Diagnostic value of standardized assays for anti-neutrophil cytoplasmic antibodies in idiopathic systemic vasculitis. EC/BCR Project for ANCA Assay Standardization

Diagnostic accuracy of ANCA serology in ANCA-associated vasculitis with renal involvement

BACKGROUND

Pauci-immune glomerulonephritis (GN) due to antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a common cause of crescentic GN. Despite advances in treatment, rates of mortality and progression to end-stage kidney disease remain high. Renal involvement is diagnosed by histological examination of kidney tissue. Serum ANCAs play a significant role in AAV; however, the value of serum ANCA quantification to predict renal involvement is not well-established.

AIM

We aimed to evaluate the diagnostic accuracy of serum ANCA titres in diagnosing AAV with renal involvement.

METHODS

We conducted a retrospective study of consecutive native kidney biopsies reported at our centre from 2016 to 2021. We included all adults who had both a kidney biopsy and ANCA serology. ANCA serology was tested using indirect immunofluorescence with reporting of titres. Antibodies to proteinase 3 and myeloperoxidase were measured using a chemiluminescent immunoassay.

RESULTS

Eight hundred and forty-eight native kidney biopsies were reported during the study period. Five hundred and seven cases were included. The biopsy prevalence of pauci-immune GN in paired samples was 41/507 (8.1%). Most of the cohort had haematuria (66.6%), proteinuria (93.4%) and/or acute kidney injury (65.0%). A positive ANCA at any titre demonstrated a sensitivity of 97.6% and a specificity of 71.2% for a diagnosis of pauci-immune GN. The area under the curve for the receiver operator characteristic was 0.93 (95% confidence interval [CI]: 0.89-0.97). A cutoff ANCA titre of 1:160 provided the optimum balance between a sensitivity of 75.6% (95% CI: 59.7%-87.6%) and a specificity of 94.0% (95% CI: 91.6%-96.0%).

CONCLUSIONS

ANCA titres are highly predictive of pauci-immune GN in the appropriate context. While serum ANCA quantitation may not replace renal biopsy, reporting will assist in the decision to start treatment early for patients with organ or life-threatening disease.

Proteinase‑3‑antineutrophil cytoplasmic antibody‑associated vasculitis secondary to subacute infective endocarditis: A case report

A 58-year-old male patient was admitted to Peking University First Hospital (Beijing, China) due to recurrent hematuria, proteinuria and kidney dysfunction. The patient was positive for proteinase-3 (PR3)-antineutrophil cytoplasmic antibody (ANCA). Pathology of the kidney showed focal proliferative necrotizing glomerulonephritis with crescent formation and immune complex-mediated glomerulonephritis. The patient was diagnosed with PR3-ANCA-associated vasculitis (AAV), received intensive immunosuppressive therapy and experienced two relapses within 1 year. After admission, aortic valve vegetation was observed via echocardiography. The patient subsequently received antibiotic treatment and valve replacement, and achieved complete remission of kidney and cardiac function. The present case emphasized the importance of identifying secondary reasons for ANCA formation, especially infective endocarditis in patients with PR3-AAV.

Headaches and Vasculitis

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system leads to pervasive injury and disability making this a disorder of paramount importance to all clinicians. Headache may be an important clue to vasculitic involvement of central nervous system (CNS) vessels. CNS vasculitis may be primary, in which only intracranial vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. Primary neurologic vasculitides can be diagnosed with assurance after intensive evaluation that incudes tissue confirmation whenever possible.

New Biomarkers for Systemic Necrotizing Vasculitides

Systemic necrotising vasculitides (SNVs) pose significant challenges due to their diverse clinical manifestations and variable outcomes. Therefore, identifying reliable biomarkers holds promise for improving precision medicine in SNVs. This review explores emerging biomarkers aiming to enhance diagnostic accuracy, prognostic assessment, and disease monitoring. We discuss recent advances in immunological biomarkers, inflammatory indicators, and other parameters that exhibit potential diagnostic and prognostic utility. A comprehensive understanding of these biomarkers may facilitate earlier and more accurate SNV detection, aiding in timely intervention and personalized treatment strategies. Furthermore, we highlight the evolving landscape of disease monitoring through innovative biomarkers, shedding light on their dynamic roles in reflecting disease activity and treatment response. Integrating these novel biomarkers into clinical practice can revolutionize the management of SNVs, ultimately improving patient outcomes and quality of life.

Effect of antinuclear antibody positivity on antineutrophil cytoplasmic antibody results by indirect immunofluorescence assay

BACKGROUND

The indirect immunofluorescence assay (IIFA) utilizing antineutrophil cytoplasmic antibodies (ANCA) is widely used as a diagnostic test for autoimmune vasculitis. The presence of antinuclear antibodies (ANA) might lead to a misleading interpretation of ANCA. This study aims to explore the impact of the presence of ANA on the interpretation of ANCA.

METHODS

This retrospective research examined samples negative for antiMPO and antiPR3 ANCA by IIFA and explored correlations between the ANA-IIFA results and the ANCA interpretation frequencies. Our analysis involved the use of suitable statistical methods, including Chi-square and kappa statistics.

RESULTS

Up to 75.2% of the ANCA-IIFA-positive samples exhibited a positive p-ANCA pattern when using the ethanol-fixed substrate, with c-ANCA positivity at 24.8%. In the ANA-IIFA-positive samples, ~77.3% displayed p-ANCA patterns on ethanol-fixed substrates. A comparison between the ANA-IIFA titers and the p-ANCA results revealed that p-ANCA positivity was notably more common in samples with higher titers, and this correlation was found to be statistically significant.

CONCLUSION

Positive ANA results by IIFA tests are linked to a higher incidence of p-ANCA interpretation, particularly in cases with higher titer patterns. This insight aids laboratories in establishing effective workflows to investigate potential p-ANCA interference.

[Management of ANCA-associated vasculitides]

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune-mediated inflammation of small and medium-sized vessels that can affect virtually any organ system and bears the risk of irreversible organ damage. Without treatment the mortality rates are high, which necessitates rapid diagnosis and initiation of treatment. Histological confirmation, which is not feasible in all cases, should be strived for, especially to delineate differential diagnoses and vasculitis mimics. The new American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) classification criteria are primarily designed for study purposes and show limitations in the routine application. Globally, the recently updated EULAR recommendations represent the most up to date management guidelines. Therapeutically, rituximab and cyclophosphamide in combination with glucocorticoids remain the pillars of treatment in remission induction for severe organ-threatening and life-threatening diseases. For the first time, mepolizumab and avacopan represent approved treatment options for specific entities that make a significant contribution to steroid reduction. New attention has been paid to patient-reported outcomes, for which a disease-specific outcome questionnaire is now available.

Antineutrophil Cytoplasmic Autoantibody-negative Pauci-immune Necrotizing Glomerulonephritis with Plasma Cell-rich Tubulointerstitial Nephritis Complicated with Pleuritis and Digital Ischemia

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) predominantly affects small vessels. Almost all AAV patients are positive for myeloperoxidase- or proteinase 3-ANCA, and ANCA plays a crucial role in the pathogenesis of AAV. We herein report an ANCA-negative AAV patient with pauci-immune necrotizing glomerulonephritis and plasma cell-rich tubulointerstitial nephritis who was complicated with pleuritis and digital ischemia. ANCA-negative AAV is a rare clinical entity that is difficult to diagnose, and pleuritis and digital ischemia are rare manifestations of AAV. An early diagnosis and appropriate treatment are important, as any delay in the diagnosis may worsen the prognosis.

Comparison of Clinico-pathologic features and outcomes of ANCA negative and ANCA positive pauci immune crescentic glomerulonephritis: A single centre study

Introduction

Pauci-immune crescentic glomerulonephritis (PICN) is an important cause of rapidly progressive renal failure. 10-40% of PICN cases have ANCA (antineutrophil cytoplasmic antibody) negative serology. The present study compared clinico-pathologic features, Brix's renal risk score, Berden's histopathological classes and differences in outcome between ANCAnegative vs ANCA positive PICN patients.

