Associated Vasculitis Research Articles

#2543 Complement receptor C5aR1 correlates with inflammatory responses driven by glomerular uPAR upregulation in renal vasculitides

Abstract Background and Aims Avacopan is a novel promising treatment for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) targeting the complement system by blocking C5a receptor C5aR1. We here pursued a transcriptome array-based approach to dissect molecular signatures associated with C5aR1 in renal vasculitis. Method C5aR1 mRNA expression levels (reporter ID: 210845_s_at, platform: Affymetrix Human Genome U133 Plus 2.0 Array, altCDF v10) were extracted from microdissected samples of renal vasculitis (glomerular: n = 23, tubulointerstitial: n = 21). Pathway analysis was performed for gene enrichment associated with PLAUR mRNA expression with a correlation threshold of ≥0.5 by using reactome (http://reactome.org), pathways with a predefined entities value of p≤0.001 were included. Results We here identified a predominant glomerular expression of C5aR1 in renal vasculitis as compared to the tubulointerstitial compartment (p < 0.0001). Furthermore, glomerular C5aR1 induction correlated with impaired kidney function (eGFR: 0.0193). Gene set enrichment identified various inflammatory signatures including neutrophil degranulation and innate immunity, and particularly enrichment of urokinase plasminogen activator receptor (uPAR). uPAR itself also correlated with impairment of kidney function in renal vasculitis and particularly active glomerular lesions (cellular crescents and necrosis, p < 0.0001). Conclusion The therapeutic implications of targeting uPAR in renal vasculitis are promising, and ongoing research endeavors are aimed at unraveling the complexities of uPAR as a potential diagnostic marker and therapeutic target for this challenging renal pathology. We here expand our current knowledge and link C5aR1 to inflammatory responses driven by glomerular uPAR upregulation in renal vasculitis.

Large-vessel involvement in ANCA-associated vasculitis: A multicenter case-control study

ObjectiveAntineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) primarily affects small vessels. Large-vessel involvement (LVI) is rare. We aimed to describe the characteristics of LVI, to identify associated risk factors, and to describe its therapeutic management. MethodsThis multicenter case-control (1:2) study included patients with AAV according to the ACR/EULAR classification and LVI as defined by the Chapel Hill nomenclature, together with controls matched for age, sex, and AAV type. ResultsWe included 26 patients, 15 (58 %) of whom were men, with a mean age of 56.0 ± 17.1 years. The patients had granulomatosis with polyangiitis (n = 20), or microscopic polyangiitis (n = 6). The affected vessels included the aorta (n = 18; 69 %) supra-aortic trunks (n = 9; 35 %), lower-limb arteries (n = 5; 19 %), mesenteric arteries (n = 5; 19 %), renal arteries (n = 4; 15 %), and upper-limb arteries (n = 2; 8 %). Imaging showed wall thickening (n = 10; 38 %), perivascular inflammation (n = 8; 31 %), aneurysms (n = 5; 19 %), and stenosis (n = 4; 15 %). Comparisons with the control group revealed that LVI was significantly associated with neurological manifestations (OR=3.23 [95 % CI: 1.11–10.01, p = 0.03]), but not with cardiovascular risk factors (OR=0.70 [95 % CI: 0.23–2.21, p = 0.60]), or AAV relapse (OR=2.01 [95 % CI: 0.70–5.88, p = 0.16]). All patients received corticosteroids, in combination with an immunosuppressant in 24 (92 %), mostly cyclophosphamide (n = 10, 38 %) or rituximab (n = 9, 35 %). ConclusionRegardless of distinctions based on vessel size, clinicians should consider LVI as a potential manifestation of AAV, with the aorta commonly affected. The risk of developing LVI appears to be greater for clinical phenotypes of AAV with neurological involvement. Standard AAV treatment can be used to manage LVI.

