Revisiting the classification of clinical phenotypes of anti-neutrophil cytoplasmic antibody-associated vasculitis: a cluster analysis

Latent class analysis of chest CT abnormalities to define subphenotypes in patients with MPO-ANCA-positive microscopic polyangiitis

BACKGROUND

Patients with microscopic polyangiitis (MPA) and positive myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) may present with various abnormalities in chest computed tomography (CT). This study aimed to identify subphenotypes using latent class analysis (LCA) and to explore the relationship between the subphenotypes and clinical patterns, as well as compare the clinical characteristics of these subphenotypes in patients with MPO-ANCA-positive MPA (MPO-MPA).

METHODS

The study identified subphenotypes using LCA based on chest CT findings in 178 patients with MPO-MPA and pulmonary involvement from June 2014 to August 2022.

RESULTS

LCA identified 27 participants (15.2%) in class 1, 43 (24.1%) in class 2, 35 (19.7%) in class 3, and 73 (41.0%) in class 4. Class 1 was characterized by prominent inflammatory exudation, class 2 by fibrosis and architectural distortion, class 3 by predominantly bronchiectasis, and class 4 by lesions mixed with inflammation and fibrosis. Class 1 had the highest level of extrapulmonary disease activity, with 77.8% of patients experiencing diffuse alveolar hemorrhage. Class 2 had the lowest level of extrapulmonary disease activity, with 41.9% of patients showing usual interstitial pneumonia. Class 3 patients were more likely to have complications involving the ear, nose, and throat, as well as pulmonary infections before treatment, and they exhibited the best outcomes. The characteristics and outcomes of class 4 were intermediate among the four classes.

CONCLUSIONS

These findings suggest that bronchiectasis may represent a unique pattern of pulmonary involvement in MPO-MPA, highlighting the importance of screening for bronchiectasis in MPO-MPA and identifying optimal management strategies.

Systemic vasculitis involving the kidney: the nephropathologist's point of view

Kidneys are often targets of systemic vasculitis (SVs), being affected in many different forms and representing a possible sentinel of an underlying multi-organ condition. Renal biopsy still remains the gold standard for the identification, characterization and classification of these diseases, solving complex differential diagnosis thanks to the combined application of light microscopy (LM), immunofluorescence (IF) and electron microscopy (EM). Due to the progressively increasing complexity of renal vasculitis classification systems (e.g. pauci-immune vs immune complex related forms), a clinico-pathological approach is mandatory and adequate technical and interpretative expertise in nephropathology is required to ensure the best standard of care for our patients. In this complex background, the present review aims at summarising the current knowledge and challenges in the world of renal vasculitis, unveiling the potential role of the introduction of digital pathology in this setting, from the creation of hub-spoke networks to the future application of artificial intelligence (AI) tools to aid in the diagnostic and scoring/classification process.

Identification of distinct subgroups of Sjögren's disease by cluster analysis based on clinical and biological manifestations: data from the cross-sectional Paris-Saclay and the prospective ASSESS cohorts

BACKGROUND

Sjögren's disease is a heterogenous autoimmune disease with a wide range of symptoms-including dryness, fatigue, and pain-in addition to systemic manifestations and an increased risk of lymphoma. We aimed to identify distinct subgroups of the disease, using cluster analysis based on subjective symptoms and clinical and biological manifestations, and to compare the prognoses of patients in these subgroups.

METHODS

This study included patients with Sjögren's disease from two independent cohorts in France: the cross-sectional Paris-Saclay cohort and the prospective Assessment of Systemic Signs and Evolution of Sjögren's Syndrome (ASSESS) cohort. We first used an unsupervised multiple correspondence analysis to identify clusters within the Paris-Saclay cohort using 26 variables comprising patient-reported symptoms and clinical and biological manifestations. Next, we validated these clusters using patients from the ASSESS cohort. Changes in disease activity (measured by the European Alliance of Associations for Rheumatology [EULAR] Sjögren's Syndrome Disease Activity Index [ESSDAI]), patient-acceptable symptom state (measured by the EULAR Sjögren's Syndrome Patient Reported Index [ESSPRI]), and lymphoma incidence during follow-up were compared between clusters. Finally, we compared our clusters with the symptom-based subgroups previously described by Tarn and colleagues.

FINDINGS

534 patients from the Paris-Saclay cohort (502 [94%] women, 32 [6%] men, median age 54 years [IQR 43-64]), recruited between 1999 and 2022, and 395 patients from the ASSESS cohort (370 [94%] women, 25 [6%] men, median age 53 years [43-63]), recruited between 2006 and 2009, were included in this study. In both cohorts, hierarchical cluster analysis revealed three distinct subgroups of patients: those with B-cell active disease and low symptom burden (BALS), those with high systemic disease activity (HSA), and those with low systemic disease activity and high symptom burden (LSAHS). During follow-up in the ASSESS cohort, disease activity and symptom states worsened for patients in the BALS cluster (67 [36%] of 186 patients with ESSPRI score <5 at month 60 vs 92 [49%] of 186 at inclusion; p<0·0001). Lymphomas occurred in patients in the BALS cluster (five [3%] of 186 patients; diagnosed a median of 70 months [IQR 42-104] after inclusion) and the HSA cluster (six [4%] of 158 patients; diagnosed 23 months [13-83] after inclusion). All patients from the Paris-Saclay cohort with a history of lymphoma were in the BALS and HSA clusters. This unsupervised clustering classification based on symptoms and clinical and biological manifestations did not correlate with a previous classification based on symptoms only.

INTERPRETATION

On the basis of symptoms and clinical and biological manifestations, we identified three distinct subgroups of patients with Sjögren's disease with different prognoses. Our results suggest that these subgroups represent different heterogeneous pathophysiological disease mechanisms, stages of disease, or both. These findings could be of interest when stratifying patients in future therapeutic trials.

FUNDING

Fondation pour la Recherche Médicale, French Ministry of Health, French Society of Rheumatology, Innovative Medicines Initiative 2 Joint Undertaking, Medical Research Council UK, and Foundation for Research in Rheumatology.

Diagnosis and management of ANCA-associated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis consists of two main diseases, granulomatosis with polyangiitis and microscopic polyangiitis, and remains among the most devastating and potentially lethal forms of autoimmune inflammatory disease. Granulomatosis with polyangiitis and microscopic polyangiitis are characterised by a necrotising vasculitis that can involve almost any organ, and have generally been studied together. The diseases commonly affect the kidneys, lungs, upper respiratory tract, skin, eyes, and peripheral nerves. Granulomatous inflammation and multinucleated giant cells are key pathological hallmarks of granulomatosis with polyangiitis, but are absent in microscopic polyangiitis. Many immune system events are essential to disease aetiopathogenesis, such as activation of the alternative complement pathway, neutrophil activation via complement receptors, and the influx of inflammatory cells, including monocytes and macrophages. These cells perpetuate inflammation and lead to organ damage. During the 21st century, the management of ANCA-associated vasculitis has moved away from reliance on cytotoxic medications and towards targeted biological medications for both the induction and maintenance of disease remission. Earlier diagnosis, partly the result of more reliable ANCA testing, has led to improved patient outcomes and better survival. Reductions in acute disease-related mortality have now shifted focus to long-term morbidities related to ANCA-associated vasculitis and their treatments, such as chronic kidney disease and cardiovascular disease. Therapeutic approaches in both clinical trials and clinical practice still remain too reliant on glucocorticoids, and continued efforts to reduce toxicity from glucocorticoids remain a priority in the development of new treatment strategies.

ANCA-Associated Vasculitis: Practical Issues in Management

ANCA associated vasculitides are multi-system autoimmune diseases which are increasing in prevalence. In this review we will discuss the clinical manifestations and review the management options. We highlight the various trials of induction and maintenance therapy and discuss the areas of unmet need. These include understanding which patients are at highest risk of relapse, clinical adaptation of improved biomarkers of disease activity and tools to discuss long term prognosis.

Antineutrophil cytoplasmic antibody-associated vasculitis classification by cluster analysis based on clinical phenotypes: a single-center retrospective cohort study

OBJECTIVE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) refers to a group of small vessel inflammatory disorders. Overlapping clinical phenotypes of AAV subgroups continually provoke controversies over their diagnostic and classification criteria.

METHODS

Using the agglomerative hierarchical clustering method, we classified 210 Korean patients diagnosed with AAV into mutually exclusive clusters according to Birmingham Vasculitis Activity Score items, ANCA specificity, sex, and age. We analyzed the resulting clusters' outcomes to investigate the clinical significance of the classification. We proposed a distance-based algorithm of patient assignment and explored its clinically relevant modification.

