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Proteinase 3 (PR3) is the major antigen for anti-neutrophil cytoplasmic antibodies (ANCAs) in the systemic autoimmune vasculitis, granulomatosis with polyangiitis (GPA). PR3 anti-neutrophil cytoplasmic antibodies (PR3-ANCAs) recognize different epitopes on PR3. We aimed to study the effect of mutations on PR3 antigenicity.The recombinant PR3 variants, iPR3 (clinically used to detect PR3-ANCAs) and iHm5 (containing three point mutations in Epitope 15 generated for epitope mapping studies, immunoassays and serum samples from patients enrolled in ANCA-associated vasculitis (AAV) trials were used to screen the differential PR3-ANCA binding. A patient-derived monoclonal ANCA (moANCA518) that selectively binds to iHm5 within the mutation-free Epitope 3 and distant from the point mutations of iHm5 was used as a gauge of remote epitope activation. Selective binding was determined by inhibition experiments.Rather than reduced binding of PR3-ANCAs to iHm5, we found substantially increased binding of the majority of PR3-ANCAs to iHm5 compared with iPR3. This differential binding of PR3-ANCA to iHm5 is similar to the selective moANCA518 binding to iHm5. Binding of iPR3 to monoclonal antibody MCPR3-2 also induced recognition by moANCA518.The preferential binding of PR3-ANCAs from patients like the selective binding of moANCA518 to iHm5 is conferred by increased antigenicity of Epitope 3 on iHm5. This can also be induced on iPR3 when captured by monoclonal antibody MCPR-2. This previously unrecognized characteristic of PR3-ANCA interactions with its target antigen has implications for studying antibody-mediated autoimmune diseases, understanding of variable performance characteristics of immunoassays and design of potential novel treatment approaches. This article is protected by copyright. All rights reserved.

Autoreactive B cells are responsible for ANCA production in ANCA-associated vasculitis (AAV). Rituximab depletes circulating B cells including autoreactive ones. We aimed to evaluate changes and associations with relapse of the circulating autoreactive B cell pool following therapeutic B cell depletion in AAV.Sequential flow-cytometry was performed on 148 samples of peripheral blood mononuclear cells from 23 proteinase-3 (PR3)-ANCAAt B cell recurrence, PR3The composition of autoreactive B cell pool varies significantly following rituximab treatment in AAV, and early plasmablast enrichment within the autoreactive pool is associated with future relapses.

ObjectivesTo evaluate efficacy and safety of abatacept in adults with active primary Sjögren’s syndrome (pSS) in a phase III, randomised, double-blind, placebo-controlled trial.MethodsEligible patients (moderate-to-severe pSS [2016 ACR/European League Against Rheumatism (EULAR) criteria], EULAR Sjögren’s Syndrome Disease Activity Index [ESSDAI] ≥5, anti-SS-related antigen A/anti-Ro antibody positive) received weekly subcutaneous abatacept 125 mg or placebo for 169 days followed by an open-label extension to day 365. Primary endpoint was mean change from baseline in ESSDAI at day 169. Key secondary endpoints were mean change from baseline in EULAR Sjögren’s Syndrome Patient Reported Index (ESSPRI) and stimulated whole salivary flow (SWSF) at day 169. Other secondary clinical endpoints included glandular functions and patient-reported outcomes. Selected biomarkers and immune cell phenotypes were examined. Safety was monitored.ResultsOf 187 patients randomised, 168 completed double-blind period and 165 continued into open-label period. Mean (SD) baseline ESSDAI and ESSPRI total scores were 9.4 (4.3) and 6.5 (2.0), respectively. Statistical significance was not reached for primary (ESSDAI −3.2 abatacept vs −3.7 placebo, p=0.442) or key secondary endpoints (ESSPRI, p=0.337; SWSF, p=0.584). No clinical benefit of abatacept over placebo at day 169 was seen with other clinical and PRO endpoints. Relative to baseline, abatacept was associated with significant differences vs placebo in some disease-relevant biomarkers (including IgG, IgA, IgM-rheumatoid factor) and pathogenic cell subpopulations (post hoc analyses). No new safety signals were identified.ConclusionsAbatacept treatment did not result in significant clinical efficacy compared with placebo in patients with moderate-to-severe pSS, despite evidence of biological activity.

BackgroundThe frequency of proteinase 3 gene (PRTN3) polymorphisms in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is not fully characterised. We hypothesise that the presence of a PRTN3 gene polymorphism (single nucleotide polymorphism (SNP) rs351111) is relevant for clinical outcomes.MethodsDNA variant calling for SNP rs351111 (chr.19:844020, c.355G>A) in PRTN3 gene assessed the allelic frequency in patients with PR3-AAV included in the Rituximab in ANCA-Associated Vasculitis trial. This was followed by RNA-seq variant calling to characterise the mRNA expression. We compared clinical outcomes between patients homozygous for PRTN3-Ile119or PRTN3-Val119.ResultsWhole blood samples for DNA calling were available in 188 patients. 75 patients with PR3-AAV had the allelic variant: 62 heterozygous PRTN3-Val119Ile and 13 homozygous for PRTN3-Ile119. RNA-seq was available for 89 patients and mRNA corresponding to the allelic variant was found in 32 patients with PR3-AAV: 25 heterozygous PRTN3-Val119Ile and 7 homozygous for PRTN3-Ile119. The agreement between the DNA calling results and mRNA expression of the 86 patients analysed by both methods was 100%. We compared the clinical outcomes of 64 patients with PR3-AAV: 51 homozygous for PRTN3-Val119and 13 homozygous for PRTN3-Ile119. The frequency of severe flares at 18 months in homozygous PRTN3-Ile119was significantly higher when compared with homozygous PRTN3-Val119(46.2% vs 19.6%, p=0.048). Multivariate analysis identified homozygous PR3-Ile119as main predictor of severe relapse (HR 4.67, 95% CI 1.16 to 18.86, p=0.030).ConclusionIn patients with PR3-AAV, homozygosity for PRTN3-Val119Ile polymorphism appears associated with higher frequency of severe relapse. Further studies are necessary to better understand the association of this observation with the risk of severe relapse.

