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Abstract Introduction Immunoglobulin G4-related disease (IgG4-RD) is a debilitating multiorgan disease characterized by recurring flares leading to organ dysfunction, decreased quality of life, and mortality. Glucocorticoids, the standard of care for IgG4-RD, are associated with substantial treatment-related toxicity. Inebilizumab, an antibody directed against CD19, mediates the rapid and durable depletion of CD19+ B cells thought to be involved in IgG4-RD pathogenesis. We describe the first international, prospective, double-blind, placebo-controlled trial to evaluate the safety and efficacy of B-cell depletion for flare prevention in IgG4-RD (MITIGATE). Methods The study was designed by an international panel of physicians with expertise in IgG4-RD. Critical trial design decisions included the selection of participants, definition of clinically meaningful primary and secondary endpoints, accommodation of standard of care, and development of flare diagnostic criteria. The study is approved for conduct in 22 countries. Planned Outcomes The primary efficacy endpoint is time from randomization to the occurrence of the first centrally adjudicated and investigator-treated disease flare during the 1-year randomized controlled period. A set of novel, organ-specific flare diagnostic criteria were developed specifically for this trial, incorporating symptoms and signs, laboratory findings, imaging study results, and pathology data. MITIGATE aims to accrue 39 flares for the primary endpoint, which provides sufficient power to detect a relative risk reduction of 65% in the inebilizumab group. It is anticipated that enrollment of 160 participants will achieve this goal. Additional endpoints include safety, annualized flare rate, flare-free complete remission, quality-of-life measures, and cumulative glucocorticoid use. MITIGATE represents the first randomized, double-blind, placebo-controlled trial of any treatment strategy conducted in IgG4-RD. Data from this study will provide insights into the natural history and pathophysiology of IgG4-RD and the efficacy and safety of B-cell depletion as a therapeutic avenue. Trial Registration NCT04540497.

Abstract Background Giant cell arteritis (GCA) is primarily treated with glucocorticoids (GCs), which have substantial toxicity. Tocilizumab, an interleukin-6-receptor inhibitor (IL-6Ri), showed beneficial effects in GCA, leading to its approval. This study investigated the efficacy and safety of sarilumab (another IL-6Ri) in GCA. Methods This Phase 3, double-blind study comprised a 52-week treatment period and a 24-week follow-up phase. Eligible GCA patients were randomized to receive sarilumab 200 mg (SAR200 + 26W) or 150 mg (SAR150 + 26W) with a 26-week GC taper, or placebo with a 52-week (PBO + 52W) or 26-week (PBO + 26W) GC taper. The primary efficacy endpoint was sustained remission (SR) at week 52. Additional endpoints were SR at week 24, cumulative GC dose, and safety. The study was discontinued prematurely due to protracted recruitment timelines, because of the impact of COVID-19. Therefore, only descriptive statistics were summarized. Results Of the planned 360 subjects, only 83 were randomized and 36 were included in the week 52 analysis. At week 52, 46% (n = 6/13) of patients in SAR200 + 26W, 43% (n = 3/7) in SAR150 + 26W, 30% (n = 3/10) in PBO + 52W, and 0 (n = 0/6) in PBO + 26W taper groups achieved SR. Sensitivity analyses, excluding acute-phase reactants from the SR definition, showed similar results for SAR groups, but 60% (n = 6/10) in PBO + 52W and 17% (n = 1/6) in PBO + 26W taper groups achieved SR at week 52. Similar findings were noted at week 24. The proportions of patients who adhered to GC taper from week 12 through week 52 in each group were as follows: 46% (n = 6/13, SAR200 + 26W), 43% (n = 3/7, SAR150 + 26W), 60% (n = 6/10, PBO + 52W), and 33% (n = 2/6, PBO + 26W). The median actual cumulative GC dose received in the SAR200 + 26W group was lower than other groups. Most patients (80–100%) experienced treatment-emergent adverse events, with similar incidences reported across groups. Conclusions Owing to the small sample size due to the early termination, it is difficult to draw clear conclusions from this study. There were no unexpected safety findings. Trial registration ClinicalTrials.gov NCT03600805. Registered on July 26, 2018.

