Eosinophilic granulomatosis with polyangiitis (Churg-Strauss): state of the art

[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.

Combination Biologic Therapy with Mepolizumab and Dupilumab for Severe Eosinophilic Granulomatosis with Polyangiitis and Chronic Rhinosinusitis with Nasal Polyp

We report the case of a 55-year-old female with eosinophilic granulomatosis with polyangiitis and chronic rhinosinusitis with nasal polyp. Rhinosinusitis recurred 6 months after full-house endoscopic sinus surgery. Although conventional treatment with azathioprine and mepolizumab with steroids was given, it was difficult to simultaneously control both rhinosinusitis and eosinophilic granulomatosis with polyangiitis. Clinical examinations showed polyps in the olfactory cleft, and the patient's anosmia gradually became persistent. Even after administering mepolizumab for a certain period of time, symptoms did not improve, but when the biologic agent was switched to dupilumab, an improvement in recalcitrant chronic rhinosinusitis with nasal polyp was observed. While dupilumab was administered intermittently for refractory chronic rhinosinusitis with nasal polyp, the rhinosinusitis improved and symptoms such as worsening of eosinophilic granulomatosis with polyangiitis paresthesia were observed. Both symptoms gradually subsided 19 months after starting intermittent administration, leading to the discontinuation of dupilumab administration. Rhinosinusitis in the setting of eosinophilic granulomatosis with polyangiitis may be refractory in some cases, and this case provides findings demonstrating the strong effect of dupilumab on eosinophilic inflammation.

Exploring the immunopathology of type 2 inflammatory airway diseases

Significant advancements have been achieved in understanding the roles of different immune cells, as well as cytokines and chemokines, in the pathogenesis of eosinophilic airway conditions. This review examines the pathogenesis of Chronic Rhinosinusitis with Nasal Polyps (CRSwNP), marked by complex immune dysregulation, with major contributions from type 2 inflammation and dysfunctional airway epithelium. The presence of eosinophils and the role of T-cell subsets, particularly an imbalance between Treg and Th17 cells, are crucial to the disease's pathogenesis. The review also investigates the pathogenesis of eosinophilic asthma, a unique asthma subtype. It is characterized by inflammation and high eosinophil levels, with eosinophils playing a pivotal role in triggering type 2 inflammation. The immune response involves Th2 cells, eosinophils, and IgE, among others, all activated by genetic and environmental factors. The intricate interplay among these elements, chemokines, and innate lymphoid cells results in airway inflammation and hyper-responsiveness, contributing to the pathogenesis of eosinophilic asthma. Another scope of this review is the pathogenesis of Eosinophilic Granulomatosis with Polyangiitis (EGPA); a complex inflammatory disease that commonly affects the respiratory tract and small to medium-sized blood vessels. It is characterized by elevated eosinophil levels in blood and tissues. The pathogenesis involves the activation of adaptive immune responses by antigens leading to T and B cell activation and eosinophil stimulation, which causes tissue and vessel damage. On the other hand, Allergic Bronchopulmonary Aspergillosis (ABPA) is a hypersensitive response that occurs when the airways become colonized by aspergillus fungus, with the pathogenesis involving activation of Th2 immune responses, production of IgE antibodies, and eosinophilic action leading to bronchial inflammation and subsequent lung damage. This analysis scrutinizes how an imbalanced immune system contributes to these eosinophilic diseases. The understanding derived from this assessment can steer researchers toward designing new potential therapeutic targets for efficient control of these disorders.

Cutaneous vasculitis: insights into pathogenesis and histopathological features

The mechanisms underlying the onset and progression of vasculitis remain poorly understood. This condition is characterized by damage to the vascular wall, recruitment of inflammatory cells, and subsequent structural remodeling, which are hallmarks of vasculitis. The histopathological classification of vasculitis relies on the size of the affected vessel and the predominant type of inflammatory cell involved - neutrophils in acute cases, lymphocytes in chronic conditions, and histiocytes in granulomatous forms. Pathological changes progress in every context, and a single vasculitic pattern can be associated with various systemic conditions. Conversely, a single causative agent may lead to multiple distinct clinical and pathological manifestations of vasculitis. Moreover, many cases of vasculitis have no identifiable cause. A foundational understanding of the normal structure of the cutaneous vascular network is crucial. Similarly, identifying the cellular and molecular participants and their roles in forming the "dermal microvascular unit" is propedeutical.

This review aims to elucidate the complex mechanisms involved in the initiation and progression of vasculitis, offering a comprehensive overview of its histopathological classification, underlying causes, and the significant role of the cutaneous vascular network and cellular dynamics. By integrating the latest insights from studies on NETosis and the implications of lymphocytic infiltration in autoimmune diseases, we seek to bridge gaps in current knowledge and highlight areas for future research. Our discussion extends to the clinical implications of vasculitis, emphasizing the importance of identifying etiological agents and understanding the diverse histopathological manifestations to improve diagnostic accuracy and treatment outcomes.

New-onset of eosinophilic granulomatosis with polyangiitis without eosinophilia and eosinophilic infiltration under benralizumab treatment: A case report

Eosinophilic granulomatosis with polyangiitis (EGPA) is a small- to medium-vessel necrotising vasculitis and eosinophilic inflammation. Mepolizumab, an anti-interleukin-5 (IL-5) monoclonal antibody has been approved in Japan since 2018 for refractory EGPA treatment. Benralizumab, an anti-IL-5 receptor monoclonal antibody, also has been reported to reduce the glucocorticoid dose in patients with refractory EGPA. On the other hand, several investigators have demonstrated new-onset EGPA under biologics, and it is unclear whether this treatment for severe allergic diseases can prevent the development of EGPA. Herein, we report a case of new-onset EGPA under benralizumab treatment. The patient had fever, weight loss, muscle pain, and paraesthesia, the serum eosinophil count was 0/μL, and the biopsy showed necrotizing vasculitis without eosinophilic infiltration. She was diagnosed as having EGPA and treated with high-dose glucocorticoid and intravenous cyclophosphamide, with a good response. Our case report indicates that anti-IL-5 agents may mask the development of EGPA and clinicians should be aware of the development of EGPA during anti-IL-5 agents.

