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OBJECTIVE: Microparticles are small vesicles that are released from activated or dying cells and that occur abundantly in the synovial fluid of patients with rheumatoid arthritis (RA). The goal of these studies was to elucidate the mechanisms by which microparticles activate synovial fibroblasts to express a proinflammatory phenotype. METHODS: Microparticles from monocytes and T cells were isolated by differential centrifugation. Synovial fibroblasts were cocultured with increasing numbers of microparticles. Gene expression was analyzed by real-time polymerase chain reaction and confirmed by Western blotting and enzyme immunoassay. Arachidonic acid labeled with tritium was used to study the transport of biologically active lipids by microparticles. The roles of NF-kappaB and activator protein 1 (AP-1) signaling were analyzed with electrophoretic mobility shift assay and transfection with small interfering RNA and IkappaB expression vectors. RESULTS: Microparticles strongly induced the synthesis of cyclooxygenase 2 (COX-2), microsomal prostaglandin E synthase 1 (mPGES-1), and prostaglandin E(2) (PGE(2)). In contrast, no up-regulation of COX-1, mPGES-2, cytosolic PGES, or phospholipase A(2) was observed. The induction of PGE(2) was blocked by selective inhibition of COX-2. Microparticles activated NF-kappaB, AP-1, p38, and JNK signaling in synovial fibroblasts. Inhibition of NF-kappaB, AP-1, and JNK signaling reduced the stimulatory effects. Arachidonic acid was transported from leukocytes to fibroblasts by microparticles. Arachidonic acid derived from microparticles was converted to PGE(2) by synovial fibroblasts. CONCLUSION: These results demonstrate that microparticles up-regulate the production of PGE(2) in synovial fibroblasts by inducing COX-2 and mPGES-1. These data provide evidence for a novel mechanism by which microparticles may contribute to inflammation and pain in RA. [ABSTRACT FROM AUTHOR]

Systemic lupus erythematosus is a potentially fatal disorder whose diagnosis is often complex. Treatment should be started as soon as possible to minimize complications and improve the prognosis of this unpredictable disease. [ABSTRACT FROM AUTHOR]

Objective: The Type 1 and 2 systemic lupus erythematosus (SLE) Model was developed to encapsulate all signs and symptoms that patients with SLE experience. Our previous qualitative work demonstrated the model accurately reflects the lived experience of people living with SLE. The objective of this study was to present the Type 1 and 2 SLE Model to rheumatologists to understand how the model fits with their experiences treating patients with SLE., Methods: We conducted a qualitative descriptive study using semistructured interviews with rheumatologists. Rheumatologists were asked about their general impression of the Type 1 and 2 SLE Model, how the model does or does not fit within their approach to treating patients with SLE, the utility of the model in clinical practice, and any suggested changes. Applied thematic analysis identified salient themes., Results: We interviewed 13 rheumatologists. The majority of rheumatologists approved of the model and found it useful to guide therapy and clinical decision-making. Several rheumatologists thought the model was helpful for patient education to manage expectations about differences between Type 1 and Type 2 symptoms and treatments. A few rheumatologists expressed concern that the model could lead to an overdiagnosis of SLE., Conclusion: The Type 1 and 2 SLE Model was accepted by most rheumatologists interviewed and welcomed as a useful approach to identifying and treating symptoms in patients with SLE. Future studies will determine how implementing the Type 1 and 2 SLE Model affects patient understanding, the physician-patient relationship, and clinical outcomes., (© 2024 The Author(s). ACR Open Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease that primarily affects young women and causes a wide range of inflammatory manifestations. The hallmark of SLE is the production of antibodies to components of the cell nucleus (antinuclear antibodies [ANAs]). These antibodies can bind to DNA, RNA, and protein complexes with nucleic acids. Among ANAs, antibodies to DNA (anti-DNA) are markers for classification and disease activity, waxing and waning disease activity in many patients. In the blood, anti-DNA antibodies can bind to DNA to form immune complexes with two distinct roles in pathogenesis: (1) renal deposition to provoke nephritis and (2) stimulation of cytokine production following uptake into innate immune cells and interaction with internal nucleic acid sensors. These sensors are part of an internal host defense system in the cell cytoplasm that can respond to DNA from infecting organisms; during cell stress, DNA from nuclear and mitochondrial sources can also trigger these sensors. The formation of immune complexes requires a source of extracellular DNA in an immunologically accessible form. As shown in in vivo and in vitro systems, extracellular DNA can emerge from dead and dying cells in both a free and a particulate form. Neutrophils undergoing the process of NETosis can release DNA in mesh-like structures called neutrophil extracellular traps. In SLE, therefore, the combination of ANAs and immunologically active DNA can create new structures that can promote inflammation throughout the body as well as drive organ inflammation and damage., (Published 2024. This article is a U.S. Government work and is in the public domain in the USA.)