Application of biological agents in the treatment of anti-neutrophil cytoplasmic antibody-associated vasculitis.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has been traditionally treated using glucocorticoids and immunosuppressants. However, these treatment modes are associated with high recurrence AAV rates and adverse reactions. Therefore, treatment strategies for AAV need to be urgently optimized. The efficacy and safety of biological agents in the treatment of vasculitis have been clinically validated. This review comprehensively summarizes the evidence-based support for the clinical use of existing biological agents in AAV. The findings reveal that multiple biological agents not only effectively reduce the adverse reactions associated with glucocorticoids and immunosuppressants but also demonstrate significant therapeutic efficacy. Notably, rituximab, an anti-CD20 antibody, has emerged as a first-line treatment option for AAV. Mepolizumab has shown promising results in relapsed and refractory eosinophilic granulomatosis with polyangiitis. Other biological agents targeting cytokines, complement, and other pathways have also demonstrated clinical benefits in recent studies. The widespread application of biological agents provides new insights into the treatment of AAV and is expected to drive further clinical research. These advancements not only improve patient outcomes but also offer more possibilities and hope in the field of AAV treatment.

Carotid intima-media thickness correlated with age and pulse wave velocity in ANCA-associated vasculitis patients

Objective: Cardiovascular diseases are the main causes of mortality in the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients. Carotid intima-media thickness (CIMT) measurement and pulse wave velocity (PWV) were performed to determine atherosclerosis and arterial stiffness as cardiovascular risk markers. Patients and Methods: The data of 31 patients with AAV were compared with 21 healthy controls. Demographic and laboratory findings were recorded. Results: Seventeen patients (54.8%) were male. Mean age was 52.6±11.5 years. CIMT was higher in the patient group [0.74 (0.65 – 0.84) vs 0.63 (0.57-0.74) mm; p=0.048]. PWV [7.9 (6.7-9.3) vs 7.8 (6.8-8.5) m/s; p=0.295] and augmentation index (AI) [22.5 (11.0-30.0) vs. 23 (9.5-30.5) mm/Hg, p=0.801] were similar in both groups. CIMT was correlated with age (r: 0.538, p

Endothelial dysfunction and complement activation are independently associated with disease duration in patients with systemic vasculitis

ObjectivesSystemic vasculitis is a heterogenous group of autoimmune diseases characterized by enhanced cardiovascular mortality. Endothelial dysfunction is associated with accelerated vascular damage, representing a core pathophysiologic mechanism contributing to excess CV risk. Recent studies have also shown that complement activation holds significant role in the pathogenesis of Anti-Neutrophilic Cytoplasmic Autoantibody (ANCA) -associated vasculitis (AAV). Given the potential crosstalk between the endothelium and complement, we aimed to assess, for the first time simultaneously, easily accessible biomarkers of endothelial dysfunction and complement activation in SV. MethodsWe measured circulating endothelial microvesicles (EMVs) and soluble complement components representative of alternative, classical and terminal activation (C5b-9, C1q, Bb fragments, respectively) in a meticulously selected group of patients with systemic vasculitis, but without cardiovascular disease. Individuals free from systemic diseases, who were matched with patients for cardiovascular risk factors(hypertension, diabetes, smoking, dyslipidemia), comprised the control group. ResultsWe studied 60 individuals (30 in each group). Patients with systemic vasculitis had elevated EMVs, higher levels of C5b-9 [536.4(463.4) vs 1200.94457.3), p = 0.003] and C1q [136.2(146.5 vs 204.2(232.9), p = 0.0129], compared to controls [232.0 (243.5) vs 139.3(52.1), p < 0.001]. In multivariate analysis both EMVs and C5b-9 were independently associated with disease duration (p = 0.005 and p = 0.004 respectively), yet not with disease activity. ConclusionPatients with systemic vasculitis exhibit impaired endothelial function and complement activation, both assessed by easily accessible biomarkers, even in the absence of cardiovascular disease manifestations. EMVs and soluble complement components such as C5b-9 and C1q could be used as early biomarkers of endothelial dysfunction and complement activation, respectively, in clinical practice during the course of SV, yet their predictive value in terms of future cardiovascular disease warrants further verification in appropriately designed studies.

Overlap syndrome of systemic sclerosis with antineutrophil cytoplasmic antibody-associated vasculitis according to 2022 ACR/EULAR criteria.

