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Rare disease data is often fragmented within multiple heterogeneous siloed regional disease registries, each containing a small number of cases. These data are particularly sensitive, as low subject counts make the identification of patients more likely, meaning registries are not inclined to share subject level data outside their registries. At the same time access to multiple rare disease datasets is important as it will lead to new research opportunities and analysis over larger cohorts. To enable this, two major challenges must therefore be overcome. The first is to integrate data at a semantic level, so that it is possible to query over registries and return results which are comparable. The second is to enable queries which do not take subject level data from the registries. To meet the first challenge, this paper presents the FAIRVASC ontology to manage data related to the rare disease anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV), which is based on the harmonisation of terms in seven European data registries. It has been built upon a set of key clinical questions developed by a team of experts in vasculitis selected from the registry sites and makes use of several standard classifications, such as Systematized Nomenclature of Medicine - Clinical Terms (SNOMED-CT) and Orphacode. It also presents the method for adding semantic meaning to AAV data across the registries using the declarative Relational to Resource Description Framework Mapping Language (R2RML). To meet the second challenge a federated querying approach is presented for accessing aggregated and pseudonymized data, and which supports analysis of AAV data in a manner which protects patient privacy. For additional security the federated querying approach is augmented with a method for auditing queries (and the uplift process) using the provenance ontology (PROV-O) to track when queries and changes occur and by whom. The main contribution of this work is the successful application of semantic web technologies and federated queries to provide a novel infrastructure that can readily incorporate additional registries, thus providing access to harmonised data relating to unprecedented numbers of patients with rare disease, while also meeting data privacy and security concerns., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

A specific biomarker that can separate active renal vasculitis from other causes of renal dysfunction is lacking, with a kidney biopsy often being required. Soluble CD163 (sCD163), shed by monocytes and macrophages, has been reported as a potential biomarker in diseases associated with excessive macrophage activation. Thus, we hypothesized that urinary sCD163 shed by crescent macrophages correlates with active glomerular inflammation. We detected sCD163 in rat urine early in the disease course of experimental vasculitis. Moreover, microdissected glomeruli from patients with small vessel vasculitis (SVV) had markedly higher levels of CD163 mRNA than did those from patients with lupus nephritis, diabetic nephropathy, or nephrotic syndrome. Both glomeruli and interstitium of patients with SVV strongly expressed CD163 protein. In 479 individuals, including patients with SVV, disease controls, and healthy controls, serum levels of sCD163 did not differ between the groups. However, in an inception cohort, including 177 patients with SVV, patients with active renal vasculitis had markedly higher urinary sCD163 levels than did patients in remission, disease controls, or healthy controls. Analyses in both internal and external validation cohorts confirmed these results. Setting a derived optimum cutoff for urinary sCD163 of 0.3 ng/mmol creatinine for detection of active renal vasculitis resulted in a sensitivity of 83%, specificity of 96%, and a positive likelihood ratio of 20.8. These data indicate that urinary sCD163 level associates very tightly with active renal vasculitis, and assessing this level may be a noninvasive method for diagnosing renal flare in the setting of a known diagnosis of SVV., (Copyright © 2016 by the American Society of Nephrology.)

ANCA vasculitis encompasses several autoimmune conditions characterised by destruction of small vessels, inflammation of the respiratory tract and glomerulonephritis. Most patients harbour autoantibodies to myeloperoxidase (MPO) or proteinase 3 (PR3). Clinical and experimental data suggest that pathogenesis is driven by ANCA-mediated activation of neutrophils and monocytes. We investigated a potential role for distinct monocyte subsets. We found that the relative proportion of intermediate monocytes is increased in patients versus control individuals, and both MPO and PR3 are preferentially expressed on these cells. We demonstrate that MPO and PR3 are expressed independently of each other on monocytes and that PR3 is not associated with CD177. MPO expression correlates with that of Fc receptor CD16 on intermediate monocytes. Monocyte subsets respond differently to antibodies directed against MPO and PR3, with anti-MPO but not anti-PR3 leading to increased IL-1β, IL-6 and IL-8 production. In concordance with the observed higher surface expression of MPO on intermediate monocytes, this subset produces the highest quantity of IL-1β in response to anti-MPO stimulation. These data suggest that monocytes, specifically, the intermediate subset, may play a role in ANCA vasculitis, and also indicate that substantial differences exist between the effect of anti-MPO and anti-PR3 antibodies on these cells.

The morbidity burden associated with anti-neutrophil cytoplasmic autoantibody-associated vasculitis is increasing, and many novel biological therapies are now entering the drug development pipeline. There is thus an urgent need to develop a representative animal model to facilitate testing of these agents. We previously examined the effect of antineutrophil cytoplasmic autoantibody on leukocyte-endothelial interactions in WKY rats via immunization with human myeloperoxidase. We now seek to extend this model so that all animals reliably develop crescentic glomerulonephritis and lung hemorrhage. We also wish to investigate whether there is a genetic contribution to vasculitis development in this rat strain. Using escalating doses of human myeloperoxidase, we found that a dose of 1600 microg/kg induced pauci-immune crescentic glomerulonephritis and lung hemorrhage in all immunized animals. We also found that the addition of pertussis toxin and killed Mycobacterium tuberculosis to the adjuvant when immunizing with 400 microg/kg of myeloperoxidase resulted in crescentic glomerulonephritis and lung hemorrhage in all animals. However, when Lewis, Wistar Furth, or Brown Norway rats were immunized using a similar protocol, no animals developed hematuria or glomerulonephritis, despite having identical levels of anti-human myeloperoxidase antibodies. We conclude that, by adjusting the immunization regimen, all WKY rats immunized with myeloperoxidase develop experimental autoimmune vasculitis, thus facilitating future therapeutic studies. The resistance of Lewis rats to experimental autoimmune vasculitis provides a genetic basis for future studies of anti-myeloperoxidase antibody-associated vasculitis.

