Renal involvement in eosinophilic granulomatosis with polyangiitis (EGPA): a multicentric retrospective study of 63 biopsy-proven cases

A case of eosinophilic granulomatosis with polyangiitis associated with diffuse alveolar haemorrhage: A case report and case-based review

A 76-year-old man with bronchial asthma was admitted for respiratory failure and bloody sputum. A significant drop in haemoglobin and multiple consolidations supported clinical diagnosis of diffuse alveolar haemorrhage (AH). Myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) was positive and urinalysis suggested glomerulonephritis. Based on eosinophilia, sinusitis, peripheral nerve involvement, and leukocytoclastic vasculitis, he was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA) associated with AH. Our case-based review suggested that male predominance (65%), high positivity for ANCA (88%), and a high frequency of renal involvement (45%) may be characteristic of AH in EGPA. Although AH is rare in EGPA, we should be aware of this life-threatening complication.

[Eosinophilic granulomatosis with polyangiitis: a review article]

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare form of ANCA-associated vasculitis (AAV) within the group of small vessel vasculitides. It is defined by vasculitis of small and medium-sized vessels with granulomatous inflammation and blood and tissue eosinophilia. Almost all patients have allergic symptoms with bronchial asthma and rhinosinusitis symptoms. Further clinical manifestations vary depending on the localisation, severity, and type of disease manifestation. Eosinophilic infiltration and inflammation may result in rhinosinusitis, pneumonitis, gastrointestinal involvement, and cardiomyopathy. The latter, in particular, is associated with a worse prognosis. As a necrotising pauci-immune small-vessel vasculitis, EGPA, similar to the other AAVs, can cause pulmonary infiltrates with alveolar haemorrhage, glomerulonephritis, cutaneous vasculitis with purpura as well as central and peripheral neurologic injuries. The presence of perinuclear ANCA (pANCA) with specificity against myeloperoxidase (MPO) is observed in approximately one-third of patients but is not specific to EGPA. MPO-ANCA-positive patients are more likely to have peripheral neurologic involvement and glomerulonephritis, whereas ANCA-negative patients are more likely to have cardiac and pulmonary involvement. What is frequently challenging in the clinical routine is to differentiate EGPA from the hypereosinophilic syndrome (HES). The therapeutic approach to EGPA depends on whether the severity of the disease is potentially organ or life-threatening. For severe forms of EGPA, acute therapy mainly includes glucocorticoids in combination with cyclophosphamide. Rituximab has come to be mentioned as an alternative treatment option in the guidelines. Various immunosuppressive therapies are available for remission maintenance. In EGPA without severe organ involvement, IL-5 blockade with mepolizumab is an approved treatment.

Evaluation of prognostic factors for patients with eosinophilic granulomatosis with polyangiitis recruited at the pneumonological centre and mainly ANCA negativity: A retrospective analysis of a single cohort in Poland

OBJECTIVES

The aim was to investigate the risk factors for relapse and death in patients with eosinophilic granulomatosis with polyangiitis (EGPA) recruited at the pneumonological centre and mainly antineutrophil cytoplasmic antibody negativity.

METHODS

We retrospectively recruited 86 patients. Relapse was defined as the recurrence or appearance of new organ symptoms. The study end-point included the final examination.

RESULTS

Relapses occurred in 34.9% of the patients, while 9.3% died. Immunosuppressive therapy (P = 0.042), prolonged low-dose corticosteroid treatments (mainly for asthma) (P = 0.006), and longer follow-up duration (P = 0.004) were associated with a higher relapse risk, while advanced EGPA severity (P = 0.0015) and activity (P = 0.044), older age of onset (P = 0.030), symptomatic cardiac involvement (P = 0.007), and postinflammatory cardiac fibrosis (P = 0.038) were associated with a higher risk of death. Sinusitis (P = 0.028) and prolonged low-dose corticosteroid treatments (P = 0.025) correlated with a better prognosis. Relapses did not have an impact on the mortality (P = 0.693).

CONCLUSIONS

Relapses in EGPA remain frequent, although they do not impact mortality. Cardiac involvement is common, but clinically symptomatic cardiomyopathy is associated with a higher risk of death. Asthma requiring chronic corticosteroid treatments is associated with a lower risk of death, although the risk of EGPA recurrence is significantly higher.