Dupilumab for relapsing or refractory sinonasal and/or asthma manifestations in eosinophilic granulomatosis with polyangiitis: a European retrospective study

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA) is often associated with glucocorticoid-dependent asthma and/or ear, nose and throat (ENT) manifestations. When immunosuppressants and/or mepolizumab are ineffective, dupilumab could be an option. We describe the safety and efficacy of off-label use of dupilumab in relapsing and/or refractory EGPA.

PATIENTS AND METHODS

We conducted an observational multicentre study of EGPA patients treated with dupilumab. Complete response was defined by Birmingham Vasculitis Activity Score (BVAS)=0 and prednisone dose ≤4 mg/day, and partial response by BVAS=0 and prednisone dose >4 mg/day. Eosinophilia was defined as an eosinophil count >500/mm3.

RESULTS

Fifty-one patients were included. The primary indication for dupilumab was disabling ENT symptoms in 92%. After a median follow-up of 13.1 months, 18 patients (35%) reported adverse events (AEs), including two serious AEs. Eosinophilia was reported in 34 patients (67%), with a peak of 2195/mm3 (IQR 1268-4501) occurring at 13 weeks (IQR 4-36) and was associated with relapse in 41%. Twenty-one patients (41%) achieved a complete response and 12 (24%) a partial response. Sixteen (31%) patients experienced an EGPA relapse while on dupilumab, which was associated with blood eosinophilia in 14/16 (88%) patients. The median eosinophil count at the start of dupilumab was significantly lower in relapsers than in non-relapsers, as was the median time between stopping anti-IL-5/IL-5R and switching to dupilumab.

CONCLUSION

These results suggest that dupilumab may be effective in treating patients with EGPA-related ENT manifestations. However, EGPA flares occurred in one-third of patients and were preceded by eosinophilia in 88%, suggesting that caution is required.

Early Ear, Nose and Throat Manifestations in Eosinophilic Granulomatosis with Poliangioitis: Results from Our Cohort Group and Literature Review

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, systemic necrotizing vasculitis affecting small-to-medium-sized vessels. EGPA's clinical manifestations are heterogeneous, affecting different organs and systems, and the upper respiratory tract can be affected by ear, nose and throat (ENT) involvement. The aim of our study was to assess type manifestations at the time of diagnosis in a cohort of EGPA patients and correlate findings with baseline variables (sex, age, antineutrophil cytoplasmic antibodies-ANCA-status) and literature reports. The main ENT manifestations in our patients at the time of diagnosis were: chronic rhinosinusitis with nasal polyposis (CRSwNP) (52%), turbinate hypertrophy (48%), nasal swelling (40%), rhinorrhea (40%), chronic rhinosinusitis without nasal polyposis (CRSsNP) (32%), nasal bone deformities (32%), nasal crusts (20%), nasal mucosal ulcers (12%), corditis (12%), hoarseness/dysphonia (12%), hearing loss (12%), mucoceles (4%) and eosinophilic rhinitis (4%). No correlations were found between sex, age, ANCA status and ENT clinical manifestations. A polymorphic ENT involvement is often observed in the early stages of EGPA. The presence of nasal, sinus, ear and/or laryngeal manifestations in patients with asthma and hypereosinophilia, independently of sex, age or ANCA status, should raise an alert for further investigation and differential diagnosis for EGPA. ENT specialists should be aware of their leading position in this diagnostic race.

Sex Differences in Clinical Manifestations of Hospitalized Patients With Eosinophilic Granulomatosis With Polyangiitis: A Retrospective Cohort Study

OBJECTIVE

To investigate the effect of sex on the clinical characteristics, prognoses, and therapeutic selection of eosinophilic granulomatosis with polyangiitis (EGPA).

METHODS

We retrospectively enrolled 170 hospitalized patients with EGPA who were managed at our hospital between 2007 and 2020. Detailed clinical data were reviewed. Manifestations, prognoses, treatments, and outcomes were compared between female and male patients. Cumulative survival rates were calculated using Kaplan-Meier curves.

RESULTS

In this cohort, the male to female ratio was 1.4:1. Renal involvement was more frequent in male patients, including serum creatinine elevation, and proteinuria > 1 g/24 h. Severe gastrointestinal (GI) involvement occurred more commonly in male patients. Female patients had longer allergy duration and higher ratios of allergic rhinitis and asthma. Sex differences in proteinuria > 1 g/24 h, serum creatinine > 150 mmol/L, severe GI involvement, and weight loss were more significant in patients aged ≤ 55 years than those in patients aged > 55 years. Overall, male patients had a higher Birmingham Vasculitis Activity Score and a worse prognosis assessed at diagnosis, with a lower proportion of 1996 Five Factor Score = 0 than females. Regarding treatment selection, methylprednisolone pulse and cyclophosphamide were administered more frequently to male patients. All-cause mortality and cumulative survival rates were comparable between the sexes.

CONCLUSION

In this Chinese EGPA cohort, male and female patients showed distinct disease phenotypes. Male patients with EGPA had a higher disease activity at diagnosis and required more aggressive treatment for remission induction.

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.