Objective Giant cell arteritis (GCA) requires treatment with high‐dose, long‐term glucocorticoids (GCs). A score assessing and quantifying patients’ baseline GC‐related toxicity may be important to risk stratification and therapeutic decision‐making in patients initiating immunosuppression. Methods We analyzed patients with GCA enrolled in the Tocilizumab in Giant Cell Arteritis (GiACTA) trial. Baseline GC‐related toxicity scores for 12 domains were derived from the Glucocorticoid Toxicity Index using baseline medications, medical history, vital signs, and laboratory values. The 12 domains examined were body mass index, glucose tolerance, blood pressure, lipid metabolism, bone and/or tendon, GC myopathy, skin toxicity, neuropsychiatric effects, infection, ocular toxicity, gastrointestinal injury, and adrenal function. Potential scores ranged from 0 to 538. We compared differences between those with newly diagnosed versus relapsing disease at baseline. Results A total of 250 patients were included (75% female, mean age 69 years). The mean ± SD baseline GC‐related toxicity score among all patients was 111.3 ± 53.2. The domains that contributed most to the overall scores were blood pressure (24.0% of the overall score), followed by glucose tolerance (22.6%) and neuropsychiatric effects (15.9%). Baseline GC‐related toxicity scores were higher in patients with relapsing disease compared with those with newly diagnosed disease (mean of 122.5 vs. 98.9; P

IgG4-related disease (IgG4-RD) is an immune-mediated multiorgan fibroinflammatory disorder with variable clinical presentations. IgG4-RD cardiovascular involvement is considered rare, with pulmonary arterial involvement reported in a small subset of cases. Known pulmonary artery manifestations include pulmonary arteritis, pulmonary artery stenoses and central pulmonary artery aneurysms. Here we report 2 different patients with multifocal dilatation of the segmental and subsegmental pulmonary arteries with differing degrees of severity. Both patients also had coronary arterial abnormalities.

Abstract Sjögren’s syndrome is a chronic autoimmune disorder whose pathogenesis is poorly understood and that lacks effective therapies. Detailed quantitative and spatial analyses of tissues affected by Sjögren’s syndrome were undertaken, including the quantitation of the frequency of selected cell–cell interactions in the disease milieu. Quantitative analyses of CD4+ T cell subsets and of CD8+ T cells in the labial salivary glands from untreated patients with primary Sjögren’s syndrome revealed that activated CD8+ cytotoxic T cells (CD8+CTLs) were the most prominent T cells in these infiltrates. An accumulation of apoptotic glandular epithelial cells, mainly ductal and acinar cells, was observed, consistent with the impaired salivary secretion often observed in patients with this disease. FasL expressing activated CD8+ T cells were seen to accumulate around Fas expressing apoptotic epithelial cells. Quantitative analyses of apoptotic cell types and of conjugates between cytotoxic T cells and epithelial cells undergoing apoptosis suggest that Sjögren’s syndrome is primarily driven by CD8+CTL mediated execution of epithelial cells mainly represented by ductal and acinar cells.

Summary: Although therapeutic B cell depletion dramatically resolves inflammation in many diseases in which antibodies appear not to play a central role, distinct extrafollicular pathogenic B cell subsets that accumulate in disease lesions have hitherto not been identified. The circulating immunoglobulin D (IgD)−CD27−CXCR5−CD11c+ DN2 B cell subset has been previously studied in some autoimmune diseases. A distinct IgD−CD27−CXCR5−CD11c− DN3 B cell subset accumulates in the blood both in IgG4-related disease, an autoimmune disease in which inflammation and fibrosis can be reversed by B cell depletion, and in severe COVID-19. These DN3 B cells prominently accumulate in the end organs of IgG4-related disease and in lung lesions in COVID-19, and double-negative B cells prominently cluster with CD4+ T cells in these lesions. Extrafollicular DN3 B cells may participate in tissue inflammation and fibrosis in autoimmune fibrotic diseases, as well as in COVID-19.