Aberrant interaction between the leukocyte and the endothelial cell (EC) results in the uncontrolled inflammation seen in systemic small vessel vasculitis. This review discusses our current understanding of this process and includes consideration of the role of adhesion molecules, proteases and the neutrophil respiratory burst. The effects of anti-neutrophil cytoplasm antibodies and anti-endothelial cell antibodies and their pathogenic roles are examined, and we look at experimental disease models. Specificity of disease-targetted endothelial beds and the role of circulating EC are discussed.

The therapeutic options for anti-neutrophil cytoplasm antibody (ANCA)-associated systemic vasculitis (AASV) remain limited and hampered by adverse effects. One potential novel therapeutic avenue involves inhibition of TNF-alpha, with encouraging uncontrolled data in humans with one agent (infliximab) but disappointing controlled data from another (etanercept). For investigating the potential role of TNF-alpha as a therapeutic target in AASV, the effect of an anti-rat TNF-alpha mAb (CNTO 1081) in a rat model of AASV was investigated. For testing the effect of TNF-alpha blockade in this model, starting on day 28 after immunization (a point when glomerulonephritis is established), animals were randomized to treatment with CNTO 1081 or control mouse IgG. Treatment with CNTO 1081 significantly reduced albuminuria (mean 1.1 +/- 0.3 mg/24 h CNTO 1081 versus 8.0 +/- 1.9 controls; P < 0.05) and crescent formation (0% CNTO 1081 versus 60% controls; P < 0.05). Lung hemorrhage was also reduced (CNTO 1081: median score 0, range 0 to 2; controls: 2, range 1 to 3; P < 0.05). When analyzed by intravital microscopy, there was a 43% inhibition of leukocyte transmigration in mesenteric venules in response to topical CXCL1 (a neutrophil chemoattractant) in the CNTO 1081 group compared with controls (P < 0.001). Anti-myeloperoxidase antibody titers were similar in both groups throughout the study. In conclusion, these findings indicate that TNF-alpha plays an important role in the pathogenesis of experimental autoimmune vasculitis and suggest that blockade of this cytokine with an mAb is effective in treating established vasculitis. The therapeutic action of anti-TNF-alpha reagents may be mediated, in part, by suppression of the enhanced leukocyte-endothelial interactions in this disorder.

A patient with antineutrophil cytoplasm antibody-associated vasculitis frequently has multisystem disease and might present to a range of medical specialities. The manifestations that result in the greatest burden of morbidity and mortality are renal and pulmonary disease. In this review we will focus on rapidly progressive glomerulonephritis due to vasculitis, with specific reference to recent advances in our understanding of pathogenesis. The current standard of care for managing renal vasculitis, be it mild, moderate or severe, has largely been established in clinical trials of prednisolone, cyclophosphamide, methotrexate, azathioprine and plasma exchange. In addition to these, newer therapies such as mycophenolate mofetil and infliximab are being used more frequently. We will review the role of each of these approaches to management of small vessel vasculitis in 2005.

Background: Previous studies in systemic vasculitis have defined a number of disease-specific factors including histological parameters and clinical vasculitis activity scores as outcome predictors. This study evaluates the previously neglected role of non-vasculitic factors in determining prognosis in this condition., Methods: We performed a retrospective study of all patients with a diagnosis of small vessel vasculitis (SVV) presenting with renal impairment to our service over a 12-year period., Results: Eighty-six patients were studied (median age 63.5 years, 64% male). Mean plasma creatinine at presentation was 533 micro M (6.3 mg/dl). Forty-seven patients (55%) required immediate dialysis, 21 (45%) recovered renal function on treatment. The presence of crescent fibrosis (P < 0.05) and interstitial fibrosis (P < 0.01) were significantly associated with a failure to recover renal function. There was a trend towards an increased relapse rate in those with a persistently positive ANCA result or a rising titre. Twelve month patient survival was 85.5% and 5-year survival was 63%. Factors independently associated with mortality were Karnofsky performance score at diagnosis (P < 0.00001), intensity of immunosuppressive treatment (P = 0.0007) and vasculitis classification (P = 0.009). Non-vasculitic co-morbidity was not independently associated with mortality. Patients who were, or became after treatment, dialysis-independent had a significant survival advantage (5-year survival 83 vs 42%, P = 0.001)., Conclusions: Non-vasculitic factors, particularly functional status as indicated by the Karnofsky performance score, play a major role in determining prognosis in SVV with renal involvement and should be an integral component of the decision making process when planning therapy, and in comparing outcomes between centres.

Environmental factors amplified by climate change contribute significantly to the global burden of disease, disproportionately impacting vulnerable populations, such as individuals with rare diseases. Researchers require innovative, dynamic data linkage methods to enable the development of risk prediction models, particularly for diseases like vasculitis with unknown aetiology but potential environmental triggers. In response, we present the Semantic Environmental and Rare Disease Data Integration Framework (SERDIF). SERDIF was evaluated with researchers studying climate-related health hazards of vasculitis disease activity across European countries (NP1 = 10, NP2 = 17, NP3 = 23). Usability metrics consistently improved, indicating SERDIF's effectiveness in linking complex environmental and health datasets. Furthermore, SERDIF-enabled epidemiologists to study environmental factors in a pregnancy cohort in Lombardy, showcasing its versatility beyond rare diseases. This framework offers for the first time a user-friendly, FAIR-compliant design for environment-health data linkage with export capabilities enabling data analysis to mitigate health risks posed by climate change. [ABSTRACT FROM AUTHOR]