RESULTS

In total, 116 patients (55%) had microscopic polyangiitis, 53 (25%) had granulomatosis with polyangiitis, and 42 (20%) had eosinophilic granulomatosis with polyangiitis. Our model grouped the patients into five clusters, namely, "limited proteinase 3 (PR3)-ANCA vasculitis," "generalized PR3-ANCA vasculitis," "ANCA-negative vasculitis," "renal-limited vasculitis," and "myeloperoxidase-ANCA vasculitis." Patients clustered under "generalized PR3-ANCA vasculitis" had a higher relapse rate (hazard ratio [HR] = 2.12, P = 0.067). The incidence of end-stage renal disease was higher in patients belonging to the "renal-limited vasculitis" cluster (HR=1.50, P=0.03), and those in the "ANCA-negative vasculitis" cluster experienced a relatively milder clinical course of AAV (mortality = 0).

CONCLUSION

Because the clusters were naturally derived from their distinguished phenotypes and have different clinical courses, our clustering method may be a more clinically relevant classification system for AAV, revealing its phenotypic diversity. We also proposed a simple and intuitive distance-based assignment algorithm, which can be easily modified according to specific clinical needs. Key Points • In this study with a single-center AAV cohort, we showed that AAV can be divided into five distinct subclasses with different disease courses based on the clinical and laboratory features of the patients. • Our study revealed ethnic differences in AAV manifestation and suggests that physicians may need to analyze their own AAV patients to assess the disease status of AAV patients. • We proposed a distance-based cluster membership assignment method that can be clinically modified to fit the specific purpose of grouping patients.

Might maintenance therapy be discontinued once clinical remission is achieved in ANCA-associated vasculitis?

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) encompasses a group of rare, multisystem autoimmune disorders characterised by the occurrence of inflammation and damage to small blood vessels, leading to a wide range of clinical manifestations. They include granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). Outcomes for patients with MPA and GPA have been transformed over recent years. However, the establishment of effective maintenance therapy aiming to balance the risks of disease relapse with those related to prolonged immunosuppression has become a clinical priority. This review aims to explore two differing perspectives on this unsolved problem. Pros and Cons of the following approaches will be discussed: "Biomarker-guided personalised approach on top of generic maintenance strategy guidelines" or "ANCA specificity-related personalised maintenance treatment after intensive B-cell depletion"?

Cardiovascular Disease in Anti-neutrophil Cytoplasm Antibody-Associated Vasculitis

PURPOSE OF REVIEW

Anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) is a rare, multisystem, autoimmune disease characterised by microvascular inflammation. Over the past 20 years, advances in immunological management have improved short-term patient outcomes. Longer-term patient outcomes remain poor with cardiovascular disease now the leading cause of death in AAV. Here, we examine the potential pathways that contribute to the increased risk of cardiovascular disease in AAV and the current evidence to manage this risk.

RECENT FINDINGS

The incidence of cardiovascular disease in AAV exceeds that expected by traditional risk factors alone, suggesting a contribution from disease-specific factors. Similarly, it is unclear how different immunosuppressive therapies contribute to and modify cardiovascular risk, and there is a paucity of data examining the efficacy of traditional cardioprotective medications in AAV. There is a lack of evidence-based cardiovascular risk assessment tools and cardioprotective therapies in patients with AAV which should be addressed to improve long-term outcomes.

Clusters based on demography, disease phenotype, and autoantibody status predicts mortality in lupus: data from Indian lupus cohort (INSPIRE)

OBJECTIVES

SLE is associated with significant mortality, and data from South Asia is limited. Thus, we analysed the causes and predictors of mortality and hierarchical cluster-based survival in the Indian SLE Inception cohort for Research (INSPIRE).

METHODS

Data for patients with SLE was extracted from the INSPIRE database. Univariate analyses of associations between mortality and a number of disease variables were conducted. Agglomerative unsupervised hierarchical cluster analysis was undertaken using 25 variables defining the SLE phenotype. Survival rates across clusters were assessed using non-adjusted and adjusted Cox proportional-hazards models.

RESULTS

Among 2072 patients (with a median follow-up of 18 months), there were 170 deaths (49.2 deaths per 1000 patient-years) of which cause could be determined in 155 patients. 47.1% occurred in the first 6 months. Most of the mortality (n = 87) were due to SLE disease activity followed by coexisting disease activity and infection (n = 24), infections (n = 23), and 21 to other causes. Among the deaths in which infection played a role, 24 had pneumonia. Clustering identified four clusters, and the mean survival estimates were 39.26, 39.78, 37.69 and 35.86 months in clusters 1, 2, 3 and 4, respectively (P < 0.001). The adjusted hazard ratios (HRs) (95% CI) were significant for cluster 4 [2.19 (1.44, 3.31)], low socio-economic-status [1.69 (1.22, 2.35)], number of BILAG-A [1.5 (1.29, 1.73)] and BILAG-B [1.15 (1.01, 1.3)], and need for haemodialysis [4.63 (1.87,11.48)].

CONCLUSION

SLE in India has high early mortality, and the majority of deaths occur outside the health-care setting. Clustering using the clinically relevant variables at baseline may help identify individuals at high risk of mortality in SLE, even after adjusting for high disease activity.

Induction failure in granulomatosis with polyangiitis: a nationwide case-control study of risk factors and outcomes

OBJECTIVE

To identify characteristics of granulomatosis with polyangiitis (GPA) associated with induction failure, describe salvage therapies and their efficacy.

METHODS

We conducted a nationwide retrospective case-control study of GPA with induction failure between 2006 and 2021. Each patient with induction failure was randomly paired to three controls matched for age, sex and induction treatment.

RESULTS

We included 51 patients with GPA and induction failure (29 men and 22 women). At induction therapy, median age was 49 years. Twenty-seven patients received intravenous cyclophosphamide (ivCYC) and 24 rituximab (RTX) as induction therapy. Patients with ivCYC induction failure more frequently had PR3-ANCA (93% vs 70%, P = 0.02), relapsing disease (41% vs 7%, P < 0.001) and orbital mass (15% vs 0%, P < 0.01) compared with controls. Patients with disease progression despite RTX induction therapy more frequently had renal involvement (67% vs 25%, P = 0.02) with renal failure (serum creatinine >100 µmol/l in 42% vs 8%, P = 0.02) compared with controls. After salvage therapy, remission was achieved at 6 months in 35 (69%) patients. The most frequent salvage therapy was switching from ivCYC to RTX (or vice versa), showing an efficacy in 21/29 (72%). Remission was achieved in nine (50%) patients with inappropriate response to ivCYC, while in patients with progression after RTX induction, remission was achieved in four (100%) who received ivCYC (with or without immunomodulatory therapy), but only in three (50%) after adding immunomodulatory therapy alone.

CONCLUSION

In patients with induction failure, characteristics of GPA, salvage therapies and their efficacy vary according to induction therapy and failure modality.

Case report: A pediatric case of MPO-ANCA-associated granulomatosis with polyangiitis superimposed on post-streptococcal acute glomerulonephritis

An eight-year-old girl was admitted with vomiting, gross hematuria, and progressive renal dysfunction. A renal biopsy revealed endocapillary proliferative glomerulopathy and crescent formation. Immunofluorescence staining revealed diffuse granular deposits of IgG and C3. Post-streptococcal acute glomerulonephritis (PSAGN) was suspected, based on the elevated anti-streptolysin O levels, decreased serum C3 concentrations, and histologic findings. The myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) test was positive, and the young patient gradually developed palisaded neutrophilic and granulomatous dermatitis (PNGD), orbital and paranasal sinus granulomatous neoplasms, along with intermittent nose, head, and orbital pain. Finally, she was diagnosed with the rare MPO-ANCA-associated granulomatosis with polyangiitis (GPA) superimposed on PSAGN. The patient was treated with aggressive renal replacement therapy, methylprednisolone pulse therapy, and intravenous pulse cyclophosphamide; her renal function normalized, and her pain symptoms improved.

Unmet needs in ANCA-associated vasculitis: Physicians' and patients' perspectives

In recent years, clinical research has increased significantly and therapies for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis have improved. However, there are still unanswered questions and unmet needs about AAV patients. The purpose of this review is to examine the frontiers of research related to emerging biomarkers eventually predicting relapse, and new therapeutic approaches, not to mention new quality of life assessment tools. Identifying predictors of relapse may help optimize therapeutic strategies, minimize disease recurrence, and reduce treatment-related side effects. In addition, it is important to recognize that patients may suffer long-term consequences of the disease and its treatment, which, although life-saving, is often associated with significant side effects. Our goal, therefore, is to highlight what has been achieved, the pitfalls, and what still needs to be done, comparing the views of physicians and patients.