Source Citation: Rech J, Tascilar K, Hagen M, et al. Abatacept inhibits inflammation and onset of rheumatoid arthritis in individuals at high risk (ARIAA): a randomised, international, multicentre, double-blind, placebo-controlled trial. Lancet. 2024;403:850-859. 38364841., Competing Interests: Disclosures: Disclosure forms are available with the article online.

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterised by antibodies to DNA (anti-DNA) and other nuclear macromolecules. Anti-DNA antibodies are markers for classification and disease activity and promote pathogenesis by forming immune complexes that deposit in the tissue or stimulate cytokine production. Studies on the antibody response to DNA have focused primarily on a conformation of DNA known as B-DNA, the classic right-handed double helix. Among other conformations of DNA, Z-DNA is a left-handed helix with a zig-zag backbone; hence, the term Z-DNA. Z-DNA formation is favoured by certain base sequences, with the energetically unfavourable flip from B-DNA to Z-DNA dependent on conditions. Z-DNA differs from B-DNA in its immunogenicity in animal models. Furthermore, anti-Z-DNA antibodies, but not anti-B-DNA antibodies, can be present in otherwise healthy individuals. In SLE, antibodies to Z-DNA can occur in association with antibodies to B-DNA as a cross-reactive response, rising and falling together. While formed transiently in chromosomal DNA, Z-DNA is stably present in bacterial biofilms; biofilms can provide protection against antibiotics and other challenges including elements of host defence. The high GC content of certain bacterial DNA also favours Z-DNA formation as do DNA-binding proteins of bacterial or host origin. Together, these findings suggest that sources of Z-DNA can enhance the immunogenicity of DNA and, in SLE, stimulate the production of cross-reactive antibodies that bind both B-DNA and Z-DNA. As such, DNA can act as a molecular chameleon that, when stabilised in the Z-DNA conformation, can drive autoimmunity., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ on behalf of EULAR.)

Objective: Systemic lupus erythematosus (SLE) flares are associated with increased damage and decreased health-related quality of life. We hypothesized that there is discordance between physicians' and patients' views of SLE flare. In this study, we aimed to explore patient and physician descriptions of SLE flares., Methods: We conducted a qualitative descriptive study using in-depth interviews with a purposeful sample of patients with SLE (who met 1997 American College of Rheumatology or Systemic Lupus International Collaborating Clinics criteria) and practicing rheumatologists. Interviews were audio-recorded, transcribed, and analyzed using applied thematic analysis., Results: Forty-two patient participants with SLE, representing a range of SLE activity, completed interviews. The majority described flare symptoms as joint pain, fatigue, and skin issues lasting several days. Few included objective signs or laboratory measures, when available, as features of flare. We interviewed 13 rheumatologists from 10 academic and 3 community settings. The majority defined flare as increased or worsening SLE disease activity, with slightly more than half requiring objective findings. Around half of the rheumatologists included fatigue, pain, or other patient-reported symptoms., Conclusion: Patients and physicians described flare differently. Participants with SLE perceived flares as several days of fatigue, pain, and skin issues. Providers defined flares as periods of increased clinical SLE activity. Our findings suggest the current definition of flare may be insufficient to integrate both perceptions. Further study is needed to understand the pathophysiology of patient flares and the best way to incorporate patients' perspectives into clinical assessments., (Copyright © 2024 by the Journal of Rheumatology.)