Interstitial Eosinophilic Aggregates and Kidney Outcome in Patients with CKD

BACKGROUND

Interstitial eosinophilic aggregates are observed in various kidney diseases, but their clinical implications remain unknown. We assessed the association between interstitial eosinophilic aggregates and kidney outcomes and further analyzed the association between blood eosinophil count, as a surrogate for interstitial eosinophilic aggregates, and the risk of kidney failure in patients with advanced CKD.

METHODS

We analyzed datasets from two retrospective cohort studies: ( 1 ) the kidney biopsy cohort including 563 patients who underwent native kidney biopsy at Osaka University Hospital between 2009 and 2021 and ( 2 ) the retrospective CKD cohort including 2877 patients with an eGFR of 10-60 ml/min per 1.73 m 2 referred to the nephrology outpatient center at Osaka University Hospital between 2005 and 2018. Interstitial eosinophilic aggregates were defined as ≥5 interstitial eosinophils in the high-power field on hematoxylin and eosin staining. This study outcome was initiation of KRT or ≥40% decline in eGFR.

RESULTS

In the kidney biopsy cohort, interstitial eosinophilic aggregates were found in 17% of patients, most frequently in those with diabetic nephropathy (50%). Interstitial eosinophilic aggregates were associated with a higher rate of the composite kidney outcome after adjustment for clinical and histological variables (hazard ratio, 3.61; 95% confidence interval, 2.47 to 5.29; P < 0.001). LASSO revealed that blood eosinophil count was the strongest predictor of interstitial eosinophilic aggregates. In the retrospective CKD cohort, higher baseline and time-updated blood eosinophil counts were significantly associated with a higher rate of KRT initiation in Cox proportional hazards models and marginal structural models.

CONCLUSIONS

Interstitial eosinophilic aggregates were associated with a higher risk of a composite of KRT initiation or ≥40% decline in eGFR.

PODCAST

This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_12_08_CJN0000000000000277.mp3.

Refractory Eosinophilic Granulomatosis with Polyangiitis Complicated with IgG4-related Disease Showing Different Treatment Responses for Each Organ

We herein report a 75-year-old woman who presented with dyspnea and purpura. She was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA) based on axonal damage observed in the left tibial nerve and skin and lung pathologies. Lung pathology showed IgG4-positive plasma cells, considered a complication of IgG4-related disease (IgG4-RD). Computed tomography revealed thickening of the abdominal aorta and a poor contrast area in the left kidney, which was indicative of IgG4-RD. Steroid administration improved the IgG4-RD. However, the EGPA resisted treatment; therefore, immunosuppressive drugs and mepolizumab were administered. Refractory EGPA complicated with IgG4-RD showed different treatment responses for each organ.

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.

Discrepancies between clinical and pathological findings seen at renal biopsy in rheumatological diseases

OBJECTIVE

Renal biopsy contributes to the diagnosis, follow-up, and treatment of many rheumatic conditions. This study assessed the diagnostic role and safety of renal biopsies in a tertiary rheumatology clinic.

METHODS

Renal biopsies performed between June 2020 and December 2022 were screened, and demographic, clinical, histopathological, and safety data were collected from patient records.

RESULTS

In this study, 33 males and 38 females were included. Except for 1 patient who received acetylsalicylic acid, antiaggregant, and/or anticoagulant drugs were stopped before the biopsy. Complications included a decrease of hemoglobin in 8 patients (11.3%) and microscopic hematuria in 40 patients (56.3%). Control ultrasonography was performed in 16 patients (22.5%), and a self-limiting hematoma was found in 4 of them (5.6%) without additional complications. While less than 10 glomeruli were obtained in 9 patients (9.9%), diagnosis success was 94.4%. Histopathological data were consistent with one of the pre-biopsy diagnoses in 54 of 67 cases (80.6%) but showed discrepancies in 19.4% (n=13) of patients. A repeat biopsy was performed in 7 patients for re-staging or insufficient biopsy.