Gastrointestinal Hemorrhage With Gastritis and Pancolitis as the Sole Presentation for Granulomatosis With Polyangiitis Flare

Granulomatosis with polyangiitis (GPA), previously known as Wegener granulomatosis, is a rare small vessel vasculitis affecting mainly Whites. The prevalence of GPA in the United States is estimated to be 3 of 100,000 individuals. Classically, GPA affects upper airways, lungs, and kidneys, with the upper airways being the most common site. Occasionally, other organs affected by GPA include eyes, skin, joints, and the nervous system. The gastrointestinal system is rarely affected; however, some cases have been reported. In this case report, we present a patient with hemorrhagic gastritis and pancolitis consistent with GPA and discuss features from the literature of gastrointestinal manifestations in patients with GPA.

Relevance of Combined Clinicopathologic Phenotype and Antineutrophil Cytoplasmic Autoantibody Serotype in the Diagnosis of Antineutrophil Cytoplasmic Autoantibody Vasculitis

Introduction

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), 2 major clinicopathologic variants of antineutrophil cytoplasmic autoantibody (ANCA) vasculitides, are mostly associated with proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA, respectively. Less is known regarding the uncommon forms of ANCA vasculitis, PR3-ANCA MPA and MPO-ANCA GPA.

Methods

In this cohort study we detailed the clinical presentation and outcome of patients with PR3-ANCA MPA and MPO-ANCA GPA from the Glomerular Disease Collaborative Network (GDCN) inception cohort. Baseline clinical manifestations, relapses, end-stage kidney disease (ESKD), and survival were compared within MPA cases by PR3-ANCA (n = 116) versus MPO-ANCA (n = 173) and within GPA cases by PR3-ANCA (n = 108) versus MPO-ANCA (n = 43). Fisher's exact test and Wilcoxon two sample test were used for comparisons. Proportional hazards models were used to evaluate the development of relapses, ESKD, and death.

Results

Patients with PR3-ANCA MPA were younger (53 years vs. 62 years, P = 0.0007) and had increased prevalence of joint involvement (56% vs. 40%, P = 0.0115) and ear, nose, and throat (ENT) involvement (44% vs. 26%, P = 0.002) than MPO-ANCA MPA. Relapses, ESKD, and survival were similar between both MPA subsets. Within the GPA group, patients with MPO-ANCA GPA were older (61 years vs. 46 years, P = 0.0007) and more likely female (56% vs. 35%, P = 0.027) than PR3-ANCA GPA patients. MPO-ANCA GPA was also characterized by less prevalent ENT manifestations (58% vs. 77%, P = 0.028) and neurologic manifestations (5% vs. 25%, P = 0.0029), and increased ESKD and mortality.

Conclusions

PR3-ANCA MPA and MPO-ANCA GPA are clinicopathologically distinct subsets of ANCA vasculitis that differ from MPO-ANCA MPA and PR3-ANCA GPA. Although the impact of these differences on the clinical management and outcome warrants further evaluation, these results support the recommendation of including both the phenotypic diagnosis and ANCA serotype in the diagnosis of ANCA vasculitis.

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.

Type of ANCA May Be Indispensable in Distinguishing Subphenotypes of Different Clinical Entities in ANCA-Associated Vasculitis

The traditional nomenclature system for classifying antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) based on clinical phenotype describes granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA) and microscopic polyangiitis (MPA) as distinct clinical entities. This classification has proved its expedience in clinical trials and everyday clinical practice; yet, a substantial overlap in clinical presentation still exists and often causes difficulties in prompt definition and clinical distinction. Additionally, new insights into the AAV pathogenesis point out that PR3 and MPO-AAV may not represent expressions of the same disease spectrum but rather two distinct disorders, as they display significant differences. Thus, it is supported that a classification based on ANCA serotype (PR3-ANCA, MPO-ANCA or ANCA-negative) could be more accurate and also closer to the nature of the disease compared to the phenotype-based one. This review aims to elucidate the major differences between PR3 and MPO-AAV in terms of epidemiology, pathogenesis, histological and clinical manifestations and response to therapeutic approaches.

Life-threatening gastrointestinal haemorrhage requiring surgical resection caused by SARS-CoV-2 induced ANCA associated vasculitis: A case report

Introduction and importance

SARS-CoV-2 infection has been linked to the de novo diagnosis of various autoimmune conditions as well as flares in pre-existing disease. With such high prevalence of SARS-CoV-2 in the community, it is important to consider rare manifestations of autoimmune conditions when patients present with severe symptoms. Multi-specialty care is required to ensure optimal outcomes and prompt diagnosis.

Case presentation

A 28-year-old male presented to our tertiary referral centre with progressive debilitating polyarthritis, a purpuric rash on both flanks and aphthous ulcers 6 weeks after infection with SARS-CoV-2. On the second day of admission, he developed severe gastrointestinal haemorrhage requiring multiple blood transfusions. Attempted angioembolisation failed to identify a site of active haemorrhage. On failing trial of conservative management, the decision was made to perform an exploratory laparotomy. The small bowel was found to have an extensive vasculitis requiring resection to control haemorrhage. Autoimmune serology revealed c-ANCA positivity with anti-PR3 antibodies.

Clinical discussion

Patients presenting with acute vasculitic pathologies related to SARS-CoV-2 have the potential to rapidly progress to severe life-threatening gastrointestinal haemorrhage. Prompt surgical management is appropriate in selected cases.

Conclusion

In the current era of COVID-19, the differential diagnosis of SARS-CoV-2 induced ANCA vasculitis must be considered for such cases with gastrointestinal haemorrhage. Compilation of similar cases and further studies are required to determine an optimal management pathway for these patients.

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SARS-CoV-2 has been associated with de novo autoimmune vasculitis.

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SARS-CoV-2 induced vasculitis can progress to severe intestinal bleeding.

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Surgical resection is paramount in refractory vasculitic gastrointestinal bleeding.

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Multi-speciality care is essential in cases of SARS-CoV-2 induced vasculitis.

Cluster analysis of patients with granulomatosis with polyangiitis (GPA) based on clinical presentation symptoms: a UK population-based cohort study

Background

Granulomatosis with polyangiitis (GPA) is small vessel vasculitis with heterogeneous clinical presentation. In the present population-based cohort study, we classified patients with GPA based on clinical features at presentation using an unsupervised clustering approach and compared their mortality, infections and frequency of comorbidities.

Methods

In this open cohort study, de-identified primary care data of patients with GPA included in the IQVIA Medical Research Data database between 1 January 1995 and 25 September 2019 was analysed retrospectively. Latent class analysis was performed to create symptom clusters of patients based on 16 categories of symptoms representing various organ involvement. All-cause mortality of resultant clusters was compared after adjusting for age, sex, Townsend deprivation quintile and smoking status at index date using extended Cox proportional hazards models. Prescription of antibiotics, considered as an indirect indicator of recurrent bacterial infection, was compared using a recurrent event model, after adjusting for quarterly use of steroid as a time-dependent covariate. Cumulative frequencies of common comorbidities were compared among the clusters at index visit, 1-year and 3-year follow-up.

Results

Altogether, 649 patients with GPA [median age 60.0 (IQR: 49.6–70.1)] were included. Three clusters were identified: patients with limited disease mainly with involvement of ENT and cough were classified into cluster 1 (n = 426); cluster 2 had generalised non-renal disease (n = 176); while patients in cluster 3 had renal-predominant disease (n = 47). Many patients in cluster 1 developed generalised disease at the end of 1 year. Mortality in clusters 2 and 3 was higher compared with cluster 1. Mortality in cluster 1 itself was 68% higher than the general population without GPA. The duration of antibiotics prescription and frequency of coexisting medical illnesses was also higher in clusters 2 and 3.

Conclusions

In a primary care setting, patients with GPA can be classified into three distinct clusters with different prognosis, susceptibility to recurrent infections and presence of comorbidities. The tendency of cluster 1 to evolve into a more generalised disease raises questions about current immunosuppressive treatment approaches in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02885-9.