IgG4-related disease-associated hypertrophic pachymeningitis (IgG4RD-HP) is a fibroinflammatory autoimmune disorder in which diagnosis is difficult without biopsy. Guidance on management of disease refractory to glucocorticoids and intravenous rituximab is limited. We present the case of a 68-year-old woman with IgG4RD-HP who developed sensorineural hearing loss with associated bulky basilar pachymeningeal enhancement. Her cerebrospinal fluid was inflammatory and had an elevated IgG4 concentration, strongly suggestive of IgG4RD-HP. Biopsy of involved meninges was not possible due to surgical risk. Over years she developed bilateral optic neuropathies and hydrocephalus, requiring intravenous rituximab and ventriculoperitoneal shunt. Her disease was refractory to glucocorticoids. Despite maintenance intravenous rituximab, she developed slowly progressive symptoms of intracranial hypertension and hydrocephalus with persistently inflammatory spinal fluid. Switching to intrathecal rituximab therapy led to dramatic improvement in gait and headache and reduced pachymeningeal bulk and metabolic activity. In patients with IgG4RD-HP refractory to glucocorticoids and intravenous rituximab, intrathecal rituximab may be an efficacious therapy.

Background The 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.Methods DNA 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-Ile119 or PRTN3-Val119.Results Whole 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-Val119 and 13 homozygous for PRTN3-Ile119. The frequency of severe flares at 18 months in homozygous PRTN3-Ile119 was significantly higher when compared with homozygous PRTN3-Val119 (46.2% vs 19.6%, p=0.048). Multivariate analysis identified homozygous PR3-Ile119 as main predictor of severe relapse (HR 4.67, 95% CI 1.16 to 18.86, p=0.030).Conclusion In 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.

Objective Immunoglobulin‐G4‐related disease (IgG4‐RD) is a systemic autoimmune disease that can affect nearly any organ, but its epidemiology remains poorly understood. Validated algorithms to identify cases in claims data will enable studies to describe IgG4‐RD epidemiology in the general population. Methods Potential claims‐based algorithms were developed by IgG4‐RD experts using a combination of International Classification of Diseases, Ninth Revision (ICD‐9) and International Classification of Diseases, 10th Revision (ICD‐10) codes, dispensed medications, and procedure codes for immunoglobulin G (IgG) subclass testing. Algorithms were tested using Medicare Parts A, B, and D linked to medical records (2007‐2017). Classification of cases as IgG4‐RD was determined using the American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) classification criteria for IgG4‐RD. We estimated the positive predictive value (PPV) of each algorithm; sensitivity was determined using a cohort of patients with IgG4‐RD also enrolled in Medicare Parts A, B, and D during the study period. Results We identified seven algorithms that used a combination of ICD‐9 and ICD‐10 codes, medication prescriptions, and/or IgG subclass tests to identify patients with IgG4‐RD. The PPV of algorithms in the derivation cohort ranged from 57% to 100%, and sensitivity ranged from 0% to 58%. The best performing algorithm in the validation cohort had a PPV of 81% and a sensitivity of 58%. Typical IgG4‐RD manifestations were observed in the cohort (n = 36) assembled by this algorithm, including 50% with sialadenitis, 64% with pancreatic disease, 31% with renal disease, and 59% with an elevated IgG4 concentration. Conclusion We derived and validated a well‐performing algorithm to identify IgG4‐RD cases with typical manifestations of the disease. The claims‐based algorithm can be used in research studies of IgG4‐RD.

Background: Glucocorticoids are the mainstay of treatment for autoimmune blistering diseases (AIBDs). The Glucocorticoid Toxicity Index (GTI) is a novel, outcome-based glucocorticoid-induced adverse effects monitoring instrument. Objective: To investigate whether the GTI score was able to accurately quantify the glucocorticoid-induced toxicity in patients with AIBDs. Methods: The prospective cohort study included patients with confirmed diagnoses of AIBDs (group1, currently receiving glucocorticoids; and group 2, had glucocorticoids ceased earlier). Data were collected minimally at baseline (V1) and 3 months (V2). Further data from patients who were able to complete the follow-up visits at 6 months (V3) and 12 months (V4) amid the COVID-19 pandemic were also included. GTI scores were calculated after data collection. Results: Analysis of data from V1 and V2 found a linear correlation between GTI score and prednisone doses (P

