A novel glucocorticoid-free maintenance regimen for anti-neutrophil cytoplasm antibody-associated vasculitis

Combination treatment with telitacicept, cyclophosphamide and glucocorticoids for severe Granulomatous polyangiitis: a case report and literature review

Granulomatous polyangiitis (GPA) is a rare autoimmune disease that can involve multiple systems throughout the body, including the ear, nose, upper and lower respiratory tracts. It is classified as an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Telitacicept is a novel recombinant fusion protein targeting B-lymphocyte stimulator (BLyS). Telitacicept can inhibit the development and maturation of abnormal B cells by blocking BLyS, and inhibit the production of antibodies by abnormal plasma cells by blocking APRIL (A proliferation-inducing ligand), which is expected to become a new drug for the treatment of GPA. We report a 64-year-old man diagnosed at our hospital with GPA involving multiple systems including kidneys, lungs, nose and ears. Renal involvement was severe, with a clinical characteristic of rapidly progressive glomerulonephritis and a pathologic manifestation of crescentic nephritis with plasma cell infiltration. The patient was treated with hormones, immunoglobulins and cyclophosphamide (CYC) with the addition of telitacicept and a rapid reduction in hormone dosage. The patient's renal function improved significantly within a short period of time, and his hearing and lung lesions improved significantly. At the same time, he did not develop serious infections and other related complications. Our report suggests that short-term control of the patient's conditions is necessary in GPA patients with organ-threatening disease. Telitacicept combined with CYC and glucocorticoids may be an induction therapy with safety and feasibility. However, more clinical trials are needed to validate the efficacy and safety of the therapeutic regimen.

An update on dıagnosıs and treatment of ANCA assocıated renal vasculıtıs

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides are a group of diseases characterised by necrotizing inflammation of small vessels such as arterioles, venules, and capillaries. ANCA-associated vasculitides (AAV) are referred to as small vessel vasculitides. Three AAV subgroups, namely granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic GPA (EGPA), are defined according to clinical features. The most common disease with renal involvement in AAV is MPA Approximately 90% of patients with MPA have renal involvement. While this rate is 70-80% in GPA, less than half of EGPA patients have renal involvement. Untreated survival in AAVs is less than one year. With appropriate immunosuppressive therapy, the 5-year renal survival rate is 70-75%. Without therapy, the prognosis is poor but treatments, typically immunosuppressants, have improved survival, albeit with considerable morbidity from glucocorticoids and other immunosuppressive medications. Current challenges include improving the measures of disease activity and risk of relapse, uncertainty about optimal therapy duration and a need for targeted therapies with fewer adverse effects. In this review, we described the treatment of renal involvement in AAV in line with current studies.

Rituximab resistance at 3months of induction therapy in newly diagnosed or relapsing ANCA-associated vasculitis: A French multicentre retrospective study in 116 patients

OBJECTIVE

To evaluate rituximab (RTX) resistance at 3months (M3) of induction therapy in antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV).

METHODS

Multicentre French retrospective study conducted between 2010 and 2020 including patients with newly diagnosed or relapsing AAV (granulomatosis with polyangiitis or microscopic polyangiitis) having received induction therapy with RTX. Primary endpoint was the presence of RTX resistance at 3months (M3) defined as uncontrolled disease (worsening feature on the BVAS/WG 1month after RTX induction) or disease flare (increase in BVAS/WG of≥1 point before M3).

RESULTS

Out of 121 patients included, we analysed 116 patients. Fourteen patients (12%) had RTX resistance at M3 with no difference in baseline demographics, vasculitis type, ANCA type, disease status or organ involvement. Patients with RTX resistance at M3 had a greater proportion of localized disease (43% vs. 18%, P<0.05) and were less often treated by initial methylprednisolone (MP) pulse (21% vs. 58%, P<0.01). Out of the 14 patients with RTX resistance, seven received additional immunosuppressive therapy. All patients were in remission at 6months. Compared to responders, patients with RTX resistance at M3 were less often treated with prophylactic trimethoprim-sulfamethoxazole (57% vs. 85%, P<0.05). Twenty-four patients died during follow-up, one-third of them from infections and half of them from SARS-CoV-2.