CONCLUSIONS

Renal biopsy significantly contributes to rheumatology practice, especially in patients with complex clinical and laboratory findings or in whom different treatments can be given according to the presence, severity, and type of renal involvement. Although the possibility of obtaining insufficient tissue and the need for re-staging and repeat biopsy in the follow-up might be expected, complication risk does not seem to be a big concern. Renal biopsy often evidenced discrepancies between pre-biopsy diagnosis and histopathological findings.

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.

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.

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.

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.

Eosinophilic granulomatosis with polyangiitis: case report and literature review

Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as Churg-Strauss syndrome, is a multisystem disorder characterised by asthma, blood and tissue eosinophilia and small-vessel vasculitis. Eosinophilic tissue infiltration and extravascular granuloma formation can lead to damage in any organ, but it is classically seen to cause pulmonary infiltrates, sino-nasal disease, peripheral neuropathy, renal and cardiac involvement, and rashes. EGPA is part of the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis syndromes, with the antibody being detected in ∼30-40% of cases and mostly against myeloperoxidase. Two genetically and clinically distinct phenotypes, defined by the presence or absence of ANCA have been identified. Treatment for EGPA focuses on inducing and maintaining disease remission. To date, oral corticosteroids remain first-line agents whilst second-line treatments include immunosuppressants such as cyclophosphamide, azathioprine, methotrexate, rituximab and mycophenolate mofetil. However, long-term steroid usage results in multiple and well-known adverse health effects and new insights into the pathophysiology of EGPA have allowed for the development of targeted biologic therapies, like the anti-eosinophilic, anti-interleukin-5 monoclonal antibodies.

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.

Eosinophile Granulomatose mit Polyangiitis – ein Übersichtsartikel

Die eosinophile Granulomatose mit Polyangiitis (EGPA) ist eine seltene Form der ANCA-assoziierten Vaskulitiden (AAV) aus der Gruppe der Kleingefäßvaskulitiden. Sie ist definiert als eine Vaskulitis kleiner und mittelgroßer Gefäße mit granulomatöser Entzündung sowie Blut- und Gewebseosinophilie. Fast alle Patienten haben allergische Symptome mit Asthma bronchiale und rhinosinusitischen Beschwerden. Das sonstige klinische Spektrum variiert je nach Lokalisation, Schweregrad und Art der Krankheitsmanifestation. Durch die eosinophile Infiltration und Inflammation kann es zu Rhinosinusitis, Pneumonitis, gastrointestinaler Beteiligung und Kardiomyopathie kommen. Insbesondere Letztere ist mit einer schlechteren Prognose assoziiert. Als nekrotisierende pauci-immune Kleingefäßvaskulitis kann die EGPA, ähnlich wie die anderen AAV, pulmonale Infiltrate mit alveolärer Hämorrhagie, eine Glomerulonephritis, kutane Vaskulitis mit Purpura, sowie zentrale und periphere neurologische Schädigungen verursachen. Das Auftreten perinukleärer ANCA (pANCA), mit Spezifität gegen die Myeloperoxidase (MPO) wird in etwa einem Drittel der Fälle beobachtet, ist allerdings nicht spezifisch für die EGPA. MPO-ANCA-positive Patienten haben häufiger eine periphere neurologische Beteiligung und eine Glomerulonephritis, während ANCA-negative Patienten häufiger eine kardiale und pulmonale Beteiligung aufweisen. Eine differentialdiagnostische Herausforderung im klinischen Alltag stellt die Abgrenzung zum hypereosinophilen Syndrom (HES) dar. Das Therapiekonzept der EGPA hängt davon ab, ob der Schweregrad der Erkrankung potentiell Organ- oder lebensbedrohlich ist. Bei schweren Formen der EGPA werden in der Akuttherapie hauptsächlich Glukokortikoide in Kombination mit Cyclophosphamid eingesetzt. Rituximab wird mittlerweile als alternative Behandlungsoption in den Leitlinien genannt. Zur Remissionserhaltung stehen verschiedene immunsuppressive Therapien zur Verfügung. Bei EGPA ohne schwere Organbeteiligung ist die IL-5 Blockade mit Mepolizumab zugelassen.

