow inflammatory eosinophils (iEos) and identified an intriguing correlation between such iEos and asthma control scores. Moreover, CD62Llow iEos were reduced after treatment with the anti-IL-5 monoclonal antibody mepolizumab. In the future, we believe that eosinophil subtypes could represent a useful biomarker in severe eosinophilic asthma, helping clinicians characterize patient endotypes and monitoring the response to biological drugs.

Eosinophilic Granulomatosis With Polyangiitis Gradually Worsening With Consecutive Pregnancies: A Case Report

This case report elucidates the diagnosis and management of eosinophilic granulomatosis with polyangiitis (EGPA), a form of systemic vasculitis, in a 32-year-old female presenting with progressive dermal, respiratory, and gastrointestinal symptoms following multiple pregnancies. The patient's history of allergic reactions and pregnancies suggested a gradual progression of EGPA, a condition rarely associated with pregnancy. Initial symptoms were misinterpreted as allergic reactions and acute gastroenteritis, delaying the correct diagnosis. Laboratory findings included eosinophilia and elevated immunoglobulin E, while further investigations ruled out other differential diagnoses, such as chronic eosinophilic leukemia. A clinical diagnosis of EGPA was made based on symptom progression, eosinophilia, and mononeuritis multiplex, absent typical granulomatous changes in the skin biopsy. Treatment with high-dose prednisolone and rituximab halted disease progression and improved symptoms, highlighting the critical importance of prompt diagnosis and treatment in preventing irreversible complications. This case emphasizes the need for general physicians to consider pregnancy as a potential trigger for autoimmune diseases like EGPA, especially in patients presenting with multi-symptom allergic reactions and high inflammatory markers.

Immunopathology of herpes simplex virus-associated neuroinflammation: Unveiling the mysteries

The immunopathology of herpes simplex virus (HSV)-associated neuroinflammation is a captivating and intricate field of study within the scientific community. HSV, renowned for its latent infection capability, gives rise to a spectrum of neurological expressions, ranging from mild symptoms to severe encephalitis. The enigmatic interplay between the virus and the host's immune responses profoundly shapes the outcome of these infections. This review delves into the multifaceted immune reactions triggered by HSV within neural tissues, intricately encompassing the interplay between innate and adaptive immunity. Furthermore, this analysis delves into the delicate equilibrium between immune defence and the potential for immunopathology-induced neural damage. It meticulously dissects the roles of diverse immune cells, cytokines, and chemokines, unravelling the intricacies of neuroinflammation modulation and its subsequent effects. By exploring HSV's immune manipulation and exploitation mechanisms, this review endeavours to unveil the enigmas surrounding the immunopathology of HSV-associated neuroinflammation. This comprehensive understanding enhances our grasp of viral pathogenesis and holds promise for pioneering therapeutic strategies designed to mitigate the neurological ramifications of HSV infections.

Eosinophilic granulomatous with polyangiitis complicated by swelling of the oral cavity floor and cervical soft tissue as initial manifestation mimicking IgG4-related disease: A case report

Eosinophilic granulomatous polyangiitis is a systemic vasculitis associated with bronchial asthma and eosinophilic sinusitis. Here, we describe an unusual presentation of eosinophilic granulomatous polyangiitis that initially manifested as swelling of the oral cavity floor and cervical soft tissue. A 58 year-old Japanese man was diagnosed with bronchial asthma during childhood but did not receive regular medication. Prior to this presentation, he had a persistent cough for over 1 month, and a local physician diagnosed him with bronchial asthma. However, 6 months later, his cough worsened, and a blood test revealed elevated eosinophil levels. Immediately afterward, swelling of the floor of the oral cavity and cervical soft tissue developed. Cellulitis was suspected and antimicrobial treatment was initiated; however, the symptoms persisted and abdominal pain developed. An endoscopic examination revealed duodenitis and a duodenal ulcer. The patient was diagnosed with eosinophilic granulomatous polyangiitis based on three items of the 2022 American College of Rheumatology/European College of Rheumatology classification criteria: obstructive airway disease, blood eosinophil count ≥1 × 109 cells/L, and extravascular eosinophilic infiltration with a score of 10. Oral prednisolone (70 mg/day), intravenous cyclophosphamide (500 mg/m2), and subcutaneous mepolizumab (300 mg every 4 weeks) were administered. The patient's symptoms improved after these treatments, and the eosinophil count and inflammatory marker levels declined. When swelling of the oral cavity floor and cervical soft tissue following an increase in eosinophilia and allergic symptoms occurs, it is crucial to consider the likelihood of eosinophilic granulomatous polyangiitis and collaborate with otolaryngologists and dentists to ensure its prompt identification.

