Active ANCA-associated Vasculitis Research Articles

Advantages of metagenomic next-generation sequencing in the management of ANCA-associated vasculitis patients with suspected pulmonary infection as a rule-out tool

ObjectivePulmonary infection is one of the leading causes of death in patients with ANCA-associated vasculitis (AAV). It is sometimes difficult to differentiate pulmonary infection from pulmonary involvement of vasculitis in AAV patients. Fiberoptic bronchoscopy and bronchoalveolar lavage fluid (BALF) assays are useful diagnostic methods. In addition to conventional microbiological tests (CMTs), metagenomic next-generation sequencing (mNGS) facilitates rapid and sensitive detection of various pathogens. The current study aimed to evaluate the advantages of additional BALF mNGS in the management of pulmonary infection in AAV patients.Methods27 patients with active AAV and suspected pulmonary infection whose BALF samples were tested by mNGS and CMTs and 17 active AAV patients whose BALF were tested by CMTs alone were retrospectively recruited. The results of microbiological tests, and adjustments of treatment following BALF mNGS, were described. The durations of antimicrobial treatment and in-hospital mortality in patients were compared.ResultsAmong the 27 patients whose BALF samples were tested by mNGS, 25.9% of patients did not have evidence of pathogenic microorganism in their BALF samples, 55.6% had polymicrobial infections, including bacteria, fungi and viruses. Of these 27 patients, 40.7% did not have evidence of pathogenic microorganism in their BALF or serum samples according to CMTs. Patients in the BALF mNGS/CMT group received a significantly shorter duration of antibacterial and total antimicrobial treatment than patients in the CMT alone group (17.3 ± 14.7 vs. 27.9 ± 19.0 days, P = 0.044; 18.9 ± 15.0 vs. 29.5 ± 17.7 days, P = 0.040, respectively). Fewer patients in the BALF mNGS/CMT group died than in the CMT alone group (4/27 vs. 7/17, P = 0.049).ConclusionCompared with CMT alone, additional mNGS tests may shorten the duration of antimicrobial treatment and possibly decrease death from severe infection by providing precise and quick diagnosis of infection.

Treatment of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis With Diffuse Alveolar Hemorrhage With Avacopan.

Avacopan, an activated complement factor 5 receptor antagonist, has been approved as adjunct therapy for severe active antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Current evidence supports the management of AAV presenting with diffuse alveolar hemorrhage (DAH) by administering glucocorticoids combined with either rituximab or cyclophosphamide in addition to supportive care. The role of avacopan in patients with DAH as a primary severe disease manifestation of AAV has not been well established. Furthermore, concerns remain regarding timely access to avacopan, the best glucocorticoid tapering regimen, and long-term efficacy and safety of the drug. We sought to identify clinical features and outcomes of patients presenting with DAH secondary to AAV who received avacopan in addition to glucocorticoids and rituximab or cyclophosphamide. We performed a retrospective cohort study of all consecutive patients presenting with DAH as part of active severe granulomatosis with polyangiitis or microscopic polyangiitis. Demographic and clinical characteristics were collected at presentation and follow-up. Fifteen patients met inclusion criteria and were observed for a median time of 17 weeks (interquartile range [IQR] 6-37 weeks) after initiation of avacopan. Patients were predominantly female and White, had never smoked, and were a median age of 66 years (IQR 52-72 years) at diagnosis. The majority had newly diagnosed severe AAV with renal involvement. Three patients progressed to respiratory failure. The timing of avacopan introduction and patterns of glucocorticoid tapers varied widely in this cohort. Two serious adverse events related to infection were observed, including one opportunistic infection leading to the patient's death, although neither was directly attributed to avacopan administration. We describe the clinical course of patients who presented with the severe AAV disease manifestation of DAH and received avacopan as adjunct therapy. Most patients achieved remission during follow-up, and adverse events, including infection, were observed.

FTY720 ameliorates experimental MPO-ANCA-associated vasculitis by regulating fatty acid oxidation via the neutrophil PPARα-CPT1a pathway.

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. 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). 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. FTY720 attenuated renal injury in EAV through upregulating FAO via the PPARα-CPT1a pathway in neutrophils, offering potential immunometabolic targets in AAV treatment.