ObjectivesWe investigated whether soluble immune checkpoints (sICPs) predict treatment resistance, relapse and infections in patients with antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV).MethodsPlasma sICP concentrations from available samples obtained during conduct of the RAVE trial were measured by immunoabsorbent assays from patients with either proteinase 3 (PR3) or myeloperoxidase (MPO)-ANCA vasculitis and were correlated with clinical outcomes, a set of biomarkers and available flow cytometry analyses focusing on T cell subsets. Log-rank test was used to evaluate survival benefits, and optimal cut-off values of the marker molecules were calculated using Yeldons J.ResultsAnalysis of 189 plasma samples at baseline revealed higher concentrations of sTim-3, sCD27, sLag-3, sPD-1 and sPD-L2 in patients with MPO-ANCA vasculitis (n=62) as compared with PR3-ANCA vasculitis (n=127). Among patients receiving rituximab induction therapy (n=95), the combination of lower soluble (s)Lag-3 (3000 pg/mL) predicted therapy failure. Twenty-four out of 73 patients (32.9%) in the rituximab arm reaching remission at 6 months relapsed during follow-up. In this subgroup, high baseline values of sTim-3 (>1200 pg/mL), sCD27 (>1250 pg/mL) and sBTLA (>1000 pg/mL) were associated with both sustained remission and infectious complications. These findings could not be replicated in 94 patients randomised to receive cyclophosphamide/azathioprine.ConclusionsPatients with AAV treated with rituximab achieved remission less frequently when concentrations of sLag-3 were low and concentrations of sCD27 were high. Higher concentrations of sTim-3, sCD27 and sBTLA at baseline predicted relapse in patients treated with rituximab. These results require confirmation but may contribute to a personalised treatment approach of AAV.

BACKGROUND Little is known about the autoreactive B cells in antineutrophil cytoplasmic antibody–associated (ANCA-associated) vasculitis (AAV). We aimed to investigate tolerance checkpoints of circulating antigen-specific proteinase 3–reactive (PR3+) B cells. METHODS Multicolor flow cytometry in combination with bioinformatics and functional in vitro studies were performed on baseline samples of PBMCs from 154 well-characterized participants of the RAVE trial (NCT00104299) with severely active PR3-AAV and myeloperoxidase-AAV (MPO-AAV) and 27 healthy controls (HCs). Clinical data and outcomes from the trial were correlated with PR3+ B cells (total and subsets). RESULTS The frequency of PR3+ B cells among circulating B cells was higher in participants with PR3-AAV (4.77% median [IQR, 3.98%–6.01%]) than in participants with MPO-AAV (3.16% median [IQR, 2.51%–5.22%]) and participants with AAV compared with HCs (1.67% median [IQR, 1.27%–2.16%], P < 0.001 for all comparisons), implying a defective central tolerance checkpoint in patients with AAV. Only PBMCs from participants with PR3-AAV contained PR3+ B cells capable of secreting PR3-ANCA IgG in vitro, proving they were functionally distinct from those of participants with MPO-AAV and HCs. Unsupervised clustering identified subtle subsets of atypical autoreactive PR3+ memory B cells accumulating through the maturation process in patients with PR3-AAV. PR3+ B cells were enriched in the memory B cell compartment of participants with PR3-AAV and were associated with higher serum CXCL13 levels, suggesting an increased germinal center activity. PR3+ B cells correlated with systemic inflammation (C-reactive protein and erythrocyte sedimentation rate, P < 0.05) and complete remission (P < 0.001). CONCLUSION This study suggests the presence of defective central antigen-independent and peripheral antigen-dependent checkpoints in patients with PR3-AAV, elucidating the selection process of autoreactive B cells. Trial registration ClinicalTrials.gov NCT00104299. Funding The Vasculitis Foundation, the National Institute of Allergy and Infectious Diseases of the NIH, and the Mayo Foundation for Education and Research.

The development of rational approaches to restore immune tolerance requires an iterative approach that builds on past success and utilizes new mechanistic insights into immune-mediated pathologies. This article will review concepts that have evolved from the clinical trial experience of the Immune Tolerance Network, with an emphasis on lessons learned from the innovative mechanistic studies conducted for these trials and new strategies under development for induction of tolerance.

Objective Improved biomarkers of current disease activity and prediction of relapse are needed in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). For clinical relevance, biomarkers must perform well longitudinally in patients on treatment and in patients with nonsevere flares. Methods Twenty-two proteins were measured in 347 serum samples from 74 patients with AAV enrolled in a clinical trial. Samples were collected at Month 6 after remission induction, then every 3 months until Month 18, or at the time of flare. Associations of protein concentrations with concurrent disease activity and with future flare were analyzed using mixed-effects models, Cox proportional hazards models, and conditional logistic regression. Results Forty-two patients had flares during the 12-month follow-up period, and 32 remained in remission. Twenty-two patients had severe flares. Six experimental markers (CXCL13, IL-6, IL-8, IL-15, IL-18BP, and matrix metalloproteinase-3 [MMP-3]) and ESR were associated with disease activity using all three methods (P < 0.05, with P < 0.01 in at least one method). A rise in IL-8, IL-15, or IL-18BP was associated temporally with flare. Combining C-reactive protein (CRP), IL-18BP, neutrophil gelatinase-associated lipocalin (NGAL), and sIL-2R alpha improved association with active AAV. CXCL13 and MMP-3 were increased during treatment with prednisone, independent of disease activity. Marker concentrations during remission were not predictive of future flare. Conclusion Serum biomarkers of inflammation and tissue damage and repair have been previously shown to be strongly associated with severe active AAV were less strongly associated with active AAV in a longitudinal study that included mild flares and varying treatment. Markers rising contemporaneously with flare or with an improved association in combination merit further study.

