Common Characteristics of Sinonasal Inflammation Associated with IgG4-Related Disease and Other Chronic Inflammatory Diseases: A Retrospective Observational Study.

INTRODUCTION: Immunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory disease characterized by elevated serum IgG4, tissue infiltration of IgG4-positive cells, and fibrosis. Although a number of IgG4-RD patients show sinonasal involvement, there is little known about sinonasal inflammation associated with IgG4-RD. This study aimed to describe the clinicopathological features of sinonasal inflammation associated with IgG4-RD and to compare with other inflammatory diseases, such as eosinophilic chronic rhinosinusitis (ECRS) and granulomatosis with polyangiitis (GPA). METHODS: A retrospective analysis of clinicopathological features of patients with sinonasal lesions and high serum IgG4 was performed. Patient data were reviewed to determine whether they fulfilled the diagnostic criteria for other inflammatory diseases. RESULTS: Six of 7 patients were diagnosed with IgG4-RD, while 1 patient was diagnosed with GPA. In the 6 patients with IgG4-RD, intranasal findings showed nasal polyps in 3 patients (50%) and nasal crusting in the 3 patients (50%). Computed tomography showed ethmoid sinus involvement in 5 patients (83%). Five of the 6 patients (83%) were diagnosed with IgG4-RD based on nasal biopsy, whereas 1 patient (17%) was diagnosed based on lacrimal gland biopsy. Four patients fulfilled the Japanese epidemiological survey of refractory ECRS (JESREC) criteria. However, none of the patients showed eosinophil infiltration. Although the patient with GPA showed high levels of serum IgG4 and tissue infiltration of IgG4-positive cells in the nasal biopsy, the patient showed common clinical features of GPA. CONCLUSION: Patients with sinonasal inflammation associated with IgG4-RD had similar clinical characteristics with ECRS and GPA. Histopathological findings of the nasal biopsy from clinically diagnosed GPA was consistent with that of IgG4-RD. Sinonasal inflammation associated with IgG4-RD should be diagnosed based not only on tissue infiltration of IgG4-positive cells but in conjunction with clinical findings such as local nasal characteristics, involvement of other organs, and serum antineutrophil cytoplasmic antibody levels. IgG4-RD should be ruled out in patients with eosinophilia without histopathological eosinophil infiltration.

[Is this iatrogenic pathology or rare disease?] / Yatrogennaya patologiya ili redkaya bolezn'?

The article is devoted to the problem of diagnosis and treatment strategy of Buerger's disease rarely found in the expert and clinical practice, that is inflammatory disease of unknown etiology, affecting mainly small and medium arteries and veins of limbs. Vascular surgeons around the world have been solving this problem for many years, both in terms of timely diagnosis of this disease and its proper pathogenic treatment. The authors of the article described an expert case of Buerger's disease larvated course in 15-years-old girl, which primarily was mistakenly assessed by specialists as iatrogenic pathology of right forearm vessels in injecting aminazin solution that, according to the clinicians' opinion, led to dry gangrene formation of right wrist and its subsequent amputation. The results of the forensic histological study and retrospective analysis of all child's medical documents allowed to correctly diagnose this rare pathology but only on the stage of commission forensic medical examination in the framework of the initiated criminal proceeding against several leading medical organizations in Saint-Petersburg with a pediatric profile. The authors noted the role of routine medical manipulation in manifestation of larvated pathologic process in a teenage girl in addition to full health and well-being. The objective of present article is devoted to understanding this problem.

The role of anti-eosinophilic therapies in eosinophilic granulomatosis with polyangiitis: a systematic review.

Eosinophilic granulomatosis with polyangiitis (EGPA) is an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, mostly affecting small-sized arteries and usually occurring in patients with an allergic background. Eosinophils seem to play a significant role in the pathogenesis of the disease and, therefore, biologics targeting interleukin 5 (IL5), a cytokine tightly linked to eosinophils, have emerged as a promising therapeutic tool. A systematic review of Medline was conducted from 2007 to 2022 to search for data regarding the use of anti-IL5 therapies in patients with EGPA. Ongoing or unpublished trials were also searched in ClinicalTrials.gov and the World Health Organization trials portal. The efficacy and safety of mepolizumab, an anti-IL5 monoclonal antibody (mAb), was confirmed by a randomized controlled trial (RCT), although a significant proportion of patients did not respond to this treatment. Other studies showed that both doses of 100 mg and 300 mg of mepolizumab are almost equally effective in EGPA. Benralizumab, an anti-IL5 receptor mAb has preliminary promising results and an RCT is planned to be conducted. Apart from their clinical efficacy in EGPA, anti-IL5 therapies may have steroid-sparing properties. Anti-IL5 therapies seem to be effective and safe in patients with refractory/relapsing EGPA and can be used as a steroid-sparing treatment. Nevertheless, more research is needed to clarify the pathophysiology of the disease; this may potentially lead to the identification of biomarkers to pinpoint patients most likely to respond to anti-IL5-blockade.