Objectives Increasing studies demonstrated the importance of C5a and anti-neutrophil cytoplasmic antibody (ANCA)-induced neutrophil activation in the pathogenesis of ANCA-associated vasculitis (AAV). Sphingosine-1-phosphate (S1P) acts as a downstream effector molecule of C5a and enhances neutrophil activation induced by C5a and ANCA. The current study investigated the role of a S1P receptor modulator, FTY720, in experimental autoimmune vasculitis (EAV) and explored the immunometabolism-related mechanisms of FTY720 in modulating ANCA-induced neutrophil activation. Methods The effects of FTY720 in EAV were evaluated by quantifying haematuria, proteinuria, crescent formation, tubulointerstitial injury and pulmonary haemorrhage. RNA sequencing of renal cortex and gene enrichment analysis were performed. The proteins of key identified pathways were analysed in neutrophils isolated from peripheral blood of patients with active AAV and normal controls. We assessed the effects of FTY720 on ANCA-induced neutrophil respiratory burst and neutrophil extracellular traps formation (NETosis). Results FTY720 treatment significantly attenuated renal injury and pulmonary haemorrhage in EAV. RNA sequencing analyses of renal cortex demonstrated enhanced fatty acid oxidation (FAO) and peroxisome proliferator-activated receptor (PPAR) signalling in FTY720-treated rats. Compared with normal controls, patients with active AAV showed decreased FAO in neutrophils. FTY720-treated differentiated HL-60 cells showed increased expression of carnitine palmitoyltransferase 1a (CPT1a) and PPARα. Blocking or knockdown of CPT1a or PPARα in isolated human neutrophils and HL-60 cells reversed the inhibitory effects of FTY720 on ANCA-induced neutrophil respiratory burst and NETosis. Conclusion FTY720 attenuated renal injury in EAV through upregulating FAO via the PPARα–CPT1a pathway in neutrophils, offering potential immunometabolic targets in AAV treatment. [ABSTRACT FROM AUTHOR]

The article discusses relapse prediction in antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) following the PEXIVAS trial. Topics discussed include the evaluation of plasma exchange and reduced-dose glucocorticoids on relapse rates, the identification of baseline predictors for relapse risk, and the need for dynamic, personalized models to forecast future relapse probabilities in AAV patients.

Objectives Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of life-threatening autoimmune diseases. Inhibitors of apoptosis proteins (IAPs) are a class of molecules engaged in cell death and inflammation, interventions of which are proven effective in a number of inflammatory diseases. Here we tested whether targeting IAPs could ameliorate AAV and explored the potential mechanism. Methods We collected 19 kidney specimens from patients with myeloperoxidase (MPO)-AAV to investigate the expression of IAPs. The IAP pan-inhibitor SM164 was used to treat the experimental autoimmune vasculitis (EAV) rat model of AAV. RNA sequencing of renal cortex and enrichment analysis were developed to interpret gene expression. Functional experiments were performed to investigate the role of SM164 on neutrophils and endothelial cells. Results The expression of three IAPs (cIAP1, cIAP2 and XIAP) was upregulated in kidneys of AAV patients compared with normal controls. SM164 dramatically reduced renal injury in EAV rats. Transcriptomic analysis revealed prominent alterations in fatty acid oxidation and respiratory burst following SM164 treatment. Functional studies demonstrated that SM164 inhibited neutrophil activation induced by MPO-ANCA positive IgG or serum from MPO-AAV patients, and such inhibitory effect was abolished by gene silencing or pharmacological inhibition of fatty acid oxidation. SM164 also inhibited the adhesion of neutrophils to endothelial cells with little effect on the endothelial injury induced by serum from MPO-AAV patients. Conclusion Inhibition of IAPs with SM164 played a protective role in AAV through enhancing intracellular fatty acid oxidation in neutrophils. [ABSTRACT FROM AUTHOR]

Avoiding end-stage kidney disease in patients with anti-neutrophil cytoplasmic antibody–associated vasculitis (AAV) has a high therapeutic priority. Although renal response is a crucial measure to capture clinically relevant changes, clinal trials have used various definitions and no well-studied key surrogate markers to predict renal outcome in AAV exist. Differences in clinical features and histopathologic and therapeutic approaches will influence the course of kidney function. Its assessment through traditional surrogates (i.e. serum creatinine, glomerular filtration rate, proteinuria, hematuria and disease activity scores) has limitations. Refinement of these markers and the incorporation of novel approaches such as the assessment of histopathological changes using cutting-edge molecular and machine learning mechanisms or new biomarkers could significantly improve prognostication. The timing is favourable since large datasets of trials conducted in AAV are available and provide a valuable resource to establish renal surrogate markers and, likely, aim to investigate optimized and tailored treatment approaches according to a renal response score. In this review we discuss important points missed in the assessment of kidney function in patients with AAV and point towards the importance of defining renal response and clinically important short- and long-term predictors of renal outcome. [ABSTRACT FROM AUTHOR]

Objective To investigate the occurrence of venous thromboembolic events (VTE) in a large cohort of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) across the European Union, Turkey, Russia, UK and North America. Methods Patients with a definite diagnosis of AAV who were followed for at least 3 months and had sufficient documentation were included. Data on VTE, including either deep vein thrombosis or pulmonary embolism, were collected retrospectively from tertiary vasculitis centres. Univariate and multivariate regression models were used to estimate odds ratios (ORs) and 95% CIs. Results Over a median follow-up of 63 (interquartile range: 29, 101) months, VTE occurred in 278 (9.7%) of 2869 AAV patients with a similar frequency across different countries (from 6.3% to 13.7%), and AAV subtype [granulomatosis with polyangiitis: 9.8% (95% CI: 8.3, 11.6%); microscopic polyangiitis: 9.6% (95% CI: 7.9, 11.4%); and eosinophilic granulomatosis with polyangiitis: 9.8% (95% CI: 7.0, 13.3%)]. Most VTE (65.6%) were reported in the first-year post-diagnosis. Multiple factor logistic regression analysis adjusted for sex and age showed that skin (OR 1.71, 95% CI: 1.01, 2.92), pulmonary (OR 1.78, 95% CI: 1.04, 3.14) and kidney [eGFR 15–60 ml/min/1.73 m2, OR 2.86 (95% CI: 1.27, 6.47); eGFR <15 ml/min/1.73 m2, OR 6.71 (95% CI: 2.94, 15.33)] involvement were independent variables associated with a higher occurrence of VTE. Conclusion Two-thirds of VTE occurred during the initial phase of active disease. We confirmed previous findings from smaller studies that a decrease in kidney function, skin involvement and pulmonary disease are independently associated with VTE. [ABSTRACT FROM AUTHOR]