Anti-Idiotypic mRNA Vaccine to Treat Autoimmune Disorders

The 80+ existing autoimmune disorders (ADs) affect billions with little prevention or treatment options, except for temporary symptomatic management, leading to enormous human suffering and a monumental financial burden. The autoantibodies formed in most ADs have been identified, allowing the development of novel anti-idiotypic antibodies to mute the autoantibodies using vaccines. Nucleoside vaccines have been successfully tested as antigen-specific immunotherapies (ASI), with mRNA technology offering multi-epitope targeting to mute multiple autoantibodies. This paper proposes using mRNA technology to produce anti-idiotypic antibodies with broad effectiveness in preventing and treating them. This paper delves into the state-of-the-art mRNA design strategies used to develop novel ASIs by selecting appropriate T cell and B cell epitopes to generate anti-idiotypic antibodies. The low cost and fast development of mRNA vaccines make this technology the most affordable for the global control of ADs.

Biologics in severe asthma: A pragmatic approach for choosing the right treatment for the right patient

The development of monoclonal antibody therapies targeting specific components of the pathways relevant to asthma pathophysiology has revolutionized treatment of severe asthma both in adults and children and helped to further unravel the heterogeneity of this disease. However, the availability of multiple agents, often with overlapping eligibility criteria, creates a need for pragmatic guidance for specialists undertaking care of patients with severe asthma. In this review, we provide an overview of the data supporting the clinical efficacy of biologics in distinct asthma phenotypes/endotypes. We also focus on the role of biomarkers and treatable traits, including comorbidities, in the choice of asthma biologics, highlight which treatments have been demonstrated to be steroid sparing in corticosteroid dependent asthma, and provide practical guidance that can drive shared decision making on treatment choice with patients. In addition, we summarize what is known to date regarding long-term safety of these drugs, and lastly, discuss future directions in biologics research.

Phytoestrogen-Based Hormonal Replacement Therapy Could Benefit Women Suffering Late-Onset Asthma

It has been observed that plasmatic concentrations of estrogens, progesterone, or both correlate with symptoms in asthmatic women. Fluctuations in female sex steroid concentrations during menstrual periods are closely related to asthma symptoms, while menopause induces severe physiological changes that might require hormonal replacement therapy (HRT), that could influence asthma symptoms in these women. Late-onset asthma (LOA) has been categorized as a specific asthmatic phenotype that includes menopausal women and novel research regarding therapeutic alternatives that might provide relief to asthmatic women suffering LOA warrants more thorough and comprehensive analysis. Therefore, the present review proposes phytoestrogens as a promising HRT that might provide these females with relief for both their menopause and asthma symptoms. Besides their well-recognized anti-inflammatory and antioxidant capacities, phytoestrogens activate estrogen receptors and promote mild hormone-like responses that benefit postmenopausal women, particularly asthmatics, constituting therefore a very attractive potential therapy largely due to their low toxicity and scarce side effects.

Eosinophilic granulomatosis with polyangiitis, asthma as the first symptom, and subsequent Loeffler endocarditis: A case report

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss syndrome, is a rare form of anti-neutrophil cytoplasmic antibody-associated vasculitis characterized by asthma, vasculitis, and eosinophilia.

CASE SUMMARY

We report an atypical case of EGPA in a 20-year-old female patient. Unlike previously reported cases of EGPA, this patient's initial symptom was asthma associated with a respiratory infection. This was followed by Loeffler endocarditis and cardiac insufficiency. She received treatment with methylprednisolone sodium succinate, low molecular weight heparin, recombinant human brain natriuretic peptide, furosemide, cefoperazone sodium/sulbactam sodium, and acyclovir. Despite prophylactic anticoagulation, she developed a large right ventricular thrombus. EGPA diagnosis was confirmed based on ancillary test results and specialty consultations. Subsequent treatment included mycophenolate mofetil. Her overall condition improved significantly after treatment, as evidenced by decreased peripheral blood eosinophils and cardiac markers. She was discharged after 17 d. Her most recent follow-up showed normal peripheral blood eosinophil levels, restored cardiac function, and a reduced cardiac mural thrombus size.