CONCLUSION

Twelve percent of patients had RTX resistance at M3. These patients more often had localized form of the disease and were less treated by initial MP pulse and by prophylactic trimethoprim-sulfamethoxazole.

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.

ExploriNg DUrable Remission with Rituximab in ANCA-associatEd vasculitis (ENDURRANCE trial): protocol for a randomised controlled trial

INTRODUCTION

Both rituximab (RTX) and cyclophosphamide (CYC) are effectively used in combination with steroids as remission induction therapy for patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Several studies have shown that the effect on achieving (clinical) remission, frequency and severity of relapses is equivalent for both therapies, but there is accumulating data that the long-term safety profile of RTX might outperform CYC. Combination of RTX with low-dose CYC (LD-CYC) has been investigated in only a few uncontrolled cohort studies, in which clinical remission and a favourable immunological state with low relapse rates was quickly achieved. In this randomised controlled trial, we aim to investigate whether the combination treatment (RTX+LD CYC) is superior in comparison to standard care with RTX only.

METHODS AND ANALYSIS

This study is an open-label, multicentre, 1:1 randomised, prospective study for patients with AAV with generalised disease, defined as involvement of major organs, that is, kidneys, lungs, heart and nervous system. In total, 100 patients will be randomised 1:1 to receive either remission induction therapy with standard of care (RTX) or combination treatment (RTX+LD CYC) in addition to steroids and both arms are followed by maintenance with RTX retreatments (tailored to B-cell and ANCA status). Our primary outcome is the number of retreatments needed to maintain clinical remission over 2 years. Secondary outcomes are relevant clinical endpoints, safety, quality of life and immunological responses.

ETHICS AND DISSEMINATION

This study has received approval of the Medical Ethics Committee of the Leiden University Medical Center (P18.216, NL67515.058.18, date: 7 March 2019). The results of this trial (positive and negative) will be submitted for publication in relevant peer-reviewed publications and the key findings presented at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT03942887.

The Sound of Interconnectivity; The European Vasculitis Society 2022 Report

The first European Vasculitis Society (EUVAS) meeting report was published in 2017. Herein, we report on developments in the past 5 years which were greatly influenced by the pandemic. The adaptability to engage virtually, at this critical time in society, embodies the importance of networks and underscores the role of global collaborations. We outline state-of-the-art webinar topics, updates on developments in the last 5 years, and proposals for agendas going forward. A host of newly reported clinical trials is shaping practice on steroid minimization, maintenance strategies, and the role of newer therapies. To guide longer-term strategies, a longitudinal 10-year study investigating relapse, comorbidity, malignancy, and survival rates is at an advanced stage. Disease assessment studies are refining classification criteria to differentiate forms of vasculitis more fully. A large international validation study on the histologic classification of anti-neutrophil cytoplasmic antibody (ANCA) glomerulonephritis, recruiting new multicenter sites and comparing results with the Kidney Risk Score, has been conducted. Eosinophilic granulomatosis with polyangiitis (EGPA) genomics offers potential pathogenic subset and therapeutic insights. Among biomarkers, ANCA testing is favoring immunoassay as the preferred method for diagnostic evaluation. Consolidated development of European registries is progressing with an integrated framework to analyze large clinical data sets on an unprecedented scale.

Recent Advancements in the Management of Anti-neutrophil Cytoplasmic Antibody-Associated Vasculitis: A Systematic Review