This study applied the 2022 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) criteria for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) to patients with systemic sclerosis (SSc) and investigated the frequency of overlap syndrome of SSc and AAV (SSc-AAV-OS). Among the 232 patients diagnosed with SSc, 105 with signs suggestive of small- or medium-vessel vasculitis, which were defined as the present of interstitial lung disease (ILD), peripheral neuropathy, or suspected renal vasculitis, were included in this study and analyzed. Among the 105 SSc patients, the detection rate of ANCA was 19.0%. When the 2022 ACR/EULAR criteria were applied, the frequency of SSc-AAV-OS was 20.0%, which was much higher than 1.7% reported with previous criteria for AAV. ANCA positivity contributed to the reclassification of SSc-AAV-OS more than ANCA negativity in SSc patients with signs suggestive of small- or medium-vessel vasculitis. The frequency of SSc-AAV-OS in SSc patients with signs suggestive of small- or medium-vessel vasculitis at diagnosis was 20.0%. Therefore, we suggest that physicians should perform ANCA tests in SSc patients exhibiting signs suggestive of small- or medium-vessel vasculitis and apply the new criteria for AAV.

Cardiovascular disease and antineutrophil cytoplasmic antibodies-associated vasculitis: A systematic review

ABSTRACT Recent evidence suggests that cardiovascular disease and antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) are interconnected. This investigation aims to examine the epidemiology, potential risk, and cardiovascular events among AAV sufferers to shed light on the intricate relationship between these seemingly unrelated conditions. A systematic review following PRISMA criteria encompassed 18 relevant studies with a pooled sample size of 21,291 ANCA-associated vasculitis patients. Studies were retrieved from PubMed, Embase, and Cochrane Library. Inclusion criteria focused on longitudinal studies reporting cardiovascular events in AAV patients. Data extraction and synthesis were performed, focusing on prevalence, types of cardiovascular events, comparison with control groups, and identification of risk factors and independent predictors. The study found that patients with ANCA-associated vasculitis had a mean age of 57.5 years, with 47% being male. The mean follow-up duration was 4.77 years. Overall, 1350 cardiovascular events were reported across the studies, yielding a pooled prevalence of 6.3%. Major adverse cardiovascular events, ischemic heart disease, stroke, venous thromboembolism, and acute coronary syndromes were the specific events. Comparison with control groups demonstrated a higher cardiovascular risk in AAV patients. Age, systolic blood pressure, estimated glomerular filtration rate, and the Birmingham Vasculitis Activity Score were independent predictors. In conclusion, ANCA-associated vasculitis patients have elevated cardiovascular risk and a variety of manifestations. AAV-specific variables,such as inflammation and disease activity, and conventional risk factors, play a role in cardiovascular complications. The study challenges conventional assessment timelines by highlighting the importance of early and proactive cardiovascular risk management.

Risk factors for severe COVID-19 infection and the impact of COVID-19 infection on disease progression among patients with AAV

To identify risk factors for COVID-19 infection and investigate the impact of COVID-19 infection on chronic kidney disease (CKD) progression and vasculitis flare in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). This cohort study retrospectively analyzed the prevalence and severity of COVID-19 infection in 276 patients with AAV who were followed up. Logistic regression was employed to estimate the risk of COVID-19 infection as well as CKD progression and vasculitis flare upon COVID-19 infection. During the 6-month observation period, 213 (77.2%) of 276 patients were diagnosed with COVID-19 infection. Of these 213 patients, 49 (23.0%) had a COVID-19-related inpatient admission, including 17 patients who died of COVID-19 infection. AAV patients with severe COVID-19 infection were more likely to be male (OR 1.921 [95% CI 1.020–3.619], P = 0.043), suffered from worse kidney function (serum creatinine [Scr], OR 1.901 [95% CI 1.345–2.687], P < 0.001), had higher C-reactive protein (CRP) (OR 1.054 [95% CI 1.010–1.101], P = 0.017) and less likely to have evidence of initial vaccination (OR 0.469 [95% CI 0.231–0.951], P = 0.036), and Scr and COVID-19 vaccination were proven to be significantly associated with severe COVID-19 infection even after multivariable adjustment. Severe COVID-19 infection was significantly associated with subsequent CKD progression (OR 7.929 [95% CI 2.030–30.961], P = 0.003) and vasculitis flare (OR 11.842 [95% CI 1.048–133.835], P = 0.046) among patients with AAV. AAV patients who were male, and with worse kidney function were more susceptible to severe COVID-19 infection, which subsequently increased the risk of CKD progression and vasculitis flare.

Deciphering three predominant biopsy-proven phenotypes of IgG4-associated kidney disease: a retrospective study.