CONCLUSION

This case illustrates the swift progression of EGPA and underscores the significance of early detection and immediate intervention to ensure a favorable prognosis.

Renal involvement in eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a necrotizing vasculitis, which typically affects small-to medium-sized blood vessels. It is characterized by the presence of tissue infiltrates rich in eosinophils, along with the formation of granulomatous lesions. About 40% of cases have positive anti-neutrophil cytoplasm antibodies (ANCA), with predominant perinuclear staining, and anti-myeloperoxidase (anti-MPO) specificity in about 65% of cases. Typical manifestations of EGPA include the late onset of asthma, nasal and sinus-related symptoms, peripheral neuropathy, and significant eosinophilia observed in the peripheral blood. In contrast to granulomatosis with polyangiitis and microscopic polyangiitis, renal involvement in EGPA is less frequent (about 25%) and poorly studied. Necrotizing pauci-immune crescentic glomerulonephritis is the most common renal presentation in patients with ANCA-positive EGPA. Although rarely, other forms of renal involvement may also be observed, such as eosinophilic interstitial nephritis, mesangial glomerulonephritis, membranous nephropathy, or focal sclerosis. A standardized treatment for EGPA with renal involvement has not been defined, however the survival and the renal outcomes are usually better than in the other ANCA-associated vasculitides. Nonetheless, kidney disease is an adverse prognostic factor for EGPA patients. Larger studies are required to better describe the renal involvement, in particular for patterns different from crescentic glomerulonephritis, and to favor the development of a consensual therapeutic approach. In this article, in addition to personal data, we will review recent findings on patient clinical phenotypes based on ANCA, genetics and the impact of biological drugs on disease management.

Eosinophilic Granulomatosis with Polyangiitis: Latest Findings and Updated Treatment Recommendations

Eosinophilic granulomatosis with polyangiitis (EGPA) causes necrotizing vasculitis and eosinophil-rich granulomatous inflammation in small- to medium-sized vessels, resulting in multiple organ damage. EGPA is classified as an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, with myeloperoxidase-ANCA detected in approximately one-third of the patients. Conventional treatment of EGPA relies on systemic glucocorticoids (GCs) in combination with cyclophosphamide when poor prognostic factors are present; however, the dilemma between disease control and drug-related adverse effects has long been a challenge. Recent studies have revealed that the genetic background, pathophysiology, and clinical manifestations differ between ANCA-positive and ANCA-negative patients; however, mepolizumab, an interleukin (IL)-5 inhibitor, is effective in both groups, suggesting that the IL-5-eosinophil axis is deeply involved in the pathogenesis of both ANCA-positive and ANCA-negative EGPA. This review summarizes the latest knowledge on the pathophysiology of EGPA and focuses on the roles of eosinophils and ANCA. We then introduce the current treatment recommendations and accumulated evidence for mepolizumab on EGPA. Based on current unmet clinical needs, we discuss potential future therapeutic strategies for EGPA.

Effectiveness and safety of anti-IL-5/Rα biologics in eosinophilic granulomatosis with polyangiitis: a two-year multicenter observational study

Background

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare vasculitis characterized by asthma, systemic manifestations, and blood and tissue eosinophilia.

Objective

To assess the effectiveness and safety of mepolizumab (anti-IL-5) and benralizumab (anti-IL-5Rα) in EGPA for 24 months.

Methods

We conducted a multicenter observational study, including patients with EGPA treated with anti-IL-5/Rα biologics in 9 Italian specialized facilities. Systemic disease activity, remission and relapse rate were evaluated from 3 to 24 months after treatment initiation. Respiratory outcomes, hematological parameters, corticosteroid (OCS) and immunosuppressants consumption were also assessed.