Comparative study of granulomatosis with polyangiitis subsets according to ANCA status: data from the French Vasculitis Study Group Registry

Objective

To investigate whether antineutrophil cytoplasm antibody (ANCA)-negative and myeloperoxidase (MPO)-ANCA–positive granulomatosis with polyangiitis (GPA) differ from proteinase-3 (PR3)-ANCA–positive GPA.

Methods

Diagnostic characteristics and outcomes of newly diagnosed French Vasculitis Study Group Registry patients with ANCA-negative, MPO-ANCA–positive or PR3-ANCA–positive GPA satisfying American College of Rheumatology criteria and/or Chapel Hill Conference Consensus Nomenclature were compared.

Results

Among 727 GPA, 62 (8.5%) were ANCA-negative, 119 (16.4%) MPO-ANCA–positive and 546 (75.1%) PR3-ANCA–positive. ANCA-negative patients had significantly (p<0.05) more limited disease (17.7% vs 5.8%) and less kidney involvement (35.5% vs 58.9%) than those PR3-ANCA–positive or MPO-ANCA–positive, with comparable relapse-free (RFS) and overall survival (OS). MPO-ANCA–positive versus PR3-ANCA–positive and ANCA-negative patients were significantly more often female (52.9% vs 42.1%), older (59.8 vs 51.9 years), with more frequent kidney involvement (65.5% vs 55.2%) and less arthralgias (34.5% vs 55.1%), purpura (8.4% vs 17.1%) or eye involvement (18.5% vs 28.4%); RFS was similar but OS was lower before age adjustment. PR3-positive patients’ RFS was significantly lower than for ANCA-negative and MPO-positive groups combined, with OS higher before age adjustment. PR3-ANCA–positivity independently predicted relapse for all GPA forms combined but not when comparing only PR3-ANCA–positive versus MPO-ANCA–positive patients.

Conclusions

Based on this large cohort, ANCA-negative versus ANCA-positive patients more frequently had limited disease but similar RFS and OS. MPO-ANCA–positive patients had similar RFS but lower OS due to their older age. PR3-ANCA–positive GPA patients’ RFS was lower than those of the two other subsets combined but that difference did not persist when comparing only PR3 versus MPO-ANCA–positive patients.

An immunogenetic perspective of ANCA-associated vasculitides

Background

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a group of small vessel vasculitides characterized by necrotizan vasculitis and inflammation. The phenotypes of AAV include microscopic polyangiitis (MPA), granulomatosis and polyangiitis (GPA), and eosinophilic granulomatosis and polyangiitis (EGPA). The pathogenesis of AAV is multifactorial, and it is suggested that both genetic and environmental factors can influence these disorders.

Main body

Several candidate gene studies and genome-wide association studies (GWAS) have been conducted to investigate the genetic associations with AAV in recent years. Numerous genes have been related to the pathogenesis of AAV, including the innate, adaptive immune system and coagulation systems.

Conclusion

This review summarizes the immunological mechanisms involved in the etiopathogenesis of AAV and recent advances in susceptibility genes.

Clinical Characteristics and Outcomes of Patients With ANCA-Associated Vasculitides in a Colombian Hospital

BACKGROUND/OBJECTIVE

Antineutrophil cytoplasmic antibody-associated vasculitides (AAVs) are uncommon systemic autoimmune diseases, of which few reports exist in Latin America. Our aim was to examine AAV evaluated in a high-complexity hospital in southwestern Colombia, with emphasis in severe forms.

METHODS

A medical records review study of 67 patients was performed, and data were collected from electronic registries. Moderate and severe AAVs were defined as the presence of life-threatening complications, unfavorable Birmingham Vasculitis Activity Score outcomes, and hospitalization requirements at the time of diagnosis and by the last follow-up, between 2011 and 2019. Clinical manifestations, treatment, and outcomes were evaluated. The AAV subtypes were compared.

RESULTS

A total of 67 cases were included. The majority were female (n = 44, 65.67%), and the median age was 52 (40-64) years. Granulomatosis with polyangiitis (GPA) was the most frequent with 42 patients (62.68%), followed by microscopic polyangiitis (MPA) and eosinophilic GPA, with 15 patients (22.38%) and 10 patients (14.92%), respectively. Forty-four patients (65.67%) presented pulmonary symptoms. The highest Birmingham Vasculitis Activity Score corresponded to MPA, with 21 (12-25) points. Fifteen patients (22.4%) were admitted to the intensive care unit throughout the course of the disease, of whom 10 had GPA. The longest stay and duration of mechanical ventilation were seen in MPA. The principal treatments were corticosteroids and cyclophosphamide, and the main outcome was end-stage renal disease.

CONCLUSIONS

In this cohort of AAV, most of cases corresponded to GPA, and pulmonary manifestations were the most common. Microscopic polyangiitis was the more severe subtype as it showed worse impairment in clinical characteristics and intensive care unit requirements.

ANCA-Associated Vasculitis in Latin America: A Systematic Literature Review: About Their Epidemiology and Their Clinical Features

ABSTRACT

Most of the existing literature, including epidemiological studies and clinical trials, on antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) include North American (mainly United States and Canada), European, and Asian populations. Few studies have focused on multiethnic populations such as the one from Latin America. Racial and ethnic differences in the incidence of AAV could partially explain the comparatively low number of AAV studies originating in Latin America. However, given the racial/ethnic diversity as well as socioeconomic differences existing in this region, better reporting of AAV presentations and outcomes in Latin America could highlight valuable gaps on the understanding and treatment of these patients. Recently, larger case series and studies have provided better clinical information regarding AAV patients in Latin American countries; however, further information is needed to address gaps such as risk factors, genetic profiles, clinical features, and predictors of clinical outcomes. For these reasons, we have performed a systematic literature review to enhance our understanding of AAV patients in Latin America. We have included 11 articles focused on the epidemiological and clinical features of AAV in Latin America; some similarities and differences with AAV in other regions are shown in these articles. We have identified differences in their prevalence across Latin American countries, which may reflect reporting bias or true ethnic differences among the countries. Our findings should encourage further investigation into AAV in Latin America; such studies will hopefully lead to the optimal management of these patients.

A glance into the future of anti-neutrophil cytoplasmic antibody-associated vasculitis

In the past decade, unprecedented progress has been made in understanding the pathogenesis, diagnosis, assessment, and treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs). International collaborations and input from several fields (e.g. immunology, rheumatology, and nephrology) have been critical for analyzing demographics, disease manifestations, and outcomes in clinical research studies. Such efforts opened new avenues for generating novel questions and rationale to design better clinical trials. In addition, clinical research has been a source of several biological discoveries and the starting point for knowledge seeking on the pathophysiology of AAV. Interestingly, the blending of clinical and basic research provides a platform for personalized medicine. Despite recent revisions on AAV classification, the incorporation of new findings on disease genetics and immunologic responses may soon result in changes in clinical practice. These advances will enhance the selection of more specific and targeted therapies. However, current unmet needs in the management of AAV are still sizable and heavily impact long-term survival. Especially, frequent relapses, damage accrual, and high morbidity contribute to poor outcomes. Finally, the lack of defined biomarkers for disease activity and the prognosis is a permanent challenge in AAV research. Our work provides an overview of the current state of the art in AAV literature and suggests bridges for the remaining knowledge gaps. It offers potential future directions for the clinical assessment, management, and research in the field toward a more personalized medicine approach.

Health-Related Quality of Life in Patients With ANCA-Associated Vasculitis and Sinonasal Involvement: A Single-Center Cross-Sectional Study

BACKGROUND/OBJECTIVE

The aim of this study was to assess the impact of sinonasal morbidity on quality of life (QoL) in antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

This cross-sectional case-control study enrolled 71 patients-44 AAV cases with (ear, nose, and throat [ENT]-AAV) or without ENT involvement (non-ENT-AAV) undergoing multidisciplinary evaluations and 27 chronic rhinosinusitis (CRS) cases. Three validated QoL questionnaires (Sino-Nasal Outcomes Test-22 [SNOT-22], Nasal Obstruction Symptom Evaluation [NOSE], and Short-Form 36) were administered, and the 3 groups were compared.

RESULTS

The ENT-AAV patients were significantly younger (p = 0.01), with less antineutrophil cytoplasmic antibody positivity frequency (p = 0.035) and lower renal involvement (p = 0.003) than the non-ENT-AAV patients.The SNOT-22 questionnaire demonstrated significantly greater sinonasal morbidity in ENT-AAV patients compared with CRS patients (p < 0.001). The NOSE score of ENT-AAV patients was comparable to those of CRS patients, but higher than that of non-ENT-AAV patients (p < 0.001). The SNOT-22 and NOSE scores positively correlated with disease activity (p = 0.037; p = 0.004, respectively). Short-Form 36 domain-by-domain analysis revealed a significantly poorer QoL in ENT-AAV patients, especially with physical functioning being progressively impaired in CRS, non-ENT-AAV, and ENT-AAV patients (p < 0.001). No significant differences in QoL came to light when AAV patients were stratified according to current systemic o local treatments.