IgG4-associated kidney disease (IgG4-RKD) encompasses a spectrum of disorders, predominantly featuring tubulointerstitial nephritis (TIN) and membranous glomerulonephropathy (MGN). The limited understanding of the co-occurrence of IgG4-RD-TIN with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) poses a diagnostic and therapeutic challenge. We examined 49 cases, comprising 21 cases of IgG4-RD-TIN (group A), 10 cases of IgG4-RD-TIN accompanied with MGN (group B), and 18 cases of IgG4-RD-TIN concurrent with AAV (group C), at the First Affiliated Hospital of Zhejiang University, China, from June 2015 to December 2022. The mean age and gender of the three IgG4-RKD subtypes were not statistically significant. IgG4-RD-TIN exhibited higher serum creatinine and a higher incidence of hypocomplementemia (group A 47.6%, group B 30%, group C 16.7%). IgG4-RD-TIN-MGN was characterized by proteinuria (group A 0.3g/d, group B 4.0g/d, group C 0.8g/d, P<0.001) and hypoalbuminemia. IgG4-RD-TIN-AAV exhibited hypohemoglobinemia (group A 103.45g/l, group B 119.60g/l, group C 87.94g/l, P<0.001) and a high level of urine erythrocytes. The primary treatment for IgG4-RD-TIN was steroids alone, whereas IgG4-RD-TIN-MGN and IgG4-RD-TIN-AAV necessitated combination therapy. Group A experienced two relapses, whereas groups B and C had no relapses. There was no significant difference in patient survival among the three groups, and only two cases in group C suffered sudden death. This study provides valuable insights into clinical manifestations, auxiliary examination features, pathological characteristics, and prognosis of IgG4-RD-TIN, IgG4-RD-TIN-MGN, and IgG4-RD-TIN concurrent AAV. Large-scale studies are required to validate these findings.

Clinical features and prognosis of ANCA-associated vasculitis patients who were double-seropositive for myeloperoxidase-ANCA and proteinase 3-ANCA

Anti-neutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) patients with dual positivity for proteinase 3-ANCA (PR3-ANCA) and myeloperoxidase-ANCA (MPO-ANCA) are uncommon. We aimed to investigate these idiopathic double-positive AAV patients’ clinical features, histological characteristics, and prognosis. We reviewed all the electronic medical records of patients diagnosed with AAV to obtain clinical data and renal histological information from January 2010 to December 2020 in a large center in China. Patients were assigned to the MPO-AAV group or PR3-AAV group or idiopathic double-positive AAV group by ANCA specificity. We explored features of idiopathic double-positive AAV. Of the 340 patients who fulfilled the study inclusion criteria, 159 (46.76%) were female, with a mean age of 58.41 years at the time of AAV diagnosis. Similar to MPO-AAV, idiopathic double-positive AAV patients were older and had more severe anemia, lower Birmingham Vasculitis Activity Score (BVAS) and C-reactive protein (CRP) levels, less ear, nose, and throat (ENT) involvement, higher initial serum creatinine and a lower estimated glomerular filtration rate (eGFR) when compared with PR3-AAV (P < 0.05). The proportion of normal glomeruli of idiopathic double-positive AAV was the lowest among the three groups (P < 0.05). The idiopathic double-positive AAV patients had the worst remission rate (58.8%) among the three groups (P < 0.05). The relapse rate of double-positive AAV (40.0%) was comparable with PR3-AAV (44.8%) (P > 0.05). Although there was a trend toward a higher relapse rate of idiopathic double-positive AAV (40.0%) compared with MPO-AAV (23.5%), this did not reach statistical significance (P > 0.05). The proportion of patients who progressed to ESRD was 47.1% and 44.4% in the idiopathic double-positive AAV group and MPO-AAV group respectively, without statistical significance. Long-term patient survival also varied among the three groups (P < 0.05). Idiopathic double-positive AAV is a rare clinical entity with hybrid features of MPO-AAV and PR3-AAV. MPO-AAV is the “dominant” phenotype in idiopathic double-positive AAV.

Thyroid disease in ANCA-associated vasculitis: a clinical and epidemiological study

ObjectivesTo describe clinical and laboratory characteristics and outcomes in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and thyroid disease (TD). We also aimed to calculate incidence and identify predictors...

The HLA region in ANCA-associated vasculitis: characterisation of genetic associations in a Scandinavian patient population

ObjectiveThe antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are inflammatory disorders with ANCA autoantibodies recognising either proteinase 3 (PR3-AAV) or myeloperoxidase (MPO-AAV). PR3-AAV and MPO-AAV have been associated with distinct loci...