Background: Type 2 systemic lupus erythematosus (SLE) symptoms, including fatigue, fibromyalgia, and brain fog, contribute to poor health-related quality of life (HRQoL) in patients with lupus. To test the hypothesis that Type 1 (classical inflammatory lupus) activity is associated with Type 2 SLE activity, we characterized the features of Type 2 SLE in patients with a range of lupus nephritis (LN) activity., Methods: This was a cross-sectional study of SLE patients [American College of Rheumatology (ACR) 1997 or Systemic Lupus International Collaborating Clinics (SLICC) 2012 classification criteria] from June 2018 to March 2020. Patients completed the Systemic Lupus Activity Questionnaire (SLAQ) and the Polysymptomatic Distress Scale. Patients were divided into groups based on their renal status. Active nephritis was defined using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) lupus nephritis parameter. Differences across groups were analyzed by Fisher's exact test and ANOVA., Results: In this cohort of 244 patients (93% female, mean age 43 years, 58% Black), 10% had active nephritis, 35% had historical nephritis, and 55% never had nephritis (non-nephritis). Active nephritis and non-nephritis patients had a similar burden of Type 2 SLE symptoms, despite a difference in Type 1 SLE activity. Patients with active nephritis had higher Type 2 PGA (Physician Global Assessment) scores and reported more Type 2 SLE symptoms than inactive nephritis patients. Patients with inactive nephritis had the lowest Type 2 SLE activity., Conclusions: While Type 2 SLE symptoms are common in SLE, our findings suggest that patients with active nephritis experience significant Type 2 SLE symptoms that may be ameliorated as nephritis improves. We also observed that non-nephritis patients had a similar burden of Type 2 SLE symptoms as patients with active nephritis, despite having on average lower Type 1 SLE activity. Therefore, the etiology of Type 2 SLE symptoms is likely multifactorial and may be driven by inflammatory and non-inflammatory biopsychosocial factors. Key Points • Patients with active nephritis experienced significant Type 2 symptoms that may be ameliorated as nephritis improves. • Non-nephritis patients had a similar burden of Type 2 SLE symptoms as patients with active nephritis, despite having on average lower Type 1 SLE activity. • Because etiology of Type 2 SLE symptoms is likely multifactorial and may be driven by inflammatory and non-inflammatory biopsychosocial factors., (© 2024. The Author(s), under exclusive licence to International League of Associations for Rheumatology (ILAR).)

Autoimmune and inflammatory diseases are highly complex, limiting treatment and the development of new therapies. Recent work has shown that cell-free DNA bound to biological microparticles is linked to systemic lupus erythematosus, a prototypic autoimmune disease. However, the heterogeneity and technical challenges associated with the study of biological particles have hindered a mechanistic understanding of their role. Our goal was to develop a well-controlled DNA-particle model system to understand how DNA-particle complexes affect cells. We first characterized the adsorption of DNA on the surface of polystyrene nanoparticles (200 nm and 2 µm) using transmission electron microscopy, dynamic light scattering, and colorimetric DNA concentration assays. We found that DNA adsorbed on the surface of nanoparticles was resistant to degradation by DNase 1. Macrophage cells incubated with the DNA-nanoparticle complexes had increased production of pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). We probed two intracellular DNA sensing pathways, toll-like receptor 9 (TLR9) and cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING), to determine how cells sense the DNA-nanoparticle complexes. We found that the cGAS-STING pathway is the primary route for the interaction between DNA-nanoparticles and macrophages. These studies provide a molecular and cellular-level understanding of DNA-nanoparticle-macrophage interactions. In addition, this work provides the mechanistic information necessary for future in vivo experiments to elucidate the role of DNA-particle interactions in autoimmune diseases, providing a unique experimental framework to develop novel therapeutic approaches., Competing Interests: Competing interests statement:The authors declare no competing interest.