Among individuals with systemic sclerosis (SSc) randomized to cyclophosphamide (CYC) (n = 34) or hematopoietic stem cell transplantation (HSCT) (n = 33), we examined longitudinal trends of clinical, pulmonary function, and quality of life measures while accounting for the influence of early failures on treatment comparisons.Assuming that data were missing at random, mixed-effects regression models were used to estimate longitudinal trends for clinical measures when comparing treatment groups. Results were compared to observed means and to longitudinal trends estimated from shared parameter models, assuming that data were missing not at random. Longitudinal trends for SSc intrinsic molecular subsets defined by baseline gene expression signatures (normal-like, inflammatory, and fibroproliferative signatures) were also studied.Available observed means for pulmonary function tests appeared to improve over time in both arms. However, after accounting for participant loss, forced vital capacity in HSCT recipients increased by 0.77 percentage points/year but worsened by -3.70/year for CYC (P = 0.004). Similar results were found for diffusing capacity for carbon monoxide and quality of life indicators. Results for both analytic models were consistent. HSCT recipients in the inflammatory (n = 20) and fibroproliferative (n = 20) subsets had superior long-term trends compared to CYC for pulmonary and quality of life measures. HSCT was also superior for modified Rodnan skin thickness scores in the fibroproliferative subset. For the normal-like subset (n = 22), superiority of HSCT was less apparent.Longitudinal trends estimated from 2 statistical models affirm the efficacy of HSCT over CYC in severe SSc. Failure to account for early loss of participants may distort estimated clinical trends over the long term.

Guidelines and recommendations developed and/or endorsed by the American College of Rheumatology (ACR) are intended to provide general guidance for commonly encountered clinical scenarios. The recommendations do not dictate the care for an individual patient. The ACR considers adherence to the recommendations described in this guideline to be voluntary, with the ultimate determination regarding their application to be made by the clinicians in light of each patient’s individual circumstances. Guidelines and recommendations are intended to promote beneficial or desirable outcomes but cannot guarantee any specific outcome. Guidelines and recommendations developed and endorsed by the ACR are subject to periodic revision as warranted by the evolution of medical knowledge, technology, and practice. ACR recommendations are not intended to dictate payment or insurance decisions, or drug formularies or other third-party analyses. Third parties that cite ACR guidelines should state that these recommendations are not meant for this purpose. These recommendations cannot adequately convey all uncertainties and nuances of patient care. The American College of Rheumatology is an independent, professional, medical and scientific society that does not guarantee, warrant, or endorse any commercial product or service. OBJECTIVE. To develop updated guidelines for the pharmacologic management of rheumatoid arthritis. METHODS. We developed clinically relevant population, intervention, comparator, and outcomes (PICO) questions. After conducting a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to rate the certainty of evidence. A voting panel comprising clinicians and patients achieved consensus on the direction (for or against) and strength (strong or conditional) of recommendations. RESULTS. The guideline addresses treatment with disease-modifying antirheumatic drugs (DMARDs), including conventional synthetic DMARDs, biologic DMARDs, and targeted synthetic DMARDs, use of glucocorticoids, and use of DMARDs in certain high-risk populations (i.e., those with liver disease, heart failure, lymphoproliferative disorders, previous serious infections, and nontuberculous mycobacterial lung disease). The guideline includes 44 recommendations (7 strong and 37 conditional). CONCLUSION. This clinical practice guideline is intended to serve as a tool to support clinician and patient decision-making. Recommendations are not prescriptive, and individual treatment decisions should be made through a shared decision-making process based on patients’ values, goals, preferences, and comorbidities.

Objective To assess the frequency of venous thromboembolism (VTE) events in the Rituximab in Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis (RAVE) trial and identify novel potential risk factors. Methods VTE events in 197 patients enrolled in the RAVE trial were analyzed. Baseline demographic and clinical characteristics were recorded, and univariate and multivariate analyses were performed to identify factors associated with VTE in ANCA-associated vasculitis (AAV). Results VTE occurred in 16 patients (8.1%) with an overall average time to event of 1.5 months (range 1.0-2.75). In univariate analyses with calculation of hazard ratios (HRs) and 95% confidence intervals (95% CIs), heart involvement (HR 17.408 [95% CI 2.247-134.842]; P = 0.006), positive proteinase 3 (PR3)-ANCA (HR 7.731 [95% CI 1.021-58.545]; P = 0.048), pulmonary hemorrhage (HR 3.889 [95% CI 1.448-10.448]; P = 0.008), and the presence of red blood cell casts (HR 15.617 [95% CI 3.491-69.854]; P

ObjectiveTo address heterogeneity complicating primary SS (pSS) clinical trials, research and care by characterizing and clustering patients by their molecular phenotypes.MethodspSS patients met American–European Consensus Group classification criteria and had at least one systemic manifestation and stimulated salivary flow of ⩾0.1 ml/min. Correlated transcriptional modules were derived from gene expression microarray data from blood (n = 47 with appropriate samples). Patients were clustered based on this molecular information using an unbiased random forest modelling approach. In addition, multiplex, bead-based assays and ELISAs were used to assess 30 serum cytokines, chemokines and soluble receptors. Eleven autoantibodies, including anti-Ro/SSA and anti-La/SSB, were measured by Bio-Rad Bioplex 2200.ResultsTranscriptional modules distinguished three clusters of pSS patients. Cluster 1 showed no significant elevation of IFN or inflammation modules. Cluster 2 showed strong IFN and inflammation modular network signatures, as well as high plasma protein levels of IP-10/CXCL10, MIG/CXCL9, BLyS (BAFF) and LIGHT. Cluster 3 samples exhibited moderately elevated IFN modules, but with suppressed inflammatory modules, increased IP-10/CXCL10 and B cell–attracting chemokine 1/CXCL13 and trends toward increased MIG/CXCL9, IL-1α, and IL-21. Anti-Ro/SSA and anti-La/SSB were present in all three clusters.ConclusionMolecular profiles encompassing IFN, inflammation and other signatures can be used to separate patients with pSS into distinct clusters. In the future, such profiles may inform patient selection for clinical trials and guide treatment decisions.