A projected cost-utility analysis of avacopan for the treatment of antineutrophil cytoplasmic antibody-associated vasculitis in Spain

ABSTRACT Background Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) are rare autoimmune diseases characterized by inflammation of blood vessels. This study aimed to assess the cost-utility of avacopan in combination with rituximab (RTX) or cyclophosphamide (CYC) compared with glucocorticoids (GC) for the treatment of severe, active AAV in Spain. Methods A 9-state Markov model was designed to reflect the induction of remission and sustained remission of AAV over a lifetime horizon. Clinical data and utility values were mainly obtained from the ADVOCATE trial, and costs (€ 2022) were sourced from national databases. Quality-adjusted life years (QALYs), and incremental cost-utility ratio (ICUR) were evaluated. An annual discount rate of 3% was applied. Sensitivity analyses were performed to examine the robustness of the results. Results Avacopan yielded an increase in effectiveness (6.52 vs. 6.17 QALYs) and costs (€16,009) compared to GC, resulting in an ICUR of €45,638 per additional QALY gained. Avacopan was associated with a lower incidence of end-stage renal disease (ESRD), relapse and hospitalization-related adverse events. Sensitivity analyses suggested that the model outputs were robust and that the progression to ESRD was a driver of ICUR. Conclusions Avacopan is a cost-effective option for patients with severe, active AAV compared to GC in Spain.

Targeting NF-κB signaling in B cells as a potential new treatment modality for ANCA-associated vasculitis

B lineage cells are critically involved in ANCA-associated vasculitis (AAV), evidenced by alterations in circulating B cell subsets and beneficial clinical effects of rituximab (anti-CD20) therapy. This treatment renders a long-term, peripheral B cell depletion, but allows for the survival of long-lived plasma cells. Therefore, there is an unmet need for more reversible and full B lineage cell targeting approaches. To find potential novel therapeutic targets, RNA sequencing of CD27+ memory B cells of patients with active AAV was performed, revealing an upregulated NF-κB-associated gene signature. NF-κB signaling pathways act downstream of various B cell surface receptors, including the BCR, CD40, BAFFR and TLRs, and are essential for B cell responses. Here we demonstrate that novel pharmacological inhibitors of NF-κB inducing kinase (NIK, non-canonical NF-κB signaling) and inhibitor-of-κB-kinase-β (IKKβ, canonical NF-κB signaling) can effectively inhibit NF-κB signaling in B cells, whereas T cell responses were largely unaffected. Moreover, both inhibitors significantly reduced B cell proliferation, differentiation and production of antibodies, including proteinase-3 (PR3) autoantibodies, in B lineage cells of AAV patients. These findings indicate that targeting NF-κB, particularly NIK, may be an effective, novel B lineage cell targeted therapy for AAV and other autoimmune diseases with prominent B cell involvement.

P204 Biomechanical Phenotype of Circulating Neutrophils Is Altered in ANCA Associated Vasculitis