CONCLUSIONS

The QoL in AAV patients is significantly reduced, especially in the presence of ENT involvement. The AAV-related nasal morbidity is consistent and comparable to that reported by CRS patients. It significantly affects patients' QoL and in particular social functioning, leading to limitation in daily/work activities. Organ-focused questionnaires and multidisciplinary management are warranted to pursue a treat-to-target approach in these patients.

Induction and maintenance of remission with mycophenolate mofetil in ANCA-associated vasculitis: A systematic review and meta-analysis

BACKGROUND

Uncertainties exist about the use of mycophenolate mofetil (MMF) in anti-neutrophil cytoplasmatic antibody (ANCA)-associated vasculitis (AAV), particularly for remission maintenance.

METHODS

Systematic review and meta-analysis of phase II and III trials assessing the use of MMF in AAV (granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA)). A comprehensive search of several databases (Medline, EMBASE, Cochrane, Web of Science, Scopus) from inception to May 5th, 2020 has been conducted. Trial data were extracted to estimate odds ratios (ORs) and estimates (ES) for MMF efficacy (remission-induction and maintenance). Severe adverse effects (SAEs) were collected.

RESULTS

From 565 articles captured, 10 met the predefined criteria, five phase II and five III trials, 4 assessed remission-induction, 3 remission-maintenance, 3 both. The pooled OR for remission-induction at 6 months was 1.06 (95% CI: [0.74, 1.52]), with no significant difference by subgroup meta-analysis of trials stratified by different study-level features (i.e. kidney disease, MPA, myeloperoxidase-ANCA-positivity, newly diagnosed disease) (p > 0.05).The overall ES for remission-maintenance at the end of follow-up ranged between 51%-91% (I2 = 74.8%). Subgroup meta-analysis identified kidney involvement as a possible source of heterogeneity, yielding a significantly higher rate of sustained remission in trials enrolling only patients with kidney involvement (92% [76%-100%]) versus those enrolling patients with and without kidney involvement (56% [45%-66%]). Results were similar in multiple sensitivity analyses.During follow-up, the frequency of SAEs in MMF-based treatment arms was 31.8%.

CONCLUSIONS

In AAV, MMF use significantly associated with higher sustained remission rates in trials enrolling only patients with kidney involvement. These findings might influence clinical practice.

Validation of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis as the Cause of End-Stage Renal Disease in the US Renal Data System

Objective

The objective of this study was to validate the diagnosis of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) as the primary cause of end‐stage renal disease (ESRD) in the US Renal Data System (USRDS).

Methods

We identified patients with ESRD in the Mass General Brigham (MGB) health care system who were enrolled in the USRDS. The health records of those with AAV listed as the primary cause of ESRD in the USRDS were reviewed to confirm the diagnosis and estimate positive predictive value (PPV). Sensitivity was estimated by evaluating the primary cause of ESRD listed in the USRDS for patients with ESRD due to AAV in the MGB AAV cohort.

Results

We identified 89 MGB patients with ESRD due to AAV in the USRDS. Of these, 85 cases were confirmed to be true cases of AAV (PPV = 94%). Among the patients classified as having AAV, 84 (99%) had an ANCA test, which was predominantly myeloperoxidase/P‐ANCA (47 [55%]); 36 (42%) had a renal biopsy, and all biopsies were supportive of the diagnosis. The majority (81 [90%]) was identified as AAV by International Classification of Diseases Ninth Revision or International Classification of Diseases 10th Revision codes for granulomatosis with polyangiitis (446.4 or M313.1). Of the 77 MGB AAV cohort patients with ESRD who were linked to the USRDS, 41 (53%) had AAV listed as the cause of ESRD; in the remainder, ESRD was attributed to nonspecific nephritis.

Conclusion

The diagnosis of AAV as the cause of ESRD in the USRDS has a high PPV; sensitivity was moderate. These findings support the continued use of the USRDS to study ESRD due to AAV.

Anticoagulant-free venovenous extracorporeal membrane oxygenation for diffuse alveolar hemorrhage with bowel bleeding caused by antineutrophil cytoplasmic antibody-associated vasculitis: A case report

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is sometimes complicated by diffuse alveolar hemorrhage (DAH), which may cause respiratory failure. Venovenous extracorporeal membrane oxygenation (VV-ECMO) without an anticoagulant because of hemorrhagic status, showed the effectiveness for severe respiratory failure by DAH with AAV. A 44-year-old woman developed DAH with bowel bleeding following the onset of AAV, with positive anti-proteinase-3 (PR3) antibodies. Although ventilator management could not support her respiratory status, VV-ECMO was performed. The patient was given immunosuppressive therapy comprising a steroid pulse, plasma exchange, and cyclophosphamide. After about 10 days of VV-ECMO and immunosuppressive therapy, VV-ECMO was withdrawn, and on day 12, ventilator support was stopped. Although a thrombus developed within the inferior vena cava (IVC), which required IVC filtration, the patient was discharged on day 51. VV-ECMO support was effective for treating DAH in this patient with new-onset AAV, which takes some time to achieve remission with immunosuppressive therapy.

A Ruptured Jejunal Arterial Aneurysm in a Young Woman Undergoing Chronic Hemodialysis Due to Myeloperoxidase-antineutrophil Cytoplasmic Antibody-associated Vasculitis

A 21-year-old woman was admitted to our hospital because of massive intestinal bleeding. She started hemodialysis due to myeloperoxidase antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) at 18 years of age. Her ANCA titers remained stable; however, her C-reactive protein increased on 5 mg/day prednisolone before admission. Computed tomography angiography revealed a ruptured jejunal arterial aneurysm. Transcatheter arterial embolization, blood transfusion and the reinforcement of steroid therapy resolved her symptoms of AAV. Our case of a young patient with AAV and medium-sized arterial vasculitis is rare and emphasizes that the ANCA titer does not always rise, especially in patients with nonrenal vasculitis flare-ups.

Rituximab Induction and Maintenance in ANCA-Associated Vasculitis: State of the Art and Future Perspectives

Antineutrophil cytoplasmatic antibody (ANCA)-associated vasculitis (AAV) is a group of rare autoimmune diseases characterized by inflammation of the vascular wall. The pathogenesis of AAV is strongly associated with B cell-derived ANCAs; thus, Rituximab (RTX) has become a promising drug in the induction and maintenance treatment of AAV. The purpose of this review is to describe the efficacy and safety of RTX in the induction of remission and maintenance therapy of AAV. Herein, we summarize the randomized controlled trials that have contributed to the refinement of the use of RTX in AAV in the past decades. RTX has been proven to be effective both in new-onset disease and in relapsing disease. Although the optimal duration of AAV maintenance therapy remains unknown, the ANCAs and the B-cell repopulation may offer support for the administration of further RTX cycles (or not). The safety of RTX is comparable with cyclophosphamide, with the advantage of a low risk of malignancy and no concern for fertility. In conclusion, RTX now plays an important role in the induction and maintenance therapy of AAV. Optimizing RTX-based treatment strategies in AAV is one of the main goals of the current research in AAV.

Classification of ANCA-associated vasculitis: differences based on ANCA specificity and clinicopathologic phenotype

The classification of vasculitis according to a schema with universal acceptance is challenging, given the heterogeneous and protean nature of these diseases. Formal nomenclature and classification criteria for anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have suffered several changes since their first description; none provides comprehensive diagnostic and classification criteria. Different factors account for the difficulties in the classification of vasculitis, including the incomplete understanding of the pathogenesis, the multisystemic nature of the disease, the non-specific patterns of vascular involvement, the overlap between entities, and the presence of various classification systems. The present article reviews the classification of AAV considering different points of view, including clinical, serologic, pathogenetic, organ predilection, therapeutic, and prognostic factors, and provides perspectives on future challenges in the understanding of AAV. There is an unmet need for a unifying view of the disease spectrum that considers the constantly evolving paradigms.

Clinical and biological clusters of sepsis patients using hierarchical clustering

Background

Heterogeneity in sepsis expression is multidimensional, including highly disparate data such as the underlying disorders, infection source, causative micro-organismsand organ failures. The aim of the study is to identify clusters of patients based on clinical and biological characteristic available at patients’ admission.