Objective We aim to describe an evidence synthesis approach using parallel streams of evidence that informed the development of the 2021 American College of Rheumatology (ACR) guideline for the management of rheumatoid arthritis (RA). Methods We developed the evidence synthesis approach using parallel streams of evidence in multiple rounds of discussion, piloting, feedback, and revisions. A number of working groups involving ACR staff, content experts, and methodologists coordinated to develop and implement the approach. Results We used a major stream of evidence that identified evidence specific to the clinical questions being addressed in the guideline (ie, we were able to match relevant articles to specific questions). We also used additional streams that identified data that applied across multiple questions. We describe in this article the different steps of the major stream, ie, screening and tagging, matching articles to question clusters, matching articles to individual questions, data abstraction and analysis, and Grading of Recommendations Assessment, Development and Evaluation (GRADEing). We then describe how we packaged the parallel streams of evidence into standardized structured tables to facilitate formulating the recommendations. These tables included information for the following factors: desirable effects, undesirable effects, certainty of evidence, valuation of outcomes, cost of interventions, and cost-effectiveness of interventions. The approach allowed us to match eligible articles for 47 of 81 clinical questions. We identified no eligible articles that addressed the remaining 34 questions. Conclusion We were successful in using parallel streams of evidence to inform the development of the 2021 ACR guideline for the management of RA.

Rheumatoid arthritis (RA) is a systemic and incurable autoimmune disease characterized by chronic inflammation in synovial lining of joints. To identify the signaling pathways involved in RA, its disease activity, and treatment response, we adapted a systems immunology approach to simultaneously quantify 42 signaling nodes in 21 immune cell subsets (e.g., IFNα→p-STAT5 in B cells) in peripheral blood mononuclear cells (PBMC) from 194 patients with longstanding RA (including 98 patients before and after treatment), and 41 healthy controls (HC). We found multiple differences between patients with RA compared to HC, predominantly in cytokine-induced Jak/STAT signaling in many immune cell subsets, suggesting pathways that may be associated with susceptibility to RA. We also found that high RA disease activity, compared to low disease activity, was associated with decreased (e.g., IFNα→p-STAT5, IL-10→p-STAT1) or increased (e.g., IL-6→STAT3) response to stimuli in multiple cell subsets. Finally, we compared signaling in patients with established, refractory RA before and six months after initiation of methotrexate (MTX) or TNF inhibitors (TNFi). We noted significant changes from pre-treatment to post-treatment in IFNα→p-STAT5 signaling and IL-10→p-STAT1 signaling in multiple cell subsets; these changes brought the aberrant RA signaling profiles toward those of HC. This large, comprehensive functional signaling pathway study provides novel insights into the pathogenesis of RA and shows the potential of quantification of cytokine-induced signaling as a biomarker of disease activity or treatment response.

Background Pulmonary disease is a potentially serious yet underdiagnosed complication of Sjogren’s syndrome, the second most common autoimmune rheumatic disease. Approximately 16% of patients with Sjogren’s demonstrate pulmonary involvement with higher mortality and lower quality of life. Research Question Clinical practice guidelines for pulmonary manifestations of Sjogren’s were developed by the Sjogren’s Foundation after identifying a critical need for early diagnosis and improved quality and consistency of care. Study Design and Methods A rigorous and transparent methodology was followed according to American College of Rheumatology guidelines. The Pulmonary Topic Review Group (TRG) developed clinical questions in the PICO (Patient, Intervention, Comparison, Outcome) format and selected literature search parameters. Each article was reviewed by a minimum of two TRG members for eligibility and assessment of quality of evidence and strength of recommendation. Guidelines were then drafted based on available evidence, expert opinion, and clinical importance. Draft recommendations with a clinical rationale and data extraction tables were submitted to a Consensus Expert Panel for consideration and approval, with at least 75% agreement required for individual recommendations to be included in the final version. Results The literature search revealed 1,192 articles, of which 150 qualified for consideration in guideline development. Of the original 85 PICO questions posed by the TRG, 52 recommendations were generated. These were then reviewed by the Consensus Expert Panel and 52 recommendations were finalized, with a mean agreement of 97.71% (range, 79%-100%). The recommendations span topics of evaluating Sjogren’s patients for pulmonary manifestations and assessing, managing, and treating upper and lower airway disease, interstitial lung disease, and lymphoproliferative disease. Interpretation Clinical practice guidelines for pulmonary manifestations in Sjogren’s will improve early identification, evaluation, and uniformity of care by primary care physicians, rheumatologists, and pulmonologists. Additionally, opportunities for future research are identified.