Abstract Background/Aims Real Time-Deformability Cytometry (RT-DC) is a novel technique able to identify morpho-rheological characteristics of individual cells such as size, deformability, and elasticity using only 50µl of whole blood. Cells in suspension flow through a microfluidic channel while hydrodynamic force is applied, leading to reversible deformation of individual cells from shear stress and pressure gradients. Cell brightness and area can be used to identify individual cell types. The morpho-rheological characteristics of immune cells in ANCA associated vasculitis (AAV) are unknown. Methods Whole blood from healthy controls (HC), patients with active AAV, or patients with AAV in remission was analysed using RT-DC. The diagnosis of AAV was based upon positive ANCA testing, with either (i) pauci-immune glomerulonephritis, or (ii) typical clinical features of extra-renal AAV. Patients with active disease may have received steroids prior to sampling but those who received other immunosuppression or cytotoxics were excluded. Remission was defined as BVAS of 0 with prednisolone dose ≤7.5mg/day. Blood was collected into K2 EDTA and diluted 1:20 in 1xPBS/0.6% methylcellulose. Cell suspensions were flowed across a Flic20 polydimethylsiloxane microfluidic chip, containing reservoirs connected by a measurement channel with a 20x20 μm2 cross-section. RT-DC measurements were collected at a flow rate of 0.12μL/s using a high-speed CMOS camera to capture images at a rate of 2000 frames/second. ShapeOut software was used to calculate cell size, deformation, and elasticity. Results There was no difference in neutrophil size between patients with active AAV (n = 15), patients with AAV in remission (n = 31), and HC (n = 15). Neutrophils from patients with active AAV were significantly stiffer than patients in remission or HC, displaying decreased deformation (median 0.084, 0.085, and 0.078 au respectively, p = 0.0068) and increased elasticity (median 0.973, 0.968 and 1.006 au respectively, p = 0.0196). In patients with active AAV, there was strong inverse correlation between neutrophil deformation and disease activity measured by BVAS score (r=-0.573, p = 0.032). Neutrophils isolated from healthy donors exhibited a trend towards decreased deformability when primed with TNF and stimulated with MPO-ANCA IgG compared to unstimulated or cells treated with healthy donor IgG (median 0.086, 0.085, and 0.083 for unstimulated, control IgG, and MPO-ANCA IgG respectively, ns). Conclusion Neutrophils from patients display distinct physical properties in active AAV which correlate with disease activity. Similar results are seen when neutrophils are stimulated in vitro with MPO-ANCA IgG. This phenotype of increased cell stiffness may lead to increased neutrophil retention in pulmonary and renal microvasculature, thus increasing the potential for neutrophil-endothelial cell interactions and microvascular damage. Morphorheological parameters can be rapidly measured using a small volume of whole blood; thus, RT-DC may be a useful technique to aid identification of disease activity in AAV and to guide treatment. Disclosure N. Pisacano: None. S.P. McAdoo: None. J. Guck: None. C.D. Pusey: None. E.R. Chilvers: None. A.C. Cowburn: None. K.M. Lodge: None. M.F. Prendecki: None.

A randomised study of rituximab and belimumab sequential therapy in PR3 ANCA-associated vasculitis (COMBIVAS): design of the study protocol

BackgroundSequential B cell-targeted immunotherapy with BAFF antagonism (belimumab) and B cell depletion (rituximab) may enhance B cell targeting in ANCA-associated vasculitis (AAV) through several mechanisms.MethodsStudy design: COMBIVAS is a randomised, double-blind, placebo-controlled trial designed to assess the mechanistic effects of sequential therapy of belimumab and rituximab in patients with active PR3 AAV. The recruitment target is 30 patients who meet the criteria for inclusion in the per-protocol analysis. Thirty-six participants have been randomised to one of the two treatment groups in a 1:1 ratio: either rituximab plus belimumab or rituximab plus placebo (both groups with the same tapering corticosteroid regimen), and recruitment is now closed (final patient enrolled April 2021). For each patient, the trial will last for 2 years comprising a 12-month treatment period followed by a 12-month follow-up period.Participants: Participants have been recruited from five of seven UK trial sites. Eligibility criteria were age ≥ 18 years and a diagnosis of AAV with active disease (newly diagnosed or relapsing disease), along with a concurrent positive test for PR3 ANCA by ELISA.Interventions: Rituximab 1000 mg was administered by intravenous infusions on day 8 and day 22. Weekly subcutaneous injections of 200 mg belimumab or placebo were initiated a week before rituximab on day 1 and then weekly through to week 51. All participants received a relatively low prednisolone (20 mg/day) starting dose from day 1 followed by a protocol-specified corticosteroid taper aiming for complete cessation by 3 months.Outcomes: The primary endpoint of this study is time to PR3 ANCA negativity. Key secondary outcomes include change from baseline in naïve, transitional, memory, plasmablast B cell subsets (by flow cytometry) in the blood at months 3, 12, 18 and 24; time to clinical remission; time to relapse; and incidence of serious adverse events. Exploratory biomarker assessments include assessment of B cell receptor clonality, B cell and T cell functional assays, whole blood transcriptomic analysis and urinary lymphocyte and proteomic analysis. Inguinal lymph node and nasal mucosal biopsies have been performed on a subgroup of patients at baseline and month 3.DiscussionThis experimental medicine study provides a unique opportunity to gain detailed insights into the immunological mechanisms of belimumab-rituximab sequential therapy across multiple body compartments in the setting of AAV.Trial registrationClinicalTrials.gov NCT03967925. Registered on May 30, 2019.

Features of BAFF and APRIL receptors on circulating B cells in antineutrophil cytoplasmic antibody-associated vasculitis.