Materials and Methods

Sixty-one patients of biopsy-proven PICN were studied. Biochemical findings and ANCA serology were recorded. Renal biopsy slides were reviewed along with direct immunofluorescence. Clinical and histological features were compared between ANCA negative and positive PICN using the Man Whitney U test and Chi-square test. Patients were compared for distribution in Berden's histological classes and Brix's renal risk categories. Patient and renal survival were compared using Kaplan-Meier survival analysis.

Results

ANCA negative PICN patients were younger (44.9 ± 16.5 years vs 53.6 ± 15.1 years, P = 0.049). Nasal (0 vs 18%, P = 0.035) and pulmonary involvement (9% vs 38%, P = 0.014) were lower in ANCA negative group. Both ANCA groups had similar renal biochemical profiles, percentage normal glomeruli, 16.3 ± 18.2 vs 21.7 ± 20.4 and percentage glomeruli with crescents, 64.5 ± 28.1 vs 64.3 ± 27.1. Twenty-seven per cent of ANCA negative cases fell in the sclerotic class in Berden's classification vs just 2.5% in ANCA positive group (p = 0.037) without significant difference in Brix's renal risk categories (p = 0.329). Thirteen per cent of ANCA negative patients achieved complete remission on treatment compared to 33% in ANCA positive patients. Patient survival and overall probability of progressing to ESRD were similar in the two groups.

Conclusion

ANCA negative PICN cases present at younger ages. Nasal and pulmonary involvement is uncommon in these patients. Patient survival and progression to ESRD are similar in both ANCA groups.

Systemic vasculitis and headache

PURPOSE OF REVIEW

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system or so called neurovasculitides, lead to pervasive injury and disability making these disorder of paramount importance to clinicians.

RECENT FINDINGS

Headache is an important clue to vasculitic involvement of central nervous system (CNS) vessels. CNS vasculitis may be primary, in which only intracranial vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. A suspicion of vasculitis based on the history, clinical examination, or laboratory studies warrants prompt evaluation and treatment to forestall progression and avert cerebral ischemia or infarction. There has been remarkable progress in the pathogenesis, diagnosis, and treatment of primary adult and pediatric CNS vasculitides predicated on achievements in primary systemic forms.

SUMMARY

Vasculitis can be diagnosed with certainty after intensive evaluation that includes tissue confirmation whenever possible. Clinicians must choose from among the available immune modulating, suppressive, and targeted immunotherapies to induce and maintain remission status and prevent relapse, tempered by the recognition of anticipated medication side effects.

A Rare Case of Anca Positivity and Antiphospholipid Antibodies in a Patient with Takayasu Arteritis: Case Report and Review of the Literature

Takayasu arteritis (TA) is a chronic large-vessel vasculitis characterized by immune-mediated panarteritis, which predominantly affects the aorta and its main branches and is most prevalent in young women. TA is unusually associated with the presence of antiphospholipid antibodies. We present a case report of a 48-year-old Caucasian woman with acute aortic dissection as an initial feature of TA, where detailed clinical, imaging and laboratory studies were performed. Computed tomography angiography (CTA) of the chest and abdomen revealed aortic dissection DeBakey I. Bentall and De Bono surgery was performed. Additional immunological tests revealed positive antineutrophil cytoplasmic antibodies (ANCAs) with the simultaneous presence of pANCA and cANCA antibodies on indirect immunofluorescence, along with anti-MPO+PR3+antibodies positivity in the absence of a clinically relevant disease. Surprisingly, antiphospholipid antibodies (aPLs) were detected. Then, we performed a thorough review of the current literature. The coexistence of aPL antibodies and dual specificity for MPO and PR3 in a patient diagnosed with Takayasu arteritis is unusual and poses a diagnostic challenge. The presented case report outlines a rare case of aortic dissection as a presenting symptom of TA, along with atypical ANCA positivity and positive APL antibodies.

Oral granulomatosis with polyangiitis a systematic review

OBJECTIVE

Granulomatosis with polyangiitis is an unusual multisystemic inflammatory disease, with vasculitis of small- and medium-sized vessels, with a predilection for upper lower airways and kidneys. The etiology remains unknown although it may originate from different stimuli, in genetically susceptible patients.

MATERIALS AND METHODS

A detailed database search was performed. The variables were demographics, localization, histopathological findings, antineutrophil cytoplasmic autoantibody, cytoplasmic (c-ANCA) tests, treatment, and follow-up.

RESULTS

Fifty-two cases were identified; the mean age was 49.6 years, with a range from 6 to 87 years. It was most frequently seen in females (57.7%). The most common race was white (59.6%). The most frequent location was in the maxillary gingiva (28.8%), followed by both the upper and lower gingiva (19.2%). The most common clinical presentation was "strawberry gingivitis" (61.5%). The main symptom was pain, in 50%. Regarding the c-ANCA test, it was positive in 71.2% of cases. The most common therapy was prednisone and cyclophosphamide, utilized in 51.9%. The average follow-up was 23.6 months, and 88.5% of patients were still alive at follow-up.

CONCLUSION

The diagnosis initially was difficult to establish, an early diagnosis and treatment are mandatory. If untreated the disease can be associated with morbidity and mortality. For the oral clinician, this disease needs to be addressed in the differential diagnosis of oral lesions.

A Smartphone-Based Low-Cost Inverted Laser Fluorescence Microscope for Disease Diagnosis

Fluorescence microscopy is an important tool for disease diagnosis, often requiring costly optical components, such as fluorescence filter cubes and high-power light sources. Due to its high cost, conventional fluorescence microscopy cannot be fully exploited in low-income settings. Smartphone-based fluorescence microscopy becomes an interesting low-cost alternative, but raises challenges in the optical system. We present the development of a low-cost inverted laser fluorescence microscope that uses a smartphone to visualize the fluorescence image of biological samples. Our fluorescence microscope uses a laser-based simplified optical filter system that provides analog optical filtering capabilities of a fluorescence filter cube. Firstly, we validated our inverted optical filtering by visualizing microbeads labeled with three different fluorescent compounds or fluorophores commonly used for disease diagnosis. Secondly, we validated the disease diagnosis capabilities by comparing the results of our device with those of a commercial fluorescence microscope. We successfully detected and visualized Trypanosoma cruzi parasites, responsible for the Chagas infectious disease and the presence of Antineutrophil cytoplasmic antibodies of the ANCA non-communicable autoimmune disease. The samples were labeled with the fluorescein isothiocyanate (FITC) fluorophore, one of the most commonly used fluorophores for disease diagnosis. Our device provides a 400× magnification and is at least one order of magnitude cheaper than conventional commercial fluorescence microscopes.

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.

Genetics of ANCA-associated vasculitis: role in pathogenesis, classification and management

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) comprises granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA), that share features of pauci-immune small-vessel vasculitis and the positivity of ANCA targeting proteinase-3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA). AAV syndromes are rare, complex diseases and their aetio-pathogenesis is mainly driven by the interaction between environmental and genetic factors. In patients with GPA and MPA, the genetic associations are stronger with ANCA specificity (PR3- versus MPO-ANCA) than with the clinical diagnosis, which, in keeping with the known clinical and prognostic differences between PR3-ANCA-positive and MPO-ANCA-positive patients, supports an ANCA-based re-classification of these disorders. EGPA is also made up of genetically distinct subsets, which can be stratified on ANCA-status (MPO ANCA-positive versus ANCA-negative); these subsets differ in clinical phenotype and possibly in their response to treatment. Interestingly, MPO-ANCA-positive patients with either MPA or EGPA have overlapping genetic determinants, thus strengthening the concept that this EGPA subset is closely related to the other AAV syndromes. The genetics of AAV provides us with essential information to understand its varied phenotype. This Review discusses the main findings of genetic association studies in AAV, their pathogenic implications and their potential effect on classification, management and prognosis.