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

Objective The objective of this study was to validate the diagnosis of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) as the primary cause of end‐stage renal disease (ESRD) in the US Renal Data System (USRDS). Methods We identified patients with ESRD in the Mass General Brigham (MGB) health care system who were enrolled in the USRDS. The health records of those with AAV listed as the primary cause of ESRD in the USRDS were reviewed to confirm the diagnosis and estimate positive predictive value (PPV). Sensitivity was estimated by evaluating the primary cause of ESRD listed in the USRDS for patients with ESRD due to AAV in the MGB AAV cohort. Results We identified 89 MGB patients with ESRD due to AAV in the USRDS. Of these, 85 cases were confirmed to be true cases of AAV (PPV = 94%). Among the patients classified as having AAV, 84 (99%) had an ANCA test, which was predominantly myeloperoxidase/P‐ANCA (47 [55%]); 36 (42%) had a renal biopsy, and all biopsies were supportive of the diagnosis. The majority (81 [90%]) was identified as AAV by International Classification of Diseases Ninth Revision or International Classification of Diseases 10th Revision codes for granulomatosis with polyangiitis (446.4 or M313.1). Of the 77 MGB AAV cohort patients with ESRD who were linked to the USRDS, 41 (53%) had AAV listed as the cause of ESRD; in the remainder, ESRD was attributed to nonspecific nephritis. Conclusion The diagnosis of AAV as the cause of ESRD in the USRDS has a high PPV; sensitivity was moderate. These findings support the continued use of the USRDS to study ESRD due to AAV.

Objective To investigate the perceived risk of coronavirus disease 2019 (COVID‐19) infection and outcomes as well as shielding practices among patients with rheumatoid arthritis (RA) during the COVID‐19 pandemic. Methods We surveyed participants with RA in a large health care system between July 16 and November 8, 2020. Participants reported RA treatment, COVID‐19 risk perception, and shielding practices (eg, masks, social distancing, and quarantining). We examined the association of demographic and disease‐specific factors with risk perception and the association of risk perception with shielding practices. Results Of 494 participants, 195 (40%), 169 (34%), and 130 (26%) strongly agreed, agreed, or were uncertain/disagreed that their RA put them at higher risk for COVID‐19 or poor outcomes, respectively. Younger age (odds ratio [OR]: 0.98), having a comorbidity (OR: 1.60), and biologic disease‐modifying antirheumatic drug (bDMARD) use (OR: 1.75) were independently associated with a higher perceived risk. Among those who strongly agreed, agreed, or were uncertain/disagreed that they had greater risk, 165 (85%), 118 (70%), and 69 (53%), respectively, practiced all three shielding measures (P < 0.0001). Those who strongly agreed or agreed that they were at higher risk were more likely to use all three shielding practices (OR: 4.16 and 1.97, respectively). bDMARD use and glucocorticoid use were associated with using all three shielding measures (OR: 1.99 and 1.81, respectively). Conclusion Perception of COVID‐19 risk among patients with RA varies substantially. Factors associated with perceived risk are different from those found to be associated with worse outcomes in observational studies. Greater perceived risk is associated with more strict shielding, which has implications for patient education and mental health.

Abstract Background Immunoglobulin G4-related disease (IgG4-RD) and systemic sclerosis (SSc) are rare autoimmune diseases characterized by the presence of CD4+ cytotoxic T cells in the blood as well as inflammation and fibrosis in various organs, but they have no established etiologies. Similar to other autoimmune diseases, the gut microbiome might encode disease-triggering or disease-sustaining factors. Methods The gut microbiomes from IgG4-RD and SSc patients as well as healthy individuals with no recent antibiotic treatment were studied by metagenomic sequencing of stool DNA. De novo assembly-based taxonomic and functional characterization, followed by association and accessory gene set enrichment analysis, were applied to describe microbiome changes associated with both diseases. Results Microbiomes of IgG4-RD and SSc patients distinctly separated from those of healthy controls: numerous opportunistic pathogenic Clostridium and typically oral Streptococcus species were significantly overabundant, while Alistipes, Bacteroides, and butyrate-producing species were depleted in the two diseases compared to healthy controls. Accessory gene content analysis in these species revealed an enrichment of Th17-activating Eggerthella lenta strains in IgG4-RD and SSc and a preferential colonization of a homocysteine-producing strain of Clostridium bolteae in SSc. Overabundance of the classical mevalonate pathway, hydroxyproline dehydratase, and fibronectin-binding protein in disease microbiomes reflects potential functional differences in host immune recognition and extracellular matrix utilization associated with fibrosis. Strikingly, the majority of species that were differentially abundant in IgG4-RD and SSc compared to controls showed the same directionality in both diseases. Compared with multiple sclerosis and rheumatoid arthritis, the gut microbiomes of IgG4-RD and SSc showed similar signatures; in contrast, the most differentially abundant taxa were not the facultative anaerobes consistently identified in inflammatory bowel diseases, suggesting the microbial signatures of IgG4-RD and SSc do not result from mucosal inflammation and decreased anaerobism. Conclusions These results provide an initial characterization of gut microbiome ecology in fibrosis-prone IgG4-RD and SSc and reveal microbial functions that offer insights into the pathophysiology of these rare diseases.