Objective: In the new Type 1 & 2 model for systemic lupus erythematosus (SLE), Type 1 SLE represents classic inflammatory manifestations, such as arthritis, while Type 2 SLE encompasses symptoms such as pain and fatigue where the relationship to inflammation is less clear. The objective of this study was to interview individuals living with SLE to determine the content and face validity of the Type 1 & 2 SLE model., Methods: We conducted a qualitative study using semi-structured interviews with a purposeful sample of participants who met classification criteria for SLE. Participants were asked to describe their experiences with Type 1 & 2 SLE symptoms and treatments, and they indicated if and how their personal experiences aligned with the Type 1 & 2 SLE model. All interviews were audio-recorded and transcribed; applied thematic analysis identified the most frequent and salient themes., Results: We interviewed 42 participants with SLE. Type 2 SLE symptoms, such as pain and fatigue, were very common, with almost all participants experiencing some Type 2 symptoms at some point during their disease course. Participants described Type 1 SLE symptoms as being acute flares and life-threatening and Type 2 SLE symptoms as "everyday lupus" that affected their daily lives and were a dominant part of their SLE disease experience. Most participants stated they want their rheumatologists to discuss Type 2 symptoms during clinical appointments in order to address their full symptom experience., Conclusion: We demonstrated content and face validity of the Type 1 & 2 SLE model with people living with SLE. Participants in our study largely understood the model and felt it accurately reflected their experience living with SLE. Type 2 SLE symptoms are very common in individuals with SLE and impact patients' quality of life. Using the model to address Type 2 SLE symptoms allows the rheumatologist to incorporate the patient's perspective and provide patient-centered care., Competing Interests: Declaration of conflicting interestsAME has received grant support from Pfizer, Exagen, Immunovant, and GlaxoSmithKline and consulting fees from Amgen. MEBC has received grant support from Pfizer, Exagen, Immunovant, GlaxoSmithKline, and Astra-Zeneca and consulting fees from GlaxoSmithKline, Amgen, and UCB. DSP has received grant support from Immunovant and Exagen; consulting fees from Immunovant and GlaxoSmithKline; and served on a Data Safety Monitor Board for Bristol Myers Squibb. MM has received consulting fees from AstraZeneca. JLR has received grant support from Pfizer, Exagen, Immunovant, Astra-Zeneca and consulting fees from GlaxoSmithKline, Amgen, Aurinia, Immunovant, Janssen, Eli Lily, and Ampel Biosolutions. All other authors have no conflicts of interest to disclose.

Antibodies to DNA are a diverse set of antibodies that bind sites on DNA, a polymeric macromolecule that displays various conformations. In a previous study, we showed that sera of normal healthy subjects (NHS) contain IgG antibodies to Z-DNA, a left-handed helix with a zig-zig backbone. Recent studies have demonstrated the presence of Z-DNA in bacterial biofilms, suggesting a source of this conformation to induce responses. To characterize further antibodies to Z-DNA, we used an ELISA assay with brominated poly(dGdC) as a source of Z-DNA and determined the isotype of these antibodies and their binding properties. Results of these studies indicate that NHS sera contain IgM and IgA as well as IgG anti-Z-DNA antibodies. As shown by the effects of ionic strength in association and dissociation assays, the anti-Z-DNA antibodies bind primarily by electrostatic interactions; this type of binding differs from that of induced anti-Z-DNA antibodies from immunized animals which bind by non-ionic interactions. Furthermore, urea caused dissociation of NHS anti-Z-DNA at molar concentrations much lower than those for the induced antibodies. These studies also showed IgA anti-Z-DNA antibodies in fecal water. Together, these studies demonstrate that antibodies to Z-DNA occur commonly in normal immunity and may arise as a response to Z-DNA of bacterial origin.