Environmental factors influencing the risk of ANCA-associated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of diseases characterized by inflammation and destruction of small and medium-sized blood vessels. Clinical disease phenotypes include microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA). The incidence of AAV has been on the rise in recent years with advances in ANCA testing. The etiology and pathogenesis of AAV are multifactorial and influenced by both genetic and environmental factors, as well as innate and adaptive immune system responses. Multiple case reports have shown that sustained exposure to silica in an occupational environment resulted in a significantly increased risk of ANCA positivity. A meta-analysis involving six case-control studies showed that silica exposure was positively associated with AAV incidence. Additionally, exposure to air pollutants, such as carbon monoxide (CO), is a risk factor for AAV. AAV has seasonal trends. Studies have shown that various environmental factors stimulate the body to activate neutrophils and expose their own antigens, resulting in the release of proteases and neutrophil extracellular traps, which damage vascular endothelial cells. Additionally, the activation of complement replacement pathways may exacerbate vascular inflammation. However, the role of environmental factors in the etiology of AAV remains unclear and has received little attention. In this review, we summarized the recent literature on the study of environmental factors, such as seasons, air pollution, latitude, silica, and microbial infection, in AAV with the aim of exploring the relationship between environmental factors and AAV and possible mechanisms of action to provide a scientific basis for the prevention and treatment of AAV.

ANCA Associated Vasculitis (AAV): A Review for Internists

Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) compromise a rare group of necrotizing small to medium vessel vasculitides that constitute three distinct disorders: granulomatosis with polyangiitis (GPA) (formerly known as Wegener's granulomatosis), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA) (formerly known as Churg-Strauss syndrome).AAV is characterized by the usual presence of circulating autoantibodies to the neutrophil proteins leukocyte proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA). These antibodies can activate neutrophils and the complement system resulting in vessel wall inflammation and damage.The clinical presentation of AAV varies from non-severe (non-life threatening) to severe often with potentially life-threatening multi-organ involvement. Early recognition and diagnosis are crucial. In the past two decades, advances in understanding the pathophysiology of AAV have led to development of new treatments and resulted in significant improvement in general outcomes and survival rates.This narrative review will focus on GPA and MPA. We will highlight clinical manifestations, diagnosis, disease monitoring, and treatment strategies in patients with AAV.

Cannonball Pulmonary Opacities Disclosing a Granulomatosis With Polyangiitis (GPA) With C-Antimyeloperoxidase (C-Anti-MPO) Antineutrophil Cytoplasm Antibodies (ANCAs)

Granulomatosis with polyangiitis (GPA) is a necrotizing granulomatous vasculitis of medium- and small-caliber vessels associated with the presence of antineutrophil cytoplasm antibodies (ANCAs) and antibodies specific for proteinase 3 (anti-PR3). The interest of this case lies on the fact that these antibodies are directed against myeloperoxidase revealed by the presence of scattered multiple pulmonary nodules.

We report a 65-year-old-female patient who presented with a productive cough with mucus sputum associated with a cephalea for six months. The chest x-ray showed multiple pulmonary nodules, first suggesting a neoplastic origin. The initial etiological assessment was non-contributory. A month later, the patient developed pulmonary condensations and ocular signs. The etiological assessment then found ANCA anti-myeloperoxidase (anti-MPO)-GPA. A good knowledge of the clinical and radiological signs of GPA is important to quickly guide the diagnosis that will condition the prognosis of this disease.

Performance of MPO-ANCA and PR3-ANCA immunoassays for the stratification of specific ANCA-associated vasculitis: A systematic review and meta-analysis

OBJECTIVE

To determine the impact of myeloperoxidase (MPO) and proteinase 3 (PR3) antigen-specific immunoassays in the stratification of patients at-risk for anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) at diagnosis.

METHODS

A Medline search was conducted to identify diagnostic accuracy studies using PR3-ANCA or MPO-ANCA for the evaluation of granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Studies estimates were pooled using the bivariate method.

RESULTS

Diagnostic accuracy varied by analyte and AAV subtype. PR3-ANCA had greater sensitivity than MPO-ANCA for GPA (74% vs 11%, p < 0.001) and MPO-ANCA greater sensitivity for MPA (73% vs 7%, p < 0.001). Specificities of both MPO-ANCA and PR3-ANCA were consistently high (mean 97%, range: 93-99%) for both AAV subtypes. There was insufficient data to perform meta-analysis for the diagnostic accuracy of EPGA.

CONCLUSION

These results validate the use of high quality MPO-ANCA and PR3-ANCA immunoassays to screen patients at-risk for AAV as well as to categorize disease as GPA or MPA subtype. However, caution must be exercised in doing so, since some assays may not have optimal performance. Each laboratory should validate appropriate algorithms based on the tests used and testing population.

ANCA Associated Vasculitis Subtypes: Recent Insights and Future Perspectives

The ANCA associated vasculitides (AAVs) affect a range of internal organs including ear nose and throat, respiratory tract, kidneys, skin and nervous system. They include granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA) and microscopic polyangiitis (MPA). The AAVs are treated with high dose glucocorticoids, immunosuppressants, and targeted biological medications. Since the 1990s classification criteria for the AAVs have been based on clinical features, laboratory tests and basic imaging; an initiative to update the classification criteria incorporating newer tests, for example, anti-neutrophil cytoplasmic antibodies (ANCA) and novel imaging techniques will be published this year. There is also evidence for classification of patients based on ANCA subtype; those with anti-proteinase 3 antibodies (PR3) or anti-myeloperoxidase antibodies (MPO) have differences in response to treatment and clinical outcomes. An update is described within this review. The pathogenesis of AAV involves necrotizing inflammation of small to medium blood vessels involving multiple immunological pathways. We present an update on emerging evidence related to auto-antibodies, complement and lymphocyte pathways. This review describes emerging treatment regimens, including evidence for plasma exchange in severe disease and the inhibitor of the complement C5a receptor (C5aR) inhibitor, Avacopan. Lastly, patient reported outcomes are key secondary outcomes in randomised controlled trials and increasingly clinical practice, we report development in disease specific and glucocorticoid-specific PROs.

A meta-analysis of the safety and efficacy of maintenance therapies for anti-neutrophil cytoplasmic antibody small-vessel vasculitis

Introduction

To compare the efficacy and safety of different regimens used for maintenance of remission in patients with antineutrophil cytoplasmic antibody (ANCA) vasculitis.

Methods

This network meta-analysis studied adult patients with ANCA vasculitis in complete remission, who were maintained with various regimens, excluding patients with eosinophilic granulomatosis with polyangiitis (GPA) and those who have ended up in end-stage kidney disease. Outcomes of interest included relapse (any/major), relapse-free survival, and adverse effects. PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and Google Scholar were systematically searched from inception.

Results

Overall, the meta-analysis was based on 10 reports, describing the outcomes of 7 randomized controlled trials (RCTs) including 752 patients with ANCA vasculitis. Relapse-free survival was significantly worse with the use of azathioprine (hazard ratio [HR]: 2.11, 95% CI: 1.19–3.74), methotrexate (HR: 2.51, 95% CI: 1.24–5.08), and mycophenolate mofetil (HR: 3.57, 95% CI: 1.70–7.46) compared with the use of rituximab. Outcomes estimated for azathioprine (HR: 0.59, 95% CI: 0.37–0.94), cyclophosphamide (HR: 0.39, 95% CI: 0.20–0.75), and leflunomide (HR: 0.30, 95% CI: 0.11–0.84) were better than those for mycophenolate mofetil. When examining relapse-free survival, relapses were more likely with use of azathioprine (odds ratio [OR]: 2.15, 95% CI: 1.00–4.59) and mycophenolate mofetil (OR: 4.42, 95% CI: 1.63–11.94) compared with the use of rituximab. The risk of major relapse calculated for azathioprine (OR: 2.39, 95% CI: 1.10–5.19), methotrexate (OR: 3.18, 95% CI: 1.14–8.89), and mycophenolate mofetil (OR: 5.20, 95% CI: 1.65–16.37) was higher than that for rituximab. The rates of serious adverse effects did not differ significantly among interventions.