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a rare multisystem autoimmune condition that causes inflammation of small and medium-sized blood vessels and is more commonly seen in the geriatric population. ANCA-associated vasculitis (AAV) is typically characterized as necrotizing vasculitis and includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). The mortality rate remains high, with especially cardiovascular disease, infections, and malignancies being the leading causes of death. Existing treatment options depend heavily on the use of glucocorticoids (GCs), often in combination with cyclophosphamide (CYC); however, as the multitude of adverse effects associated with these agents has increased, numerous studies are being conducted to reduce not only these harmful effects but also improve remission rates. Rituximab, avacopan, corticosteroids, including intravenous pulse methylprednisolone, plasma exchange, and immunological targeting are among the emerging treatments. The purpose of this review is to emphasize the pathogenesis and traditional treatment modalities and give insights into the recent advances in managing this disorder in an attempt to spare the adverse effects of conventional therapies while achieving better remission rates with combination therapies as well. The authors explored multiple databases, employing appropriate keywords, satisfying the quality appraisal, after which a total of 14 reports were included in this review. Upon overall analysis, it can be concluded that rituximab and CYC, when used in combination, provided a safer alternative to GCs while exhibiting equal, if not superior, effectiveness and results, thus, paving the way for additional in-depth research in a larger population of interest.

[Biologics for connective tissue diseases and vasculitides]

Despite therapy with glucocorticoids (GC) and conventional immunosuppressants, patients with connective tissue diseases and vasculitides often develop functionally relevant and prognostically unfavourable internal organ damage. Based on new pathogenetic insights, biologics and small molecules have recently been studied as targeted therapies for collagen vascular diseases and vasculitides. The B lymphocyte stimulator antagonist belimumab has been used for the treatment of systemic lupus erythematosus (SLE) for several years and has recently also been approved as an add-on therapy for lupus nephritis. Anifrolumab, an antibody against the type‑1 interferon receptor, has also been shown to be effective in phase III trials for the treatment of SLE. The interleukin (IL)-6-antagonist tocilizumab showed efficacy in the treatment of interstitial lung disease (ILD) in systemic sclerosis (SSc) and thus has been approved in the USA, although the phase III trial had a negative primary endpoint. In Europe the tyrosine inhibitor nintedanib is approved for progressive ILD in SSc. Tocilizumab is approved for the treatment of giant cell arteritis and reduces both the risk of recurrence and the cumulative GC requirement. The B‑lymphocyte depleting antibody rituximab is approved for induction and maintenance therapy of granulomatosis with polyangiitis and microscopic polyangiitis (MPA) and is currently also being investigated for the treatment of eosinophilic granulomatosis with polyangiitis (EGPA). In patients with EGPA, the IL‑5 antibody mepolizumab leads to improved disease control and reduces GC requirements. A phase III trial of the small molecule antagonist avacopan targeting the complement C5a receptor as a replacement for high-dose GC in induction therapy of GPA and MPA met its primary endpoints. Various other biologics and small molecule antagonists are currently in clinical development for several type of vasculitis and collagen vascular diseases, some of them at advanced stages.

Predictive factors of mortality in granulomatosis with polyangiitis: A single-center study

Objectives

The aim of this study was to identify predictors of mortality in granulomatosis with polyangiitis (GPA) patients and to seek the ways of improving survival in GPA patients.

Patients and methods

Between January 2005 and June 2020, a total of 60 patients (26 males, 34 females; median age: 49 years; range, 19 to 75 years) who were diagnosed with GPA were retrospectively analyzed. Demographic, clinical, laboratory, and radiological findings of all patients were recorded. Survival rates were analyzed using the Kaplan-Meier plot.

Results

The median follow-up was 36 months, and 10 (16.7%) patients died during the study period. Univariate analysis showed that the prognostic values were attributed to high serum creatinine levels (>2.1 mg/dL; p=0.01), proteinuria (p=0.01), dialysis-requiring renal damage at the time of diagnosis (p=0.01) or at any time during follow-up (p=0.01), low lymphocyte levels (p=0.01), hypoalbuminemia (p=0.04), absence of upper respiratory tract involvement (p=0.01), presence of lung involvement with cavitary lesions (p=0.01), high Birmingham Vascular Activity Score (p=0.02), and history of serious infection (p=0.01). In the multivariate analysis, the presence of renal damage requiring dialysis at any time during follow-up (relative risk [95% confidence interval]: 21 [4.1-18.3]; p=0.01) was found to be an independent predictor of mortality. Immunosuppressive drugs exerted no effect on mortality, and the most common causes of death were infections (50%).