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disorder that affects the joints and produces pain, swelling, and stiffness. It has a lifetime prevalence of up to 1% worldwide. An extract of Tripterygium wilfordii Hook F (TwHF), a member of the Celastraceae herbal family widely available in south China, has been used for treatment of RA since 1960s., Methods: The current consensus practice guidance (CPG) aims to offer guidance on the application of TwHF in the clinical management of active RA. The CPG followed World Health Organisation (WHO)'s recommended process, carried out three systematic reviews to synthesize data from 19 randomised controlled trials (RCT) involving 1795 participants. We utilized Grading of Recommendations, Assessment, Development and Evaluation (GRADE) to evaluate certainty of evidence and derive recommendations. We rigorously followed The Appraisal of Guidelines for Research and Evaluation II (AGREE II) as conduct guides to minimise bias and promote transparency., Results: There was no obvious difference between TwHF monotherapy and methotrexate (MTX) monotherapy on ACR20 (RCT = 2, N = 390, RR = 1.06, 95%CI 0.90-1.26, moderate certainty), ACR50 (RCT = 3, N = 419, RR = 1.03, 95%CI 0.80-1.34, moderate certainty), ACR70 (RCT = 2, N = 390, RR = 1.12, 95%CI 0.69-1.79, low certainty). TwHF monotherapy may be better than salicylazosulfapyridine monotherapy on ACR20 and the effect may be similar on ACR50 and ACR70. Seven RCTs compared MTX combined with TwHF versus MTX monotherapy, and the meta-analysis results favoured combination therapy group on ACR20 (RCT = 3, N = 470, RR = 1.44, 95%CI 1.28-1.62, moderate certainty), ACR50 (RCT = 4, N = 500, RR = 1.88, 95%CI 1.56-2.28, moderate certainty) and ACR70 (RCT = 2, N = 390, RR = 2.12, 95%CI 1.40-3.19, low certainty). We found no obvious difference between groups on critical safety outcomes, including infection (RCT = 3, N = 493, RR = 1.37, 95%CI 0.84-2.23), liver dysfunction (RCT = 5, N = 643, RR = 1.14, 95%CI 0.71-1.85), renal damage (RCT = 3, N = 450, RR = 2.20, 95%CI 0.50-9.72)., Conclusion: Upon full review of the evidence, the guidance panel reached consensus on recommendations for the use of TwHF in people with active RA, either as monotherapy or as combination therapy with MTX., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objective: To account for heterogeneity in systemic lupus erythematosus (SLE) and bridge discrepancies between patient- and physician-perceived SLE activity, we developed the Type 1 and 2 SLE model. We examined PROMIS-29 scores, a composite patient-reported outcome (PRO) measure, through the lens of the model., Methods: Patients completed PROMIS-29 and the polysymptomatic distress scale (PSD). Rheumatologists completed the SLE disease activity index (SLEDAI), and physician's global assessments (PGAs) for Type 1 and 2 SLE. We defined Type 1 SLE using SLEDAI, Type 1 PGA, and active nephritis, and Type 2 SLE using PSD and Type 2 PGA. We compared PROMIS-29 T-scores among Type 1 and 2 SLE groups and explored whether PROMIS-29 can predict Type 1 and 2 SLE activity., Results: Compared to the general population, patients with isolated Type 1 SLE reported greater pain and physical dysfunction but less depression and improved social functions; patients with high Type 2 SLE (irrespective of Type 1 activity) reported high levels of pain, fatigue, and social and physical limitations. Patients with minimal Type 1 and 2 SLE had less depression and greater physical functioning with other domains similar to national norms. PROMIS-29 predicted Type 2 but not Type 1 SLE activity., Conclusion: PROMIS-29 similarities in patients with high Type 2 SLE, with and without active Type 1 SLE, demonstrate the challenges of using PROs to assess SLE inflammation. In conjunction with the Type 1 and 2 SLE model, however, PROMIS-29 identified distinct symptom patterns, suggesting that the model may help clinicians interpret PROs., (© 2023. The Author(s).)