Conclusion

Rituximab appears predominant in maintaining remission in patients with ANCA vasculitis with no cost in adverse events.

Prevalence of ANCA-associated vasculitis amid natural gas drilling sites in West Virginia

BACKGROUND

The epidemiology of ANCA-associated vasculitis (AAV) varies by ethnicity and region. Environmental exposure has been implicated in the pathophysiology of MPO-AAV. The aim of this study was to evaluate the epidemiology of AAV and explore a potential relationship with environmental factors in north central West Virginia.

METHODS

This is a retrospective cohort study of 212 patients diagnosed with AAV at West Virginia University and its affiliated hospitals from January 1, 1990 to December 31, 2019. We assessed prevalence of AAV over time according to patient's zip codes and counties. Silica exposure through natural gas extraction was considered as a possible environmental factor.

RESULTS

The proportion of patients with MPO-ANCA increased after 2010 (37.5% before 2010 vs 61% after 2010, p = 0.008). At the same time, the prevalence of AAV in Monongalia and surrounding counties has increased significantly after 2010 from 64.8 to 141.9 cases per million (p = 0.001). The increase in prevalence of AAV was primarily due to an increase in MPO-AAV (43 vs 101.7 cases per million before and after 2010, respectively, p = 0.028). During this time, the production of natural gas through fracking increased, rising more than tenfold after 2010 (p-value < 0.001). Heat mapping reveals that the increase in cases of AAV occurred in areas of increased fracking activity.

CONCLUSIONS

There was an increase in the prevalence of patients who were newly diagnosed with AAV over time in north central West Virginia. Further studies are required to ascertain the potential role of environmental exposure in the pathophysiology of AAV.

Laboratory Diagnosis of ANCA-Associated Vasculitis (AAV) Using a Combination of Immunofluorescence Test (IIFT) and Line Immunoassay (LIA): Single-Centre Report From India

INTRODUCTION

Anti-neutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) is a small vessel vasculitis with insufficient epidemiological estimates in India. We aimed to determine demographic, clinical features, and laboratory diagnosis of AAV patients presenting to a large tertiary care centre in India.

MATERIAL AND METHODS

1289 patient samples were screened for ANCA by indirect immunofluorescence test (IIFT) and confirmation of ANCA target antigens was done by line immunoassay. Association between IIFT and LIA was determined in AAV.

RESULTS

By IIFT, ANCA was detected in 13.0% (168 out of 1289), of which 23.8% (40/168) were positive with P-ANCA pattern, 25.0% (42/168) were positive with C-ANCA and 47.6% (80/168) showed an atypical pattern. On evaluation with a line immunoassay, 6.7% (86/1289) were positive out of which 52.3% (45/86), 41.9% (36/86), 8.8% (6/86) were positive for anti-MPO, anti-PR3, and anti-GBM respectively. In eosinophilic granulomatosis with polyangiitis (EGPA) 87.5% (7/8), and microscopic polyangiitis (MPA/RLV) 91.3% (21/23), anti-MPO was the predominantly observed antibody. In granulomatosis with polyangiitis (GPA) anti-PR3 antibody was predominant in 87.5% (28/32) cases. Out of 168 IIF positive samples 8, 32, and 23 cases of EGPA, GPA, and MPA/RLV were observed respectively.

CONCLUSIONS

The primary aim of the study was to provide single-centre data to determine the laboratory diagnosis of AAV. A combination of IIFT and LIA was found to be an optimum testing strategy for the laboratory diagnosis of AAV.

Novel pediatric granulomatosis with polyangiitis with a marked bloody pericardial effusion and bloody stool: a case report

Background

Granulomatosis with polyangiitis (GPA) is a syndrome of refractory vasculitis involving the upper respiratory tract, lungs, kidneys, and systemic small and medium-sized arteries that affects all age groups. No pediatric case with a bloody pericardial effusion resulting in cardiac tamponade and co-existing hematochezia has been reported.

Case presentation

A 14-year-old boy was referred for evaluation of prolonged fever, chest pain, and intermittent hematochezia. Diagnostic imaging showed a prominent pericardial effusion. Immediately after admission, his systolic blood pressure decreased. Emergent pericardiocentesis resulted in aspiration of a massive amount of bloody pericardial fluid. This was diagnosed as cardiac tamponade because his blood pressure recovered immediately after the drainage. The patient had an elevated serine proteinase 3-anti-neutrophil cytoplasmic antibody (PR3-ANCA) level on serological examination. Head MRI showed thickening of nasal and sinusoidal mucosa and a cystic mass in the left sphenoid sinus. After ruling out malignancy based on the cytology of the effusion, chest MRI, and gallium scintigraphy, total colonoscopy showed multiple irregular-shaped aphthae from the right transverse colon to the cecum on the contralateral side of the mesenteric attachments. Biopsy specimens of aphthous lesions confirmed necrotizing granulomatous inflammation. A diagnosis of GPA was made based on these findings, and oral prednisolone (PSL) and azathioprine were started. The hematochezia disappeared rapidly, and no recurrence of pericardial effusion was seen after PSL tapering was completed. The PR3-ANCA level decreased into the normal range immediately after the initial therapy.

Conclusions

Pericarditis is a common cardiac complication of GPA, but there have been no reports of resultant cardiac tamponade. This is the first case of pediatric GPA with cardiac and gastrointestinal complications preceding the common symptoms such as respiratory or renal symptoms. A case of pediatric GPA with hematochezia is also extremely rare. In conclusion, serial measurement of ANCA levels is important in patients with persistent fever and bloody stool, such as in inflammatory bowel disease, to make the diagnosis of a vasculitic syndrome.

Hypocomplementemia at Diagnosis of Pauci-immune Glomerulonephritis Is Associated With Advanced Histopathological Activity Index and High Probability of Treatment Resistance

Introduction

Recent evidence suggests that complement activation is important in the pathogenesis of pauci-immune (PI) vasculitis. This is a retrospective investigation of the frequency of hypocomplementemia at pauci-immune glomerulonephritis (PIGN) diagnosis, in relation to vasculitic manifestations, renal histopathology, and treatment outcomes.

Methods

A total of 115 patients with biopsy-proven PIGN were categorized based on their serum complement C3 (sC3). Histopathology evaluation included activity and chronicity indexes. The primary outcome of interest was treatment resistance, defined as a progressive decline in kidney function, with persistently active urine sediment, leading to dialysis dependency or vasculitis-related death.

Results

In all, 20.9% of patients had low sC3 levels associated with more advanced renal impairment (P < 0.01), requiring acute dialysis (P < 0.01) more frequently compared to patients with normal sC3. Within 1 year, 85.7% of patients with normal sC3 responded to therapy, versus 58.3% of those with low sC3 (P = 0.001). The probability of treatment resistance was strongly associated with low sC3 (P = 0.004), high serum creatinine (P < 0.001), acute dialysis requirement (P < 0.001), and high histopathological score of chronicity (P < 0.01). Advanced histopathological activity was related to more intense interstitial leukocyte infiltration (P = 0.005) and higher likelihood of fibrinoid necrosis documentation in a vessel wall (P = 0.02). The probability of treatment resistance was higher in patients with low sC3 (odds ratio [OR] = 6.47, 95% confidence interval [CI] 1.47-28.35, P = 0.013), oliguria (OR = 29.57, 95% CI = 4.74-184, P < 0.0001), and high chronicity score (OR = 1.77, 95% CI = 1.23-2.54, P = 0.002).

Conclusion

Low sC3 is emerging as an independent predictor of treatment resistance in patients with PIGN associated with higher index of histopathological activity at diagnosis compared to normal sC3.