Therapeutic Advances in Eosinophilic Granulomatosis with Polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is an eosinophilic vasculitis that affects a variety of organ systems. Historically, glucocorticoids and a variety of other immunosuppressants were used to abrogate the inflammation and tissue injury associated with EGPA. The management of EGPA has evolved greatly during the last decade with the development of novel targeted therapeutics that have resulted in significantly improved outcomes for these patients, with many more novel targeted therapies emerging.

HES and EGPA: Two Sides of the Same Coin

Elevated eosinophil counts are implicated in multiple diseases, from relatively prevalent organ-specific disorders such as severe eosinophilic asthma, to rare multisystem disorders such as hypereosinophilic syndrome (HES) and eosinophilic granulomatosis with polyangiitis (EGPA). Patients with these multisystem diseases, often associated with markedly elevated eosinophil counts, have a substantial risk of morbidity and mortality due to delayed diagnosis or inadequate treatment. A thorough workup of symptomatic patients presenting with elevated eosinophil counts is essential, although in some cases the differential diagnosis may remain difficult because of overlapping presentations between HES and EGPA. Notably, first- and second-line treatment options and response to therapy may differ for specific HES and EGPA variants. Oral corticosteroids are the first line of treatment for HES and EGPA, except when HES is the result of specific mutations driving clonal eosinophilia that are amenable to targeted treatment with a kinase inhibitor. Cytotoxic or immunomodulatory agents may be required for those with severe disease. Novel eosinophil-depleting therapies, such as those targeting interleukin 5 or its receptor, have shown great promise in reducing blood eosinophil counts, and reducing disease flares and relapses in patients with HES and EGPA. Such therapies could reduce the side effects associated with long-term oral corticosteroids or immunosuppressant use. This review provides a pragmatic guide to approaching the diagnosis and clinical management of patients with systemic hypereosinophilic disorders. We highlight practical considerations for clinicians and present cases from real-world clinical practice to show the complexity and challenges associated with diagnosing and treating patients with HES and EGPA.

Neurologic Manifestations of Rheumatologic Disease

OBJECTIVE

This article describes the neurologic manifestations of systemic rheumatologic disorders.

LATEST DEVELOPMENTS

Although most have historically been classified as autoimmune disorders, rheumatologic diseases are increasingly conceptualized as distributed along a spectrum with various contributions of autoimmune (adaptive immune dysregulation) and autoinflammatory (innate immune dysregulation) mechanisms. Our evolving understanding of systemic immune-mediated disorders has been accompanied by an expansion in our differential diagnoses and therapeutic options.

ESSENTIAL POINTS

Rheumatologic disease involves both autoimmune and autoinflammatory mechanisms. Neurologic symptoms can be the first manifestation of these disorders, and familiarity with the systemic manifestations of specific diseases is essential to establish the correct diagnosis. Conversely, knowledge of the neurologic syndromes that are most likely to be associated with specific systemic disorders can help narrow the differential and increase confidence when attributing a neuropsychiatric symptom to an underlying systemic disorder.

Evidence-Based Guideline for the diagnosis and management of eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, characterized by asthma, eosinophilia and granulomatous or vasculitic involvement of several organs. The diagnosis and management of EGPA are often challenging and require an integrated, multidisciplinary approach. Current practice relies on recommendations and guidelines addressing the management of ANCA-associated vasculitis and not specifically developed for EGPA. Here, we present evidence-based, cross-discipline guidelines for the diagnosis and management of EGPA that reflect the substantial advances that have been made in the past few years in understanding the pathogenesis, clinical subphenotypes and differential diagnosis of the disease, as well as the availability of new treatment options. Developed by a panel of European experts on the basis of literature reviews and, where appropriate, expert opinion, the 16 statements and five overarching principles cover the diagnosis and staging, treatment, outcome and follow-up of EGPA. These recommendations are primarily intended to be used by healthcare professionals, pharmaceutical industries and drug regulatory authorities, to guide clinical practice and decision-making in EGPA. These guidelines are not intended to limit access to medications by healthcare agencies, nor to impose a fixed order on medication use.

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.

New Insights into Pathogenesis and Treatment of ANCA-Associated Vasculitis: Autoantibodies and Beyond

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of rare systemic diseases affecting small-caliber vessels. The damage caused by AAV mainly involves the lung and kidneys. AAV includes three different types: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Although the different phenotypic forms of AAV share common features, recent studies have shown that there are significant differences in terms of pathogenetic mechanisms involving both the adaptive and innate immune systems. Advances in our understanding of pathogenesis have enabled the development of immuno-targeted therapies. This review illustrates the characteristics of the various forms of AAV and the new therapies available for this disease that can have lethal consequences if left untreated.

Cardiac involvement and cardiovascular risk factors in pediatric primary systemic vasculitides

Pediatric primary systemic vasculitides are a complex group of diseases. Vasculitis subgroups are mainly determined according to the size of the predominantly affected vessels. In patients with primary systemic vasculitis, the location of vascular involvement, the size of the vessels, the extent of vascular damage, and the underlying pathology determine the disease phenotype and severity. Cardiac involvement is rare in some pediatric vasculitis, such as IgA vasculitis and polyarteritis nodosa, while it is more common in some others like Kawasaki disease and Takayasu arteritis. On the other hand, chronic inflammation in the setting of systemic vasculitis forms a major cardiovascular risk factor. Accelerated atherosclerosis and the tendency to thrombosis are the main issues determining the cardiovascular risks in pediatric systemic vasculitis. Early diagnosis and treatment are essential in these patients to minimize morbidity and mortality. In this review, we aimed to raise physicians' awareness of cardiac involvement and cardiovascular risks in pediatric patients with primary systemic vasculitis.