Objective: Manifestations of SLE can be categorised as type 1 (classic signs and symptoms of SLE) or type 2 (fatigue, widespread pain and brain fog with an unclear relationship to inflammation). While measures of type 1 SLE activity exist, most current physician-reported measures do not encompass type 2 SLE manifestations. To better evaluate type 2 SLE symptoms, we developed and psychometrically evaluated a physician-reported measure of type 2 symptoms, the Type 2 Physician Global Assessment ('Type 2 PGA')., Methods and Analysis: The Type 2 PGA was developed and evaluated by six rheumatologists practising in the same academic lupus clinic. The study began with a roundtable discussion to establish consensus guidelines for scoring the Type 2 PGA. Following the roundtable, the Type 2 PGA was psychometrically evaluated using data prospectively collected from 263 patients with SLE enrolled in the Duke Lupus Registry., Results: There was strong intra-rater and inter-rater reliability (intraclass correlation coefficient=0.83), indicating the Type 2 PGA scores were consistent within a rheumatologist and across rheumatologists. The Type 2 PGA was correlated with patient-reported symptoms of polysymptomatic distress (r=0.76), fatigue (r=0.68), cognitive dysfunction (r=0.63), waking unrefreshed (r=0.62) and forgetfulness (r=0.60), and weakly correlated with the Type 1 PGA and the Systemic Lupus Erythematosus Disease Activity Index., Conclusion: The Type 2 PGA performed well as a physician-reported measure of type 2 SLE symptoms. The incorporation of the Type 2 PGA into a routine rheumatology visit may improve patient care by bringing the provider's attention to certain symptoms not well represented in conventional measures of disease activity., Competing Interests: Competing interests: MEBC has received grant support from AstraZeneca, Pfizer, Exagen and Immunovant. JLR has received grant support from Pfizer, Exagen and Immunovant, and consulting fees from Aurinia, Immunovant, Janssen, Eli Lilly, Ampel Biosolutions, GlaxoSmithKline and Amgen. TC has received grant support from Merck and consulting fees from Regenxbio. DSP has received grant support from Immunovant and Exagen, consulting fees from Immunovant and GlaxoSmithKline, and served on a Data Safety Monitor Board for Bristol Myers Squibb. MM has received consulting fees from AstraZeneca. AME has received grant support from Pfizer, Exagen and Immunovant, and consulting fees from Amgen., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

To explore the antibody response to Z-DNA, a DNA conformation with a zig-zag structure, blood of patients with systemic lupus erythematosus (SLE) and otherwise healthy individuals (NHS) were assayed by ELISA using brominated poly(dGdC), a synthetic Z-DNA antigen. These studies showed that SLE patients commonly express antibodies to Z-DNA; NHS also had binding in this assay. In SLE blood, levels of antibodies to Z-DNA were related to those to B-DNA using calf thymus DNA as a source of B-DNA; cross-reactivity was demonstrated by adsorption experiments using DNA cellulose. As shown by dissociation assays, antibody binding of SLE anti-Z-DNA is sensitive to the effects of ionic strength, suggesting electrostatic binding. Since Z-DNA structure can be found in bacterial DNA as well as bacterial biofilms, these findings suggest that, in SLE, anti-DNA antibody responses can result from stimulation by DNA of bacterial origin, with cross-reactivity leading to autoreactivity., Competing Interests: Declaration of Competing Interests DS, ES have none. DSP has received funding from Immunovant and serves on a Data Safety Monitoring Board of BMS. RC has received consulting fees from GSK, BMS, Kyverna and Calabetta; participated on a Data Safety Monitoring Board or Advisory Board for Lupus Research Alliance – Sponsored ACEi Trial in SLE (payment provided to RC) and served on a Scientific Advisory Board for the Lupus Advisory Board (no payment). RC has received payment from Quest Diagnostics for lecture/presentation. IG has received payment from Otsuka for lecture/presentation and has received payment for expert testimony from Vifor Pharma., (Published by Elsevier Inc.)

The rheumatic diseases are a diverse group of conditions that can display autoantibody production, functional immune disturbances and systemic disease manifestations. These autoantibodies can serve as markers for classification, diagnosis, prognosis and disease activity. Among specificities prominently expressed by patients, those directed to nuclear antigens (antinuclear antibodies or ANAs) are markers for specific rheumatic diseases. ANAs can bind to DNA, RNA and complexes of proteins with nucleic acids. Other autoantibodies expressed in the rheumatic diseases are directed to proteins, including IgG, post-translational modifications of proteins and soluble mediators such as cytokines. While autoantibodies have been investigated for over 50 years, recent studies published in the Annals of the Rheumatic Diseases (ARD ) have provided an exciting perspective on the mechanisms of autoantibody production and the power of new technologies to identify novel autoantibody targets to elucidate aetiology and underpin patient evaluation. Furthermore, in-depth serological studies have demonstrated a phenomenon known as clustering; clustering defines sets of autoantibodies that are commonly expressed together in patients with a given rheumatic disease. Other research reported in ARD has used B cell phenotyping and genotypic analysis to subtype patients, and has explored the relationship of autoantibodies, complement activation and patterns of gene expression as exemplified by the interferon gene signature. Together, these studies provide important new insights into disease mechanisms as well as actionable information to facilitate personalised patient care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Source Citation: Smith RM, Jones RB, Specks U, et al; RITAZAREM co-investigators. Rituximab versus azathioprine for maintenance of remission for patients with ANCA-associated vasculitis and relapsing disease: an international randomised controlled trial. Ann Rheum Dis. 2023;82:937-944. 36958796., Competing Interests: Disclosures: The commentator has reported no disclosures of interest. The form can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=J23-0057.