Clinical characteristics of eosinophilic granulomatosis with polyangiitis involving the lung in 13 patients. / 13ä¾‹ç´¯åŠè‚ºéƒ¨çš„å—œé ¸æ€§è‚‰èŠ½è‚¿æ€§å¤šè¡€ç®¡ç‚Žçš„ä¸´åºŠç‰¹å¾.

OBJECTIVES: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis, which often starts with respiratory symptoms such as asthma, and it is difficult to make early clinical diagnosis.This study aims to improve the therapeutic level of EGPA with lung involvement via analyzing the clinical characteristics, diagnosis, and treatment . METHODS: We retrospectively analyzed the clinical data of 13 EGPA patients with lung involvement who were diagnosed from February 1, 2014 to July 31, 2021 in the Second Xiangya Hospital, Central South University. RESULTS: The ratio of male to female in 13 patients was 7꞉6. The patients were diagnosed at median age 52 (46-68) years old and 6 had been diagnosed as "bronchial asthma". Pulmonary clinical manifestations mainly included cough, expectoration, wheezing, and shortness of breath; while extra-pulmonary manifestations mainly included rash and subcutaneous mass, fever, limb numbness, muscle and joint pain, abdominal pain, etc. Peripheral blood tests of all patients showed that 11 patients had eosinophils ≥10%, 10 had elevated inflammatory indicators, and 3 were anti-neutrophil cytoplasmic antibody (ANCA) positive. The major lung imaging features were patches or strips of increased density, multiple nodules, bronchiectasis, bronchial wall thickening, exudation, mediastinal lymph nodes, and so on. Eight patients had sinusitis and 9 with abnormal electromyography. Extravascular eosinophil infiltration was found in 9 patients. Six patients with lung biopsy showed eosinophil, lymphocyte, and plasma cell infiltration, 3 patients were involved in small blood vessels, and 1 had granuloma. Pulmonary function tests were performed in 7 patients, 5 of them showed different degrees of pulmonary ventilation dysfunction, and 4 of them had diffusion dysfunction. Almost all patients respond well to glucocorticoid and immunosuppressant. CONCLUSIONS: EGPA is rare in clinical, often involving multiple systems with great harm and may combine with asthmatic manifestations. Pulmonary involvement is relatively common. However, due to insufficient recognition of this disease and huge heterogeneity of pulmonary imaging manifestations, misdiagnosis and missed diagnosis are easy to occur. Relevant laboratory, imaging, and biopsy examination should be performed as early as possible with comprehensive consideration of extrapulmonary involvement. Early identification has great significance to improve the diagnosis rate and prognosis of diseases.

Relapse rate and renal prognosis in ANCA-associated vasculitis according to long-term ANCA patterns.

Long-term observation of patients with ANCA-associated vasculitis (AAV) allows the identification of different longitudinal patterns of ANCA levels during follow-up. This study aimed to characterize these patterns and to determine their prognostic significance. All ANCA determinations performed in two university hospitals during a 2-year period were retrospectively reviewed. Patients were included in the analysis if they had high titers of anti-myeloperoxidase (anti-MPO) or anti-proteinase 3 (anti-PR3) antibodies at least once, ≥ 5 serial ANCA determinations and AAV diagnosed by biopsy or American College of Rheumatology (ACR) classification criteria. Patients' time-course ANCA patterns were classified as monophasic, remitting, recurrent or persistent. Associations between ANCA patterns and prognostic variables (relapse rate and renal outcome) were analysed by univariate and multivariate statistics. A total of 99 patients [55 with microscopic polyangiitis (MPA), 36 with granulomatosis with polyangiitis (GPA) and eight with eosinophilic granulomatosis with polyangiitis (EGPA)] were included. Median follow-up was 9 years. Among patients diagnosed with MPA or GPA, recurrent or persistent ANCA patterns were associated with a higher risk of clinical relapse [hazard ratio (HR) = 3·7, 95% confidence interval (CI) = 1·5-9·1 and HR = 2·9, 95% CI = 1·1-8·0, respectively], independently of clinical diagnosis or ANCA specificity. In patients with anti-MPO antibodies, the recurrent ANCA pattern was associated with worsening renal function [odds ratio (OR) = 5·7, 95% CI = 1·2-26·0]. Recurrent or persistent ANCA patterns are associated with a higher risk of clinical relapse. A recurrent ANCA pattern was associated with worsening renal function in anti-MPO-associated vasculitis.