Results

49 patients with relapsing-refractory EGPA were included [26 (53.1%) benralizumab 30mg, 20 (40.8%) mepolizumab 100mg, 3 (6.1%) mepolizumab 300mg]. Overall, 38.8% and 57.1% achieved remission after 12 and 24 months, respectively (69.2% benralizumab and 43.5% mepolizumab). Lower OCS intake and higher blood eosinophil count at baseline were associated with remission at 24 months. Both biologics exerted beneficial effects on severe asthma outcomes. Indeed, 61.2% (61.5% benralizumab and 60.8% mepolizumab) remained exacerbation-free during treatment. Lung function parameters showed improvements in the overall cohort (all p<0.05), but began to decline from month 12, especially with mepolizumab. Marked reduction in blood eosinophils was registered with mepolizumab (p<0.0001), while benralizumab depleted both eosinophils (p<0.0001) and basophils (p<0.0001). In general, 69.6% (76% benralizumab and 61.9% mepolizumab) of OCS-dependent patients lowered their daily dose by 75%, while 28.3% discontinued these drugs. Immunosuppressants were suspended in 88.2% of cases. Adverse events were reported in 8.2% of patients.

Conclusions

These real-world data suggest that anti-IL-5/Rα biologics are effective and safe in the long-term as add-on treatments for patients with EGPA.

The Functional Role of Group 2 Innate Lymphoid Cells in Asthma

Asthma is a heterogeneous disease characterized by chronic airway inflammation. Group 2 innate lymphoid cells (ILC2) play an important role in the pathogenesis of asthma. ILC2s lack antigen-specific receptors and respond to epithelial-derived cytokines, leading to the induction of airway eosinophilic inflammation in an antigen-independent manner. Additionally, ILC2s might be involved in the mechanism of steroid resistance. Numerous studies in both mice and humans have shown that ILC2s induce airway inflammation through inflammatory signals, including cytokines and other mediators derived from immune or non-immune cells. ILC2s and T helper type 2 (Th2) cells collaborate through direct and indirect interactions to organize type 2 immune responses. Interestingly, the frequencies or numbers of ILC2 are increased in the blood and bronchoalveolar lavage fluid of asthma patients, and the numbers of ILC2s in the blood and sputum of severe asthmatics are significantly larger than those of mild asthmatics. These findings may contribute to the regulation of the immune response in asthma. This review article highlights our current understanding of the functional role of ILC2s in asthma.

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.

Basophils beyond allergic and parasitic diseases

Basophils bind IgE via FcεRI-αβγ2, which they uniquely share only with mast cells. In doing so, they can rapidly release mediators that are hallmark of allergic disease. This fundamental similarity, along with some morphological features shared by the two cell types, has long brought into question the biological significance that basophils mediate beyond that of mast cells. Unlike mast cells, which mature and reside in tissues, basophils are released into circulation from the bone marrow (constituting 1% of leukocytes), only to infiltrate tissues under specific inflammatory conditions. Evidence is emerging that basophils mediate non-redundant roles in allergic disease and, unsuspectingly, are implicated in a variety of other pathologies [e.g., myocardial infarction, autoimmunity, chronic obstructive pulmonary disease, fibrosis, cancer, etc.]. Recent findings strengthen the notion that these cells mediate protection from parasitic infections, whereas related studies implicate basophils promoting wound healing. Central to these functions is the substantial evidence that human and mouse basophils are increasingly implicated as important sources of IL-4 and IL-13. Nonetheless, much remains unclear regarding the role of basophils in pathology vs. homeostasis. In this review, we discuss the dichotomous (protective and/or harmful) roles of basophils in a wide spectrum of non-allergic disorders.

Successful Treatment With Mepolizumab for Eosinophilic Granulomatosis With Polyangiitis: A Case Report

Eosinophilic granulomatosis with polyangiitis (EGPA) is an uncommon antineutrophil cytoplasmatic antibody (ANCA) associated vasculitis involving small and medium size blood vessels. It has a variable clinical presentation depending on the main organ involved, making it difficult to diagnose. Treatment is mainly based on high-dose steroids and other immunosuppressants like cyclophosphamide, which may prevent end-organ damage and induce remission at the expense of having important adverse effects. However, new therapeutic agents had been shown to provide better results with favorable safety profiles. Biologic therapy with monoclonal antibodies such as Rituximab and Mepolizumab has been approved for its use in ANCA vasculitis including eosinophilic granulomatosis with polyangiitis. These cases describe two patients with EGPA whose initial presentation was severe asthma and who appeared to have extrapulmonary end-organ damage. Mepolizumab was used in both cases with a successful response.