Objective: COVID‐19 is a novel infectious disease with a broad spectrum of clinical severity. Patients with systemic vasculitis have an increased risk of serious infections and may be at risk of severe outcomes following COVID‐19. We undertook this study to establish the risk factors for severe COVID‐19 outcomes in these patients, including the impact of immunosuppressive therapies. Methods: A multicenter cohort was developed through the participation of centers affiliated with national UK and Ireland vasculitis registries. Clinical characteristics and outcomes are described. Logistic regression was used to evaluate associations between potential risk factors and a severe COVID‐19 outcome, defined as a requirement for advanced oxygen therapy, a requirement for invasive ventilation, or death. Results: The cohort included 65 patients with systemic vasculitis who developed COVID‐19 (median age 70 years, 49% women), of whom 25 patients (38%) experienced a severe outcome. Most patients (55 of 65 [85%]) had antineutrophil cytoplasmic antibody–associated vasculitis (AAV). Almost all patients required hospitalization (59 of 65 [91%]), 7 patients (11%) were admitted to intensive care, and 18 patients (28%) died. Background glucocorticoid therapy was associated with severe outcomes (adjusted odds ratio [OR] 3.7 [95% confidence interval 1.1–14.9]; P = 0.047), as was comorbid respiratory disease (adjusted OR 7.5 [95% confidence interval 1.9–38.2]; P = 0.006). Vasculitis disease activity and nonglucocorticoid immunosuppressive therapy were not associated with severe outcomes. Conclusion: In patients with systemic vasculitis, glucocorticoid use at presentation and comorbid respiratory disease were associated with severe outcomes in COVID‐19. These data can inform clinical decision‐making relating to the risk of severe COVID‐19 in this vulnerable patient group. [ABSTRACT FROM AUTHOR]

The article describes the case of acute renal allograft failure in a 31-year-old female patient with vasculitis. Topics discussed include the symptoms of the patient such as headache, polyarthralgia, epistaxis, fatigue and vomiting, factors considered that led to the diagnosis of destruction of the renal transplant, namely, the presence of donor-specific antibodies (DSA) and focal necrotising glomerulonephritis, and significance of the novel diagnostics used in the case.

Type I interferon (IFN) dysregulation is a major contributory factor in the development of several autoimmune diseases, termed type I interferonopathies, and is thought to be the pathogenic link with chronic inflammation in these conditions. Anti-neutrophil cytoplasmic antibody (ANCA)-Associated Vasculitis (AAV) is an autoimmune disease characterised by necrotising inflammation of small blood vessels. The underlying biology of AAV is not well understood, however several studies have noted abnormalities in type I IFN responses. We hypothesised that type I IFN responses are systemically dysregulated in AAV, consistent with features of a type I interferonopathy. To investigate this, we measured the expression of seven interferon regulated genes (IRGs) (ISG15, SIGLEC1, STAT1, RSAD2, IFI27, IFI44L and IFIT1) in peripheral blood samples, as well as three type I IFN regulated proteins (CXCL10, MCP-1 and CCL19) in serum samples from AAV patients, healthy controls and disease controls. We found no difference in type I IFN regulated gene or protein expression between AAV patients and healthy controls. Furthermore, IRG and IFN regulated protein expression did not correlate with clinical measurements of disease activity in AAV patients. Thus, we conclude that systemic type I IFN responses are not key drivers of AAV pathogenesis and AAV should not be considered a type I interferonopathy. [ABSTRACT FROM AUTHOR]

An international consensus on anti-neutrophil cytoplasm antibodies (ANCA) testing in eosinophilic granulomatosis with polyangiitis (EGPA) is presented. ANCA, specific for myeloperoxidase (MPO), can be detected in 30-35% of EGPA patients. MPO-ANCA should be tested with antigen-specific immunoassays in any patient with eosinophilic asthma and clinical features suggesting EGPA, including constitutional symptoms, purpura, polyneuropathy, unexplained heart, gastrointestinal or kidney disease, and/or pulmonary infiltrates or hemorrhage. A positive MPO-ANCA result contributes to the diagnostic work‑up for EGPA. Patients with MPO-ANCA associated EGPA have more frequently vasculitis features, such as glomerulonephritis, neuropathy, and skin manifestations than patients with ANCA negative EGPA. However, the presence of MPO-ANCA is neither sensitive nor specific enough to identify whether a patient should be subclassified as having "vasculitic" or "eosinophilic" EGPA. At present, ANCA status cannot guide treatment decisions, that is, whether cyclophosphamide, rituximab or mepolizumab should be added to conventional glucocorticoid treatment. In EGPA, monitoring of ANCA is only useful when MPO-ANCA was tested positive at disease onset. [ABSTRACT FROM AUTHOR]