Pulmonary Eosinophilic Granulomatosis with Polyangiitis Has IgG4 Plasma Cells and Immunoregulatory Features.

The immunologic mechanisms promoting eosinophilic granulomatosis with polyangiitis (EGPA) are unclear. To characterize the mechanisms underlying pulmonary EGPA, we examined and compared EGPA paraffin-embedded lung biopsies with normal lung biopsies, using immunostaining, RNA sequencing, and RT-PCR. The results revealed novel type 2 as well as immuneregulatory features. These features included basophils and increased mast cell contents; increased immunostaining for tumor necrosis factor ligand superfamily member 14; sparse mast cell degranulation; numerous forkhead box protein P3 (FoxP3)+ regulatory T cells and IgG4 plasma cells; and abundant arachidonate 15-lipoxygenase and 25-hydroxyvitamin D-1 α hydroxylase, mitochondrial. Significantly decreased 15-hydroxyprostaglandin dehydrogenase [NAD(+)], which degrades eicosanoids, was observed in EGPA samples. In addition, there was significantly increased mRNA for chemokine (C-C motif) ligands 18 and 13 and major collagen genes, IgG4-rich immune complexes coating alveolar macrophages, and increased immunostaining for phosphorylated mothers against decapentaplegic homolog 2/SMAD2, suggesting transforming growth factor-ß activation. These findings suggest a novel self-promoting mechanism of activation of alveolar macrophages by arachidonate 15-lipoxygenase-derived eicosanoids to express chemokines that recruit a combined type 2/immunoregulatory immune response, which produces these eicosanoids. These results suggest that the pulmonary EGPA immune response resembles the immune response to a tissue-invasive parasite infection.

Eosinophilic granulomatosis with polyangiitis: Cutaneous clinical and histopathologic differential diagnosis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, but severe systemic vasculitis that can affect skin and other organ systems. Diagnostic criteria have evolved, and many attempts have been made to classify the vasculitides based on clinical and/or histopathologic features, with an aim to develop standardized criteria. According to the EGPA Consensus Task Force recommendations, EGPA is a syndrome of asthma, eosinophilia, pulmonary infiltrates, and extrapulmonary vasculitis (such as cutaneous involvement with purpura). Histopathologic evidence of vasculitis in EGPA may be associated with eosinophilic infiltration and/or perivascular granulomatous inflammation. We review clinicopathologic criteria of this enigmatic vasculopathy.

Tumor-like Lesions in Patients with Granulomatosis with Polyangiitis: A Case Series.

BACKGROUND: Granulomatosis with polyangiitis (GPA) is a rare small vessel vasculitis. It usually involves the respiratory tract and kidney. Rarely, tumor-resembling inflammatory changes ensue. OBJECTIVES: To report three unique cases of GPA presenting with tumor-like lesions in various organs. METHODS: We presented three cases of GPA. Case 1 presented with typical upper respiratory symptoms of GPA and a mediastinal mass. Case 2 presented with low back pain, a large retroperitoneal mass, and nodular skin lesions. Case 3 presented with epigastric pain and a paravertebral inflammatory mass. RESULTS: The patients were treated successfully with rituximab. CONCLUSIONS: Clinicians should be aware of this presentation of granulomatosis with polyangiitis, which is known as Tumefaction Wegener's granulomatosis.

ANCA-Associated Vasculitis: Core Curriculum 2020.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of disorders characterized by inflammation and destruction of small- and medium-sized blood vessels and the presence of circulating ANCA. Clinical disease phenotypes include granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, and renal-limited vasculitis. Serologic classification of AAV into proteinase 3-ANCA disease and myeloperoxidase-ANCA disease correlates with a number of disease characteristics. AAV has a predilection for the kidney, with >75% of patients having renal involvement characterized by rapidly progressive glomerulonephritis. The cause and pathogenesis of AAV are multifactorial and influenced by genetics, environmental factors, and responses of the innate and adaptive immune system. Randomized controlled trials in the past 2 decades have refined the therapy of AAV and transformed AAV from a fatal disease to a chronic illness with relapsing course and associated morbidity. This article in AJKD's Core Curriculum in Nephrology series provides a detailed review of the epidemiology, pathogenesis, diagnosis, and advances in the management of AAV.