Management of antineutrophil cytoplasmic antibody-associated vasculitis: a review of recent guidelines

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune rheumatic disease consisting of three discrete diagnoses of microscopic polyangiitis, granulomatosis with polyangiitis, and eosinophilic granulomatosis with polyangiitis. Among diseases treated in a rheumatology department, AAV has poor clinical outcomes, with high rates of mortality and progression to end-stage renal disease and frequent disease relapse. Due to the frequent negative patient outcomes, optimal therapeutic strategies are essential in the management of AAV. In the present review, four guidelines for management of AAV are summarized: British Society for Rheumatology (BSR) and British Health Professionals in Rheumatology (BHPR) guideline for the management of adults with AAV; European League Against Rheumatism (EULAR)/European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) recommendation for the management of AAV; 2021 American College of Rheumatology (ACR)/Vasculitis Foundation Guideline for the Management of AAV; Kidney Disease: Improving Global Outcome (KDIGO) 2021 Clinical Practice Guideline for the Management of Glomerular Diseases, which will aid in clinicians' medical decisions. Finally, the summary of the 2022 Update of the EULAR Recommendations on the Management of AAV, presented in the EULAR Congress 2022 is also introduced.

Hidden Comorbidities in Asthma: A Perspective for a Personalized Approach

Bronchial asthma is the most frequent inflammatory non-communicable condition affecting the airways worldwide. It is commonly associated with concomitant conditions, which substantially contribute to its burden, whether they involve the lung or other districts. The present review aims at providing an overview of the recent acquisitions in terms of asthma concomitant systemic conditions, besides the commonly known respiratory comorbidities. The most recent research has highlighted a number of pathobiological interactions between asthma and other organs in the view of a shared immunological background underling different diseases. A bi-univocal relationship between asthma and common conditions, including cardiovascular, metabolic or neurodegenerative diseases, as well as rare disorders such as sickle cell disease, α1-Antitrypsin deficiency and immunologic conditions with hyper-eosinophilia, should be considered and explored, in terms of diagnostic work-up and long-term assessment of asthma patients. The relevance of that acquisition is of utmost importance in the management of asthma patients and paves the way to a new approach in the light of a personalized medicine perspective, besides targeted therapies.

EGPA Phenotyping: Not Only ANCA, but Also Eosinophils

Background: Eosinophilic Granulomatosis with Polyangiitis (EGPA) is a small-vessel necrotizing vasculitis. The anti-neutrophil cytoplasmic antibodies’ (ANCA) role in defining clinical EGPA phenotypes is well established. Although the role of eosinophils in disease pathogenesis has been clearly demonstrated, the value of blood eosinophil count (BEC) as a biomarker of disease phenotypes is currently uncertain. Methods: We retrospectively analyzed EGPA patients referred to our Immunology Clinic. Demographic, laboratory and clinical features were retrieved from clinical records, and a Logistic Regression was fitted to evaluate the predictive power of all baseline clinical and laboratory features to define EGPA phenotypes. Results: 168 patients were recruited. BEC ≤ 1500 cells/mL was predictive of a clinical involvement characterized by asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and lung opacities (OR 0.18, 95% CI 0.07–0.43; respiratory-limited phenotype); BEC > 3500/mL was predictive of extrapulmonary organ involvement (OR 3.5, 95% CI 1.7–7.1; systemic phenotype). BEC was also predictive of peripheral nervous system (PNS) involvement, with a positive trend with increasing BEC (<1500/mL: OR 0.17, 95%CI, 0.06–0.47; >3500/mL: OR 2.8, 95% CI, 1.5–5.28). ANCA positivity was also predictive of extrapulmonary involvement (OR 4.7, 95% CI 1.9–11.99). Conclusions: according to BEC and irrespective of the ANCA status, two EGPA phenotypes could be identified, named systemic and respiratory-limited phenotypes, with different organ involvement and possibly different prognoses.