Systemic sclerosis is a progressive inflammatory disease that is frequently fatal and has limited treatment options. High-dose chemotherapy with autologous hematopoietic cell transplantation (AHCT) has been evaluated as treatment for this disease in observational studies, multicenter randomized controlled clinical trials, and meta-analyses. On behalf of the American Society for Blood and Marrow Transplantation (ASBMT), a panel of experts in transplantation and rheumatology was convened to review available evidence and make a recommendation on AHCT as an indication for systemic sclerosis. Three randomized trials have compared the efficacy of AHCT with cyclophosphamide only, and all demonstrated benefit for the AHCT arm for their primary endpoint (improvement in the American Scleroderma Stem Cell versus Immune Suppression Trial, event-free survival in Autologous Stem Cell Transplantation International Scleroderma trial, and change in global rank composite score in Scleroderma: Cyclophosphamide or Transplantation trial). AHCT recipients also had better overall survival and a lower rate of disease progression. These findings have been confirmed in subsequent meta-analyses. Based on this high-quality evidence, the ASBMT recommends systemic sclerosis should be considered as a "standard of care" indication for AHCT. Close collaboration between rheumatologists and transplant clinicians is critical for optimizing patient selection and patient outcomes. Transplant centers in the United States are strongly encouraged to report patient and outcomes data to the Center for International Blood and Marrow Transplant Research on their patients receiving AHCT for this indication.

Objectives. To study the determinants of the pharmacokinetics (PK) of rituximab (RTX) in patients with ANCA-associated vasculitis (AAV) and its association with clinical outcomes.Methods. This study included data from 89 patients from the RTX in AAV trial who received the full dose of RTX (four weekly infusions of 375 mg/m(2)). RTX was quantified at weeks 2, 4, 8, 16 and 24, and summarized by computing the trapezoidal area under the curve. We explored potential determinants of the PK-RTX, and analysed its association with clinical outcomes: achievement of remission at 6 months, duration of B-cell depletion and time to relapse in patients who achieved complete remission.Results. RTX serum levels were significantly lower in males and in newly diagnosed patients, and negatively correlated with body surface area, baseline B-cell count and degree of disease activity. In multivariate analyses, the main determinants of PK-RTX were sex and new diagnosis. Patients reaching complete remission at month 6 had similar RTX levels compared with patients who did not reach complete remission. Patients with higher RTX levels generally experienced longer B-cell depletion than patients with lower levels, but RTX levels at the different time points and area under the curve were not associated with time to relapse.Conclusion. Despite the body-surface-area-based dosing protocol, PK-RTX is highly variable among patients with AAV, its main determinants being sex and newly diagnosed disease. We did not observe any relevant association between PK-RTX and clinical outcomes. The monitoring of serum RTX levels does not seem clinically useful in AAV.

Fibroinflammatory disorders are rare disorders characterized by chronic inflammation in combination with fibrosis that affect multiple organs. Among the fibroinflammatory disorders, 2 present with specific cardiovascular involvement, the immunoglobulin G4–related disease, which presents with

We thank Dr. Evangelatos for his interest in the guideline and his efforts to provide further clarity to this clinical scenario. During the guideline process, the voting panel thoroughly discussed many of these aspects of hypogammaglobulinemia during rituximab treatment that Dr. Evangelatos has adeptly described.

Objective To identify risk alleles relevant to the causal and biologic mechanisms of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV). Methods A genome-wide association study and subsequent replication study were conducted in a total cohort of 1,986 cases of AAV (patients with granulomatosis with polyangiitis [Wegener's] [GPA] or microscopic polyangiitis [MPA]) and 4,723 healthy controls. Meta-analysis of these data sets and functional annotation of identified risk loci were performed, and candidate disease variants with unknown functional effects were investigated for their impact on gene expression and/or protein function. Results Among the genome-wide significant associations identified, the largest effect on risk of AAV came from the single-nucleotide polymorphism variants rs141530233 and rs1042169 at the HLA–DPB1 locus (odds ratio [OR] 2.99 and OR 2.82, respectively) which, together with a third variant, rs386699872, constitute a triallelic risk haplotype associated with reduced expression of the HLA–DPB1 gene and HLA–DP protein in B cells and monocytes and with increased frequency of complementary proteinase 3 (PR3)–reactive T cells relative to that in carriers of the protective haplotype. Significant associations were also observed at the SERPINA1 and PTPN22 loci, the peak signals arising from functionally relevant missense variants, and at PRTN3, in which the top-scoring variant correlated with increased PRTN3 expression in neutrophils. Effects of individual loci on AAV risk differed between patients with GPA and those with MPA or between patients with PR3-ANCAs and those with myeloperoxidase-ANCAs, but the collective population attributable fraction for these variants was substantive, at 77%. Conclusion This study reveals the association of susceptibility to GPA and MPA with functional gene variants that explain much of the genetic etiology of AAV, could influence and possibly be predictors of the clinical presentation, and appear to alter immune cell proteins and responses likely to be key factors in the pathogenesis of AAV.

Background: Immunopathologic features predict renal function at baseline and follow-up in antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (GN). The interstitial infiltrate consists predominantly of T lymphocytes, but their pathophysiologic significance is unclear, especially in light of the success of B-cell-directed therapy. Methods: Renal biopsies from 33 patients treated with cyclophosphamide (CYC; n = 17) or rituximab (RTX; n = 16) in the RTX in ANCA-associated vasculitis (RAVE) trial were classified according to the new ANCA GN classification. T- and B-cell infiltration in the interstitium was assessed by immunostaining for CD3 and CD20. Correlations of clinical and histologic parameters with renal function at set time points were examined. Results: The mean (SD) baseline estimated glomerular filtration rate was 36 (20) mL/min/1.73 m2. ANCA GN class distribution was 46% focal, 33% mixed, 12% sclerotic and 9% crescentic. The interstitial infiltrate consisted of >50% CD3 positive cells in 69% of biopsies, but >50% CD20 positive cells only in 8% of biopsies. In a multiple linear regression model, only baseline glomerular filtration rate (GFR) correlated with GFR at 6, 12, and 18 months. Interstitial B- and T-cell infiltrates had no significant impact on long-term prognosis, independent of the treatment limb. A differential effect was noted only at 6 months, where a dense CD3 positive infiltrate predicted lower GFR in the RTX group and a CD20 positive infiltrate predicted higher GFR in the CYC group. Conclusions: In ANCA-associated GN, the interstitial infiltrate contains mainly T lymphocytes. However, it is neither reflecting baseline renal function nor predictive of response to treatment, regardless of the immunosuppression regimen employed.