Sphingosine-1-phosphate (S1P) is a pleiotropic lysosphingolipid derived from the metabolism of plasma membrane lipids. The interaction between S1P and its ubiquitously expressed G-protein-coupled receptors (S1PR1-5) is crucial in many pathophysiological processes. Emerging evidence suggested a potential role for S1P receptors in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). In the present study, we investigated the effects of three different S1P receptors modulators (FTY720, SEW2871 and TY52156) in a recognized rat model of experimental autoimmune vasculitis (EAV). The effects of treatments were evaluated with clinico-pathological parameters including hematuria, proteinuria, crescent formation, pulmonary hemorrhage, etc. In vitro functional studies were performed in a Jurkat T-cell line following stimulations of serum from myeloperoxidase-AAV patients. We found that only the FTY720 treatment significantly alleviated hematuria and proteinuria, and diminished glomerular crescent formation, renal tubulointerstitial lesions and pulmonary hemorrhage in EAV. The attenuation was accompanied by less renal T-cell infiltration, up-regulated mRNA of S1PR1 and down-regulated IL-1ß in kidneys, but not altered circulating ANCA levels, suggesting that the therapeutic effects of FTY720 were B-cell independent. Further in vitro studies demonstrated that FTY720 incubation could significantly inhibit the proliferation, adhesion, and migration, and increase apoptosis of T cells. In conclusion, the S1P modulator FTY720 could attenuate EAV through the reduction and inhibition of T cells, which might become a novel treatment of ANCA-associated vasculitis. [ABSTRACT FROM AUTHOR]

ANCA-associated vasculitis (AAV) is a severe systemic autoimmune disease. A key feature of AAV is the presence of Anti-Neutrophil Cytoplasmic Antibodies (ANCA) directed against myeloperoxidase (MPO) or proteinase-3 (PR3). ANCA are key to the pathogenesis of AAV, where they activate innate immune cells to drive inflammation. Pre-activation or 'priming' of immune cells appears to be important for complete cellular activation in AAV. The burgeoning field of immunometabolism has illuminated the governance of immune cell function by distinct metabolic pathways. There is ample evidence that the priming events synonymous with AAV alter immune cell metabolism. In this review we discuss the pathogenesis of AAV and its intersection with recent insights into immune cell metabolism. [ABSTRACT FROM AUTHOR]

Background Prior work has shown that urinary soluble CD163 (usCD163) displays excellent biomarker characteristics for detection of active renal vasculitis using samples that included new diagnoses with highly active renal disease. This study focused on the use of usCD163 in the detection of the more clinically relevant state of mild renal flare and compared results of usCD163 testing directly to testing of urinary monocyte chemoattractant protein-1 (uMCP-1). Methods Patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV, n  = 88) were identified within a serially sampled, longitudinal and multicentre cohort. Creatinine-normalized usCD163 and uMCP-1 levels were measured by enzyme-linked immunosorbent assay and, both alone and in combination, were compared between times of active renal AAV and during remission and/or active non-renal AAV. Results Samples from 320 study visits included times of active renal vasculitis (n  = 39), remission (n  = 233) and active extrarenal vasculitis (n  = 48). Median creatinine levels were 0.9 mg/dL [interquartile range (IQR) 0.8–1.2] in remission and 1.4 mg/dL (IQR 1.0–1.8) during renal flare. usCD163 levels were higher in patients with active renal vasculitis compared with patients in remission and those with active extrarenal vasculitis, with median values of 162 ng/mmol (IQR 79–337), 44 (17–104) and 38 (7–76), respectively (P < 0.001). uMCP-1 levels were also higher in patients with active renal vasculitis compared with patients in remission and those with active extrarenal vasculitis, with median values of 10.6 pg/mmol (IQR 4.6–23.5), 4.1 (2.5–8.4) and 4.1 (1.9–6.8), respectively (P < 0.001). The proposed diagnostic cut-points for usCD163 and uMCP-1 were 72.9 ng/mmol and 10.0 pg/mmol, respectively. usCD163 and uMCP-1 levels were marginally correlated (r 2 = 0.11, P < 0.001). Combining novel and existing biomarkers using recursive tree partitioning indicated that elevated usCD163 plus either elevated uMCP-1 or new/worse proteinuria improved the positive likelihood ratio (PLR) of active renal vasculitis to 19.2. Conclusion A combination of usCD163 and uMCP-1 measurements appears to be useful in identifying the diagnosis of subtle renal vasculitis flare. [ABSTRACT FROM AUTHOR]

Low Density Granulocytes (LDGs), which appear in the peripheral blood mononuclear cell layer of density-separated blood, are seen in cancer, sepsis, autoimmunity, and pregnancy. Their significance in ANCA vasculitis (AAV) is little understood. As these cells bear the autoantigens associated with this condition and have been found to undergo spontaneous NETosis in other diseases, we hypothesized that they were key drivers of vascular inflammation. We found that LDGs comprise a 3-fold higher fraction of total granulocytes in active vs. remission AAV and disease controls. They are heterogeneous, split between cells displaying mature (75%), and immature (25%) phenotypes. Surprisingly, LDGs (unlike normal density granulocytes) are hyporesponsive to anti-myeloperoxidase antibody stimulation, despite expressing myeloperoxidase on their surface. They are characterized by reduced CD16, CD88, and CD10 expression, higher LOX-1 expression and immature nuclear morphology. Reduced CD16 expression is like that observed in the LDG population in umbilical cord blood and in granulocytes of humanized mice treated with G-CSF. LDGs in AAV are thus a mixed population of mature and immature neutrophils. Their poor response to anti-MPO stimulation suggests that, rather than being a primary driver of AAV pathogenesis, LDGs display characteristics consistent with generic emergency granulopoiesis responders in the context of acute inflammation. [ABSTRACT FROM AUTHOR]