Dual MPO/PR3 ANCA positivity and vasculitis: insights from a 7-cases study and an AI-powered literature review.

Anti-neutrophil cytoplasm antibodies (ANCA)-associated vasculitides (AAV) are rare conditions characterized by inflammatory cell infiltration in small blood vessels, leading to tissue necrosis. While most patients with AAV present antibodies against either myeloperoxidase (MPO) or proteinase 3 (PR3), rare cases of dual positivity for both antibodies (DP-ANCA) have been reported, and their impact on the clinical picture remains unclear. The goal of this study was to investigate the clinical implications, phenotypic profiles and outcomes of patients with DP-ANCA. A retrospective screening for DP-ANCA cases was conducted at Brest University Hospital's immunology laboratory (France), analysing ANCA results from March 2013 to March 2022. Clinical, biological, imaging, and histological data were collected for each DP-ANCA case. Additionally, a comprehensive literature review on DP-ANCA was performed, combining an artificial intelligence (AI)-based search using BIBOT software with a manual PUBMED database search. The report of our cases over the last 9 years and those from the literature yielded 103 described cases of patients with DP-ANCA. We identified four distinct phenotypic profiles: (i) idiopathic AAV (∼30%); (ii) drug-induced AAV (∼25%); (iii) autoimmune disease associated with a low risk of developing vasculitis (∼20%); and (iv) immune-disrupting comorbidities (infections, cancers, etc) not associated with AAV (∼25%). This analysis of over a hundred DP-ANCA cases suggests substantial diversity in clinical and immunopathological presentations. Approximatively 50% of DP-ANCA patients develop AAV, either as drug-induced or idiopathic forms, while the remaining 50%, characterized by pre-existing dysimmune conditions, demonstrates a remarkably low vasculitis risk. These findings underscore the complex nature of DP-ANCA, its variable impact on patient health, and the necessity for personalized diagnostic and management approaches in these cases.

Protective effect of astaxanthin on ANCA-associated vasculitis

ObjectiveAnti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic autoimmune disease characterized by inflammation and fibrinoid necrosis of medium and small vessels, and its pathogenesis is closely related to inflammation and oxidative stress. Astaxanthin (ATX) is a carotenoid with anti-inflammatory, antioxidant, and immunomodulatory effects. We hypothesized that ATX could play a role in AAV treatment. This study aimed to investigate whether ATX has a protective effect against AAV and to elucidate its regulatory mechanism. MethodsIn vitro experiments, neutrophils isolated from healthy people were treated with ATX or not and cultured with serum from myeloperoxidase (MPO) -ANCA-positive patients and healthy persons. The levels of IL-6 and TNF-α in neutrophil culture supernatant before and after stimulation were measured. Neutrophil extracellular traps (NETs) and intracellular reactive oxygen species (ROS) in neutrophils were detected after stimulation. In vivo study, experimental autoimmune vasculitis (EAV) rat models were established and then treated with ATX via intragastric administration for 6 consecutive weeks. Urinary erythrocytes, urinary proteins, and serum creatinine were detected and HE staining was performed to assess renal injury in rats. Lung hemorrhage was observed by gross dissection and microscopic Prussian blue staining. The level of serum MPO-ANCA was detected. Serum IL-6, TNF-α, superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) in rats were measured to explore the effects of ATX on oxidative stress and inflammation in EAV rats. The deposition of MPO in kidney and lung of rats was detected by immunohistochemistry. ResultsATX significantly inhibited neutrophil secretion of inflammatory factors IL-6 and TNF-α. ATX reduced the elevated levels of ROS in neutrophils stimulated by serum from AAV patients and alleviated the release of NETs. ATX administration was observed to reduce the degree of hematuria, proteinuria, and glomerular crescent formation in EAV rats. The degree of pulmonary hemorrhage was significantly reduced. Besides, the serum levels of IL-6 and TNF-α were attenuated, and antioxidant SOD and GSH-px increased in serum. Pathological results showed that MPO deposition was decreased in lung and kidney tissues after ATX treatment. ConclusionATX could ameliorate the organ damages in EAV rats. It could serve as a hopeful therapy for AAV by its anti-inflammatory and anti-oxidative feature as a unique nature carotenoid.