Clinical features and management of Chinese anti-neutrophil cytoplasmic antibody-associated vasculitis patients with spontaneous renal hemorrhage: a single-center report and systematic review

INTRODUCTION

Spontaneous renal hemorrhage (SRH) in ANCA-associated vasculitis (AAV) is rare but fatal. We aimed to characterize clinical manifestations and managements of AAV patients with SRH.

METHOD

Hospitalized AAV patients were screened from January 2000 to April 2021, at Peking Union Medical College Hospital (PUMCH). Also, a systematic review was based on retrieving all the relevant literature from PubMed, MedlinePlus, and Web of Science until April 2021. Clinical features, management, and prognosis of the patients were collected and concluded.

RESULTS

In PUMCH, four out of 1640 AAV patients with SRH were included in our study; three had granulomatosis with polyangiitis (GPA) and one had microscopic polyangiitis (MPA). The ratio of men to women was 3 to 1, and the average age of onset was 55 years. The Birmingham Vasculitis Activity Score (BVAS) ranged from 21 to 23. Combining with documented reports, 13 patients were diagnosed as AAV complicated with SRH (including four from PUMCH), 7 with GPA, and 6 with MPA. Mean BVAS was 25.2 ± 6.6. The symptoms of SRH presented as severe back or abdominal pain. Patients with SRH to age- and gender-matched patients without SRH were compared, and we found that in the SRH group, the duration of disease was shorter, and BVAS, renal function, and inflammatory markers (WBC and ESR) were significantly greater, whereas Hb, Alb, and renal function greatly reduced.

CONCLUSION

This is the first summary of clinical features and treatments of SRH in AAV. Patients with AAV in early stage and with high disease activity appeared to be more likely to develop SRH. Key Points • This is the first summary of clinical features and treatments of SRH in AAV. • SRH more likely occurs in AAV patients in the early stage (≤ 3 months) and with high disease activity. • Clinicians should be aware of the possibility of SRH when AAV patients complain of back or abdominal pain.

Targeting the interleukin-5 pathway in EGPA: evidence, uncertainties and opportunities

Only a minority of patients with eosinophilic granulomatosis with polyangiitis (EGPA) can be weaned-off glucocorticoids (GC) using conventional treatment strategies. The development of biological agents specifically inhibiting the IL-5 pathway provided the opportunity to treat EGPA by targeting one of the crucial regulators of eosinophils, reducing the GC dose required to control the disease.The anti-IL-5 antibody mepolizumab at the dose of 300 mg/4 weeks has proven to be safe and effective in EGPA. While relapsing patients-who often experience recurrent respiratory manifestations-benefit from this treatment, data are not enough to support its use combined with GC alone in remission induction of severe active forms, or in remission maintenance without conventional immunosuppressants in patients with vasculitic manifestations. Ultimately, the profile of the best candidate for mepolizumab is still unclear.Several real-life reports suggest that mepolizumab at the dose of 100 mg/4 weeks, approved for eosinophilic asthma/chronic rhinosinusitis with nasal polyposis (CRSwNP), effectively maintains remission of EGPA-related asthma and, to a lesser extent, CRSwNP. Preliminary data on the IL-5 pathway-inhibitors benralizumab and reslizumab in EGPA as steroid-sparing agents are also accumulating.Overall, it remains to be proven whether targeting the IL-5 pathway could block progression of organ damage in EGPA, on top of reducing relapses and sparing GC. Other disease-related factors further complicate the understanding of the real anti-IL-5 agent efficacy, such as the lack of a clear definition of remission, of an effective tool to measure disease activity, and of well-defined treat-to-target approaches or goals of treatment.

Effective treatment with mepolizumab in a patient with severe eosinophilic granulomatosis with polyangiitis complicated with small intestine perforation

Eosinophilic granulomatosis with polyangiitis (EGPA) is systemic vasculitis caused by eosinophilia affecting small to medium-sized blood vessels, which damages the organs. Antineutrophil cytoplasmic antibody-associated vasculitis EGPA treatment guidelines added anti-interleukin-5 antibody mepolizumab to the standard treatment protocol for active-non-severe EGPA based on the MIRRA study. Nevertheless, the role of mepolizumab in treating patients with active severe EGPA has not been established. We treated a patient with EGPA complicated with small intestine perforation using steroid pulse intravenous, high-dose glucocorticoids, intravenous high-dose immunoglobulin therapy, and mepolizumab without immunosuppression agents; the patient went into remission, suggesting that mepolizumab is an effective therapeutic agent that could lead to remission in severe EGPA.

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.

Vasculitis and Kidney Disease

Pediatric vasculitis is a complex group of disorders that commonly presents with multisystem involvement. Renal vasculitis can be isolated to the kidneys or can occur as part of a broader multiorgan vasculitis. Depending on severity, renal vasculitis may present as acute glomerulonephritis (AGN) often associated with hypertension and sometimes with a rapidly deteriorating clinical course. Prompt diagnosis and initiation of therapy are key to preserving kidney function and preventing long-term morbidity and mortality. This review focuses on the clinical presentation, diagnosis, and treatment objectives for common forms of renal vasculitis seen in pediatric patients.

The new indications for biologicals in type 2 diseases: perspectives

PURPOSE OF REVIEW

To provide a literature review of what is on the market and under study for some diseases treated with drugs targeting type 2 (T2) inflammation.

RECENT FINDINGS

Literature data have shown that drugs targeting type 2 inflammation are effective in asthma and nasal polyposis, conditions for which they are on the market, and have promising expectations in the case of eosinophilic esophagitis, especially using anti-IL-5/IL-5 receptor and IL-4 receptor antibodies, while concerning eosinophilic granulomatosis with polyangitis (EGPA), mepolizumab (MEP) was approved by FDA and EMA as a drug for the treatment of this condition because of the promising results obtained in trials and in real life.