Objective: The treatment of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) aims to suppress disease activity and prevent subsequent disease flare. This study sought to explore the association of early disease control with long‐term outcomes to validate early disease control as an end point for future clinical trials in AAV. Methods: Data from 4 European Vasculitis Society inception clinical trials in AAV (1995–2002) and subsequent data on long‐term outcomes from the trial data registry were studied. Clinical parameters in patients with AAV at baseline and at 3 and 6 months after diagnosis were assessed to study the long‐term risk of death and end‐stage renal failure (ESRF). At 6 months, outcomes were defined based on a disease status of either sustained remission (remission by 3 months, sustained to 6 months), late remission (remission after 3 months and by 6 months), relapsing disease (remission by 3 months but relapse by 6 months), or refractory disease (no remission by 6 months). Results: Of the 354 patients with AAV who were followed up for a median of 5.7 years, 46 (13%) developed ESRF, 66 (18.6%) died, and 89 (25.1%) had either died or developed ESRF. At 6 months, predictors of the composite end point of death or ESRF were as follows: age (hazard ratio [HR] 1.02, 95% confidence interval [95% CI] 1–1.05; P = 0.012), estimated glomerular filtration rate (HR 0.94, 95% CI 0.92–0.95; P < 0.001), and disease status at 6 months (late remission, HR 2.94, 95% CI 1.1–7.85 [P = 0.031]; relapsing disease, HR 8.21, 95% CI 2.73–24.65 [P < 0.001]; refractory disease, HR 4.89, 95% CI 1.96–12.18 [P = 0.001]). Similar results were observed when these analyses were performed separately for death and for ESRF. Conclusion: The results of this study suggest that disease status at 3 and 6 months following the diagnosis of AAV may be predictive of the long‐term risk of mortality and ESRF, and therefore these may be valid end points for induction trials in AAV. The current findings need to be validated in a larger data set. [ABSTRACT FROM AUTHOR]

Background Early detection of renal involvement in anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is of major clinical importance to allow prompt initiation of treatment and limit renal damage. Urinary soluble cluster of differentiation 163 (usCD163) has recently been identified as a potential biomarker for active renal vasculitis. However, a significant number of patients with active renal vasculitis test negative using usCD163. We therefore studied whether soluble CD25 (sCD25), a T cell activation marker, could improve the detection of renal flares in AAV. Methods sCD25 and sCD163 levels in serum and urine were measured by enzyme-linked immunosorbent assay in 72 patients with active renal AAV, 20 with active extrarenal disease, 62 patients in remission and 18 healthy controls. Urinary and blood CD4+ T and CD4+ T effector memory (TEM) cell counts were measured in 22 patients with active renal vasculitis. Receiver operating characteristics (ROC) curves were generated and recursive partitioning was used to calculate whether usCD25 and serum soluble CD25 (ssCD25) add utility to usCD163. Results usCD25, ssCD25 and usCD163 levels were significantly higher during active renal disease and significantly decreased after induction of remission. A combination of usCD25, usCD163 and ssCD25 outperformed all individual markers (sensitivity 84.7%, specificity 95.1%). Patients positive for sCD25 but negative for usCD163 (n  = 10) had significantly higher C-reactive protein levels and significantly lower serum creatinine and proteinuria levels compared with the usCD163-positive patients. usCD25 correlated positively with urinary CD4+ T and CD4+ TEM cell numbers, whereas ssCD25 correlated negatively with circulating CD4+ T and CD4+ TEM cells. Conclusion Measurement of usCD25 and ssCD25 complements usCD163 in the detection of active renal vasculitis. [ABSTRACT FROM AUTHOR]

Antineutrophil cytoplasm antibody associated systemic vasculitides (AASV) have traditionally been managed with a combination of cyclophosphamide and glucocorticoids during the induction phase, followed by azathioprine in the maintenance phase. Whilst these therapies have markedly improved the prognosis in AASV, treatment related adverse events remain a major challenge and include complications such as infection, glucocorticoid related side effects, malignancy, cardiovascular disease, infertility and death. Newer biologic therapies have been shown to demonstrate equivalent efficacy as cyclophosphamide for remission but the hoped for reduction in adverse events has yet to be realised. More recent efforts have been focused on refining existing therapeutic regimens and strategies, tailoring individual treatment to disease severity, patient age and kidney function to derive maximum treatment efficacy while minimising treatment toxicity. In particular, current interventional trials are targeting a reduction in corticosteroid exposure in an effort to make induction and maintenance regimens safer. [ABSTRACT FROM AUTHOR]

Objectives. Rituximab is effective in inducing remission in ANCA-associated vasculitis (AAV), with randomized evidence to support its use as four infusions of 375 mg/m2 (the conventional lymphoma dosing schedule). As B cell depletion (BCD) appears to occur very rapidly after the first dose, we questioned the need for repeat dosing and adopted a standard single-dose protocol of 375 mg/m2 to treat active AAV.Methods. All consecutive cases with newly diagnosed or relapsing AAV for whom conventional immunosuppression was contraindicated or ineffective were enrolled. All were rituximab naive. Circulating CD19+ B cells and clinical and serological markers of disease activity were recorded at regular intervals. Complete remission (CR) was defined as the absence of clinical features of AAV with a prednisolone dose <10 mg/day.Results. Nineteen patients were included, 17 (89%) with generalized disease and 2 (11%) with severe disease (creatinine level >500 μM). Eight (42%) were on additional immunosuppression at the time of rituximab treatment. Satisfactory BCD (<0.005 cells/μl) was achieved in 89% of patients after a median of 13 days. Three-month BCD probability was 89%. Median time to CR following a single dose of rituximab was 38 days and the 3-month probability of CR was 80%. Median time to B cell repopulation was 9.2 months and to disease relapse/redose was 27 months. Use of this single-dose protocol saved an estimated £4533/patient (US$7103; €5276) compared with a 4 × 375 mg/m2 dosing schedule.Conclusion. Our single-centre experience suggests that a single dose of rituximab of 375 mg/m2 is a reasonable and more cost-effective therapy for inducing remission in patients with AAV. [ABSTRACT FROM PUBLISHER]