Methods

All patients included in a national prospective multicenter ICU cohort OUTCOMEREA and admitted for sepsis or septic shock (Sepsis 3.0 definition) were retrospectively analyzed. A hierarchical clustering was performed in a training set of patients to build clusters based on a comprehensive set of clinical and biological characteristics available at ICU admission. Clusters were described, and the 28-day, 90-day, and one-year mortality were compared with log-rank rates. Risks of mortality were also compared after adjustment on SOFA score and year of ICU admission.

Results

Of the 6,046 patients with sepsis in the cohort, 4,050 (67%) were randomly allocated to the training set. Six distinct clusters were identified: young patients without any comorbidities, admitted in ICU for community-acquired pneumonia (n = 1,603 (40%)); young patients without any comorbidities, admitted in ICU for meningitis or encephalitis (n = 149 (4%)); elderly patients with COPD, admitted in ICU for bronchial infection with few organ failures (n = 243 (6%)); elderly patients, with several comorbidities and organ failures (n = 1,094 (27%)); patients admitted after surgery, with a nosocomial infection (n = 623 (15%)); young patients with immunosuppressive conditions (e.g., AIDS, chronic steroid therapy or hematological malignancy) (n = 338 (8%)). Clusters differed significantly in early or late mortality (p < .001), even after adjustment on severity of organ dysfunctions (SOFA) and year of ICU admission.

Conclusions

Clinical and biological features commonly available at ICU admission of patients with sepsis or septic shock enabled to set up six clusters of patients, with very distinct outcomes. Considering these clusters may improve the care management and the homogeneity of patients in future studies.

Prognostic Factors and Long-Term Outcome with ANCA-Associated Kidney Vasculitis in Childhood

BACKGROUND AND OBJECTIVES

ANCA-associated vasculitis is extremely rare in children. We report the clinicopathologic features, long-term outcomes, and prognostic factors of a large pediatric cohort of patients with ANCA-associated kidney vasculitis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective study included 85 consecutive patients with kidney biopsy specimen-proven ANCA-associated vasculitis from tertiary referral centers in Italy and Canada. Kidney biopsy specimens were categorized as focal, crescentic, sclerotic, or mixed, according to the Berden classification. The prognostic significance of baseline clinical, laboratory, and histologic findings was analyzed with respect to kidney failure or CKD stage 3-5/kidney failure.

RESULTS

A total of 53 patients had microscopic polyangiitis (62%), and 32 had granulomatosis with polyangiitis (38%). Rapidly progressive GN was the most frequent presentation (39%); a third of the patients also had nephrotic-range proteinuria. Kidney biopsy specimens were classified as focal in 21% of the patients, crescentic in 51%, sclerotic in 15%, and mixed in 13%. Remission-induction therapies included cyclophosphamide in 78% of patients. A total of 25 patients (29%) reached kidney failure. The median (interquartile range) time to kidney failure or last follow-up was 35 (6-89) months in the whole cohort, and 73 (24-109) months among the patients who did not reach this outcome. Patients whose biopsy specimens showed sclerotic histology had significantly shorter kidney survival (hazard ratio, 11.80; 95% confidence interval, 2.49 to 55.99) and survival free of CKD stage 3-5 (hazard ratio, 8.88; 95% confidence interval, 2.43 to 32.48), as compared with those with focal/mixed histology. Baseline eGFR, low serum albumin, hypertension, central nervous system complications, and sclerotic histology, which reflected severe kidney involvement, were associated with both kidney failure and CKD stage 3-5/kidney failure at unadjusted analysis; no independent prognostic factors emerged at multivariable analysis.

CONCLUSIONS

Children with ANCA-associated kidney vasculitis often have aggressive presentation; a third of such children progress to kidney failure and this usually occurs early during follow-up. A severe clinical presentation is associated with the development of CKD or kidney failure.

Lupus nephritis and ANCA-associated vasculitis: towards precision medicine?

Historically the treatment of lupus nephritis (LN) and anti-neutrophil cytoplasmic antibody (ANCA) vasculitis was 'one size fits all'; however, with the emergence of precision medicine initiatives, the field is moving towards more personalized treatment approaches. The recent development of a more accurate and reproducible histopathological classification system for LN could lead to better disease categorization and therefore more targeted therapies. A better understanding of the pathophysiology of LN has provided evidence that not only T but also B cells play an important role, opening new opportunities for individualized treatment approaches. Recent trials have shown calcineurin inhibitors and the anti-CD20 antibodies rituximab and ofatumumab to be effective in the treatment of LN, adding new treatment options. State-of-the-art targeted therapy in ANCA-associated vasculitis (AAV) takes interindividual heterogeneity in disease severity, type of ANCA antibody [myeloperoxidase versus proteinase 3 (PR3)] and the risk for side effects of therapy into consideration. In addition, within an individual, induction therapy differs from maintenance therapy, the same holding true in incident and relapsing disease. Rituximab is now widely used in AAV and it has become clear that prolonged B cell depletion, as in LN, must be achieved to obtain a long-lasting clinical response, especially in anti-PR3-associated disease. Still, despite these advances, molecular and genetic markers are rarely incorporated into diagnostic and treatment algorithms and true precision medicine remains an aspiration that hopefully can be achieved.

ANCA Status or Clinical Phenotype - What Counts More?

PURPOSE OF REVIEW

There is ongoing debate concerning the classification of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. That is, whether classification should be based on the serotype (proteinase 3 (PR3)- or myeloperoxidase (MPO)-ANCA) or on the clinical phenotype (granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA)). To add clarity, this review focused on integration of the most recent literature.

RECENT FINDINGS

Large clinical trials have provided evidence that a serology-based risk assessment for relapses is more predictive than distinction based on the phenotype. Research conducted in the past decade indicated that a serology-based approach more closely resembles the genetic associations, the clinical presentation (i.e., lung involvement), biomarker biology, treatment response, and is also predicting comorbidities (such as cardiovascular death). Our review highlights that a serology-based approach could replace a phenotype-based approach to classify ANCA-associated vasculitides. In future, clinical trials and observational studies will presumably focus on this distinction and, as such, translate into a "personalized medicine."

Gastrointestinal symptoms as first remarkable signs of ANCA-associated granulomatosis with polyangiitis: a case report and reviews

Background

Systemic vasculitis associated with antineutrophil cytoplasmic autoantibodies (ANCA) have an extremely wide variety of symptoms, therefore the fast and proper diagnosis is difficult to establish even for experienced physicians. Gastrointestinal manifestations in ANCA-associated granulomatosis with polyangiitis (GPA) may be present, however, severe, life-threatening complications (such as perforations) are rare.

Case presentation

A case of an 18-year-old male patient is presented, where gastrointestinal symptoms (abdominal pain, vomiting, diarrhoea) were the first remarkable signs of GPA. The initial diagnosis of inflammatory bowel disease delayed the administration of proper immunosuppressive therapy, which might have contributed to the rare and life-threatening complication of arterial duodenal bleeding with perforation. Our systematic review of the literature found only a few case reports where gastrointestinal symptoms were the first signs of GPA, however, this entity might be more frequent if physicians would think of this possibility more often.

Conclusions

Gastrointestinal bleeding is a rare but potential lethal complication of vasculitis. Consequently, we recommend investigating the patients diagnosed with GPA for gastrointestinal bleeding during the treatment.

Healthcare and economic burden of ANCA-associated vasculitis in Italy: an integrated analysis from clinical and administrative databases

ANCA-associated vasculitides (AAV) comprise a group of systemic vasculitides characterized by inflammation of small-sized blood vessels leading to multi-organ involvement. The worldwide annual incidence of AAV ranges from 1.2 to 3.3 cases per 100 000 individuals with a prevalence of 4.6-42.1 cases per 100 000 individuals. The prevalence of AAV is geographically heterogeneous; therefore, regional epidemiological studies can be more informative to improve health care systems. Even though clinicians are aware that the healthcare burden and the risk of hospitalization of AAV appear high, data on hospitalization and cost of illness due to AAV are still scarce or even lacking. This study aims to characterize the economic burden of AAV in Friuli Venezia Giulia (FVG), Italy. Thus, a retrospective study was conducted through the integration of many administrative health databases of the FVG as the source of information. From data integration, we estimated that more than two-thirds of AAV patients showed at least one hospitalization in their medical history, most frequently caused by the disease itself or superimposed infections. Around 10% of patients developed end-stage renal disease. In an 8-year follow-up, the overall healthcare cost was € 1,215,078, corresponding to € 6,168 patient-year. ANCA-positive patients showed much higher costs than ANCA-negative patients did. Overall, AAV are rare diseases, but imply very high healthcare costs. Early diagnosis and optimal treatment probably still remain unmet needs for AAV.