Predictors of medications-free and long-term remission in anti-neutrophil cytoplasmic antibody-associated vasculitis: Real-world evidence.

In this study, we report the outcomes of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in daily practice based on Connective Tissue Diseases Research Center-Vasculitis Registry (CTDRC-VR) data. Patients were included if they were 18 years or older, had a diagnosis of the groups of AAV based on 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis and microscopic polyangiitis, and were followed for a period longer than 2 years or were died. Complete clinical remission was defined as granulomatosis with polyangiitis (BVAS/GPA) of 0. Sustained remission was defined as a complete clinical remission for at least six months and tapering prednisolone dose to ≤ 7.5 mg/d. Long-term remission was defined as complete clinical remission for ≥ 5 years and tapering prednisolone dose to ≤ 7.5 mg/d. Medications-free remission was defined as complete clinical remission and discontinuation of glucocorticoids, cytotoxic medications and biologics. Sixty patients with AAV were enrolled in this study. Sustained and long-term remission were developed in 91.7 and 72.1 percent of patients, respectively. Relapse was developed in 27 (45%) patients. Medications-free remission was developed in 23 (33.3%) patients. Vasculitis induced damage was developed in 40 (66.7%) patients. Patients with damage had significantly lower age and higher BVAS at the baseline. Upper airway and renal involvement, and non-adherence in patients with damage was significantly more common. Induction therapy leads to long-term and medications-free remission in 72% and 38% of patients with AAV, respectively.

Real-World Experience With Avacopan in Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis

Postmarketing data on outcomes of avacopan use in antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) are lacking. We performed a multicenter retrospective analysis of 92 patients with newly diagnosed or relapsing AAV who received therapy with avacopan. The coprimary outcome measures were clinical remission at 26 and 52 weeks. We use descriptive statistics and univariate logistic regression to assess outcomes and predictors of remission, respectively. Of the 92 patients, 23% (n = 21) had a baseline estimated glomerular filtration rate (eGFR)< 15 ml/min per 1.73 m2 and 10% on kidney replacement therapy at baseline. Among those with kidney involvement, mean (SD) enrollment eGFR was 33 (27) ml/min per 1.73 m2 with a mean (SD) change of+12 (25) and+20 (23) ml/min per 1.73 m2 at weeks 26 and 52, respectively. In addition to avacopan, 47% of patients received combination therapy of rituximab and low-dose cyclophosphamide, and 14% of patients received plasma exchange (PLEX). After induction, the median (interquartile range [IQR]) time to start avacopan was 3.6 (2.1-7.7) weeks, and the median time to discontinue prednisone after starting avacopan was 5.6 (3.3-9.5) weeks. Clinical remission was achieved in 90% of patients at week 26 and 84% of patients at week 52. Of the patients, 20% stopped avacopan due to adverse events, with the most common being elevated serum aminotransferases (4.3%). A high rate of remission and an acceptable safety profile were observed with the use of avacopan in the treatment of AAV in this postmarketing analysis, including the populations excluded from the ADVOCATE trial.

Transcription factor Nrf2 activation regulates NETosis, endothelial injury, and kidney disease in myeloperoxidase-positive antineutrophil cytoplasmic antibody-associated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic autoimmune disease pathologically characterized by vascular necrosis with inflammation. During AAV development, activated neutrophils produce reactive oxygen species (ROS), leading to the aberrant formation of neutrophil extracellular traps (NETs) via NETosis and subsequent fibrinoid vascular necrosis. Nuclear factor-erythroid 2-related factor 2 (Nrf2) functions as an intracellular defense system to counteract oxidative stress by providing antioxidant properties. Herein, we explored the role of Nrf2 in the pathogenesis of AAV. The role and mechanism of Nrf2 in ANCA-stimulated neutrophils and subsequent endothelial injury were evaluated invitro using Nrf2 genetic deletion and Nrf2 activator treatment. In corresponding invivo studies, the role of Nrf2 in ANCA-transfer AAV and spontaneous AAV murine models was examined. Pharmacological activation of Nrf2 invitro suppressed ANCA-induced NET formation via the inhibition of ROS. In contrast, NET formation was enhanced in Nrf2-deficient neutrophils. Furthermore, Nrf2 activation protected endothelial cells from ANC-induced NETs-mediated injury. Invivo, Nrf2 activation ameliorated glomerulonephritis in two AAV models by upregulating antioxidants and inhibiting ROS-mediated NETs. Furthermore, Nrf2 activation restrained the expansion of splenic immune cells, including T lymphocytes and limited the infiltration of Th17 cells into the kidney. In contrast, Nrf2 genetic deficiency exacerbated vasculitis in a spontaneous AAV model. Thus, the pathophysiological process in AAV may be downregulated by Nrf2 activation, potentially leading to a new therapeutic strategy by regulating NETosis.