To investigate the features of circulating B cells, their expressing receptors, serum levels of B-cell activation factor of the TNF family (BAFF), and a proliferation-inducing ligand (APRIL) in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Blood samples from 24 patients with active AAV (a-AAV), 13 with inactive AAV (i-AAV), and 19 healthy controls (HC) were included in this study. The proportion of B cells and their expressing BAFF receptor (BAFF-R), transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), and B-cell maturation antigen were analyzed via flow cytometry. Serum levels of BAFF, APRIL, and interleukin (IL)-4, IL-6, IL-10, and IL-13 were also evaluated using an enzyme-linked immunosorbent assay. The proportion of plasmablasts (PB)/plasma cells (PC) and serum levels of BAFF, APRIL, IL-4, and IL-6 were significantly higher in a-AAV than in HC. Higher serum levels of BAFF, APRIL, and IL-4 were observed in i-AAV than in HC. Lower expression of BAFF-R on memory B cells and higher expression of TACI on CD19+ cells, immature B cells, and PB/PC were demonstrated in a-AAV and i-AAV than in HC. The population of memory B cells was positively associated with serum APRIL levels and BAFF-R expression in a-AAV. In conclusion, decreased expression of BAFF-R on memory B cells and increased expression of TACI on CD19+ cells, immature B cells, and PB/PC, as well as increased serum levels of BAFF and APRIL, were sustained even in the remission phase of AAV. Persistent aberrant signaling of BAFF/APRIL may contribute to disease relapse.

Mitochondrial DNA: a novel indicator of active inflammation in ANCA-associated vasculitides.

ANCA-associated vasculitis (AAV) includes granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). ANCA triggers neutrophil extracellular trap formation, which releases either mitochondrial (mt) DNA or nuclear DNA (n) DNA, contributing to inflammation. Our aim was to prospectively examine the extent and nature of circulating DNA in AAV and the clinical utility of DNA quantification. DNA was isolated from platelet-free plasma of consecutive GPA and MPA patients and healthy controls (HCs). mtDNA and nDNA copy numbers were quantified by PCR. Clinical data, including the BVAS, were collected. Ninety-two HCs (median age 51 years, 58.7% female) and 101 AAV patients (80 GPA, 21 MPA, median age 64 years, 50.5% female, BVAS range: 0-30) were included. Median mtDNA copies were 13-fold higher in patients with AAV than in HCs; nDNA concentrations did not differ. Patients with active AAV (BVAS > 0) had 4-fold higher median mtDNA copies than patients in remission (P = 0.03). mtDNA, unlike nDNA, correlated with BVAS (r = 0.30, P = 0.002) and was associated with AAV activity at multivariable analysis. Receiver operating characteristic curve analysis indicated that mtDNA quantification differentiates patients with active AAV (BVAS > 0) from HCs with 96.1% sensitivity and 98.9% specificity (area under the curve 0.99). In 27 AAV patients with follow-up, mtDNA changes but not CRP or ANCA-titres correlated with BVAS changes (r = 0.56, P = 0.002). mtDNA, unlike nDNA, is elevated in the plasma of AAV patients and may contribute to systemic inflammation. mtDNA could be superior to established biomarkers in the laboratory monitoring of AAV activity.

EE656 A Cost-Utility Analysis of Avacopan for the Treatment of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis, a Rare Disease, in Spain

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a rare, heterogeneous, life-threatening, autoimmune condition. This study aimed to evaluate the cost-utility of avacopan in combination with rituximab or cyclophosphamide compared with glucocorticoids (GC) and cyclophosphamide or rituximab for the treatment of severe, active AAV from the Spanish National Health System perspective.

FC075: Role of Factor H and its Related Proteins (FHR-1, FHR-2 FHR-5) in ANCA-Associated Vasculitis: A Genetic and Longitudinal Serological Study