SUMMARY

The use of these drugs is certainly an important achievement in the treatment of complex diseases such as those mentioned above, which are too often orphaned from innovative treatments and limited to the use of immunosuppressants and systemic corticosteroid for their control.

Therapeutical Targets in Allergic Inflammation

From the discovery of IgE to the in-depth characterization of Th2 cells and ILC2, allergic inflammation has been extensively addressed to find potential therapeutical targets. To date, omalizumab, an anti-IgE monoclonal antibody, and dupilumab, an anti-IL-4 receptor α monoclonal antibody, represent two pillars of biologic therapy of allergic inflammation. Their increasing indications and long-term follow-up studies are shaping the many different faces of allergy. At the same time, their limitations are showing the intricate pathogenesis of allergic diseases.

At the Heart of Eosinophilic Granulomatosis with Polyangiitis: into Cardiac and Vascular Involvement

PURPOSE OF REVIEW

To provide an overview of existing literature on pathogenetic and clinical aspects of cardiac and vascular involvement in eosinophilic granulomatosis with polyangiitis (EGPA).

RECENT FINDINGS

In EGPA, cardiac and vascular involvement are more common than previously thought. However, no international recommendations on the topic are available yet. Herein, we summarize the existing evidence on the topic and propose a diagnostic approach for cardiac involvement in EGPA. The prevalence of cardiovascular involvement in patients with EGPA varies greatly among published studies, ranging between 3.1-18.7% for occlusive arterial disease, 5.8-30% for venous thrombosis and 17-92% for heart involvement. Cardiac involvement in EGPA is associated with high mortality even though manifestations are heterogeneous. In principle, every anatomical structure of the heart can be involved, and EGPA-related heart disease may be completely asymptomatic at first. A careful diagnostic work-up for early detection and prompt treatment initiation is therefore required. While cardiac manifestations are more common in anti-neutrophil cytoplasmic antibodies (ANCA)-negative patients, arterial and venous thrombotic events are not linked to ANCA status but correlate closely with disease activity and accumulate at disease onset. Thrombotic events (mainly venous) are considerably more frequent in EGPA than in the general population contributing substantially to morbidity and highlighting the importance of developing specific prevention strategies for patients who are diagnosed with EGPA.

Benralizumab monotherapy was insufficient to induce remission in patients with active eosinophilic granulomatosis with polyangiitis

Eosinophils play an important pathogenetic role in the development of eosinophilic granulomatosis with polyangiitis (EGPA). EGPA has long been treated with systemic corticosteroids and immunosuppressive agents. However, in recent years, biologic agents targeting eosinophils (anti-IL-5 antibody; mepolizumab) have also been used. Evidence regarding the effectiveness of using benralizumab, anti-IL-5 receptor α monoclonal antibody that depletes eosinophils via antibody-dependent cell-mediated cytotoxicity, has been growing. Benralizumab is used as a steroid-sparing treatment option for EGPA. Clinical studies have evaluated the effects of using mepolizumab or benralizumab in combination with steroids for the treatment of EGPA. However, to date, there have been no reports of using biologics alone. Herein, we describe the case of a patient with active EGPA refractory to benralizumab monotherapy. The patient achieved significant improvement in symptoms after administration of corticosteroids during hospitalization. Benralizumab monotherapy might not be considered a therapeutic option for patients with active EGPA in whom corticosteroids are initially indicated.

SAFit2 reduces neuroinflammation and ameliorates nerve injury-induced neuropathic pain

Background

Neuropathic pain is experienced worldwide by patients suffering from nerve injuries, infectious or metabolic diseases or chemotherapy. However, the treatment options are still limited because of low efficacy and sometimes severe side effects. Recently, the deficiency of FKBP51 was shown to relieve chronic pain, revealing FKBP51 as a potential therapeutic target. However, a specific and potent FKBP51 inhibitor was not available until recently which hampered targeting of FKBP51.

Methods

In this study, we used the well-established and robust spared nerve injury model to analyze the effect of SAFit2 on nerve injury-induced neuropathic pain and to elucidate its pharmacodynamics profile. Therefore, the mice were treated with 10 mg/kg SAFit2 after surgery, the mice behavior was assessed over 21 days and biochemical analysis were performed after 14 and 21 days. Furthermore, the impact of SAFit2 on sensory neurons and macrophages was investigated in vitro.

Results

Here, we show that the FKBP51 inhibitor SAFit2 ameliorates nerve injury-induced neuropathic pain in vivo by reducing neuroinflammation. SAFit2 reduces the infiltration of immune cells into neuronal tissue and counteracts the increased NF-κB pathway activation which leads to reduced cytokine and chemokine levels in the DRGs and spinal cord. In addition, SAFit2 desensitizes the pain-relevant TRPV1 channel and subsequently reduces the release of pro-inflammatory neuropeptides from sensory neurons.

Conclusions

SAFit2 ameliorates neuroinflammation and counteracts enhanced neuronal activity after nerve injury leading to an amelioration of nerve injury-induced neuropathic pain. Based on these findings, SAFit2 constitutes as a novel and promising drug candidate for the treatment of nerve injury-induced neuropathic pain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02615-7.