Abstract Background Placebo-controlled clinical trials have demonstrated the efficacy of tocilizumab (TCZ) for remission maintenance and glucocorticoid sparing in patients with giant cell arteritis (GCA). However, limited data exist on the effectiveness and safety of TCZ for GCA in real-world clinical practice. Methods This was a retrospective, single-center analysis of patients with GCA treated with intravenous or subcutaneous TCZ (2010–2018). Outcomes evaluated before and after TCZ initiation included occurrence of flare, time to flare, annualized flare rate, flare characteristics (i.e., polymyalgia rheumatica [PMR] symptoms, cranial manifestations), prednisone use, and safety. Flare was defined as the recurrence of unequivocal GCA manifestations requiring treatment intensification. Subgroup analyses of patients with PMR or visual manifestations at GCA diagnosis were performed. Results Sixty patients with GCA were included. The median (IQR) disease duration before and after the start of TCZ was 0.6 (0.2–1.6) and 0.5 (0.3–1.4) years, respectively. At least 1 flare was observed in 43 patients (71.7%) before and in 18 (30.0%) after TCZ initiation. Median (IQR) time to flare was 0.5 (0.3–0.7) years before TCZ treatment and 2.1 (0.6–2.6) years after TCZ initiation (HR 0.22; 95% CI 0.10–0.50; p = 0.0003). The annualized flare rate significantly decreased following TCZ use (before TCZ 1.4 [95% CI 1.0–2.1]; after TCZ 0.6 [95% CI 0.3–1.0] events/year; p

Objective Originator intravenous rituximab is an important rheumatology treatment but is costly, and administration requires several hours. Because biosimilar rituximab may cost less and subcutaneous rituximab requires a shorter visit, both may reduce costs and increase treatment capacity (infusions per year). Methods We implemented time‐driven activity‐based costing (TDABC), a method to assess costs and opportunities to increase capacity, throughout the care pathway for 26 patients receiving a total of 30 rituximab infusions. Using the TDABC estimates, we created a base case, which included provider time, salaries, infusion rates and times, and drug formulation, to simulate an induction cycle (two infusions). We varied these parameters in sensitivity analyses and assessed the impact of infusion rates and formulation (biosimilar vs. subcutaneous) on capacity before and after assuming a fixed budget. Results The base‐case cost was $19 452; more than 90% was due to drug cost. In sensitivity analyses, varying projected biosimilar cost led to the greatest cost savings ($8,988 per cycle). Faster infusion rates and subcutaneous rituximab increased annual capacity (300% and 800%, respectively). With a fixed budget, subcutaneous rituximab led to a relative increase in capacity over biosimilar rituximab except when biosimilar cost savings relative to originator rituximab exceeded 40%; faster biosimilar infusion rates did not meaningfully affect these findings. Conclusion Using TDABC, we demonstrate that rituximab cost is the primary driver of treatment cost, but capacity is largely driven by treatment time. Subcutaneous rituximab leads to higher capacity than biosimilar rituximab across a range of plausible costs; its use in rheumatology should be studied.

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.