Objectives. To identify the determinants of fatigue among patients with ANCA-associated vasculitis (AAV).Methods. A multicentre cross-sectional study was conducted. Subjects fulfilling the European Medicines Agency criteria for granulomatosis with polyangiitis (Wegener’s), microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis (Churg–Strauss) were approached according to consecutive clinic attendance and invited to complete a questionnaire assessing fatigue and putative biopsychosocial determinants of this symptom. Concurrently, potential clinical determinants were recorded. Independent associations of fatigue were identified using forward stepwise logistic regression modelling and their overall impact expressed as population attributable risk (PAR).Results. The majority (74.8%) of participants (n = 410) reported high levels of fatigue that were found to be significantly associated with numerous biopsychosocial and clinical factors. Sleep disturbance [odds ratio (OR) 5.3, 95% CI 2.7, 10.5] and pain (OR 3.8, 95% CI 2.0, 7.3) were the strongest independent associations of fatigue and, on a population level, each was more than twice as important as any other putative determinant (PAR 18.1% and 16.5%, respectively). Female gender (OR 2.1, 95% 1.1, 4.0), elevated CRP (OR 3.7, 95% CI 1.7, 8.1) and the dysfunctional coping strategies of behavioural disengagement (OR 2.4, 95% CI 1.04, 5.6) and denial (OR 2.4, 95% CI 0.9, 6.7) were also independently associated with fatigue.Conclusion. The data suggest that AAV-related fatigue is multifactorial in origin. Sleep disturbance and pain were found to be most important, although inflammation, as measured by CRP, was also associated. This study has identified potentially modifiable determinants that will inform future interventions aimed at alleviating fatigue. [ABSTRACT FROM AUTHOR]

A 43-year-old man with a cardiac device for dilated cardiomyopathy presented with fever, night sweats, and weight loss. Investigations revealed pancytopenia, acute renal failure, abnormal lung function, and raised inflammatory markers. A renal biopsy demonstrated pauci-immune necrotizing crescentic glomerulonephritis. He was diagnosed with pulmonary-renal antineutrophil cytoplasmic antibody-negative systemic small vessel vasculitis. He commenced immunosuppression with prednisolone and cyclophosphamide with recovery from pancytopenia and improvement in renal function 3 months later. Subsequently, a bone marrow culture grew Mycobacterium fortuitum. Isolation on repeat peripheral mycobacterial blood cultures prompted treatment with ciprofloxacin and clarithromycin. Four months later, he presented with neutropenic sepsis, influenza A/H1N1, and Aspergillus flavus pneumonia. Despite treatment he deteriorated. A transthoracic echocardiogram revealed a vegetation on the right ventricular pacing wire. The device was removed. The vegetation revealed acid and alcohol fast bacilli on Ziehl-Neelsen staining and grew M. fortuitum on culture, sensitive to ciprofloxacin and clarithromycin. Despite device removal and antimicrobial therapy, the patient succumbed to treatment-related complications. The association between glomerulonephritis and endocarditis is well known; however, this is the first case to our knowledge describing pauci-immune necrotizing crescentic glomerulonephritis in the context of M. fortuitum endocarditis. Clinicians should maintain a high index of suspicion for endocarditis in patients with a cardiac device who present with fever and pauci-immune necrotizing crescentic glomerulonephritis. Patients should be investigated with mycobacterial blood cultures, at least three sets of standard blood cultures and transthoracic and transesophageal echocardiography. Clinicians should beware the perils of immunosuppression in the face of an occult sepsis. [ABSTRACT FROM AUTHOR]

Evidence is lacking for direct pathogenicity of human anti-proteinase-3 (PR3) antibodies in development of systemic vasculitis and granulomatosis with polyangiitis (GPA, Wegener's granulomatosis). Progress in study of these antibodies in rodents has been hampered by lack of PR3 expression on murine neutrophils, and by different Fc-receptor affinities for IgG across species. Therefore, we tested whether human anti-PR3 antibodies can induce acute vasculitis in mice with a human immune system. Chimeric mice were generated by injecting human haematopoietic stem cells into irradiated NOD-scid-IL2Rγ-/- mice. Matched chimera mice were treated with human IgG from patients with: anti-PR3 positive renal and lung vasculitis; patients with non-vasculitic renal disease; or healthy controls. Six-days later, 39% of anti-PR3 treated mice had haematuria, compared with none of controls. There was punctate bleeding on the surface of lungs of anti-PR3 treated animals, with histological evidence of vasculitis and haemorrhage. Anti-PR3 treated mice had mild pauci-immune proliferative glomerulonephritis, with infiltration of human and mouse leukocytes. In 3 mice (17%) more severe glomerular injury was present. There were no glomerular changes in controls. Human IgG from patients with anti-PR3 autoantibodies is therefore pathogenic. This model of anti-PR3 antibody-mediated vasculitis may be useful in dissecting mechanisms of microvascular injury. [ABSTRACT FROM AUTHOR]

Objective. Assessment of disease activity in vasculitis can be achieved using the BVAS, a clinical checklist of relevant symptoms, signs and features of active disease. The aim of this study was to revalidate the BVAS version 3 (BVAS v. 3) in a cohort of patients with systemic vasculitis.Methods. A total of 238 patients with vasculitis from seven countries in Europe were evaluated at a single time point. Spearman’s correlation coefficients were calculated between BVAS v. 3 scores, vasculitis activity index (VAI), physician’s global assessment (PGA), the physician’s treatment decision, CRP and the vasculitis damage index (VDI) to demonstrate that the BVAS v. 3 measures disease activity.Results. WG (63%), Churg–Strauss syndrome (9%) and microscopic polyangiitis (9%) were the most common diagnoses. The BVAS v. 3 showed convergent validity with the VAI [ρ = 0.82 (95% CI 0.77, 0.85)], PGA [ρ = 0.85 (95% CI 0.81, 0.88)] and the physician’s treatment decision [ρ = 0.54 (95% CI 0.44, 0.62)]. There was little or no correlation between BVAS v. 3 and the CRP level [ρ = 0.18 (95% CI 0.05, 0.30)] or with the VDI [ρ = −0.10 (95% CI 0.22, 0.03)]. The inter-observer reliability was very high with an intra-class correlation coefficient (ICC) of 0.996 (95% CI 0.990, 0.998) for the total BVAS v. 3 score.Conclusion. The BVAS v. 3 has been evaluated in a large cohort of patients with vasculitis and the important properties of the tool revalidated. This study increases the utility of the BVAS v. 3 in different populations of patients with systemic vasculitis. [ABSTRACT FROM PUBLISHER]

Background. There are no clear guidelines on renal transplantation in patients with antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. [ABSTRACT FROM PUBLISHER]

The article discusses research which investigated a steroid-free maintenance protocol in antibody-associated vasculitis (AAV). It examines the rates of remission and relapses which showed that some patients failed to follow the pre-assigned protocol. Additionally, the study indicated that steroid dosage is an important factor for infectious predisposition and that cyclophosphamide reduction or avoidance failed to reduce infectious complications.