Assessment of the correlation of commonly used laboratory tests with clinical activity, renal involvement and treatment of systemic small-vessel vasculitis with the presence of ANCA antibodies

Background

The aim of the study was to assess the correlation of commonly used laboratory tests with clinical activity, degree of kidney involvement and treatment of systemic small-vessel vasculitis with the presence of ANCA antibodies.

Methods

The study included 28 patients with active AAV (BVAS ≥ 3). The following tests were performed: MPO-ANCA, PR3-ANCA, peripheral blood count, ESR, CRP, procalcitonin, creatinine, GFR, urea, albumin, fibrinogen, d-dimer, components of the C3 and C4 complement systems, urinalysis with sediment evaluation and diurnal proteinuria. The assessments were conducted twice: at study entry (A0) and after 6 months (A6) (BVAS = 0).

Results

At the time of inclusion in the study, the mean creatinine concentration was 3.39 mg/dl (GFR 33.17 ml/min/1.73 m²), after achieving remission in 11 patients (39.3 %) GFR remained below 30 ml/min/1.73 m², 4 patients (14.3 %) continued renal replacement therapy, and 3 patients (10.7 %) with advanced renal failure died. Microscopic hematuria occurred in 80.9 % of the studied population, withdrew in most patients, strongly correlated with renal involvement p < 0.001 and was not related to disease severity p = 0.147. CRP, ESR, fibrinogen, d-dimer, albumin and hemoglobin in the peripheral blood showed a strong correlation with the clinical activity of AAV and well identified severe patients. High procalcitonin concentrations correlated with a severe form of the disease, pulmonary involvement with respiratory failure and alveolar hemorrhage (mean 3.41 ng/ml, median 0.91 ng/ml, SD 7.62, p = 0.000), and were associated with the occurrence of infectious complications and the need to administer antibiotic therapy. ANCA antibodies were useful in the evaluation of patients with AAV, the amount of antibodies did not correlate with the severity of vasculitis (p = 0.685) and the results in many patients did not match the expected assumptions.

Conclusions

CRP, ESR, fibrinogen, d-dimers, albumin and hemoglobin in the peripheral blood correlate well with the activity of vasculitis and identify severe patients. The resolution of microscopic hematuria suggests remission of the disease in the renal area. Procalcitonin may be slightly increased in patients with active AAV without infection, high concentrations are strongly associated with infectious complications. ANCA antibodies should always be interpreted in the context of the observed clinical symptoms.

Anti-Neutrophil Cytoplasmic Antibodies: To Care or Not to Care

Anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis is a disease process with a wide range of presentations, from asymptomatic or minimally symptomatic disease with positive laboratory testing, to florid acute end-organ damage. Consensus has not been established as to the frequency and/or protocol by which ANCA testing should be repeated. We present the case of a 53-year-old woman who initially came to medical attention with persistent dyspnea and pulmonary infiltrates presumed to be due to acute exacerbation of chronic diastolic congestive heart failure. Extensive infectious disease testing was negative, but ANCA testing was positive. However, because antinuclear antibody (ANA) interference in the original sample rendered the test result difficult to interpret, the test was not repeated. The patient presented eight months after the initial hospitalization with acute hypoxemic respiratory failure requiring intubation, with an ANCA titer of 1:1280 with a negative ANA titer, and renal biopsy-proven severe crescentic glomerulonephritis. In the discussion of our case, we review the importance of interpreting ANCA testing in the correct clinical context. The ANCA laboratory testing requires cautious interpretation, and diagnosed ANCA-associated vasculitis (AAV) requires vigilance for prompt and proactive treatment.

Indications and diagnostic outcome of antineutrophil cytoplasmic antibody testing in hospital medicine: a pattern of over-screening

INTRODUCTION/OBJECTIVE

Antineutrophil cytoplasmic antibodies (ANCA) serology can aid in the diagnosis and classification of ANCA-associated vasculitides (AAV). However, it is often ordered in patients without clinical manifestations of vasculitis. In this retrospective chart review, we aim to better understand the clinical practices on ANCA testing.

METHODS

We retrospectively reviewed patients' charts for the indications and diagnostic outcomes of ANCA tests. All ANCA tests ordered at two Canadian hospitals (a community hospital and an academic tertiary hospital) between January and December 2016 were included in the study. Descriptive statistics are used.

RESULTS

A total of 302 ANCA tests were included. The majority (n = 198, 65.6%) were ordered without an indication for testing. For those patients with at least 1 clinical manifestation of AAV (n = 104), 25% were ANCA positive and 18.3% resulted in a diagnosis of AAV. In comparison, among those without a clinical manifestation of AAV (n = 198), only 1.5% were ANCA positive and none was diagnosed with AAV. All patients diagnosed with AAV had at least 1 indication for ANCA testing. The three most common clinical presentations in patients with a final diagnosis of AAV were glomerulonephritis (81.8%), pulmonary hemorrhage (45.5%), and multiple lung nodules (31.8%).

CONCLUSION

To our knowledge, this is the first study that evaluates patients with both positive and negative ANCA test results in an inpatient setting. We demonstrated a low rate of ANCA positivity and AAV diagnosis in patients without clinical manifestations of AAV. Overall, there is a high rate of ANCA testing without an indication at our academic institution. This over-testing may be curbed by strategies such as a gating policy, culture changes, and clinician education. Key Points • AAV is a clinical-pathological diagnosis, and despite the usefulness of ANCA testing, it does not confirm nor rule out AAV. • ANCA testing for the diagnosis of AAV is generally only indicated when there is a clear manifestation of AAV. • Although patients with AAV may occasionally present without classic signs and symptoms, the diagnostic utility of ANCA serology in this setting is low, and testing is more likely to result in a false-positive or false-negative test. • If clinical suspicion remains high despite negative ANCA testing, clinicians should seek consultation with a rheumatologist.

Utility of anti-neutrophil cytoplasmic antibody screening in idiopathic interstitial lung disease

Background:

Interstitial lung disease (ILD) is an established manifestation of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Autoimmune serologic screening is recommended by international consensus guidelines during the evaluation of idiopathic ILD, but ANCA testing only on a case-by-case basis.

Objective:

We aimed to evaluate the role of ANCA screening in patients with idiopathic ILD.

Methods:

We performed a retrospective review of patients seen between September 2015 and April 2017 in the ILD clinic at Toronto General Hospital. Patients referred with confirmed or suspected connective tissue disease were excluded. Patient demographics, symptoms, chest imaging, and pulmonary function testing was collected. We performed descriptive statistics based on the presence of ANCAs and estimated operating characteristics for ANCA screening.

Results:

In total, 360 patients with idiopathic ILD were reviewed, 159 met study inclusion criteria and 4 (2.5%) tested positive for ANCAs. Two patients (1.2%) had elevated myeloperoxidase-ANCAs (MPO-ANCA) and 2 (1.2%) had elevated proteinase-3-ANCAs (PR3-ANCA). There were no significant associations between patient demographics and ANCAs. One patient (0.6%) with PR3-ANCAs was diagnosed with vasculitis following rheumatologic evaluation. Despite negative ANCA testing, 1 patient (0.6%) was diagnosed with vasculitis following rheumatologic evaluation. The sensitivity and specificity of ANCA screening for vasculitis in patients with ILD was calculated as 50% (95% CI, 1.3%-98.7%) and 98% (95%CI, 4.4-155.5) respectively. Negative and positive likelihood ratios were 0.5 (95%CI 0.1-2.0) and 26.2 (95%CI 4.4-155.5) respectively.

Conclusion:

ANCA screening in patients with idiopathic ILD rarely yields positive results. These results support an individualized approach to ANCA testing as opposed to widespread screening.