Abstract Introduction The safety profile of tocilizumab (TCZ) in patients with rheumatoid arthritis (RA) is well established. TCZ was approved to treat giant cell arteritis (GCA) in 2017 in the USA and Europe, and its safety profile in patients with GCA continues to be defined. The objective of this analysis was to examine incidence rates (IRs) of adverse events of special interest (AESI) occurring during the TCZ clinical development program and in healthcare claims data in patients with GCA or RA. Methods TCZ-naïve patients with GCA or RA were identified in the MarketScan administrative healthcare claims database. TCZ-treated patients with GCA from the GiACTA trial and TCZ-treated patients with RA from pooled clinical trial data were analyzed. The IRs of AESI (AESI IRs) were calculated for all cohorts. In the claims cohorts, risks of AESI were estimated using Poisson regression. Results TCZ-naïve claims cohorts comprised 4804 patients with GCA [mean (standard deviation) age 73.4 (9.8) years; follow-up 3.9 (3.1) years] and 15,164 patients with RA [age 60.3 (8.2) years; follow-up, 4.5 (2.8) years]. TCZ-treated clinical trial cohorts comprised 149 patients with GCA [age 69.5 (8.4) years; exposure approx. 138 patient-years (PY)] and 7647 with RA [age 52 (12.6) years; exposure approx. 22,394 PY]. The IRs of infections, stroke, malignancies, myocardial infarction, and gastrointestinal perforations in the GCA claims cohort exceeded those in the RA claims cohort; the risk of AESI (adjusted for age and glucocorticoid use) was higher in patients with GCA than in those with RA. Similar patterns to the claims cohorts in terms of the AESI IRs were observed in clinical trial cohorts, although the number of events was limited in the GCA trial cohort. Conclusion Higher IRs of AESI were observed in patients with GCA versus those with RA in both TCZ-naïve and -treated cohorts. Differences in underlying disease, age, and glucocorticoid use may influence AESI incidence, irrespective of intervention. Funding This study was funded by F. Hoffmann-La Roche Ltd and Genentech, Inc. Article processing charges were funded by F. Hoffmann-La Roche Ltd. Plain Language Summary Plain language summary is available for this article.

Abstract Background Patients with giant cell arteritis (GCA) treated with tocilizumab (TCZ) every week or every other week and prednisone tapering achieved superior rates of sustained remission to patients treated with placebo and prednisone tapering in a randomised controlled trial. Health-related quality of life (HRQOL) in patients from this trial is now reported. Methods Exploratory analyses of SF-36 PCS and MCS and domain scores, PtGA and FACIT-Fatigue were performed in patients treated with weekly subcutaneous TCZ 162 mg plus 26-week prednisone taper (TCZ-QW + Pred-26) or placebo plus 26-week or 52-week prednisone tapers (PBO + Pred-26 or PBO + Pred-52). These analyses were performed on responder and non-responder patients, including those who achieved the primary outcome and those who experienced flare and received escape prednisone doses. Results Baseline SF-36 PCS, MCS and domain scores were low, indicating impaired HRQOL related to GCA. At week 52, least squares mean (LSM) changes in PCS scores improved with TCZ-QW + Pred-26 but worsened in both PBO + Pred groups (p

Background: The utility of ANCA testing as an indicator of disease activity in ANCA-associated vasculitis (AAV) remains controversial. This study aimed to determine the association of ANCA testing by various methods and subsequent remission and examine the utility of a widely used automated addressable laser-bead immunoassay (ALBIA) to predict disease relapses.Methods: Data from the Rituximab vs. Cyclophosphamide for ANCA-Associated Vasculitis (RAVE) trial were used. ANCA testing was performed by direct ELISA, capture ELISA, and ALBIA. Cox proportional hazards regression models were used to evaluate the association of PR3-ANCA level and subsequent remission or relapse. The ALBIA results are routinely reported as >8 when the value is high. For this study, samples were further titrated. A decrease and increase in PR3-ANCA were defined as a halving or doubling in value, respectively.Results: A decrease in ANCA by ALBIA at 2 months was associated with shorter time to sustained remission (HR 4.52, p = 0.035). A decrease in ANCA by direct ELISA at 4 months was associated with decreased time to sustained remission (HR 1.77, p = 0.050). There were no other associations between ANCA decreases or negativity and time to remission. An increase in PR3-ANCA by ALBIA was found in 78 of 93 subjects (84%). Eleven (14%) had a PR3-ANCA value which required titration for detection of an increase. An increase of ANCA by ALBIA was associated with severe relapse across various subgroups.Conclusions: A decrease in ANCA by ALBIA at 2 months and by direct ELISA at 4 months may be predictive of subsequent remission. These results should be confirmed in a separate cohort with similarly protocolized sample and clinical data collection. A routinely used automated ALBIA for PR3-ANCA measurement is comparable to direct ELISA in predicting relapse in PR3-AAV. Without titration, 14% of the increases detected by ALBIA would have been missed. Titration is recommended when this assay is used for disease monitoring. The association of an increase in PR3-ANCA with the risk of subsequent relapse remains complex and is affected by disease phenotype and remission induction agent.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a small- to medium-vessel necrotizing vasculitis responsible for excess morbidity and mortality (1). The AAVs, which include granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA), are among the most difficult types of vasculitis to treat. Although clinicopathologic disease definitions have been used traditionally to categorize patients into one of these three diagnoses, more recently ANCA specificity for either proteinase 3 (PR3) or myeloperoxidase (MPO) has been advocated for the purpose of disease classification (2). This is because differences in genetics, pathogenesis, risk factors, treatment responses, and outcomes align more closely with PR3- or MPO-ANCA type than with the clinocopathologic diagnosis. Moreover, classifying patients as GPA or MPA can be challenging because biopsies are not obtained routinely in most cases and existing classification systems can provide discrepant classification for the same patient (3). In this review, we address the recent literature supporting the use of ANCA specificity to study and personalize the care of AAV patients (Table 1). We focus particularly on patients with GPA or MPA.