Objective S100A8/A9 (calprotectin) has shown promise as a biomarker for predicting relapse in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). This study was undertaken to investigate serum S100A8/A9 level as a biomarker for predicting future relapse in a large cohort of patients with severe AAV.Methods Serum levels of S100A8/A9 were measured at baseline and months 1, 2, and 6 following treatment initiation in 144 patients in the Rituximab in ANCA-Associated Vasculitis trial (cyclophosphamide/azathioprine versus rituximab [RTX] for induction of remission) in whom complete remission was attained.Results Patients were divided into 4 groups: proteinase 3 (PR3)-ANCA with relapse (n=37), PR3-ANCA without relapse (n=56), myeloperoxidase (MPO)-ANCA with relapse (n=6), and MPO-ANCA without relapse (n=45). Serum S100A8/A9 level decreased in all groups during the first 6 months of treatment. The percentage reduction from baseline to month 2 was significantly different between patients who experienced a relapse and those who did not in the PR3-ANCA group (P=0.046). A significantly higher risk of relapse was associated with an increase in S100A8/A9 level between baseline and month 2 (P=0.0043) and baseline and month 6 (P=0.0029). Subgroup analysis demonstrated that patients treated with RTX who had increased levels of S100A8/A9 were at greatest risk of future relapse (P=0.028).Conclusion An increase in serum S100A8/A9 level by month 2 or 6 compared to baseline identifies a subgroup of PR3-ANCA patients treated with RTX who are at higher risk of relapse by 18 months. Since RTX is increasingly used for remission induction in PR3-ANCA-positive patients experiencing a relapse, S100A8/A9 level may assist in identifying those patients requiring more intensive or prolonged treatment.

Rheumatoid arthritis (RA), a chronic autoimmune disease characterized by circulating autoantibodies, involves many cytokine-mediated signaling pathways in multiple immune cell subsets. Most studies of immune cells in RA have limitations, such as analysis of a small number of cell subsets or pathways, and limited longitudinal data on patient phenotypes. In this study, we used an innovative systems immunology approach to simultaneously quantify up to 882 signaling nodes (Jak/STAT signaling readouts modulated by cytokines and other stimuli) in 21 immune cell subsets. We studied 194 RA patients and 41 controls, including 146 well-characterized RA patients prior to, and 6 months after, initiation of methotrexate or biologic agents from the Treatment Efficacy and Toxicity in RA Database and Repository (TETRAD). There was strikingly attenuated signaling capacity in RA patients in IFNα stimulation followed by measurement of phosphorylated STAT1 [IFNα→p-STAT1] in six immune cell subsets. Multiple nodes showed negative association with disease activity, including IFNα→STAT5 signaling in naive and memory B cells. In contrast, IL-6-induced STAT1 and STAT3 activation in central memory CD4-negative T cells showed a positive association with disease activity. Multiple nodes were associated with treatment response, including IFNα→STAT1 in monocytes and IL-6→STAT3 in CD4+ naive T cells. Decision tree analysis identified a model combining these two nodes as a high-performing classifier of treatment response to TNF inhibitors. Our study provides novel information on RA disease mechanisms and serves as a framework for the discovery and validation of biomarkers of treatment response in RA.

Objective: To investigate serum IL-6 (sIL-6) levels during active disease, complete remission (CR), and relapse in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), and to explore the association of changes in sIL-6 with clinical outcomes.Methods: sIL-6 levels were measured at baseline and longitudinally over 18 months, in 78 patients with AAV enrolled in a randomized controlled trial comparing treatment with either rituximab (RTX) or cyclophosphamide (CYC)/azathioprine (AZA). Outcome variables included baseline clinical features, ANCA specificity, disease activity (active disease versus CR), time to relapse events, B cell repopulation, and ANCA titer increases.Results: At baseline, sIL6 levels were detectable in 81% of patients; 73% (n = 57) of subjects were proteinase 3 (PR3)-ANCA positive, sIL-6 levels were higher in subjects with PR3-ANCAs and positively correlated with their levels (r(s) = 0.36,p 0.05).Conclusion: At baseline, sIL-6 concentrations correlate with PR3-ANCA titers and are associated with specific clinical manifestations of AAV. Baseline sIL6 concentrations do not predict CR at 6 months, but the increase in sIL-6 concentrations during CR is associated with subsequent severe relapse among RTX-treated patients. Further investigation into the mechanistic role of IL6 in AAV might lead to identifying this pathway as a potential therapeutic target in this disease.