Case report of osteolytic lesions in a patient with multisystem granulomatous disease

We present a case of a 70-year-old Caucasian woman with multisystem granulomatous disease involving her lungs, bones and lymph nodes. The patient initially presented with cervical lymphadenopathy and subsequently developed progressive breathlessness. Imaging revealed extensive mediastinal, hilar and intra-abdominal lymphadenopathy as well as bilateral pulmonary parenchymal infiltrates. Lymph node and lung biopsy confirmed non-necrotising granulomatous inflammation while a BAL showed scanty growth of Cryptococcus neoformans and moderate growth of Staphylococcus aureus The patient received intravenous ceftriaxone and had a good response to treatment. She also completed 3 months of oral fluconazole. Although a diagnosis of sarcoidosis was considered most likely, the patient was not initially started on systemic corticosteroids due to concern around possible infection and initial response to antimicrobials. However, her exercise tolerance gradually deteriorated. A craniofacial CT revealed multiple lytic lesions involving the skull and visualised cervical spine. Biopsy of a clivus lesion revealed non-necrotising granulomatous inflammation while fungal cultures and histopathological stains were negative. The patient was diagnosed with widespread sarcoidosis and she was initiated on prednisolone and methotrexate which led to marked clinical and radiological improvement.

Granulomatosis with polyangiitis presenting as pancreatic disease

Granulomatosis with polyangiitis (GPA) is a rare necrotising small vessel vasculitis typically associated with oronasal, pulmonary and renal manifestations. Pancreatic disease is an exceedingly rare initial presentation and is associated with delayed diagnosis and rapid progression. We discuss a 66-year-old woman presenting with epigastric pain, elevated lipase and radiographic evidence of focal pancreatitis. She had no relevant medical history and no lithiasis seen on imaging. Pertinent findings include strawberry gingivitis, positive proteinase-antineutrophil cytoplasm antibody (98% specificity) and focal nodular parenchymal lung lesions on CT chest-all of which are consistent with a diagnosis of GPA. She was promptly started on high-dose steroids which resulted in significant clinical and biochemical improvement. Cyclophosphamide was added once biopsy confirmed the absence of malignancy. In order to optimise the clinical outcomes of GPA, physicians must keep a wide differential and high index of suspicion in the setting of unexplained pancreatitis with systemic features.

Clinical implications of ANCA positivity in a hospital setting: a tertiary center experience

ANCA testing plays an established critical role in the diagnosis of ANCA Associated vasculitis (AAV). The spectrum of diseases associated with positive ANCA has recently broadened, thus calling into question the diagnostic implications of ANCA positivity in a hospital setting. We retrospectively studied all adult patients who had a positive ANCA test (by Indirect Immunofluorescence (IIF), ELISA or both) performed over the span of 19 years. Subjects were then divided into discordant (positive on one assay) and concordant ANCA (positive on both assays) groups based on their ANCA positivity status. The two groups were then compared with regards to their demographic, clinical and laboratory characteristics, the indication for ANCA testing in both groups and their final diagnoses. Of the 9189 ANCA tests ordered during the 19-year span of the study, 389 (4.2%) were positive. Two hundred and forty subjects met the exclusion criteria (patients aged less than 18 years or the lack of clinical and laboratory data in the medical file) thus resulting in a final cohort of 149 subjects. Of them, 122 subjects had discrepant ANCA results and 27 had matching ANCA results. Most cases in the discrepancy group were IIF positive and ELISA negative (86.8%). The diagnosis of AAV was highly unlikely in cases with discrepant IIF and ELISA serologies compared to cases with matching IIF and ELISA serologies (4.1% versus 44.4%, p value < 0.001). The diagnosis of AAV in unlikely in subjects with discrepancies between IIF and ELISA, particularly with only positive IIF.

Antibody subtypes and titers predict clinical outcomes in ANCA-associated vasculitis

The objective of this study is to evaluate the association between antineutrophil cytoplasmic autoantibody (ANCA) subtype and ANCA titers on clinical outcomes and disease activity among a cohort of patients from Central Appalachia diagnosed with ANCA-associated vasculitis (AAV) over a 3-decade period. This is a retrospective chart review of all patients diagnosed with AAV. ANCA subtypes (myeloperoxidase (MPO) and proteinase 3 (PR3)) and titers at the time of diagnosis and at the time of relapse or last follow-up were evaluated along with patient outcomes. Outcomes of interest included relapse, development of end-stage renal disease (ESRD) and mortality. Sensitivity analysis and multivariable analysis were performed. Of the 202 patients, 111 patients were MPO-ANCA positive and 91 patients were PR3-ANCA positive. Relapse was more frequent among patients with PR3-ANCA compared to MPO-ANCA (35% vs 12%, p < 0.001). In both ANCA subgroups, the strongest predictor of relapse was an increase in titers prior to relapse, HR 8.1 (95% CI 1.6-40), p 0.009. Patients who achieved serological remission had a lower risk of ESRD [sub-HR 0.31 (95% CI 0.11-0.89)] and mortality [HR (95% CI) 0.24 (0.07-0.7)]. PR3-ANCA was associated with higher risk of ESRD [sub-HR 3.1 (95% CI 1.1-8.5)]. There was no difference in mortality between patients with MPO-ANCA and PR3-ANCA. Our study supports the use of both ANCA subtypes and titer levels for predicting clinical outcomes in patients receiving treatment for AAV. Monitoring of ANCA antibody titers may be useful since both serological remission and increase in titers provide prognostic information.

Radiologic Approach for Pulmonary Vasculitis

혈관염은 혈관벽의 염증을 특징으로 하는 드문 전신 질환으로 간혹 미만성 폐출혈이나 급성 사구체신염으로 생명을 위협하기도 한다. 원인을 알 수 없는 일차성 혈관염도 있지만 자가면역 질환이나 약물, 감염, 종양 등 수많은 원인들에 의해 발생하는 이차성 혈관염도 있으며 분류가 복잡하고 명확한 진단검사가 없어 진단에 어려움이 있다. 또한 다양하고 비특이적인 증상과 징후 및 검사 소견을 보여 혈관염의 진단에는 임상양상, 영상 검사, 자가항체 검사, 병리 소견 등 여러 가지 결과를 종합하는 것이 필수적이다. 이 종설에서는 혈관염의 분류와 진단에 중요한 증상 및 징후, 특징적으로 폐를 침범하는 대표적인 폐혈관염의 영상 소견과 감별 진단, 그리고 새로운 혈관염 분류를 위한 국제적 연구인 Diagnostic and Classification Criteria in Vasculitis에 대해 소개하고자 한다.

Highly Sensitive Flow Cytometric Detection of Residual B-Cells After Rituximab in Anti-Neutrophil Cytoplasmic Antibodies-Associated Vasculitis Patients

Background

B-cell depletion with rituximab (RTX) is an effective treatment for anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) patients. Nevertheless, relapses are frequent after RTX, often preceded by B-cell repopulation suggesting that residual autoreactive B-cells persist despite therapy. Therefore, this study aimed to identify minimal residual autoimmunity (MRA) in the B-cell compartment of AAV patients treated with RTX.

Methods

EuroFlow-based highly-sensitive flow cytometry (HSFC) was employed to study B-cell and plasma cell (PC) subsets in-depth in AAV patients before and after RTX treatment. Additionally, peripheral blood mononuclear cells (PBMCs) of these RTX-treated AAV patients were cultured and in vitro stimulated with CpG, IL-2, and IL-21 to induce antibody-secreting cells (ASC). (ANCA)-IgG was measured in these supernatants by ELISA.

Results

By employing EuroFlow-based HSFC, we detected circulating CD19⁺ B-cells at all timepoints after RTX treatment, in contrast to conventional low-sensitive flow cytometry. Pre-germinal center (Pre-GC) B-cells, memory B-cells and CD20⁺CD138⁻ plasmablasts (PBs) were rapidly and strongly reduced, while CD20⁻CD138⁻ PrePC and CD20^-CD138⁺ mature (m)PCs were reduced slower and remained detectable. Both memory B-cells and CD20⁻ PCs remained detectable after RTX. Serum ANCA-IgG decreased significantly upon RTX. Changes in ANCA levels strongly correlated with changes in naive, switched CD27⁺ and CD27⁻ (double-negative) memory B-cells, but not with plasma cells. Lastly, we demonstrated in vitro ANCA production by AAV PBMCs, 24 and 48 weeks after RTX treatment reflecting MRA in the memory compartment of AAV patients.