Exploratory classification of clinical phenotypes in Japanese patients with antineutrophil cytoplasmic antibody-associated vasculitis using cluster analysis

A novel patient cluster in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) may be identified in Japan. We performed multiple correspondence and cluster analysis regarding 427 clinically diagnosed AAV patients excluding eosinophilic granulomatosis with polyangiitis. Model 1 included the ANCA phenotype, items of the Birmingham Vasculitis Activity Score, and interstitial lung disease; model 2 included serum creatinine (s-Cr) and C-reactive protein (CRP) levels with model 1 components. In seven clusters determined in model 1, the ANCA-negative (n = 8) and proteinase 3-ANCA-positive (n = 41) groups emerged as two distinct clusters. The other five myeloperoxidase-ANCA-positive clusters were characterized by ear, nose, and throat (ENT) (n = 47); cutaneous (n = 36); renal (n = 256), non-renal (n = 33); and both ENT and cutaneous symptoms (n = 6). Four clusters in model 2 were characterized by myeloperoxidase-ANCA negativity (n = 42), without s-Cr elevation (< 1.3 mg/dL) (n = 157), s-Cr elevation (≥ 1.3 mg/dL) with high CRP (> 10 mg/dL) (n = 71), or s-Cr elevation (≥ 1.3 mg/dL) without high CRP (≤ 10 mg/dL) (n = 157). Overall, renal, and relapse-free survival rates were significantly different across the four clusters in model 2. ENT, cutaneous, and renal symptoms may be useful in characterization of Japanese AAV patients with myeloperoxidase-ANCA. The combination of s-Cr and CRP levels may be predictive of prognosis.

Advances in cutaneous vasculitis research and clinical care

Vasculitis is characterized by inflammation and destruction of blood vessels, resulting in downstream ischemic tissue damage. Diagnosis of vasculitis is a careful exercise in clinical-pathologic correlation, depending upon the clinical manifestations, organs involved, the size of affected blood vessels, imaging, and laboratory findings. While some vasculitis subtypes may be confined to the skin, serious internal organ involvement or underlying disease states may also occur. Accordingly, the skin plays an important role in the diagnostic process and may be prognostically important in some cases, signifying more severe systemic disease. The skin also provides opportunities for tissue-based translational research, improving understanding of disease pathophysiology. Dermatologists, therefore, play a critical role in evaluating vasculitis and helping to advance vasculitis clinical care and research. Recent updates in vasculitis nomenclature and terminology, evidence-based diagnosis, pathogenesis, and investigations of targeted therapies are changing vasculitis research and leading to fundamental shifts in disease management. Treatment advances favoring evidence-based and targeted, rather than broadly immunosuppressive, therapies are in development, while a multicenter trial for skin-limited vasculitis is ongoing. Collaborative multidisciplinary research networks are key to current and future advances in vasculitis research. In this review, we describe recent developments in vasculitis clinical care and research, starting with a discussion of efforts to develop diagnostic and classification criteria, followed by updates on the evaluation and treatment of vasculitis.

Impaired Kidney Function Associated with Increased Risk of Side Effects in Patients with Small Vessel Vasculitis Treated with Rituximab as an Induction Therapy

Rituximab (RTX), a monoclonal antibody against the CD20 molecule, is used as an induction therapy in the treatment of small vessel vasculitis (SVV). The aim of the study was to evaluate the efficacy and safety of RTX induction therapy for refractory SVV. A retrospective analysis of 20 patients treated with RTX for active SVV (BVAS/WG ≥ 3) was performed to assess the remission rate and the drug-related severe adverse events 6 months after therapy. The mean age of the studied population was 49 ± 13 years (50% female), 90% of which were PR3-ANCA positive. Complete remission was achieved in 85% of patients, and partial remission was achieved in a further 10% within 6 months after RTX infusions. The remission rate was not influenced by kidney function. Adverse events such as infections (25%), a late onset of neutropenia (10%) and severe hypogammaglobulinemia (5%) were noted. The patients who developed adverse events were older (42 ± 11 vs. 57 ± 12 years; p = 0.014) and had a higher serum creatinine level (1.3 mg/dL vs. 3.35 mg/dL; p = 0.044). Patients with a glomerular filtration rate (eGFR) lower than 30 mL/min/1.73 m² had a nine-fold higher risk of side effects (OR 9.0, 95%CI: 1.14-71.0). In conclusion, RTX was highly effective as an induction therapy in patients with SVV. Advanced kidney failure with an eGFR lower than 30 mL/min/1.73 m² was one of the risk factors for the occurrence of side effects.

Granulomatosis with polyangiitis: Study of 795 patients from the French Vasculitis Study Group registry

OBJECTIVE

To describe the characteristics and long-term outcomes of patients with granulomatosis with polyangiitis (GPA) from the French Vasculitis Study Group database.

METHODS

Patients' clinical and laboratory characteristics, Birmingham Vasculitis Activity Score (BVAS)-assessed disease activity, malignancies, opportunistic infections, and vital status were collected at diagnosis and each visit. Estimated probabilities and predictors of overall (OS) and relapse-free survival (RFS) were analyzed by Cox regression.

RESULTS

We enrolled 795 newly diagnosed patients, followed for a median of 3.5 years. Initial clinical manifestations involved ear, nose & throat (ENT; 80%), lungs (68%) and kidneys (56%). Among the 728 available ELISA results, 75.0% were PR3-ANCA-positive, 16.5% MPO-ANCA-positive and 62 (8.5%) ANCA-negative. Relapses occurred in 394 (50%) patients, involving ≥1 organ(s) affected at onset in 179 (46%), mainly ENT, lungs and kidneys, with mean BVAS 10.2 points below that at diagnosis (p<0.001). Five- and 10-year RFS rates were 37% and 17%, respectively. PR3-ANCA-positivity independently predicted relapse (p = 0.05) and prolonged survival (p = 0.038). OS-but not RFS-improved significantly over time (p<0.001); 10-year OS reached 88.2% (95% CI 83.9 to 92.7) for the 660 patients diagnosed after 2000. Infections were the main causes of death. Malignancy or opportunistic infection each occurred in ≤5% of the patients.

CONCLUSION

Survival has improved dramatically over the last decades but the high relapse rate remains a major concern for GPA patients, once again stressing the need for therapeutic strategy optimization to lower it. PR3-ANCA-positivity was associated with increased probability of relapse and survival.

Association between age at disease onset of anti-neutrophil cytoplasmic antibody-associated vasculitis and clinical presentation and short-term outcomes

OBJECTIVES

ANCA-associated vasculitis (AAV) can affect all age groups. We aimed to show that differences in disease presentation and 6 month outcome between younger- and older-onset patients are still incompletely understood.

METHODS

We included patients enrolled in the Diagnostic and Classification Criteria for Primary Systemic Vasculitis (DCVAS) study between October 2010 and January 2017 with a diagnosis of AAV. We divided the population according to age at diagnosis: <65 years or ≥65 years. We adjusted associations for the type of AAV and the type of ANCA (anti-MPO, anti-PR3 or negative).

RESULTS

A total of 1338 patients with AAV were included: 66% had disease onset at <65 years of age [female 50%; mean age 48.4 years (s.d. 12.6)] and 34% had disease onset at ≥65 years [female 54%; mean age 73.6 years (s.d. 6)]. ANCA (MPO) positivity was more frequent in the older group (48% vs 27%; P = 0.001). Younger patients had higher rates of musculoskeletal, cutaneous and ENT manifestations compared with older patients. Systemic, neurologic,cardiovascular involvement and worsening renal function were more frequent in the older-onset group. Damage accrual, measured with the Vasculitis Damage Index (VDI), was significantly higher in older patients, 12% of whom had a 6 month VDI ≥5, compared with 7% of younger patients (P = 0.01). Older age was an independent risk factor for early death within 6 months from diagnosis [hazard ratio 2.06 (95% CI 1.07, 3.97); P = 0.03].

CONCLUSION

Within 6 months of diagnosis of AAV, patients >65 years of age display a different pattern of organ involvement and an increased risk of significant damage and mortality compared with younger patients.