Autoimmune diseases are a diverse group of conditions characterized by aberrant B cell and T cell reactivity to normal constituents of the host. These diseases occur widely and affect individuals of all ages, especially women. Among these diseases, the most prominent immunological manifestation is the production of autoantibodies, which provide valuable biomarkers for diagnosis, classification and disease activity. Although T cells have a key role in pathogenesis, they are technically more difficult to assay. In general, autoimmune disease results from an interplay between a genetic predisposition and environmental factors. Genetic predisposition to autoimmunity is complex and can involve multiple genes that regulate the function of immune cell populations. Less frequently, autoimmunity can result from single-gene mutations that affect key regulatory pathways. Infection seems to be a common trigger for autoimmune disease, although the microbiota can also influence pathogenesis. As shown in seminal studies, patients may express autoantibodies many years before the appearance of clinical or laboratory signs of disease - a period called pre-clinical autoimmunity. Monitoring autoantibody expression in at-risk populations may therefore enable early detection and the initiation of therapy to prevent or attenuate tissue damage. Autoimmunity may not be static, however, and remission can be achieved by some patients treated with current agents., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Extracellular chromatin, for example in the form of neutrophil extracellular traps (NETs), is an important element that propels the pathological progression of a plethora of diseases. DNA drives the interferon system, serves as autoantigen, and forms the extracellular scaffold for proteins of the innate immune system. An insufficient clearance of extruded chromatin after the release of DNA from the nucleus into the extracellular milieu can perform a secret task of moonlighting in immune-inflammatory and occlusive disorders. Here, we discuss (I) the cellular events involved in the extracellular release of chromatin and NET formation, (II) the devastating consequence of a dysregulated NET formation, and (III) the imbalance between NET formation and clearance. We include the role of NET formation in the occlusion of vessels and ducts, in lung disease, in autoimmune diseases, in chronic oral disorders, in cancer, in the formation of adhesions, and in traumatic spinal cord injury. To develop effective therapies, it is of utmost importance to target pathways that cause decondensation of chromatin during exaggerated NET formation and aggregation. Alternatively, therapies that support the clearance of extracellular chromatin are conceivable., (© 2023. The Author(s).)

Systemic lupus erythematosus is a complex, systemic autoimmune disease characterised by immune dysregulation. Pathogenesis is multifactorial, contributing to clinical heterogeneity and posing challenges for diagnosis and treatment. Although strides in treatment options have been made in the past 15 years, with the US Food and Drug Administration approval of belimumab in 2011, there are still many patients who have inadequate responses to therapy. A better understanding of underlying disease mechanisms with a holistic and multiparametric approach is required to improve clinical assessment and treatment. This Review discusses the evolution of genomics, epigenomics, transcriptomics, and proteomics in the study of systemic lupus erythematosus and ways to amalgamate these silos of data with a systems-based approach while also discussing ways to strengthen the overall process. These mechanistic insights will facilitate the discovery of functionally relevant biomarkers to guide rational therapeutic selection to improve patient outcomes., Competing Interests: Declaration of interests AR reports consulting fees from AbbVie, Galapagos, Novartis, and Pfizer, and honoraria for lectures from AbbVie, Alexion, Angelini, Novartis, Reckitt-Benckiser, Pfizer, and Sobi. AM reports consulting fees from AbbVie, Eli Lilly, EMD Serono, Idorsia, Janssen, Novartis, and Pfizer, and has participated on a data safety advisory or monitoring board for EMD Serono and Pfizer. DSP has served on advisory boards for Immunovant and Bristol Myers Squibb, and a data safety advisory board for Bristol Myers Squibb. All other authors declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Source Citation: Devauchelle-Pensec V, Carvajal-Alegria G, Dernis E, et al. Effect of tocilizumab on disease activity in patients with active polymyalgia rheumatica receiving glucocorticoid therapy: a randomized clinical trial. JAMA. 2022;328:1053-62. 36125471.