Serum ANCA as Disease Biomarkers: Clinical Implications Beyond Vasculitis

Usually associated with autoimmune diseases, anti-neutrophil cytoplasmic antibodies are also detected in other conditions, such as infections, malignancies, and after intake of certain drugs. Even if the mechanisms of production and their pathogenic role have not been fully elucidated yet, ANCA are widely recognized as a clinically alarming finding due to their association with various disorders. While ANCA target several autoantigens, proteinase-3, and myeloperoxidase are the ones proved to be most frequently related to chronic inflammation and tissue damage in murine models. Albeit these autoantibodies could be present as an isolated observation without any implications, ANCA are frequently used in clinical practice to guide the diagnosis in a suspect of small vessel vasculitis. Conditions that should prompt the clinician to test ANCA status range from various forms of lung disease to renal or peripheral nervous system impairment. ANCA positivity in the presence of an autoimmune disease, especially rheumatoid arthritis, or connective tissue diseases, is frequently correlated with more clinical complications and treatment inefficacy, even in the absence of signs of vasculitis. For this reason, it has been postulated that ANCA could represent the final expression of an immune dysregulation rather than a pathogenic event responsible for organs damage. Recently, it has also been proposed that ANCA specificity (PR3 or MPO) could possibly define ANCA-associated vasculitides better than clinical phenotype. This review aims at summarizing the latest advancements in the field of ANCA study and clinical interpretation.

Eosinophilic Gastroenteritis in the Small Intestine Mimicking Eosinophilic Granulomatosis With Polyangiitis in a Young Male Patient

Eosinophilic gastroenteritis (EGE) is a disease involving the gastrointestinal tract that involves the invasion of eosinophils into the lumen of the tract. Invasion of eosinophils in the tract causes edema and inflammation of the wall, resulting in acute or chronic diarrhea and abdominal pain. EGE can cause chronic inflammation in the small intestine, thereby mimicking chronic vasculitis. We report the case of a 24-year-old male patient with the chief complaint of acute progressive abdominal pain. Endoscopic findings of the small intestine were chronic and similar to those of polyangiitis (eosinophilic granulomatosis with polyangiitis). This case shows the presence of various clinical courses of EGE and the discrepancy between the symptoms and endoscopic appearance of vasculitis. Physicians should focus not only on acute symptoms but also on chronic phases of the disease to prevent disease progression and modify patients’ help-seeking behaviors according to their symptoms.

The Role of T Helper Type 2 (Th2) Cytokines in the Pathogenesis of Eosinophilic Granulomatosis with Polyangiitis (eGPA): an Illustrative Case and Discussion

Purposeof Review

The pathogenesis of eosinophilic granulomatosis with polyangiitis (eGPA) is driven largely by CD4 + type 2 helper T cells (Th2), B cells, and eosinophils. Interleukin (IL)-4 and IL-13 are critical cytokines in Th2 cell–mediated inflammation; however, inhibition of IL-4 and IL-13 does not reduce serum eosinophil counts and has even been associated with hypereosinophilia. This review explores the role of IL-4, IL-5, and IL-13 in Th2-mediated inflammation to consider the potential clinical consequences of inhibiting these individual cytokines in eGPA.

Recent Findings

Treatments for eosinophilic granulomatosis with polyangiitis (eGPA) are rapidly evolving through using biologic therapies to modulate the Th2 inflammatory response via eosinophil inhibition. While IL-4, IL-5, IL-13, and IL-25 can all affect eosinophils, only IL-5 inhibition has demonstrated therapeutic benefit to-date. In this review, we report a clinical vignette of a patient with adult-onset asthma who developed severe manifestations of eGPA after switching from mepolizumab (an IL-5 inhibitor) to dupilumab (an inhibitor of IL-4 and IL-13).

Summary

By understanding the role of IL-4, IL-5, and IL-13 in Th2-mediated vasculitis, we can start to understand how eGPA might respond differently to focused cytokine inhibition.

Intractable middle ear effusion in EGPA patients might cause permanent hearing loss: a case-control study

Background

Ear, nose, and throat involvement are common in eosinophilic granulomatosis with polyangiitis (EGPA). Among otologic manifestation, middle ear effusion (MEE) is less recognized but a problematic condition as it may progress to hearing impairment when left untreated. This study aimed to evaluate the characteristics, risk factors and clinical outcomes of MEE in EGPA patients.

Methods

This is a case–control study of patients who were diagnosed and treated for EGPA from January 1995 to November 2018. Patients with ear symptoms (ear fullness, ear discharge, tinnitus or hearing loss) were assessed by otologists and were included in the case group (n = 23) if clinically relevant. The other patients without MEE were included in the control group (n = 52). Risk of MEE was calculated using the Cox proportional-hazard model.

Results

During median follow-up of 9.9 years, 23 (30.7%) out of 75 patients had MEE. In MEE group, 12 (52.2%) patients had hearing loss; conductive type in 10 (10/12, 83.3%) and mixed type in two (2/12, 16.7%). In multivariable regression analysis, major organ involvement at diagnosis (adjusted hazard ratio [aHR] 65.4; 95% confidence interval [CI], 1.50—2838.39; P = 0.030] , early onset of ear symptom after systemic therapy (< 6 months) (aHR 40.0; 95% CI, 1.35—1183.43; P = 0.033) and continuing the maintenance steroid without cessation (aHR 8.59; 95% CI, 1.13—65.42; P = 0.038) were independently associated with a risk of MEE. To control MEE, 16 (69.6%) patients had to increase maintenance steroid dose and 9 (39.1%) patients experienced recurrent MEE whenever maintenance dose was tapered.

Conclusions

MEE is a common but frequently neglected condition in EGPA which is often intractable. The maintenance steroid dose should be adequately adjusted to control MEE and to prevent from progressive hearing loss. Novel biologic agents possibly have a role in controlling MEE in EGPA.