Delayed neutrophil apoptosis in granulomatosis with polyangiitis: dysregulation of neutrophil gene signature and circulating apoptosis-related proteins.

Objectives: Neutrophil apoptosis is mandatory for resolving inflammation and is regulated by expression of pro- and anti-apoptotic genes. We studied neutrophils isolated from patients with granulomatosis with polyangiitis (GPA) to investigate apoptosis alterations and to identify transcriptional and circulating factors affecting this process.Method: We enrolled 36 patients (18 in active stage, 18 in remission) and 18 healthy controls. Circulating levels of tumour necrosis factor-α (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage migration inhibitory factor, plasminogen activator inhibitor-1, interferon-γ, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, platelet endothelial cell adhesion molecule-1, soluble Fas (sFas), sFas ligand, survivin, and pentraxin-3 (PTX3) were evaluated by enzyme-linked immunosorbent assay/Luminex; circulating apoptotic neutrophils by flow cytometry; and apoptosis-related gene transcripts by real-time polymerase chain reaction.Results: Patients had decreased fractions of circulating apoptotic neutrophils and delayed neutrophil apoptosis was present in vitro. Circulating levels of TNF-α, GM-CSF, sFas, and PTX3 were higher in GPA. Delayed neutrophil apoptosis was accompanied by decreased mRNA of pro-apoptotic genes and transcription factors (DIABLO, PMAIP1, BAX, CASP3, CASP7, RUNX3, E2F1, TP53) and increased anti-apoptotic CFLAR and BCL2A1 mRNA. TNF-α and sFas levels correlated with circulating apoptotic neutrophils and expression of apoptosis genes. Stimulation with TNF-α of neutrophils from controls significantly down-regulated E2F1 and CASP3 expression.Conclusions: Circulating neutrophils in GPA have anti-apoptotic phenotype involving both intrinsic and extrinsic pathways of apoptosis. This is accompanied by increased levels of circulating pro-survival factors (GM-CSF, TNF-α, sFas), independent of disease activity. Anti-apoptotic phenotype of neutrophils in GPA is reproduced by exposure to low concentrations of TNF-α.

From strawberry gingivitis to palatal perforation: The clinicopathological spectrum of oral mucosal lesions in granulomatosis with polyangiitis.

BACKGROUND: Reports of oral manifestations of granulomatosis with polyangiitis (GPA) usually refer to single-case reports; "strawberry gingivitis" has been increasingly reported. OBJECTIVE: To study the clinicopathological findings of four patients in which the diagnosis of GPA was suspected from the observation of their oral lesions and compare these to existent data. METHODS: Retrospective study of a case series. RESULTS: One patient presented typical "strawberry gingivitis" with localized disease and negative ANCA results. Two patients presented rapidly growing oral ulcers associated with systemic compromise and high ANCA levels. One patient presented with a chronic granulomatous lesion that leaded to palatal perforation. CONCLUSION: Oral manifestations of GPA may vary from rapidly evolving lesions in acutely ill patients to chronic and locally destructive lesions in slowing developing disease. These differences are also evident in the histopathological findings.

Cutaneous Manifestations of Granulomatosis with Polyangiitis: A Case Series Study.

The aim of this study was to determine the prevalence and type of cutaneous manifestations which occur in patients with granulomatosis with polyangiitis and to explore the potential association between cutaneous and systemic involvement in these patients. A retrospective case series study was designed, including all granulomatosis with polyangiitis cases diagnosed between 2010 and 2018 at the Hospital Universitario Virgen de las Nieves. Thirty-nine patients with granulomatosis with polyangiitis were identified, of which 53.85% presented cutaneous manifestations. In decreasing order of frequency, the types of cutaneous problems observed included: palpable purpura, mucocutaneous ulcers, subcutaneous nodules, pyoderma gangrenosum-like ulcers, digital necrosis, papulonecrotic lesions and livedo reticularis. Patients with palpable purpura presented a higher frequency of renal involvement (p = 0.008). Cutaneous manifestations of granulomatosis with polyangiitis may facilitate early disease diagnosis. Likewise, a manifestation such as palpable purpura may be a predictor of kidney damage.