Background: We recently reported that, in a small number of subjects, the proportion of proteinase 3 (PR3)-specific B cells was higher in patients with PR3-ANCA-associated vasculitis (AAV) compared to healthy controls (HCs). Objectives: The objectives of this work were to replicate our previous findings on a larger number of subjects, including myeloperoxidase (MPO)-AAV patients as disease controls, and to study the association of PR3-specific B cell proportions with clinical and biological features in patients with PR3-AAV. Methods: We analyzed frozen PBMCs from 166 patients who participated in the RAVE trial, including 113 patients with PR3-AAV and 53 patients with MPO-AAV, as well as 27 HCs. We measured the proportion of PR3-specific B cells and subsets among PBMCs using a multi-color flow cytometry panel including CD19, IgD, CD27, CD38, CD24, and a biotinylated PR3 revealed by fluorescent streptavidin. In parallel, one million PBMCs from each sample were cultivated in vitro for 12 days and stimulated by CpG, BAFF, and IL-21. PR3-ANCAs were quantified in the culture supernatants and in the serum. Results: The mean (SD) proportion of PR3-specific B cells was higher in patients with PR3-AAV compared to patients with MPO-AAV and to HCs: 2.78% (2.64) vs 1.97% (1.2) vs 1.24% (0.49) respectively, p Conclusion: The proportion of circulating PR3-specific B cells is higher in patients with PR3-AAV than in patients with MPO-AAV and HCs, and importantly, their repartition is shifted towards a memory phenotype. Further studies are ongoing to characterize the dynamics of the PR3-specific B cells after therapy, and to understand the differences of these autoreactive B cells between patients with PR3-AAV and HCs. Reference [1] Cornec D, Berti A, Hummel A, Peikert T, Pers JO, Specks U. Identification and phenotyping of circulating autoreactive proteinase 3-specific B cells in patients with PR3-ANCA associated vasculitis and healthy controls. J Autoimmun. 2017Nov;84:122-131. Disclosure of Interests: Divi Cornec: None declared, Alvise Berti: None declared, Amber Hummel: None declared, Eva Carmona: None declared, Tobias Peikert: None declared, Carol Langford: None declared, Paul Monach: None declared, Peter Merkel: None declared, Philip Seo: None declared, Robert Spiera Grant/research support from: Roche-Genentech, GlaxoSmithKline, Bristol-Myers Squibb, Boehringer Ingelheim, Cytori, Chemocentryx, Corbux, Consultant for: Roche-Genentech, GlaxoSmithKline, CSL Behring, Sanofi Aventis, E. William St. Clair Grant/research support from: Bristol-Myers Squibb, Consultant for: Bristol-Myers Squibb, Fernando Fervenza: None declared, Kristina Harris: None declared, John H. Stone Grant/research support from: F. Hoffmann-La Roche, Genentech, Xencor, Consultant for: Chugain, F. Hoffmann-La Roche, Genentech, Xencor, Jacques-Olivier Pers: None declared, Peter Heeringa: None declared, Wayel Abdulahad: None declared, Ulrich Specks: None declared

Objective Patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have an elevated risk of cardiovascular disease (CVD). This study was undertaken to develop a clearer understanding of the association between changes in disease activity and lipid levels in AAV, which may inform CVD risk stratification in this population. Methods Lipid levels were assessed in stored serum samples (obtained at baseline and month 6) from the Rituximab for ANCA-Associated Vasculitis (RAVE) trial, which randomized patients to receive either rituximab or cyclophosphamide followed by azathioprine. Paired t-tests and multivariable linear regression were used to assess changes in lipid levels. Results Of the 142 patients with serum samples available, the mean ± SD age was 52.3 ± 14.7 years, 72 (51%) were male, 95 (67%) were proteinase 3 (PR3)-ANCA positive, 72 (51%) had received a new diagnosis of AAV, and 75 (53%) were treated with rituximab. Several lipid levels increased between baseline and month 6, including total cholesterol (+12.4 mg/dl [95% confidence interval (95% CI) +7.1, +21.0]), low-density lipoprotein (+10.3 mg/dl [95% CI +6.1, +17.1]), and apolipoprotein B (+3.5 mg/dl [95% CI +1.0, +8.3]). These changes were observed among newly diagnosed and PR3-ANCA-positive patients but not among those with relapsing disease or myeloperoxidase-ANCA-positive patients. There was no difference in change in lipid levels between rituximab-treated patients and cyclophosphamide-treated patients. Changes in lipid levels correlated with changes in erythrocyte sedimentation rate but not with other inflammatory markers or glucocorticoid exposure. Conclusion Lipid levels increased during remission induction among patients with newly diagnosed AAV and those who were PR3-ANCA positive. Disease activity and ANCA type should be considered when assessing lipid profiles to stratify CVD risk in patients with AAV.

ObjectiveProteinase 3 (PR3) is the major antigen for anti-neutrophil cytoplasmic antibodies (ANCAs) in the systemic autoimmune vasculitis, granulomatosis with polyangiitis (GPA). PR3 anti-neutrophil cytoplasmic antibodies (PR3-ANCAs) recognize different epitopes on PR3. We aimed to study the effect of mutations on PR3 antigenicity.MethodsThe recombinant PR3 variants, iPR3 which is clinically used to detect PR3-ANCAs and iHm5 which contains three point mutations in Epitope 1 and 5 generated for epitope mapping studies, immunoassays and serum samples from patients enrolled in ANCA-associated vasculitis (AAV) clinical trials were used to screen the differential PR3-ANCA binding. Selective binding was determined by inhibition experiments.ResultsRather than a reduced binding of PR3-ANCAs to iHm5, we found substantially increased binding of the majority of PR3-ANCAs to iHm5 compared with iPR3. A monoclonal ANCA (moANCA518) from a patient with GPA was found to selectively bind to iHm5 within the mutation-free Epitope 3 and distant from the point mutations of iHm5 contained in Epitope 1 and 5. Binding of iPR3 to monoclonal antibody MCPR3-2 also induced recognition by moANCA518.ConclusionThe preferential binding of PR3-ANCAs from patients like the selective binding of moANCA518 to iHm5 is conferred by increased antigenicity of Epitope 3 on iHm5. This can also be induced on iPR3 when it is captured by monoclonal antibody MCPR-2. This previously unrecognized characteristic of PR3-ANCA interactions with its target antigen has implications for studying antibody-mediated autoimmune diseases, understanding of variable performance characteristics of immunoassays and design of potential novel treatment approaches.