IgG4-related disease (IgG4-RD) is a systemic condition of unknown cause characterized by highly fibrotic lesions, with dense lymphoplasmacytic infiltrates containing a preponderance of IgG4-expressing plasma cells. CD4+ T cells and B cells constitute the major inflammatory cell populations in IgG4-RD lesions. IgG4-RD patients with active, untreated disease show a marked expansion of plasmablasts in the circulation. Although the therapeutic depletion of B cells suggests a role for these cells in the disease, a direct role for B cells or IgG4 in the pathogenesis of IgG4-RD is yet to be demonstrated. Among the CD4+ T-cell subsets, Th2 cells were initially thought to contribute to IgG4-RD pathogenesis, but many previous studies were confounded by the concomitant history of allergic diseases in the patients studied and the failure to use multi-color staining to definitively identify T-cell subsets in tissue samples. More recently, using an unbiased approach to characterize CD4+ T-cell subsets in patients with IgG4-RD – based on their clonal expansion and ability to infiltrate affected tissue sites – CD4+ CTLs have been identified as the major CD4+ T-cell subset in disease lesions as well as in the circulation. CD4+ CTLs in affected tissues secrete pro-fibrotic cytokines including IL-1β, TGF-β1, and IFN-γ as well as cytolytic molecules such as perforin and granzymes A and B. In this review, we examine possible mechanisms by which activated B cells and plasmablasts may collaborate with the expanded CD4+ CTLs in driving the fibrotic pathology of the disease and describe the lacunae in the field and in our understanding of IgG4-RD pathogenesis.

Abstract Background Family screening of a 48‐year‐old male with recently diagnosed IgG4‐related disease (IgG4‐RD) revealed unanticipated elevations in plasma IgG4 in his two healthy teenaged sons. Methods We performed gene sequencing, immune cell studies, HLA typing, and analyses of circulating cytotoxic CD4+ T lymphocytes and plasmablasts to seek clues to pathogenesis. DNA from a separate cohort of 99 patients with known IgG4‐RD was also sequenced for the presence of genetic variants in a specific gene, FGFBP2. Results The three share a previously unreported heterozygous single base deletion in fibroblast growth factor binding protein type 2 (FGFBP2), which causes a frameshift in the coding sequence. The FGFBP2 protein is secreted by cytotoxic T‐lymphocytes and binds fibroblast growth factor. The variant sequence in the FGFBP2 protein is predicted to form a disordered random coil rather than a helical‐turn‐helix structure, unable to adopt a stable conformation. The proband and the two sons had 5–10‐fold higher numbers of circulating cytotoxic CD4 + T cells and plasmablasts compared to matched controls. The three members also share a homozygous missense common variant in FGFBP2 found in heterozygous form in ~40% of the population. This common variant was found in 73% of an independent, well characterized IgG4‐RD cohort, showing enrichment in idiopathic IgG4‐RD. Conclusions The presence of a shared deleterious variant and homozygous common variant in FGFBP2 in the proband and sons strongly implicates this cytotoxic T cell product in the pathophysiology of IgG4‐RD. The high prevalence of a common FGFBP2 variant in sporadic IgG4‐RD supports the likelihood of participation in disease.