Conclusion

We demonstrated that RTX induced strong reductions in circulating B-cells, but never resulted in complete B-cell depletion. Despite strongly reduced B-cell numbers after RTX, ANCA-specific memory B-cells were still detectable in AAV patients. Thus, MRA is identifiable in AAV and can provide a potential novel approach in personalizing RTX treatment in AAV patients.

The value of anti-neutrophil cytoplasmic antibodies (ANCA) testing for the diagnosis of ANCA-associated vasculitis, a systematic review and meta-analysis

The testing of anti-neutrophil cytoplasmic antibodies (ANCA) takes an important place in the diagnostic workup to ANCA-associated vasculitis (AAV). Nowadays, it is recommended to screen for the presence of PR3 and MPO specific antibodies first using immunoassay, without the need for ANCA measurement by indirect immunofluorescence (IIF). A literature search was performed to assess the diagnostic test value of ANCA IIF and PR3- and MPO-antibody immunoassay to diagnose AAV. This meta-analysis shows that the c-ANCA testing by IIF has a pooled sensitivity of 75.2% and a pooled specificity of 98.4%. For PR3-antibody immunoassay, the pooled sensitivity depended on the immunoassay method used, and ranged from 79.8% to 86.6%, whereas the pooled specificity ranged from 96.8% to 98.3%. For both p-ANCA IIF and MPO-antibody immunoassay (all methods) sensitivity varied considerably showing pooled values of respectively 46.3% and 58.1%, whereas respective pooled specificity was 91.4% and 95.6%. These findings support the 2017 international consensus that primary anti-PR3 and anti-MPO screening by immunoassay, based on superior immunoassay sensitivity without the need for IIF ANCA testing, improves the diagnostic workup of AAV.

Granulomatosis (Wegener's granulomatosis) with polyangiitis presented as pulmonary manifestation: a case report

Pulmonary vasculitis can be the manifestation of several systemic illnesses such as primary systemic vasculitis, collagen vascular diseases, and systemic diseases associated with autoantibodies. It may be associated with granulomatous, eosinophilic, lymphoplasmacytic and neutrophilic inflammatory diseases. In this case report, we describe a 22-year-old female presented with intermittent fever, sweating and shivering, haemoptysis, sore throat, shortness of breath, fatigue, loss of appetite, nausea, non-projectile vomiting, dizziness, and dark coloured urine. The diagnosis of granulomatosis with polyangiitis was made utilizing biochemical and radiological tests. Several pharmacological therapies were tried including rituximab. The patient made a good recovery and was discharged home after 12 days of hospitalization. The knowledge of the main radiographic and computed tomography (CT) scan findings, in association with clinical and laboratory data, often enables non-invasive diagnosis of pulmonary vasculitis.

Laboratory Diagnosis of ANCA-Associated Vasculitis (AAV) Using a Combination of Immunofluorescence Test (IIFT) and Line Immunoassay (LIA): Single-Centre Report From India

INTRODUCTION

Anti-neutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) is a small vessel vasculitis with insufficient epidemiological estimates in India. We aimed to determine demographic, clinical features, and laboratory diagnosis of AAV patients presenting to a large tertiary care centre in India.

MATERIAL AND METHODS

1289 patient samples were screened for ANCA by indirect immunofluorescence test (IIFT) and confirmation of ANCA target antigens was done by line immunoassay. Association between IIFT and LIA was determined in AAV.

RESULTS

By IIFT, ANCA was detected in 13.0% (168 out of 1289), of which 23.8% (40/168) were positive with P-ANCA pattern, 25.0% (42/168) were positive with C-ANCA and 47.6% (80/168) showed an atypical pattern. On evaluation with a line immunoassay, 6.7% (86/1289) were positive out of which 52.3% (45/86), 41.9% (36/86), 8.8% (6/86) were positive for anti-MPO, anti-PR3, and anti-GBM respectively. In eosinophilic granulomatosis with polyangiitis (EGPA) 87.5% (7/8), and microscopic polyangiitis (MPA/RLV) 91.3% (21/23), anti-MPO was the predominantly observed antibody. In granulomatosis with polyangiitis (GPA) anti-PR3 antibody was predominant in 87.5% (28/32) cases. Out of 168 IIF positive samples 8, 32, and 23 cases of EGPA, GPA, and MPA/RLV were observed respectively.

CONCLUSIONS

The primary aim of the study was to provide single-centre data to determine the laboratory diagnosis of AAV. A combination of IIFT and LIA was found to be an optimum testing strategy for the laboratory diagnosis of AAV.

A Case of Myeloma Kidney with Perinuclear Anti-Neutrophil Cytoplasmic Antibody and Anti-Myeloperoxidase Positivity: The Importance of Determining the True Cause of Renal Impairment

Acute kidney injury (AKI) is a common presentation which can result from a number of different underlying pathological processes. Haematological malignancies, particularly multiple myeloma (MM), are known to frequently present with AKI. Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare condition which can cause crescentic glomerulonephritis (GN), resulting in AKI. We present the case of a 60-year-old man who presented with clinical features suggestive of AAV in the context of blood tests which demonstrated AKI and positive perinuclear ANCA (p-ANCA) and anti-myeloperoxidase (anti-MPO) titres. Further investigations demonstrated an underlying diagnosis of MM. A renal biopsy was ultimately required to determine the cause of AKI, a cast nephropathy. This case is the first to our knowledge which demonstrates a rare situation in which myeloma kidney is associated with positive p-ANCA and anti-MPO titres, without any evidence of a crescentic GN. It highlights the importance of following up on all investigations sent in the context of AKI, even when a potential diagnosis seems evident. Furthermore, it demonstrates the role of renal biopsy in confirming a diagnosis in the context of AKI with multiple differential diagnoses.

Immunosuppressive and glucocorticoid therapy for the treatment of ANCA-asssociated vasculitis

ANCA-associated vasculitis (AAV) is a systemic, potentially organ and life threatening chronic autoimmune disease. With current management strategies, such as high-dose glucocorticoids in combination with cyclophosphamide or rituximab, outcomes have progressively improved with overall remission rates of 70–90%. However, relapse rates after discontinuation of therapy are consistently high, and treatment-related toxicity, mainly driven by glucocorticoids, still determines morbidity and quality of life. Prevention of relapses while minimizing adverse events is a major goal of long-term treatment, but the optimal duration of maintenance therapy and the role and utility of glucocorticoids in this context remains controversial. This review of induction and maintenance treatment of AAV aims to offer practical advice on immunosuppressive therapies and patient care, addressing individual risk factors and their therapeutic implications. It will discuss benefits and harms of the use of glucocorticoids, particularly focusing on recent advances in steroid sparing concepts.

Distinct HLA and non-HLA associations in different subtypes of ANCA-associated vasculitides in North India

AIM

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is an autoimmune disease characterized by necrotizing small vessel vasculitis that can affect various organs and present multiple symptoms. Susceptibility to AAV is multifactorial and most likely caused by an amalgamation of genetic and environmental factors. The aim of the present study was to explore the distribution of human leukocyte antigen (HLA)-DRB1/DQB1, protein tyrosine phosphatase non-receptor type 22 (PTPN22) and cytotoxic T-Lymphocyte-associated protein 4 (CTLA-4) polymorphisms in North Indian AAV patients and their associations with clinical and pathological characteristics associated with the disease.