Objective. To examine the relationship of antineutrophil cytoplasmic antibody (ANCA) type and ANCA-associated vasculitis (AAV) diagnosis with demographic features, disease manifestations, and clinical outcomes. We focused on patients who account for the differences between ANCA type and disease type classifications: antimyeloperoxidase (MPO)-ANCA-positive and ANCA-negative patients with granulomatosis with polyangiitis (Wegener's) (GPA). Methods. We performed a pooled analysis of the Wegener's Granulomatosis Etanercept Trial and the Rituximab in ANCA-Associated Vasculitis trial comparing patients with MPO-ANCA-positive GPA and patients with ANCA-negative GPA to patients with proteinase 3 (PR3)-ANCA-positive GPA and patients with MPO-ANCA-positive microscopic polyangiitis (MPA). Results. Of the 365 patients analyzed, 273 (75%) had PR3-ANCA-positive GPA, 33 (9%) had MPO-ANCA-positive GPA, 15 (4%) had ANCA-negative GPA, and 44 (12%) had MPO-ANCA-positive MPA. MPO-ANCA-positive GPA patients were younger at diagnosis compared to MPO-ANCA-positive MPA patients (53 versus 61 years; P=0.02). Their disease manifestations and rates of relapse were similar to those of PR3-ANCA-positive GPA patients. Relapse was more frequent in MPO-ANCA-positive GPA patients than in patients with MPO-ANCA-positive MPA at trial entry as well as at 12 and 18 months. ANCA-negative patients with GPA had lower Birmingham Vasculitis Activity Score for Wegener's Granulomatosis scores at trial entry than PR3-ANCA-positive patients with GPA (4.5 versus 7.7; P

Source Citation Charles P, Terrier B, Perrodeau E, et al; French Vasculitis Study Group. Comparison of individually tailored versus fixed-schedule rituximab regimen to maintain ANCA-associated vasc...

Objective. To evaluate circulating cytokine profiles in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), classified by antineutrophil cytoplasmic antibody (ANCA) specificity (proteinase 3 ANCA [PR3-ANCA] versus myeloperoxidase ANCA [MPO-ANCA]) or by clinical diagnosis (granulomatosis with polyangiitis [GPA] versus microscopic polyangiitis [MPA]).Methods. A panel of 29 cytokines was tested in 186 patients with active AAV at inclusion into the Rituximab in AAV trial. Cytokine concentrations were compared between groups within each classification system. Multivariable analyses adjusted for age, sex, and renal insufficiency were performed, with each biomarker as a dependent variable and ANCA specificity and clinical diagnosis as explanatory variables of interest.Results. Levels of 9 circulating cytokines (interleukin-6 [IL-6], granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-15, IL-18, CXCL8/IL-8, CCL-17/thymus and activation-regulated chemokine [TARC], IL-18 binding protein [IL-18 BP], soluble IL-2 receptor [sIL-2R], and nerve growth factor [NGF]) were significantly higher in PR3-AAV than MPO-AAV, 4 cytokines (sIL6R, soluble tumor necrosis factor receptor type II [sTNFRII], neutrophil gelatinase-associated lipocalin [NGAL], and soluble intercellular adhesion molecule 1 [sICAM-1]) were higher in MPO-AAV than in PR3-AAV, 6 cytokines (IL-6, GM-CSF, IL-15, IL-18, sIL-2R, and NGF) were higher in GPA than in MPA, and 3 cytokines (osteopontin, sTNFRII, and NGAL) were higher in MPA than in GPA (all P Conclusion. Distinct cytokine profiles were identified for PR3-AAV versus MPO-AAV and for GPA versus MPA. Differences in these circulating immune mediators are more strongly associated with ANCA specificity than with clinical diagnosis, suggesting that heterogeneity in the AAV subtypes extends beyond clinical phenotypes.

OBJECTIVE To examine the association between macrophage migration inhibitory factor (MIF) promoter polymorphisms and granulomatosis with polyangiitis (GPA) in human subjects, and to assess the role of MIF in a murine model of granulomatous vasculitis. METHODS The human study involved 1,077 patients with GPA and healthy controls whose serum was genotyped by capillary electrophoresis for the MIF -794 CATT5-8 promoter microsatellite (rs5844572). MIF promoter, CATT-length-dependent gene expression in response to β-glucan was assessed by gene reporter assays. In mouse studies, granulomatous disease was induced by injection of Candida albicans β-glucan into wild-type (WT) or Mif-knockout (Mif-KO) C57BL/6 mice and C57BL/6 mice transgenically overexpressing Mif in lung epithelium (Mif lung-Tg2.1). Mice were treated with a neutralizing anti-MIF antibody and analyzed for the density of pulmonary granulomas, expression of inflammatory chemokines, and frequency of mortality. RESULTS The percentage of human subjects carrying >5 CATT repeats in each MIF allele (high genotypic MIF expressers) was 60.2% among patients with GPA and 53.9% among healthy controls (adjusted P = 0.049). In response to granulomatous stimulation, human MIF gene expression increased proportionally with CATT length. Mif lung-Tg2.1 mice exhibited more pulmonary granulomas than WT mice, which in turn showed more granulomas than Mif-KO mice. A significantly higher percentage of Mif lung-Tg2.1 mice, compared to Mif-KO or WT mice, died when injected with Candida albicans β-glucan, and treatment of these mice with an anti-MIF monoclonal antibody protected against a lethal outcome. Levels of MIF-dependent neutrophil/macrophage chemokines were elevated in the bronchoalveolar lavage fluid or plasma of Mif lung-Tg2.1 mice. CONCLUSION Patients with GPA have an increased frequency of high MIF expression CATT alleles. Higher Mif expression increases the incidence of mortality and pulmonary granulomas in Mif lung-Tg2.1 mice, while anti-MIF treatment protects these mice against death. Blockade of MIF in high genotypic MIF expressers may therefore offer a selective pharmacologic therapy for GPA.