Significance of clinical-immunological patterns and diagnostic yield of biopsies in microscopic polyangiitis and granulomatosis with polyangiitis.

Microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) are the two major antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). To characterize a homogenous AAV cohort and to assess the impact of clinicopathological profiles and ANCA serotypes on clinical presentation and prognosis. Clinical differences in GPA patients according to ANCA serotype and the diagnostic yield for vasculitis of biopsies in different territories were also investigated. This retrospective study (2000-2021) included 152 patients with AAV (77 MPA/75 GPA). MPA patients (96.1% myeloperoxidase [MPO]-ANCA and 2.6% proteinase 3 [PR3]-ANCA) presented more often with weight loss, myalgia, renal involvement, interstitial lung disease (ILD), cutaneous purpura, and peripheral nerve involvement. Patients with GPA (44% PR3-ANCA, 33.3% MPO, and 22.7% negative/atypical ANCA) presented more commonly with ear, nose, and throat and eye/orbital manifestations, more relapses, and higher survival than patients with MPA. GPA was the only independent risk factor for relapse. Poor survival predictors were older age at diagnosis and peripheral nerve involvement. ANCA serotypes differentiated clinical features in a lesser degree than clinical phenotypes. A mean of 1.5 biopsies were performed in 93.4% of patients in different territories. Overall, vasculitis was identified in 80.3% (97.3% in MPA and 61.8% in GPA) of patients. The identification of GPA presentations associated with MPO-ANCA and awareness of risk factors for relapse and mortality are important to guide proper therapeutic strategies in AAV patients. Biopsies of different affected territories should be pursued in difficult-to-diagnose patients based on their significant diagnostic yield.

The impact of coronavirus-19 vaccination on anti-nuclear cytoplasmic antibody vasculitis hospitalisations in a Sydney health network.

There have been reports of COVID-19 vaccination triggering anti-nuclear cytoplasmic antibody (ANCA)-associated vasculitis (AAV), but no robust studies have examined the link. This retrospective cohort study assessed the impact of COVID vaccination on the rate of denovo and relapsed AAV in a Sydney Local Health District from 2018 to 2022. Despite more than 95% of the population receiving vaccination, the case rate of AAV was stable. These findings do not support a relationship between COVID vaccination and AAV.

Immunohistological analysis reveals IgG1-dominant immunophenotype of tubulointerstitial nephritis unassociated with IgG4-related diseases

PurposeTubulointerstitial nephritis (TIN) has various etiologies, including IgG4-related disease (IgG4-RD), autoimmune diseases, antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), and others. IgG4-positive plasma cell infiltration can occasionally be found in TIN unrelated to IgG4-RD. Therefore, there may be problems with usage of IgG4 immunostaining to differentiate between TIN with and TIN without IgG4-RD. This study aimed to compare the proportion of plasma cells that are positive for each IgG subclass and to clarify the predominant IgG subclass trends and clinical characteristics associated with IgG4-RD and non-IgG4-related interstitial nephritis.MethodsThe study enrolled 44 cases of TIN: 6 of IgG4-RD, 8 of autoimmune disease, 9 of AAV, and 21 of unknown disease group. In addition to clinical characteristics, IgG subclass composition of interstitial plasma cells was evaluated among 4 groups by immunohistochemistry.ResultsIgG1 was the predominant IgG subclass in TIN unrelated to IgG4-RD. In the IgG4-RD group, the IgG subclass rate was high in both IgG1 and IgG4. The rate of average IgG4-positive cells was significantly lower in the autoimmune disease group and unknown disease group compared with the IgG4-RD group.ConclusionThe present study revealed IgG1-dominant immune profiles of TIN unrelated to IgG4-RD. Further investigation is required to elucidate the clinicopathological differences between IgG1-dominant and IgG4-dominant groups in IgG4-RD.