METHODS

A total of 150 AAV patients and 150 healthy controls were recruited. The clinical classification showed 128 as granulomatosis with polyangiitis (GPA) and 21 as microscopic polyangiitis. Only 1 case of eosinophilic granulomatosis with polyangiitis was encountered, which was excluded from analysis. HLA-DRB1/DQB1 alleles were determined by polymerase chain reaction-sequence-specific primer (PCR-SSP) method and single nucleotide variant genotyping for CTLA-4 and PTPN22 was done by simple probe-based SNP arrays.

RESULTS

A significant predispositional association of DRB1*03 and DQB1*02 alleles, were confirmed in proteinase 3 (PR3)-AAV patients, whereas DRB1*10, DRB1*14 and DQB1*05 were protective alleles in AAV, PR3-AAV and GPA patients. GG genotype of CTLA-4 + 49A/G was increased in patients as compared to controls and showed an association with AAV, PR3-AAV and GPA patients.

CONCLUSION

The study indicated strong genetic associations were linked with PR3 antineutrophil cytoplasmic antibody specificity and it appears that PR3-AAV and MPO-AAV have distinct genetic backgrounds.

Multiple pulmonary nodules in granulomatous polyangiitis: A case series

Granulomatous polyangiitis (GPA) is a multiple systemic necrotizing vasculitis. Diagnosis of pulmonary nodules in GPA is still challenging in clinical practice, however, other extrapulmonary manifestations, serology, and histopathology may help the diagnosis of GPA. This case series was of limed GPA with one of the largest pulmonary nodules which had a poor treatment response in contrast with previous literature.

Updates in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis for the ENT surgeon

ENT involvement is common in ANCA-associated vasculitis (AAV), particularly in GPA and EGPA. Early recognition and treatment is important for good outcomes, yet evidence suggests that UK ENT surgeons may not consistently recognise the early features of AAV, despite a similar incidence to vestibular schwannoma. AAV is a rapidly advancing field, with significant developments in the understanding of its pathogenesis, classification and treatment over the past decade. Relevant vasculitis mimics are also discussed with a particular focus on the increasing prevalence of vasculitis mimics driven by an increase in recreational cocaine use, as well as the emergence and reclassification of several other vasculitis mimics in the head and neck. This article reviews key recent updates in the vasculitis literature, with a particular focus on those relevant to recognition and diagnosis of AAV for the ENT surgeon. Strengths and limitations of relevant diagnostic testing are discussed, and a method of evaluation of patients with features of AAV presenting to ENT services is outlined.

Rapidly progressive course of pauci-immune pulmonary capillaritis in a 70-year-old Asian male refractory to immunosuppression and plasma exchange

A 70-year-old man presented with acute respiratory failure, alveolar infiltrates and haemoptysis requiring supplemental oxygen. Flexible bronchoscopy with bronchoalveolar lavage identifies diffuse alveolar haemorrhage. Clinical and serological evaluations do not identify a precise aetiology and histopathology establishes the diagnosis of isolated pauci-immune pulmonary capillaritis. The patient received induction therapy with high dose methylprednisolone at 1000 mg/day for 5 days and weekly rituximab at 375 mg/m² scheduled over 4 weeks. Although the patient demonstrated clinical improvement after the first week, he experienced a rapid relapse requiring mechanical ventilation. His induction rituximab regimen was continued and plasma exchange was initiated. Despite these therapies, the patient's condition deteriorated and passed away. Our case adds insight to the management of this rare entity and describes the use of plasma exchange as salvage therapy.

Proteinase-3 and myeloperoxidase serotype in relation to demographic factors and geographic distribution in anti-neutrophil cytoplasmic antibody-associated glomerulonephritis

Background

In anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis, antigen specificity varies between myeloperoxidase (MPO) and proteinase 3 (PR3). This has been reported to vary in relation to age, gender, geography and extrarenal manifestations. However, studies are difficult to compare as criteria for inclusion vary. The aim of this study was to investigate the relationship between ANCA serotype, latitude, ultraviolet (UV) radiation levels, age, gender and renal function at diagnosis in a large study with uniform inclusion criteria.

Methods

Patients with biopsy-proven ANCA-associated glomerulonephritis were identified from regional or nationwide registries in 14 centres in Norway, Sweden, the UK, the Czech Republic, Croatia, Italy and the USA during the period 2000-13. UV radiation levels for 2000-13 in Europe were obtained from the Swedish Meteorological and Hydrological Institute.

Results

A total of 1408 patients (45.2% PR3-ANCA) were included in the study. In univariable analysis, PR3-ANCA was significantly associated with male gender {odds ratio [OR] 2.12 [95% confidence interval (CI) 1.71-2.62]}, younger age [OR per year 0.97 (95% CI 0.96-0.98)] and higher glomerular filtration rate [OR per mL/min 1.01 (95% CI 1.01-1.02); P < 0.001] at diagnosis but not with latitude or UV radiation. In multivariable logistic regression analysis, latitude and UV radiation also became significant, with higher odds for PR3-ANCA positivity at northern latitudes/lower UV radiation levels. However, the latitudinal difference in MPO:PR3 ratio is smaller than differences previously reported concerning microscopic polyangiitis and granulomatosis with polyangiitis.

Conclusions

The ratio between PR3-ANCA and MPO-ANCA varies in glomerulonephritis with respect to age, gender, renal function and geographic latitude/UV radiation levels.

Evaluation of PR3-ANCA Status After Rituximab for ANCA-Associated Vasculitis

INTRODUCTION

The value of antineutrophil cytoplasmic antibody (ANCA) measurements among patients with an established diagnosis of ANCA-associated vasculitis (AAV) to assess disease activity or predict relapse remains controversial, but recent evidence suggests a possible role for rituximab-treated patients.

PATIENTS AND METHODS

All patients with active vasculitis and positive proteinase 3 (PR3)-ANCA who were starting a 2-year treatment course of rituximab for induction of remission at Addenbrooke's Hospital between January 2011 and January 2016 were included in this study. Common department practice consists of 6 g of rituximab given over 2 years, concomitant corticosteroids (0.5-1.0 mg/kg) with rapid taper over 3 months, and cessation of oral maintenance immunosuppressive agents at time of first rituximab dose. Clinical and laboratory data were collected retrospectively using electronic patient records.

RESULTS

Fifty-seven patients with current PR3-ANCA positivity were included in the analysis. Median follow-up was 59 months. PR3-ANCA negativity was achieved in 25 patients (44%) with a median time of 14 months. Clinical remission was achieved in 53 patients (93%) with a median time of 3 months. Among the 53 patients who achieved remission during follow-up, 24 (45%) relapsed with a median time to relapse of 36 months from remission. Both PR3-ANCA-negative status and 50% reduction in PR3-ANCA from baseline (as time-varying covariates) were significantly associated with a longer time to relapse (PR3-ANCA-negative status: hazards ratio, 0.08 [95% confidence interval, 0.01-0.63, p = 0.016]; 50% reduction in PR3-ANCA: hazards ratio, 0.25 [95% confidence interval, 0.18-0.99, p = 0.046]).

CONCLUSIONS

Achieving and maintaining PR3-ANCA negativity after rituximab was associated with longer-lasting remission.

The role of complement in antineutrophil cytoplasmic antibody-associated vasculitis

PURPOSE OF REVIEW

To provide a comprehensive overview of the current insight into the role of complement activation in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). In addition, the therapeutic options targeting the complement system in AAV are discussed.

RECENT FINDINGS

It has become increasingly clear that complement, and more specifically signalling through the C5a receptor, contributes to the immunopathology of AAV. This has led to the design of clinical trials with a C5a receptor blocker. The first results show a reduction in tissue damage and a favourable safety profile, as other parts of the complement defence system are left intact.

SUMMARY

Although AAV was initially regarded as a pauci-immune disease, it is now well established that, in addition to autoantibodies, complement plays an essential role in the disease process. Animal models delivered the first insight, but the effective therapeutic interventions using complement inhibitors provided the proof that indeed complement activation contributes to disease activity and tissue damage in human AAV.