The complexity of classifying ANCA-associated small-vessel vasculitis in actual clinical practice: data from a multicenter retrospective survey.

The different sets of criteria for diagnosis or classification of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) lead to numerous overlapping and reclassified diagnoses in clinical practice. We designed this study to assess the difficulties in classifying patients with AAV. As a secondary objective, different variables were tested to predict prognosis. We conducted a retrospective chart review in a Western Spain multicentre survey. A total of 115 adult patients diagnosed with AAV from 2002 to 2013 and followed for at least 3 years were included. They were classified according to (1) Chapel Hill Consensus Conference (CHCC), (2) European Medicines Agency algorithm and (3) French Vasculitis Study Group/European Vasculitis Society phenotypes. Fifty-three patients (46%) had neither distinctive histopathological data of a single AAV definition nor any surrogate markers for granulomatous inflammation and thus did not fulfill any diagnostic criteria. Ocular, ear, nose, throat, skin, and lung involvement were more frequent with proteinase 3 (PR3) antibodies, whereas peripheral neuropathy was more frequent with myeloperoxidase (MPO) antibodies. When the disease was severe at diagnosis, the HR for mortality was 10.44. When induction treatment was not given in accordance with the guidelines, the HR for mortality was 4.00. For maintenance treatment, the HR was 5.49 for mortality and 2.48 for relapse. AAV classification is difficult because many patients had neither specific clinical data nor distinctive histological features of a single CHCC definition. A structured clinical assessment of patient severity is the best tool to guide the management of AAV.

Pulmonary granulomas in a patient with positive ANCA and history of tuberculosis: case report.

BACKGROUND: Granulomatous polyangiitis (GPA) is a rare multisystem autoimmune disease of unknown aetiology that is pathologically characterised by necrotising vasculitis, tissue necrosis and granulomatous inflammation, typically in the presence of anti-neutrophil cytoplasmic antibodies (ANCA). However infectious diseases may induce high titre ANCA and mimic vasculitis. Tuberculosis may share many clinical features with GPA including fever, arthralgia, granulomatous inflammation and pulmonary lesions and patients. CASE PRESENTATION: A 39 year old patient was admitted with ocular irritation and redness, arthralgia and multiple new pulmonary lesions. The past medical history was significant for two episodes of tuberculosis previously requiring prolonged treatment. ANCA antibodies were positive and CT showed multiple pulmonary lesions including cavitatory lesions. After extensive investigation, the patient was treated for GPA with high dose immune suppression with good clinical response. CONCLUSIONS: Here we review the diagnostic considerations between differentiating GPA and tuberculosis in patients from endemic regions. It is recommended that biopsies of lung lesions, sputum microscopy and multidisciplinary team input are sought as part of the workup when these two differentials are being considered.

Serum Mannose-Binding Lectin Levels Are Correlated with the Disease Activity of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Single-Center Study.

Mannose-binding lectin (MBL) is a soluble pattern-recognition molecule, which plays a crucial role in the innate immune system and the activation of lectin complement pathway. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune disease affecting the small vasculatures and is characterized by the alteration of innate and adaptive immunity and complement activation. In this study, we investigated whether serum MBL is associated with disease activity of AAV, which was measured by ELISA. Associations between serum MBL and AAV-specific indices, as well as clinical and laboratory data were assessed using Kendall's tau. Among the 80 patients, 42 (52.5%), 21 (26.3), and 17 (21.3%) patients were classified as microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA), respectively. The median values of erythrocyte sedimentation rate, C-reactive protein, and serum MBL were 36.5 (normal range < 20) mm/h, 2.4 (normal range < 8) mg/dL, and 8.6 ng/mL, respectively. The median serum levels of MBL in MPA, GPA, and EGPA patients were 8.4, 9.3, and 8.2 ng/mL. Correlation analysis showed that serum MBL was associated with Birmingham Vasculitis Activity Score (BVAS) (R = 0.169, p = 0.027), but not with other AAV-specific indices and clinical and laboratory data. In addition, serum MBL was significantly associated with the pulmonary manifestation score based on BVAS (R = 0.247, p = 0.001). In summary, among the AAV-specific indices and clinical and laboratory variables analyzed, serum MBL is correlated with BVAS and pulmonary manifestation score based on the BVAS.