The Diagnostic Challenge of Eosinophilic Granulomatosis With Polyangiitis Presenting as Acute Eosinophilic Myocarditis: Case Report and Literature Review

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis involving small-to-medium-sized vessels characterized by asthma, vasculitis, and peripheral eosinophilia. EGPA-associated eosinophilic myocarditis (EM) occurs rarely, yet can be fatal if left untreated. Moreover, the accurate diagnosis of EGPA-associated EM without vasculitis is exceptionally difficult because of the overlapping features with EM of other causes. We report a case of probable EGPA with subclinical neurological involvement that presented with acute EM. The constellation of peripheral eosinophilia, left ventricular dysfunction, and normal epicardial coronary arteries raised suspicion of acute EM, which was confirmed by cardiac magnetic resonance (CMR) investigation and endomyocardial biopsy (EMB). Prompt systemic administration of corticosteroids completely restored and normalized myocardial structure and function. Although the patient's history suggested the presumed hypersensitivity myocarditis, EMB revealed EM without vasculitis, not hypersensitivity, leading to a tentative diagnosis of idiopathic hypereosinophilic syndrome. Interestingly, the characteristic findings of vasculitis on CMR imaging strongly suggested EGPA-associated EM. Although the patient had no clinical neurological manifestations, a nerve conduction study confirmed mononeuritis multiplex, leading to the final diagnosis of probable EGPA. Therefore, this case highlights the diagnostic challenge associated with EGPA and the diagnostic synergy of CMR and EMB for an exploratory diagnosis of EGPA-associated EM.

Serum Proteomic Analysis Identifies SAA1, FGA, SAP, and CETP as New Biomarkers for Eosinophilic Granulomatosis With Polyangiitis

Background

Eosinophilic granulomatosis with polyangiitis (EGPA) is characterized by asthma-like attacks in its early stage, which is easily misdiagnosed as severe asthma. Therefore, new biomarkers for the early diagnosis of EGPA are needed, especially for differentiating the diagnosis of asthma.

Objectives

To identify serum biomarkers that can be used for early diagnosis of EGPA and to distinguish EGPA from severe asthma.

Method

Data-independent acquisition (DIA) analysis was performed to identify 45 healthy controls (HC), severe asthma (S-A), and EGPA patients in a cohort to screen biomarkers for early diagnosis of EGPA and to differentiate asthma diagnosis. Subsequently, parallel reaction monitoring (PRM) analysis was applied to a validation cohort of 71 HC, S-A, and EGPA patients.

Result

Four candidate biomarkers were identified from DIA and PRM analysis-i.e., serum amyloid A1 (SAA1), fibrinogen-α (FGA), and serum amyloid P component (SAP)-and were upregulated in the EGPA group, while cholesteryl ester transfer protein (CETP) was downregulated in the EGPA group compared with the S-A group. Receiver operating characteristics analysis shows that, as biomarkers for early diagnosis of EGPA, the combination of SAA1, FGA, and SAP has an area under the curve (AUC) of 0.947, a sensitivity of 82.35%, and a specificity of 100%. The combination of SAA1, FGA, SAP, and CETP as biomarkers for differential diagnosis of asthma had an AUC of 0.921, a sensitivity of 78.13%, and a specificity of 100%, which were all larger than single markers. Moreover, SAA1, FGA, and SAP were positively and CETP was negatively correlated with eosinophil count.

Conclusion

DIA-PRM combined analysis screened and validated four previously unexplored but potentially useful biomarkers for early diagnosis of EGPA and differential diagnosis of asthma.

Successful Treatment for Eosinophilic Granulomatosis with Polyangiitis Causing Severe Myocarditis Followed by Cardiac Magnetic Resonance

A 38-year-old woman had a history of asthma for 20 years. Bullous lesions had appeared in her left side of the back. Two months before admission, and biopsy revealed eosinophilic cellulitis. She experienced numbness in both legs one month later. She was admitted to our hospital for emergency treatment due to chest pain and loss of consciousness. Emergency coronary angiography revealed triple-vessel vasospasm. She had cardiac arrest for four minutes during the examination. We suspected eosinophilic granulomatosis with polyangiitis due to pulmonary infiltrate, eosinophilia, and a history of illness. We therefore started methylprednisolone pulse therapy. Although her condition and laboratory findings improved, cardiac magnetic resonance (CMR) imaging performed on day 16 showed myocardial edema and myocardial fibrosis on late gadolinium enhancement (LGE). Coronary angiography on day 35 revealed no spasm, and myocardial biopsy showed absence of vasculitis. There was no improvement in myocardial edema. CMR showed enlargement of LGE and formation of ventricular aneurysm. As myocarditis did not improve sufficiently, five courses of intravenous cyclophosphamide pulse therapy were administered. CMR on day 152 showed disappearance of the myocardial edema. We report a unique case of successful treatment of severe myocarditis and the usefulness of follow-up CMR.

The clinical features and treatment of eosinophilic granulomatosis with polyangiitis (EGPA) in Turkey: one or two distinct diseases?

Eosinophilic granulomatosis with polyangiitis (EGPA) is defined the disease as having two subgroups, ANCA (+) and ANCA (-). We aimed to compare EGPA subgroups in terms of clinical features, outcomes, and treatments. A multidisciplinary team was established under our vasculitis centre since October 2014. Totally 50 EGPA patients were enrolled. Clinical features, treatments, and outcomes (FFS, VDI, relapse) were reviewed. For relapse-free survival analysis, time to first relapse was compared according to ANCA phenotype by Kaplan-Meier survival analysis and log-rank test. 17 (34%) patients were in ANCA (+), 33 (66%) patients were in ANCA (-) group. ANCA (-) patients were significantly younger at the diagnosis time (37.9 ± 14.3 vs 53.8 ± 16.3; p = 0.001) and had more nasal polyposis (45.5% vs 11.8%; p = 0.017). ANCA (+) patients had higher BVAS (17[13] vs 9[4]; p = 0.002), renal involvement and peripheral neuropathy were more common in this group, while cardiac involvement was seen only in ANCA (-) group (n = 3). Biological agents (mepolizumab or rituximab) were prescribed to nine patients in ANCA (-) and two patients in ANCA (+) group. The median duration of follow-up was 47 (IQR 69.9) months. ~ 40% of patients had at least one relapse, but relapse-free survival rate was similar between the groups. However, the predictor of first relapse was elevated Ig E level [OR (95% CI): 6.5 (1.09-38.63) p = 0.04]. Consequently, both clinical features, disease activity, and treatments appear to be significantly different between EGPA subgroups. The relapse risk was similar although clinical features and treatment strategies were different. Also, elevated Ig E levels may be a precursor for the relapse.