Abstract BACKGROUND AND AIMS The complement system was not initially thought to be associated with the development of ANCA-associated vasculitis (AAV). Convincing evidence from animal models and clinical observations indicates, however, that activation of the complement system, the alternative pathway (ACP) in particular, is pivotal for the development of AAV. Recently, a phase 3 clinical trial has shown that C5a receptor inhibition with avacopan was effective in replacing high dose glucocorticoids in AAV patients treated with rituximab or cyclophosphamide during induction treatment. We hypothesized that in AAV, a disorder in regulatory factors of ACP or in its related proteins (FHR-1, FHR-2, FHR-5) could be present, similar to other diseases in which its dysregulation have been shown. Method We measured longitudinal levels of alternative complements factors (FH, FB, properdin, FHR-1, FHR-2, FHR-5) and performed a genetic study for these factors in three cohorts: active renal ANCA vasculitis (active AAV, n = 54), inactive ANCA vasculitis (remission, n = 48) and in a control cohort of healthy individuals (n = 99). RESULTS ANCA serology was positive in all patients; 83.3% showed activity against MPO, whereas activity against PR3 was identified in 16.7% of patients. Median BVAS at the onset was 15 (IQR 14–19). Extrarenal involvement was present in 46.3% of participants. Haplotype CFH-H6 and the allele CFB32R are significantly associated with increased risk to develop AAV [OR 3.32; 95% confidence interval (95% CI) 1.39–7.89; P = 0.008 and OR 1.71, 95% CI 1.11–2.54; P = 0.008, respectively]. The allele frequency of ΔCFHR3/1 was significantly decreased in patients with severe AAV (T3, BVAS > 16) compared with patients with a lower BVAS score (T1-T2 ≤ 15). Circulating levels of regulatory factors (FH, FB, properdin) were significantly lower in patients with active disease compared to samples in remission, and FHR1 (FH competitor) levels were higher. C3 levels increased over time, while sC5b-9 decreased after initiating the immunosuppressive treatment, with the biggest change observed after the first month of treatment. After 12 months of follow-up, FHR-1 levels decreased in responder patients and did not decrease in nonresponders. CONCLUSION This is the first study to associate the presence of certain alleles of regulatory factors of the alternative complement pathway (Factor H and Factor B) with an increased risk of developing ANCA-associated vasculitis. Likewise, the absence of the ΔCHR3-CFHR1 deletion was associated with more severe forms of the disease. We could conclude that ACP is not a simple additional factor in the inflammatory loop in AAV and, like in other glomerular diseases related to ACP, dysregulation of FH and its regulatory proteins play an essential role in its development.

FC063: Serum and Urine Galectin-9, Ip-10 and Siglec-1 as Biomarkers of Disease Activity in Patients with Systemic Lupus Erythematosus Compared to Anca-Associated Vasculitis: A Longitudinal Study

Abstract BACKGROUND AND AIMS Galectin-9, interferon-inducible protein-10 (IP-10) and sialoadhesin (SIGLEC-1) are considered as potential biomarkers reflecting disease activity in patients with systemic lupus erythematosus (SLE). In this study, we aimed to investigate the association of serum and urine galectin-9, IP-10 and SIGLEC-1 with disease activity in patients with SLE. Also, we compared the results with ANCA-associated vasculitis (AAV) to test the specificity of the biomarkers. METHOD A total of 63 patients with active SLE (31 renal and 32 extrarenal) were included in the study. A total of 30 patients with inactive SLE (15 renal and 15 extrarenal), 17 with renal active AAV and 32 healthy volunteers were selected as control groups. Serum (s) and urine (u) levels of galectin-9, IP-10 and SIGLEC-1 were tested using ELISA. Urine levels of biomarkers were normalized by urine creatinine. RESULTS Of 142 participants, 109 (76.7%) were female and median age was 36 (28.75–48) years. Groups were comparable with regard to sex and age distribution except for AAV. In AAV group, seven patients (41.1%) were female and median age was 60 (48–65.5) years. Proliferative lupus nephritis (LN) (class III/III + V and IV/IV + V) were found in 22 patients with active renal SLE (70.9%), while 6 patients (19.3%) had pure class V and 3 (9.7%) had class II LN. Levels of sIP-10, uIP-10, sGalectin-9 and uSIGLEC-1 were significantly higher in the active SLE group compared to the inactive SLE group (sIP-10; P = 0.046, uIP-10; P < 0.001, sGalectin-9; P = 0.031 and uSIGLEC-1; P = 0.006); however, no differences were detected in the comparison of uGalectin-9 and sSIGLEC-1 between these two groups (uGalectin-9; P = 0.180 and sSIGLEC-1; P = 0.699). sIP-10 (P < 0.001), uIP-10 (P = 0.029) and uGalectin-9 (P < 0.001) were significantly higher in patients with active SLE compared to AAV (Table 1). Serum and urine galectin-9, IP-10 and SIGLEC-1 did not differ between patients with active renal and extrarenal SLE. Levels of sIP-10, uIP-10 and uSIGLEC-1 were correlated with SLE Disease Activity Index (SLEDAI). ROC analyses confirmed that sIP-10, uIP-10, sGalectin-9 and uSIGLEC-1 discriminated disease activity in SLE (Figure 1). Serum and urine levels of all biomarkers were retested in 41 of 63 patients (65%) with active SLE after a median treatment of 8 (5–22.5) months. At the time of the second tests, there was a significant decrease in disease activity as measured by SLEDAI [2 (0–4)] compared to the time of the first tests [10 (6–15.5)]. Comparison of sGalectin-9 levels between the sample at the time of active disease and remission showed a very significant decline (P < 0.001). uGalectin-9, sIP-10 and uSIGLEC-1 also decreased after treatment; however, the difference was not statistically significant. CONCLUSION sIP-10, uIP-10, sGalectin-9 and uSIGLEC-1 are associated with disease activity in SLE. None is able to discriminate active renal from active extrarenal disease. sIP-10 and uIP-10 are specific for active SLE compared to renal active AAV. sGalectin-9 may be a valuable biomarker to monitor response after treatment for active disease. Funded by Scientific Research Projects Coordination Unit of Istanbul University. Project number: TSA-2019–34 218.