Nasal polyps in eosinophilic granulomatosis with polyangiitis: Structured histopathology and CD105 expression.

PURPOSE: Distinguishing the prodromal nasal polyposis of eosinophilic granulomatosis with polyangiitis (EGPA) from chronic rhinosinusitis with nasal polyps (CRSwNP) is a challenge for rhinologists and rheumatologists. It has recently been reported that angiogenesis and CD105 expressed on vascular endothelial cells could have a role in the pathogenesis and development of nasal polyps. This exploratory study examined the structured histopathology of nasal polyps in patients with EGPA and CRSwNP, comparing CD105 expression in their nasal tissue with that of a control group with no chronic sinonasal inflammation. METHODS: A structured histopathological study was performed on surgical specimens of nasal tissue from 32 adults (13 with EGPA, 14 with CRSwNP, 5 controls), considering CD105 as a marker to determine microvessel density (MVD). RESULTS: The mean eosinophil count was higher in EGPA patients with tissue inflammation (p = .002), and in CRSwNP patients with sub-epithelial edema (p = .009). Neutrophil infiltration was significantly associated with severe tissue inflammation in EGPA patients (p = .04), but with the absence of fibrosis in CRSwNP patients (p = .04). In the EGPA group, CD105-MVD correlated with tissue eosinophil count (p = .05). Mean CD105-MVD was significantly higher in EGPA patients with mucosal ulceration (p = .004). In the CRSwNP group, a CD105-MVD correlated positively and significantly with tissue eosinophil count (p = .01). CONCLUSION: Alongside the known abundance of eosinophils, other cells might contribute to inflammatory processes. Neutrophils may amplify inflammation, eosinophil recruitment and tissue damage. CD105 expression in CRSwNP and EGPA nasal polyps supports the hypothesized involvement of angiogenesis in the pathogenesis and development of nasal polyps.

Immunopathogenesis of ANCA-Associated Vasculitis.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is an autoimmune disorder which affects small- and, to a lesser degree, medium-sized vessels. ANCA-associated vasculitis encompasses three disease phenotypes: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). This classification is largely based on clinical presentations and has several limitations. Recent research provided evidence that genetic background, risk of relapse, prognosis, and co-morbidities are more closely related to the ANCA serotype, proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA, compared to the disease phenotypes GPA or MPA. This finding has been extended to the investigation of biomarkers predicting disease activity, which again more closely relate to the ANCA serotype. Discoveries related to the immunopathogenesis translated into clinical practice as targeted therapies are on the rise. This review will summarize the current understanding of the immunopathogenesis of ANCA-associated vasculitis and the interplay between ANCA serotype and proposed disease biomarkers and illustrate how the extending knowledge of the immunopathogenesis will likely translate into development of a personalized medicine approach in the management of ANCA-associated vasculitis.

Granulomatosis with Polyangiitis Restricted to the Back Muscle: The First Case Report.

Granulomatosis with polyangiitis (GPA) is an autoimmune disease which is a type of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis that frequently affects the lungs and kidneys. However, GPA limited to a single organ has also been reported. A 71-year-old man was admitted for back pain and fever. We detected elevated levels of inflammatory markers and myeloperoxidase-ANCA. Magnetic resonance imaging indicated diffuse inflammation of the back and psoas muscles. Histology showed degenerated muscle fibers and granulomatosis vasculitis with mixed lymphoplasma cell infiltration. High-dose methylprednisolone therapy improved his symptoms. A final diagnosis of GPA limited to the muscles was made.

How to improve the histopathological diagnosis of systemic vasculitides in daily practice?

The most common group of systemic vasculitides in adulthood are anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). AAV represent autoimmune systemic vasculitides and include 3 clinical phenotypes: Granulomatosis with polyangiitis (GPA, formerly Wegener granulomatosis), Microscopic polyangiitis (MPA) and Eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss syndrome). Histological features are similar to each other in all affected locations, and there are represented by necrotizing vascular inflammation of small and medium calibers, often venules, capillaries or arteriols, typically with fibrinoid vessel wall necrosis. The consequences of this condition are bleeding, as well as compromise of the lumen which may result in downstream tissue ischemia and necrosis. Typically affected locations in biopsy practice are: ENT, lung, skin, GIT, and kidney. The aim of this review is to provide a comprehensive overview of the important histopathological findings. ANCA positive vasculitis is a serious life-threatening disease and therefore requires a rapid diagnosis and appropriate therapy.