Glomerulonephritis and Interstitial Nephritis Originating from Vasculitis of the Interlobular Arteries of the Kidney in a Patient with Eosinophilic Granulomatosis with Polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a type of antineutrophil cytoplasmic antibody-associated vasculitis. Patients often present with peripheral neuropathy and purpura, suggesting impairment of small vessels, especially capillaries. However, medium-sized vessels and small vessels with a vascular diameter larger than that of capillaries may also be impaired, causing atypical findings. We report a case of EGPA treated with corticosteroids, cyclophosphamide, and mepolizumab. Renal biopsy revealed vasculitis of the interlobular arteries as the cause of glomerulonephritis and interstitial nephritis. This case suggests the importance of considering vessels upstream of capillaries dominant EGPA as a differential diagnosis in patients with eosinophilia.

Clinical Significance of MPO-ANCA in Eosinophilic Granulomatosis With Polyangiitis: Experience From a Longitudinal Chinese Cohort

Objectives

The aim of this study is to investigate the clinical significance of myeloperoxidase (MPO)–antineutrophil cytoplasmic antibody (ANCA) on eosinophilic granulomatosis with polyangiitis (EGPA) from a longitudinal Chinese cohort.

Methods

A total of 120 patients with EGPA were consecutively enrolled and followed up. Two patients with PR3 ANCA was excluded and our analysis focused on the 118 patients with EGPA. On the basis of MPO-ANCA status, baseline clinical manifestations, treatment, and outcomes were analyzed. Logistic regression analysis was performed to analyze the independently associated factors for renal involvement.

Results

ANCA positivity was observed in 24.2% of patients with EGPA. Patients with MPO-ANCA accounted for 20.8%. Patients with positive MPO-ANCA had higher levels of erythrocyte sedimentation rate (ESR), C-reactive protein, Birmingham Vasculitis Activity Score (BVAS), higher ratios of fever, myalgia, renal involvement, and biopsy-proven vasculitis. Heart manifestations and asthma were more common in patients with negative ANCA. Baseline MPO-ANCA titers positively correlated with ESR, eosinophil count, and BVAS and were higher in patients with methylprednisolone pulse. Among patients with renal involvement, patients with positive MPO-ANCA had higher proportions of female, fever, biopsy-proven vasculitis, and faster ESR; patients with negative ANCA developed more skin and cardiac involvement. MPO-ANCA positivity, male, and ear involvement were the independent factors associated with renal involvement. Intravenous cyclophosphamide and immunoglobulins were prescribed more frequently in patients with positive MPO-ANCA.

Conclusion

In this cohort, patients with positive MPO-ANCA and negative ANCA displayed distinct clinical features, suggesting that MPO-ANCA might be a valuable biomarker for EGPA stratification. Baseline MPO-ANCA level correlated positively with disease activity of EGPA. MPO-ANCA was a significant independent factor associated with renal involvement.

ANCA-Negative Vasculitis in Eosinophilic Granulomatosis with Polyangiitis Complicated with Membranous Nephropathy: A Case Report and Brief Literature Review

Renal involvement in eosinophilic granulomatosis with polyangiitis (EGPA) typically occurs in anti-neutrophil cytoplasmic autoantibody (ANCA)-positive cases presenting with rapidly progressive renal insufficiency and urinary abnormalities induced by primarily necrotizing crescentic glomerulonephritis (NCGN). Recently, ANCA-negative EGPA has also been reported to manifest with renal involvement, such as NCGN or non-NCGN, including membranous nephropathy (MN). Herein, we report a 70-year-old female who presented with purpura on the lower legs, upper limb numbness, renal dysfunction (eGFR, 20.5 ml/min/1.73 m2), and eosinophilia (eosinophils, 37,570/μl). MPO-and PR3-ANCA were negative, and urinalysis revealed urine protein (0.63 g/day) but without red blood cells in the urine sediment. Thus, she was diagnosed with ANCA-negative EGPA with rapidly progressive renal dysfunction. A renal biopsy revealed vasculitis in the interlobular arteries without NCGN, with the vasculitis being complicated by MN. Micrograph findings on fluorescence immunostaining contained both primary and secondary characteristics of MN (dominance of IgG subclass 4 more than subclass 1 vs. negativity of PLA2R and THSD7A). After treatment with prednisolone, her eosinophil counts normalized, and renal dysfunction improved. Furthermore, urine protein did not increase above 1.0 g/day during the clinical course. This is a rare case of ANCA-negative EGPA presenting with acute renal dysfunction without NCGN and subclinical MN with unknown etiology. It is important to recognize that EGPA pathology varies widely throughout the disease course, and the clinical course of subclinical MN should be carefully assessed in further follow-ups.