CSF2-dependent monocyte education in the pathogenesis of ANCA-induced glomerulonephritis

ObjectivesMyeloid cell activation by antineutrophil cytoplasmic antibody (ANCA) is pivotal for necrotising vasculitis, including necrotising crescentic glomerulonephritis (NCGN). In contrast to neutrophils, the contribution of classical monocyte (CM) and non-classical...

Neutrophil-derived extracellular vesicles induce endothelial inflammation and damage through the transfer of miRNAs

The critical role of neutrophils in pathological inflammation, notably in various autoimmune disorders, is currently the focus of renewed interest. Here, we demonstrate for the first time that activation of neutrophils with various inflammatory stimuli induces the release of extracellular vesicles (EVs) that are internalized by endothelial cells (ECs), thus leading to the transfer of miR-223, miR-142–3p and miR-451 and subsequent endothelial damage. Indeed, while miR-223 has little effect on EC responses, we show that the induced expression of miR-142–3p and miR-451 in ECs results in profound cell damage, especially in inflammatory conditions, characterized by a dramatic increase in cell apoptosis, impaired angiogenic repair responses, and the induction of IL-6, IL-8, CXCL10 and CXCL11 expression. We show that the strong deleterious effect of miR-142–3p may be due in part to its ability to block the activation of ERK1/2 and eNOS-mediated signals in ECs. miR-142–3p also inhibits the expression of RAC1, ROCK2 and CLIC4, three genes that are critical for EC migration and angiogenic responses. Importantly, miR-223, miR-142–3p and miR-451 are markedly increased in kidney biopsies from patients with active ANCA-associated vasculitis, a severe autoimmune disease that is prototypical of a neutrophil-induced microvascular damage. Taken together, our results suggest that miR-142–3p and miR-451 released in EVs by activated neutrophils can target EC to trigger an inflammatory cascade and induce direct vascular damage, and that therapeutic strategies based on the inhibition of these miRNAs in ECs will have implications for neutrophil-mediated inflammatory diseases.

Is There a Place for Complement Inhibition with Monoclonal Anti-C5a Antibody Vilobelimab in the Treatment of Patients with ANCA-associated Vasculitis?

Recent studies have implicated the complement system in the pathogenesis of antineutrophil cytoplasmic antibody-associated vasculitis (AAV), prompting the development of novel therapeutic agents to target the complement system accordingly. The pivotal role of complement component C5a, in particular, has been the subject of a number of phase II and phase III clinical trials. Indeed, the US Food and Drug Administration has already approved avacopan, an oral C5a receptor inhibitor, as an adjunct for the treatment of active severe AAV, based on its favourable safety profile and non-inferiority to glucocorticoids (GCs) (at Week 26). The novel monoclonal anti-C5a antibody vilobelimab has also been studied in a phase II trial in patients with AAV (IXchange; ClinicalTrials.gov Identifier: NCT03895801). The results appear promising; in addition to decreased GC toxicity index, a smaller number of treatment-emergent adverse events have been observed in vilobelimab-treated patients. However, the study was not powered statistically to compare the efficacy of vilobelimab to standard GC treatment. This editorial summarizes the study findings and outlines potential future directions.