Umbilicated papulonodules on the elbows with purpuric papules on the fingers

This case describes an unusual cutaneous presentation. Our patient had purpuric papules on the fingers and umbilicated nodules over the elbows, and interestingly, both lesion types showed similar histopathological features of necrobiotic granuloma with neutrophils.

Severe Asthma Where Eosinophilic Granulomatosis with Polyangiitis Became Apparent after the Discontinuation of Dupilumab

The use of biologic agents has enabled control of severe asthma, but there is a risk that eosinophilic granulomatosis with polyangiitis (EGPA) may be masked in some cases. We herein report a 71-year-old man who was administered dupilumab for 2 years to stabilize his asthma symptoms. A few months after discontinuation of dupilumab administration, an increase in the eosinophil count in peripheral blood, leg pain, and a rash appeared. Based on pathology, he was diagnosed with EGPA. EGPA in this case was considered to have become apparent due to the discontinuation of dupilumab administration.

Stellate ganglion block as an intervention in refractory eosinophilic granulomatosis with polyangiitis: a case report

Background

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare vasculitis. Although glucocorticoid therapy with or without immunosuppressants leads to remission in the majority of cases, most EGPA patients remain dependent on glucocorticoid therapy and experience frequent relapses. Here, we report a case of refractory EGPA which responded to stellate ganglion blocks (SGBs).

Case presentation

A 32-year-old woman with aggravated wheezing, purpura, numbness of multiple fingers, and epigastric and abdominal pain was referred to our clinic. Laboratory and radiographic studies led to the diagnosis of EGPA. After an initial favorable response to glucocorticoid and immunosuppressant therapy, she experienced a relapse during a glucocorticoid taper. We found that SGB brought symptomatic relief and impeded disease progression. The mechanism of action of SGB on EGPA is undetermined, but may be related to vasodilation, immune modulation, and central nervous system regulation.

Conclusions

This report not only proposes a novel treatment modality for EGPA, but also provides a clinical reference point for further in-depth studies of SGB in multiple immune-linked disorders.

[ANCA-associated small-vessel vasculitides]

ANCA-associated vasculitides refer to systemic small-vessel vasculitides. The paper shows the role of antineutrophil cytoplasmic antibodies in the development of immune inflammation of blood vessels and tissues. It considers the pathogenesis of granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis and presents the clinical and morphological manifestations of the diseases.

Pathogenesis-based new perspectives of management of ANCA-associated vasculitis

While the pathogenesis of anti-neutrophil cytoplasmic autoantibody associated vasculitis (AAV) is still not fully elucidated, there is a mounting evidence that it is initiated by inflammation and activation of innate immunity in the presence of predisposing factors, innate immunity, aberrant responses of the adaptive immune system, and complement system activation. Biologics targeting inflammation-related molecules in the immune system have been explored to treat AVV, and these treatments have provided revolutionary advances. When focusing on the pathogenic mechanisms of AVV, this review presents the new findings regarding novel therapeutic approaches for the management of these conditions.

Retropharyngeal edema: A rare manifestation of eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is characterized by excessive eosinophil accumulation in the peripheral blood and affected tissues with development of granulomatous vasculitic organ damage. Although upper airway and neck involvement is seen in patients with EGPA, retropharyngeal inflammation has never been reported. We report a case of retropharyngeal edema in a 70-year-old woman with EGPA. Her symptoms improved and the retropharyngeal edema disappeared on computed tomography following treatment. EGPA should be considered as a differential diagnosis in patients with asthma presenting with neck swelling and dysphagia.

Society for Cardiovascular Magnetic Resonance 2020 Case of the Week series

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). Case of the week is a case series hosted on the SCMR website ( https://www.scmr.org ) that demonstrates the utility and importance of CMR in the clinical diagnosis and management of cardiovascular disease. Each case consists of the clinical presentation and a discussion of the condition and the role of CMR in diagnosis and guiding clinical management. The cases are all instructive and helpful in the approach to patient management. We present a digital archive of the 2020 Case of the Week series of 11 cases as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar search engine.

Systemic hypereosinophilic syndromes: when autoimmunity is Th2 mediated

PURPOSE OF REVIEW

Clinical conditions associated with hypereosinophilia represent a field of particular interest, taking into account the epidemiological impact of the different primary and secondary forms. In addition to a classical Th1 response, also Th2 cells can be involved in the pathogenesis of autoimmune diseases, among them eosinophilic forms such as eosinophilic granulomatosis with polyangiitis.

RECENT FINDINGS

In patients with severe asthma, recent evidence highlights the role of pathogenic autoantibodies against autologous eosinophil proteins (e.g. eosinophil peroxidase) suggest the role of autoimmune mechanisms, particularly in patients in which asthma is included in eosinophilic vasculitis with antineutrophilic autoantibody positivity. Is now evident that in addition to Th2 cells, also type 2 innate lymphoid cells and Th1/Th17 cells play a central role in the pathogenesis of hypereosinophilic syndrome.

SUMMARY

The definition of cellular and molecular mechanisms and the critical role of specific cytokines involved in the pathogenesis of hypereosinophilic syndrome open the way to new therapeutic strategies by using biological agents targeting these specific factors.