Conclusion

The presence of dialysis-requiring renal damage is the most important risk factor for mortality in GPA patients. These patients should be followed more closely and carefully to improve survival.

Multi-targeted therapy for refractory eosinophilic granulomatosis with polyangiitis characterized by intracerebral hemorrhage and cardiomyopathy: a case-based review

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic autoimmune disorder classified under anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, predominantly affecting small- to medium-sized vessels, characterized by asthma, eosinophilia, and necrotizing granulomatous inflammation. Most patients with EGPA experience peripheral neuropathy, whereas intracerebral hemorrhage is rare as EGPA-related presentation in central nervous system involvement, causing severe morbidity and mortality. Here, we present a 45-year-old man with refractory EGPA who developed intracerebral hemorrhage as the first manifestation, followed by cardiac involvement. This patient with a history of bronchial asthma developed a right putaminal hemorrhage caused by EGPA. Although intravenous cyclophosphamide (IVCY) and mepolizumab (MPZ) induced remission, relapse was frequently observed. Subsequently, he developed cardiomyopathy despite administration of rituximab (RTX) substituted from IVCY and MPZ. Combined immunosuppressive therapy, including IVCY, MPZ, and RTX was required to inhibit vascular inflammation, leading to sustained remission. We review previously published literature while focusing on the clinical features of patients with intracerebral hemorrhage caused by EGPA and describe clinical characteristics for detecting EGPA in patients with intracerebral hemorrhage, emphasizing rapid evaluation and recognition of EGPA and adequate intervention in the early vasculitic phase of this disease. We also refer to the immunological aspects of this case. It is important to consider "multi-targeted therapy" through interleukin-5 suppression and B cell depletion in the management of refractory EGPA.

Update in the Management of ANCA-Associated Vasculitis: Recent Developments and Future Perspectives

Significant progress has been made in the treatment of ANCA-associated vasculitides (AAV), notably in granulomatosis with polyangiitis and microscopic polyangiitis. Over the past few years, many innovative studies have changed the way we now induce and maintain remission in AAV; achieving remission while limiting treatment toxicity is the key. This article provides an in-depth, up-to-date summary of recent trials and suggests treatment algorithms for induction and maintenance of remission based on the latest guidelines. Future possible therapies in AAV will also be discussed.

ANCA-Associated Vasculitis: An Update

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) represents a group of small vessel vasculitides characterized by granulomatous and neutrophilic tissue inflammation, often associated with the production of antibodies that target neutrophil antigens. The two major antigens targeted by ANCAs are leukocyte proteinase 3 (PR3) and myeloperoxidase (MPO). AAV can be classified into 3 categories based on patterns of clinical involvement: namely, granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic GPA (EGPA). Clinically, AAV involves many organ systems including the lungs, kidneys, skin, and nervous system. The prognosis of AAV has improved dramatically due to advances in the understanding of its pathogenesis and treatment modalities. This review will highlight some of the recent updates in our understanding of the pathogenesis, clinical manifestations, and treatment options in patients with AAV focusing on kidney involvement.

Treatment Updates in Antineutrophil Cytoplasmic Autoantibodies (ANCA) Vasculitis

ANCA vasculitis is a small-vessel vasculitis (SVV) resulting in inflammation of small- and medium-sized blood vessels. Since the initial description of SVV, there have been tremendous advances in our understanding of its pathogenesis. Over the last decade, we have made significant progress in understanding the pathogenesis and improving the treatment and prognosis of patients with ANCA vasculitis. Patient and renal survival has improved, and treatment is moving toward individualizing care, minimizing severe adverse events, and preventing relapse. This review focuses on treatment updates in ANCA vasculitis, duration of therapy, and management of relapses. We also describe the existing treatment protocols used at our institution.

Corticosteroids are the major contributors to the risk for serious infections in autoimmune disorders with severe renal involvement

INTRODUCTION

We sought to investigate the infection profile and associated risk factors in a compiled cohort of patients with autoimmune disorders with severe renal involvement treated with aggressive immunosuppressive (IS) regimens.