Increased gene expression of B cell-activating factor of tumor necrosis factor family, in remitting antineutrophil cytoplasmic antibody-associated vasculitis patients.

To study the expression of B cell-activating factor of tumor necrosis factor family (BAFF) and A proliferation-inducing ligand (APRIL) genes in active and remitting patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) and healthy controls and their correlation with disease activity. This was a prospective case-control study. Gene expressions of BAFF and APRIL were studied in 32 patients with AAV (16 each with active disease and in remission) and 30 healthy age and sex matched controls by real-time polymerase chain reaction. Out of 32 AAV patients, 26 had granulomatosis with polyangiitis (GPA) and 6 had microscopic polyangiitis (MPA). Mean ages of patients in active (12 GPA and 4 MPA) and remission (14 GPA and 2 MPA) groups were 39.4±17.2 and 44.6±16.1years, respectively. BAFF gene expression was significantly higher in both the active AAV group and remission AAV group compared to controls (P<.01). The BAFF expression was significantly higher in AAV patients in remission compared to active AAV patients (P=.003). In contrast, APRIL expression did not differ between AAV patients and controls (P=.829). However, APRIL had significantly higher expression in remission as compared to active patients (P=.048). There was no significant correlation of both BAFF and APRIL expression with disease activity markers (erythrocyte sedimentation rate, C-reactive protein, platelets and Birmingham Vasculitis Activity Score version 3). BAFF gene is significantly expressed in patients with AAV. Among AAV patients, there is a significantly higher expression of BAFF and APRIL in remitting state of the disease as compared to active state. There is no significant change in APRIL gene expression in patients with AAV as compared to controls. This makes a case for anti-BAFF therapy in future for AAV patients in northern India.

Avacopan: First Approval.

Avacopan (TAVNEOS™) is a complement 5a receptor (C5aR) antagonist developed by ChemoCentryx for the treatment of autoimmune diseases including anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis. The therapeutic effects of avacopan are attributed to the inhibition of C5aR activity on neutrophils, however, the exact mechanism of therapeutic efficacy in patients with ANCA-associated vasculitis has not been established. In September 2021, avacopan received its first approval in Japan for the treatment of microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA), the two most common forms of ANCA-associated vasculitis, where it is being commercialized by Kissei Pharmaceutical through a partnership with Vifor Pharma. In October 2021, avacopan was approved in the USA as an adjunctive treatment in adults for severe active ANCA-associated vasculitis (specifically MPA and GPA) in combination with standard therapy including glucocorticoids (avacopan does not eliminate glucocorticoid use). Avacopan has received a positive opinion in the EU, and is also undergoing regulatory review in Switzerland and Canada. Avacopan is being investigated for the treatment of complement component 3 glomerulopathy, hidradenitis suppurativa, lupus nephritis and IgA nephropathy. This article summarizes the milestones in the development of avacopan leading to these first approvals in Japan and the USA.

Comparative efficacy and safety of rituximab, mycophenolate, and cyclophosphamide in active antineutrophil cytoplasmic antibody-associated vasculitis: A Bayesian network meta-analysis of randomized controlled trials.

The aim of the present study was to compare the effectiveness and safety of rituximab, mycophenolate mofetil (MMF), and cyclophosphamide (CYC) for the treatment of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We conducted a Bayesian network meta-analysis to incorporate direct and indirect data from sixrandomized controlled trials (comprising 541 patients) that investigated the effectiveness and safety of rituximab, MMF, and CYC for the treatment of patients with AAV and met the inclusion criteria. Rituximab and MMF demonstrated a trend toward a higher response rate than CYC, (OR 1.41, 95% credible interval (CrI) 0.84-2.40) and (OR 1.20, % CrI 0.73-1.93), respectively. The surface under the cumulative ranking curve (SUCRA) revealed that rituximab has the highest probability of being a better remission-induction therapy (SUCRA = 0.797), followed by MMF and CYC (-SUCRA = 0.537 and 0.166, respectively). However, CYC displayed a propensity for a lower relapse than rituximab and MMF (OR 0.81, 95% CrI 0.42-1.50; OR 0.72, % CrI 0.39-1.27), further confirmed by -SUCRA rankings. Rating likelihood based on -SUCRA revealed that rituximab was more likely to be the safest medication since it displayed a lower incidence of serious adverse effects (SAEs), followed by CYC and MMF. Rituximab may serve as an effective remission-induction therapy for patients with AAV and decrease the incidence of SAEs. Although rituximab showed a high relapse rate, the accompanying desirable safety profile indicates that it is the first therapeutic choice for patients with AAV.