Intense immunostaining of heat shock protein 70 within renal interstitium associates with long-term renal survival in an ANCA-associated vasculitis cohort

In anti-neutrophilic cytoplasmic antibody (ANCA)-associated vasculitis (AAV) genetic predisposition, ANCA autoantibodies, neutrophil extracellular traps (NETs), complement activation, and toll-like receptor signaling are implicated in AAV pathogenesis. Heat shock proteins (HSPs), a highly conserved group of small-sized molecular chaperones, take part in protein folding during cellular stress. Although HSPs were initially observed intracellularly, it has been shown that they can be secreted in the extracellular space and modulate the immune response in various autoimmune diseases including AAV. The scope of the present study is to investigate the role of heat shock protein 60 (HSP60) and 70 (HSP70) in the long renal effects in an ANCA vasculitis cohort. In this cohort of ANCA-associated vasculitis, 29 patients were followed up over 20 years. At diagnosis, immunohistochemistry was performed for HSP60 and HSP70 within the various nephron compartments. Higher renal HSP60 expression was associated with increased interstitial inflammatory infiltrates at diagnosis, while HSP70 expression was associated with a greater extent of interstitial fibrosis at diagnosis. Notably, intense tissue expression of HSP70 at the time of biopsy was associated with a worsened kidney survival. Renal HSP70 expression was associated with poor renal outcomes during long-term follow-up. This finding may indicate a role of HSPs in renal disease progression in ANCA vasculitis. Further validating studies are needed to verify a causative association between HSP70 expression and renal outcomes in ANCA-associated vasculitis.

Proposal for a more practical classification of antineutrophil cytoplasmic antibody-associated vasculitis

The nomenclature for antineutrophil cytoplasmic antibody (ANCA)-associated kidney disease has evolved from honorific eponyms to a descriptive-based classification scheme (Chapel Hill Consensus Conference 2012). Microscopic polyangiitis, granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis do not correlate with presentation, response rates and relapse rates as when comparing myeloperoxidase versus leukocyte proteinase 3. Here we discuss the limitations of the currently used classification and propose an alternative, simple classification according to (i) ANCA type and (ii) organ involvement, which provides important clinical information of prognosis and outcomes.

Topic modeling to characterize the natural history of ANCA-Associated vasculitis from clinical notes: A proof of concept study

OBJECTIVES

Clinical notes from electronic health records (EHR) are important to characterize the natural history, comorbidities, and complications of ANCA-associated vasculitis (AAV) because these details may not be captured by claims and structured data. However, labor-intensive chart review is often required to extract information from notes. We hypothesized that machine learning can automatically discover clinically-relevant themes across longitudinal notes to study AAV.

METHODS

This retrospective study included prevalent PR3- or MPO-ANCA+ AAV cases managed within the Mass General Brigham integrated health care system with providers' notes available between March 1, 1990 and August 23, 2018. We generated clinically-relevant topics mentioned in notes using latent Dirichlet allocation-based topic modeling and conducted trend analyses of those topics over the 2 years prior to and 5 years after the initiation of AAV-specific treatment.

RESULTS

The study cohort included 660 patients with AAV. We generated 90 topics using 113,048 available notes. Topics were related to the AAV diagnosis, treatment, symptoms and manifestations (e.g., glomerulonephritis), and complications (e.g., end-stage renal disease, infection). AAV-related symptoms and psychiatric symptoms were mentioned months before treatment initiation. Topics related to pulmonary and renal diseases, diabetes, and infections were common during the disease course but followed distinct temporal patterns.

CONCLUSIONS

Automated topic modeling can be used to discover clinically-relevant themes and temporal patterns related to the diagnosis, treatment, comorbidities, and complications of AAV from EHR notes. Future research might compare the temporal patterns in a non-AAV cohort and leverage clinical notes to identify possible AAV cases prospectively.

Cardiac Involvement in Eosinophilic Granulomatosis With Polyangiitis: A Retrospective Study in the Chinese Population

Introduction: Cardiac involvement in eosinophilic granulomatosis with polyangiitis (EGPA) is associated with a poor prognosis and high mortality; however, few studies about cardiac involvement in EGPA in the Chinese population are available. We conducted this study to determine the clinical characteristics and overall outcomes of Chinese EGPA patients with cardiac involvement. Materials and Methods: We retrospectively collected the clinical data of 83 patients diagnosed with EGPA and analyzed the differences between the patients with and without cardiac involvement. Results: The prevalence of cardiac involvement in EGPA in this cohort was 27.7%. Compared with those without cardiac involvement, EGPA patients with cardiac involvement tended to have a younger age at onset (mean ± SD: 38.4 ± 10.5 vs. 42.1 ± 15.9 years, respectively, p = 0.039), higher eosinophil count (median [IQR]: 5810 [4020-11090] vs. 2880 [1530-6570] n/μL, respectively, p = 0.004), higher disease activity assessed using the Birmingham vasculitis activity score (BVAS) (median [IQR]: 20 [16-28] vs. 15 [12-18], respectively, p = 0.001), and poorer prognosis (Five Factor Score [FFS] ≥ 1: 100% vs. 38.3%, respectively, p = 0.001). In the cardiac involvement group, 43.5% of patients were asymptomatic, but cardiac abnormalities could be detected by cardiac examinations. With appropriate treatment, the overall outcomes of EGPA patients with cardiac involvement in our cohort were good, with only 3 (13.0%) patients dying in the acute phase and no patients dying during follow-up. Conclusions: Cardiac involvement in EGPA was associated with a younger age at onset, higher eosinophil count, higher disease activity, and a poorer prognosis. Comprehensive cardiac examinations and appropriate treatment are essential to improve the prognosis of those with cardiac involvement.

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.

Rituximab maintenance therapy for patients with antineutrophil cytoplasmic antibody-associated vasculitis in Japan

OBJECTIVES

We examined the efficacy and safety of rituximab (RTX) maintenance therapy for patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in Japan.

METHODS

We conducted a retrospective study using a multi-center cohort database of vasculitis patients. All maintenance treatment courses were divided into three groups: a RTX group, a group treated with other immunosuppressant drugs (IS) and a group receiving glucocorticoid monotherapy (GC). The primary endpoint was the comparison of relapse-free survival after 1 year. We also analyzed the occurrence of severe adverse events (SAEs) to assess safety.

RESULTS

We included 123 courses of 107 patients (RTX n = 14, IS n = 64, GC n = 45). Twelve of 14 in the RTX group patients were diagnosed with granulomatosis with polyangiitis (GPA). The relapse-free survival of RTX maintenance therapy was comparable to that in the other groups (p = .122). After 1 year of treatment, the RTX group was administered lower steroid doses and one-third of them could withdraw corticosteroid. The overall incidence of SAE was 0.54/patient-year in the RTX group, 0.39/patient-year in the IS group and 0.34/patient-year in the GC group.

CONCLUSION

RTX maintenance therapy could be effective and safe in Japanese GPA patients.

Clinical phenotypes of IgG4-related disease reflect different prognostic outcomes

Introduction

Four clinical phenotypes of IgG4-related disease (IgG4-RD) have been recently identified by latent class analysis (LCA): pancreato-biliary (group 1); retroperitoneum/aortitis (group 2); head and neck limited (group 3); and Mikulicz/systemic (group 4). The reproducibility of this classification in clinical practice and its relevance for patient management, however, remain unknown.

Methods

The study included 179 patients. Four IgG4-RD experts were asked to classify a validation cohort of 40 patients according to published LCA-derived phenotypes based on clinical judgement. Agreement between LCA and clinical clustering was calculated. To assess differences among disease phenotypes, the following variables were recorded on an additional 139 patients: serum IgG4 and IgE; inflammatory markers; eosinophils; plasmablasts; IgG4-RD responder index (RI); history of atopy, diabetes, osteoporosis, relapses and malignancy; cumulative dose of glucocorticoids; and use of rituximab.

Results

Clinical judgement replicated LCA classification with strong agreement among IgG4-RD experts (κ = 0.841, P &lt; 0.0005). At disease onset, group 1 showed the highest levels of serum IgG4 and IgE. Groups 2 and 4 had the lowest and highest IgG4-RD RI, respectively. At 2 years’ follow-up, group 3 received the highest cumulative dose of glucocorticoids, but higher incidences of diabetes mellitus were observed in groups 1 and 4, consistent with the higher likelihood of pancreatic involvement in groups 1 and 4. No difference among the four groups was observed in terms of disease recurrence, time to relapse and frequency of rituximab infusion.

Conclusion

Clinical phenotypes of IgG4-RD reflect differences in epidemiological features and prognostic outcomes.