METHODS

A total of 162 patients with aggressive glomerulonephritis [101 with lupus nephritis (LN), 24 with cryoglobulinemic vasculitis (CryoVasc), and 37 with ANCA-associated vasculitis (AAV)] were retrospectively reviewed for any infection occurrence. Infection incidence, type, site, and grade (1-5) were recorded. Multivariate Cox proportional hazard regression analysis was performed to identify independent risk factors for infections.

RESULTS

A total of 179 infection episodes occurred during a follow-up of 468 patient-years. Eighty-two patients (50.6%) had at least one infection. The incidence rates of infections and severe infections were 38.2 and 14.3 events per 100 patient-years. Patients with AAV had more infections than those with CryoVasc and LN (100.6, 47.5, and 26.6 infections per 100-patient-years, respectively; p = 0.002). Most patients developed infections early during the initial induction therapy (62.1% in the first 6 months of follow-up). In multivariate Cox regression analysis, high-dose oral corticosteroids (≥ 0.5 mg/kg/day in the first month of induction therapy) was an independent predictor of any infection (HR 2.66; 95% CI, 1.5-4.73), severe infections (HR 2.45; 95% CI, 1.03-5.82), and pulmonary infections (HR 2.91; 95% CI, 1.05-8.01). Pulmonary involvement increased the risk for pulmonary infections (HR 3.67; 95% CI, 1.32-10.1) and severe infections (HR 2.45; 95% CI, 1.01-5.92).

CONCLUSION

Infections occur frequently with current IS regimens in aggressive glomerulonephritis. Pulmonary involvement and high-dose corticosteroid regimen were the most significant risk factors for infections. Key Points • Infections occur frequently with current immunosuppressive regimens in autoimmune aggressive glomerulonephritis. • High-dose corticosteroids are the major contributors to the risk for serious infections.

Study Protocol for DeCOmPRESS: Defining the Disease Course and Immune Profile of COVID-19 in the Immunosuppressed Patient

The ongoing coronavirus disease 2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current advisory guidelines for high-risk groups—including people with autoimmune disease taking immunosuppressive therapies—are to take increased precautions and avoid any unnecessary contacts. The aim of the DeCOmPRESS study is to define the disease course and immune profile of COVID-19 in immunosuppressed patients. We will clinically phenotype patients with ANCA-associated vasculitis (AAV) who develop COVID-19 using a customized REDCap data collection instrument embedded within the Rare Kidney Disease (RKD) Biobank. This dataset will be interoperable with the rheum-COVID, Global Rheumatology Alliance, and SPRINT-SARI datasets, facilitating international data linkage. Acute and convalescent blood samples will be analysed by flow cytometry and ELISA to define the immunophenotype and cytokine profile. Patients will track COVID-19 and AAV symptoms through a bespoke smartphone app. DeCOmPRESS study findings will rapidly inform management of immunosuppressed patients who contract COVID-19 by defining the natural history and immunological manifestations of the disease in these patients. We will also determine whether pre-existing immunosuppressant therapy lessens the cytokine storm associated with severe COVID-19 disease, thereby paradoxically improving rather than worsening clinical outcomes. This protocol document details the procedures for end-to-end completion of the DeCOmPRESS project and is complemented by an associated comprehensive Study Manual (accessible at: https://www.tcd.ie/medicine/thkc/decompress/).

Using the World Apheresis Association Registry Helps to Improve the Treatment Quality of Therapeutic Apheresis

Therapeutic apheresis (TA) is prescribed to patients that suffer from a severe progressive disease that is not sufficiently treated by conventional medications. A way to gain more knowledge about this treatment is usually by the local analysis of data. However, the use of large quality assessment registries enables analyses of even rare findings. Here, we report some of the recent data from the World Apheresis Association (WAA) registry. Data from >104,000 procedures were documented, and TA was performed on >15,000 patients. The main indication for TA was the collection of autologous stem cells (45% of patients) as part of therapy for therapy. Collection of stem cells from donors for allogeneic transplantation was performed in 11% of patients. Patients with indications such as neurological diseases underwent plasma exchange (28%). Extracorporeal photochemotherapy, lipid apheresis, and antibody removal were other indications. Side effects recorded in the registry have decreased significantly over the years, with approximately only 10/10,000 procedures being interrupted for medical reasons.