Chemokine/Cytokine Levels Correlate with Organ Involvement in PR3-ANCA-Associated Vasculitis

Background: ANCA-associated vasculitis (AAV) is a rare small vessel disease characterized by multi-organ involvement. Biomarkers that can measure specific organ involvement are missing. Here, we ask whether certain circulating cytokines and chemokines correlate with renal involvement and if distinct cytokine/chemokine patterns can differentiate between renal, ear/nose/throat, joints, and lung involvement of AAV. Methods: Thirty-two sets of Birmingham vasculitis activity score (BVAS), PR3-ANCA titers, laboratory marker, and different cytokines were obtained from 17 different patients with AAV. BVAS, PR3-ANCA titers, laboratory marker, and cytokine concentrations were correlated to different organ involvements in active AAV. Results: Among patients with active PR3-AAV (BVAS > 0) and kidney involvement we found significant higher concentrations of chemokine ligand (CCL)-1, interleukin (IL)-6, IL21, IL23, IL-28A, IL33, monocyte chemoattractant protein 2 (MCP2), stem cell factor (SCF), thymic stromal lymphopoietin (TSLP), and thrombopoietin (TPO) compared to patients without PR3-ANCA-associated glomerulonephritis. Patients with ear, nose, and throat involvement expressed higher concentrations of MCP2 and of the (C-X-C motif) ligand-12 (CXCL-12) compared to patients with active AAV and no involvement of these organs. Conclusion: We identified distinct cytokine patterns for renal manifestation and for ear, nose and throat involvement of PR3-AAV. Distinct plasma cytokines might be used as non-invasive biomarkers of organ involvement in AAV.

The significance of metalloproteinase 3 (MMP-3), chemokine CXC ligand 13 (CXCL-13) and complement component C5a in different stages of ANCA associated vasculitis

The aim of the study was to evaluate the significance of metalloproteinase 3 (MMP-3), chemokine CXC ligand 13 (CXCL-13) and complement component 5a (C5a) in different stages of ANCA associated vasculitis (AAV). 89 adults were included into the study. 28 patients with active AAV (Birmingham Vasculitis Activity Score, BVAS > 3) formed the Active Group. 24 individuals who were in remission after 6 months of induction therapy formed the Short R Group, while 34 patients with longitudinal remission formed the Long R Group. 28 patients without autoimmune diseases similar in terms of age, gender and stage of kidney disease formed the Control Group. Receiver operating characteristic curve analysis (ROC) was used to evaluate MMP-3, CXCL-13 and C5a as markers of the different phases of vasculitis. In ROC analysis, MMP-3, CXCL-13 and C5a presented a good ability in distinguishing active vasculitis (Active Group) from the Control Group (AUC > 0.8), whereas only CXCL-13 displayed potential ability in distinguishing active vasculitis (Active Group) from long term remission (Long R Group, AUC = 0.683). MMP-3 significantly and positively correlated with serum creatinine concentration (r = 0.51, p = 0.011; r = 0.44, p = 0.009; r = −0.66, p < 0.001) and negatively with eGFR (r = −0.5, p = 0.012; r = −0.35, p = 0.039; r = −0.63, p < 0.001) in the Short R, Long R and Control Groups. MMP-3, CXCL-13, C5a can be potential markers in differentiating an active phase of vasculitis from other pathologies. However they can be treated as complementary to the well-known markers. CXCL-13 seems to be a potential marker in distinguishing active vasculitis from long term remission. MMP-3 level can be related to kidney function expressed by eGFR, therefore its elevation should be interpreted with caution in patients with kidney failure.