An introduction to the journal is presented that focuses on a study that shows a potential mechanism for the observed complement factor H dysfunction in anti-neutrophil cytoplasmic antibody-associated vasculitis, with topics mentioned such as regulators of complement activation, myeloperoxidase, and monocytes.

A correction to the article "A novel glucocorticoid-free maintenance regimen for anti-neutrophil cytoplasm antibody-associated vasculitis" is presented.

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"? • In managing AAV, it's crucial to balance controlling the disease with avoiding treatment-related side effects. • Stratifying patients by ANCA status, B-cell repopulation and new biomarkers can help identify those at higher relapse risk. • Intensive induction regimens like the IBCD protocol have shown rapid remission induction and longer disease-free survival. • Achieving negative ANCA status following induction therapy is of utmost importance for patient's subsequent outcome. • Growing evidence suggests that, at least in MPO-AAV, maintenance may not be required, especially after an IBCD regimen. [ABSTRACT FROM AUTHOR]

Macrophages are key players in the immunopathology of anti-neutrophil cytoplasmic antibody (ANCA) mediated-vasculitis (AAV) with glomerulonephritis (ANCA GN). Different macrophage phenotypes are expected to play distinct roles in ANCA GN. Macrophages expressing CD163 and CD206 are found in lesions associated with ANCA GN. Hence, we aimed to investigate the clinicopathological significance of CD206 and CD163 in ANCA GN in a multicenter retrospective cohort study. Patients with ANCA-associated vasculitis, with clinical data, serum and urine samples were included from three cohorts. Serum soluble CD206 (ssCD206) and urinary soluble CD163 (usCD163) levels were measured. Human kidney tissue samples (n = 53) were stained for CD206 and CD163 using immunohistochemistry and immunofluorescence, and findings were correlated with clinical and pathological data. In total, 210 patients were included (i.e., ANCA GN, n = 134; AAV without GN, n = 24; AAV in remission n = 52). Increased levels of both ssCD206 and usCD163 were seen in ANCA GN. High levels of ssCD206 declined after reaching remission, however, ssCD206 did not improve the accuracy of usCD163 to detect ANCA GN. Soluble markers correlated with histopathological findings. CD163+CD206- macrophages were found in the glomerulus and may play pivotal roles in glomerulonephritis, whereas CD206+CD163- and CD206+CD163+ macrophages were located tubulointerstitially and likely play a more prominent role in ANCA-associated tubulointerstitial inflammation. In ANCA GN patients increasing levels of ssCD206 increased the risk for end-stage renal disease and mortality. Our results confirm and extend the notion that CD206+ and CD163+ macrophages are prominent components of the cellular infiltrate in ANCA GN. We found distinct macrophage phenotypes that may play distinct roles in the immunopathology of ANCA GN and elaborate on a potential mechanism underlying the findings of this study. usCD163 remains an excellent marker to detect active ANCA GN, whereas ssCD206 seems a more prominent marker for risk prediction. • Distinct macrophage subsets can be found in biopsies of ANCA GN patients. • Distinct macrophage subsets correlate with histopathology and soluble markers. • Macrophage subsets can help assess treatment response & risk stratification in ANCA. • UsCD163 reflects ANCA GN activity. • SsCD206 can be useful for treatment response, prognosis for ESKD and death in ANCA. [ABSTRACT FROM AUTHOR]

Background: Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis is a severe condition encompassing two major syndromes: granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis) and microscopic polyangiitis. Its cause is unknown, and there is debate about whether it is a single disease entity and what role ANCA plays in its pathogenesis. We investigated its genetic basis. Methods: A genomewide association study was performed in a discovery cohort of 1233 U.K. patients with ANCA-associated vasculitis and 5884 controls and was replicated in 1454 Northern European case patients and 1666 controls. Quality control, population stratification, and statistical analyses were performed according to standard criteria. Results: We found both major-histocompatibility-complex (MHC) and non-MHC associations with ANCA-associated vasculitis and also that granulomatosis with polyangiitis and microscopic polyangiitis were genetically distinct. The strongest genetic associations were with the antigenic specificity of ANCA, not with the clinical syndrome. Anti–proteinase 3 ANCA was associated with HLA-DP and the genes encoding α1-antitrypsin (SERPINA1) and proteinase 3 (PRTN3) (P=6.2×10−89, P=5.6×10−12, and P=2.6×10−7, respectively). Anti–myeloperoxidase ANCA was associated with HLA-DQ (P=2.1×10−8). Conclusions: This study confirms that the pathogenesis of ANCA-associated vasculitis has a genetic component, shows genetic distinctions between granulomatosis with polyangiitis and microscopic polyangiitis that are associated with ANCA specificity, and suggests that the response against the autoantigen proteinase 3 is a central pathogenic feature of proteinase 3 ANCA–associated vasculitis. These data provide preliminary support for the concept that proteinase 3 ANCA–associated vasculitis and myeloperoxidase ANCA–associated vasculitis are distinct autoimmune syndromes. (Funded by the British Heart Foundation and others.) [ABSTRACT FROM PUBLISHER]