Conclusion

Collection of data from TA procedures within a multinational and multicenter concept facilitates the improvement of treatment by enabling the analysis of and feedback on indications, procedures, effects, and side effects.

Long-term outcomes in elderly patients with ANCA-associated vasculitis

Objective

ANCA-associated vasculitis (AAV) is a small vessel vasculitis that commonly presents in the elderly. However, there are few long-term outcome data for these patients. Here, we assessed long-term outcomes in a single-centre cohort of elderly patients with AAV. Additionally, we tested whether a pre-morbid frailty score could aid prognosis.

Methods

Using a prospectively-compiled dataset, we investigated patients over the age of 65 who presented with AAV between 2005 and 2017 to a regional vasculitis centre. We used a Cox model to determine the factors associated with mortality. We also compared outcomes in pre-specified subgroups stratified by baseline frailty score, ANCA serotype and induction immunosuppression (with cyclophosphamide, rituximab or mycophenolate mofetil used as the main glucocorticoid-sparing agent).

Results

83 patients were included in the study and were followed for a median of 1203 days. Median age was 74 years (range 65–92). Two- and five-year survival in the overall cohort were 83% (95% CI 75, 92%) and 75% (95% CI 65, 86%), respectively. The median cumulative dose of oral prednisolone was 2030 mg during the first three months. Only one patient received intravenous glucocorticoids. Age, frailty score and CRP at presentation were independently associated with mortality; all deaths occurred in patients aged over 75 at presentation. Patients treated with a cyclophosphamide-based induction regimen tended to be younger than those treated with rituximab or mycophenolate mofetil. Survival was better in the cyclophosphamide-treated group.

Conclusion

In the contemporary era, the overall prognosis of AAV in elderly patients is good. Baseline frailty associates with disease outcomes including mortality. A low-dose glucocorticoid regimen (avoiding intravenous methylprednisolone) can be used to treat AAV effectively in elderly patients.

ANCA-associated vasculitis

The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are a group of disorders involving severe, systemic, small-vessel vasculitis and are characterized by the development of autoantibodies to the neutrophil proteins leukocyte proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA). The three AAV subgroups, namely granulomatosis with polyangiitis (GPA), microscopic polyangiitis and eosinophilic GPA (EGPA), are defined according to clinical features. However, genetic and other clinical findings suggest that these clinical syndromes may be better classified as PR3-positive AAV (PR3-AAV), MPO-positive AAV (MPO-AAV) and, for EGPA, by the presence or absence of ANCA (ANCA⁺ or ANCA^-, respectively). Although any tissue can be involved in AAV, the upper and lower respiratory tract and kidneys are most commonly and severely affected. AAVs have a complex and unique pathogenesis, with evidence for a loss of tolerance to neutrophil proteins, which leads to ANCA-mediated neutrophil activation, recruitment and injury, with effector T cells also involved. Without therapy, prognosis is poor but treatments, typically immunosuppressants, have improved survival, albeit with considerable morbidity from glucocorticoids and other immunosuppressive medications. Current challenges include improving the measures of disease activity and risk of relapse, uncertainty about optimal therapy duration and a need for targeted therapies with fewer adverse effects. Meeting these challenges requires a more detailed knowledge of the fundamental biology of AAV as well as cooperative international research and clinical trials with meaningful input from patients.

Urinary soluble CD163 as a biomarker of disease activity and relapse in antineutrophil cytoplasm antibody-associated glomerulonephritis

Background

Antineutrophil cytoplasm antibody (ANCA)-associated vasculitis is a chronic relapsing and remitting autoimmune disease. Urinary soluble CD163 (usCD163) has been proposed as a biomarker of active renal vasculitis. We aimed to assess the potential usefulness of usCD163 for diagnosing renal relapse in patients with ANCA-associated glomerulonephritis.