ANCA-associated vasculitis and IgG4-related disease overlap syndrome: a case report and literature review

Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides are infrequent autoimmune diseases characterized by inflammation of the walls of small vessels leading to tissue and endothelial damage. On the other hand, IgG4-related disease is a fibroinflammatory disease characterized histologically by lymphoplasmacytic infiltrates with IgG4+ plasma cells, storiform fibrosis, and obliterative phlebitis that may affect nearly every organ of the body. There are similarities in clinical, serological, radiological, and histopathological features between both diseases, and hence, they usually mimic each other complicating the differential diagnosis. Furthermore, reports of patients with the coexistence of both conditions (overlap syndrome) have been reported. We herein report a patient with an unequivocal diagnosis of ANCA-associated vasculitis, specifically granulomatosis with polyangiitis (posterior uveitis, polyneuropathy, pauci-immune glomerulonephritis with crescent formation and granulomas, and MPO-ANCA positivity) and IgG4-related disease (thoracic aortitis, tubulointerstitial nephritis with prominent IgG4+ plasma cell infiltration, fibrosis, and obliterative arteritis, high levels of serum IgG4, and eosinophilia) overlap syndrome.

Renal Involvement as Rare Acute Tubulointerstitial Nephritis in a Patient with Eosinophilic Disorder Treated with Early Add-on Administration of Mepolizumab

A 39-year-old man presented with peripheral eosinophilia, pulmonary eosinophilic infiltrate, and renal failure due to acute tubulointerstitial nephritis (TIN). He had experienced childhood asthma and was negative for anti-neutrophil cytoplasmic antibody (ANCA). He was tentatively diagnosed with ANCA-negative eosinophilic granulomatous polyangiitis (EGPA) or idiopathic hypereosinophilic syndrome (HES). Renal involvement of isolated TIN with eosinophil infiltration is rare in EGPA and HES and does not seem to have a good prognosis in the literature. However, his condition improved well with corticosteroids and mepolizumab. The revised classification of EGPA based on the etiology should dictate the proper treatment in suspected EGPA patients with nonsystemic vasculitis.

The prevalence, burden of disease, and healthcare utilization of patients with eosinophilic granulomatosis with polyangiitis in Japan: a retrospective, descriptive cohort claims database study

OBJECTIVES

To estimate eosinophilic granulomatosis with polyangiitis (EGPA) prevalence and disease burden in patients with newly diagnosed EGPA in Japan.

METHODS

This retrospective descriptive cohort study (GSK ID: 209751, HO-18-19652) used administrative claim data from patients (aged ≤74 years) with EGPA (study period: January 1, 2005-December 31, 2017), identified from their first ICD-10 code for EGPA (index). Data were examined during the 12 months before (baseline) and 12 months following the index date (follow-up). EGPA prevalence, respiratory comorbidities, all-cause healthcare utilization, and oral corticosteroid (OCS) use were assessed.

RESULTS

EGPA prevalence (95%CI) increased from 4.2 (0,23.7)/million people (2005) to 38.0 (31.8,45.1)/million people (2017), was generally more common in females versus males, and increased with age. Of the 45 patients with newly diagnosed EGPA, 57.8% had acute bronchitis and 42.2% had upper respiratory tract infections during baseline. During follow-up, 60.0% of patients were hospitalized at least once and 77.8% used OCS (OCS dependent [≥80% of days]: 73.1%).

CONCLUSIONS

In Japan, EGPA prevalence increased over time, was generally more common in females, and increased with patient age. EGPA burden was high; respiratory comorbidities were common, and most patients required hospitalization and OCS use. Our data suggest additional EGPA treatment options are needed.