Methods

One hundred and fifty-six samples from 47 patients with ANCA-associated glomerulonephritis belonging to two different cohorts (incident and prevalent) and 20 healthy controls were studied. Patients from the incident cohort were prospectively followed up, and usCD163 concentrations were measured every 3 months. Renal relapses were identified and changes in usCD163 concentrations were analysed.

Results

Normalized usCD163 concentrations were elevated at disease onset in all patients with active renal vasculitis, with a median concentration of 601 ng/mmol (interquartile range 221–1404 ng/mmol). On the other hand, usCD163 concentrations were undetectable among control patients with renal vasculitis in remission. Except for non-responders, usCD163 concentrations progressively decreased in all patients after treatment. In the presence of vasculitis relapse, there was a consistent increase in usCD163 concentrations, compared with previous values. The area under the receiver-operating characteristic curve of absolute and relative changes in usCD163 concentrations to identify relapse of ANCA-associated glomerulonephritis was 0.96 [95% confidence interval (CI) 0.91–1.00; P = 0.001] and 0.95 (95% CI 0.90–1.00; P = 0.001), respectively. Sensitivity and specificity for a relative increase of 20%, or an absolute increase of 20 ng/mmol, in usCD163 concentrations were 100% for both, and 89.3% and 87.5%, respectively. Urinary sCD163 concentrations significantly correlated with Birmingham Vasculitis Activity Score scores at Month 6 (r = 0.737; P = 0.006) and Month 12 (r = 0.804; P = 0.005).

Conclusions

usCD163 represents an accurate biomarker for the detection of active renal vasculitis and relapse. Its close association with disease activity provides additional information for monitoring treatment response.

Therapeutic Myeloperoxidase Inhibition Attenuates Neutrophil Activation, ANCA-Mediated Endothelial Damage, and Crescentic GN

BACKGROUND

Myeloperoxidase released after neutrophil and monocyte activation can generate reactive oxygen species, leading to host tissue damage. Extracellular glomerular myeloperoxidase deposition, seen in ANCA-associated vasculitis, may enhance crescentic GN through antigen-specific T and B cell activation. Myeloperoxidase-deficient animals have attenuated GN early on, but augmented T cell responses. We investigated the effect of myeloperoxidase inhibition, using the myeloperoxidase inhibitor AZM198, to understand its potential role in treating crescentic GN.

METHODS

We evaluated renal biopsy samples from patients with various forms of crescentic GN for myeloperoxidase and neutrophils, measured serum myeloperoxidase concentration in patients with ANCA-associated vasculitis and controls, and assessed neutrophil extracellular trap formation, reactive oxygen species production, and neutrophil degranulation in ANCA-stimulated neutrophils in the absence and presence of AZM198. We also tested the effect of AZM198 on ANCA-stimulated neutrophil-mediated endothelial cell damage in vitro, as well as on crescentic GN severity and antigen-specific T cell reactivity in the murine model of nephrotoxic nephritis.

RESULTS

All biopsy specimens with crescentic GN had extracellular glomerular myeloperoxidase deposition that correlated significantly with eGFR and crescent formation. In vitro, AZM198 led to a significant reduction in neutrophil extracellular trap formation, reactive oxygen species production, and released human neutrophil peptide levels, and attenuated neutrophil-mediated endothelial cell damage. In vivo, delayed AZM198 treatment significantly reduced proteinuria, glomerular thrombosis, serum creatinine, and glomerular macrophage infiltration, without increasing adaptive T cell responses.

CONCLUSIONS

Myeloperoxidase inhibition reduced neutrophil degranulation and neutrophil-mediated endothelial cell damage in patients with ANCA-associated vasculitis. In preclinical crescentic GN, delayed myeloperoxidase inhibition suppressed kidney damage without augmenting adaptive immune responses, suggesting it might offer a novel adjunctive therapeutic approach in crescentic GN.