Objective: Evobrutinib is a highly selective, orally administered Bruton's tyrosine kinase (BTK) inhibitor. The objective of this phase II, multicenter, randomized, double-blind, placebo-controlled trial was to evaluate the efficacy and safety of evobrutinib in patients with active autoantibody-positive systemic lupus erythematosus (SLE)., Methods: Patients were diagnosed with SLE by either the Systemic Lupus International Collaborating Clinics criteria or at least four American College of Rheumatology criteria 6 months or more prior to screening, had an SLE Disease Activity Index-2000 score of 6 or more, were autoantibody-positive and on standard-of-care therapy. Randomization was 1:1:1:1 to oral evobrutinib 25 mg once daily (QD), 75 mg QD, 50 mg twice daily, or placebo. Primary efficacy endpoints were SLE responder index (SRI)-4 response at week 52 and SRI-6 response at week 52 in the high disease activity subpopulation. Safety endpoints included treatment-emergent adverse events (TEAEs)., Results: A total of 469 patients were randomized and received at least one dose of evobrutinib or placebo at the time of primary analysis. Mean (SD) age at baseline was 40.7 (±12.3) years; 94.9% of patients were female. Neither primary efficacy endpoint was met. All doses of evobrutinib were well tolerated, and there was no clear dose effect on the incidence of reported TEAEs, or serious TEAEs, including severe infections., Conclusion: This phase II, dose-ranging trial in SLE failed to show a treatment effect of evobrutinib versus placebo at any dose. Evobrutinib was generally well tolerated, with no dose effect observed for TEAEs. These results suggest that BTK inhibition does not appear to be an effective therapeutic intervention for patients with SLE., (© 2022 The Authors. ACR Open Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)

Nucleic acid-binding polymers can have anti-inflammatory properties and beneficial effects in animal models of infection, trauma, cancer, and autoimmunity. PAMAM G3, a polyamidoamine dendrimer, is fully cationic bearing 32 protonable surface amines. However, while PAMAM G3 treatment leads to improved outcomes for mice infected with influenza, at risk of cancer metastasis, or genetically prone to lupus, its administration can lead to serosal inflammation and elevation of biomarkers of liver and kidney damage. Variants with reduced density of cationic charge through the interspersal of hydroxyl groups were evaluated as potentially better-tolerated alternatives. Notably, the variant PAMAM G3 50:50, similar in size as PAMAM G3 but with half the charge, was not toxic in cell culture, less associated with weight loss or serosal inflammation after parenteral administration, and remained effective in reducing glomerulonephritis in lupus-prone mice. Identification of such modified scavengers should facilitate their development as safe and effective anti-inflammatory agents., Competing Interests: Duke University has applied for patents on the strategy to reduce inflammation via nucleic acid scavengers. Lyra Olson, Nicole Hunter, Rachel Rempel, and Bruce Sullenger are listed as inventors on such patents., (© 2022 The Author(s).)

Objective: We have developed a new conceptual model to characterise the signs and symptoms of SLE: the Type 1 and 2 SLE Model. Within the original model, Type 1 SLE consists of inflammatory manifestations like arthritis, nephritis and rashes; Type 2 SLE includes symptoms of fatigue, myalgia, mood disturbance and cognitive dysfunction. Through in-depth interviews, we explored how the Type 1 and 2 SLE Model fits within the lived experience of patients with SLE, with a focus on the connection between Type 1 and Type 2 SLE symptoms., Methods: Semistructured in-depth interviews were conducted among adult participants meeting 1997 American College of Rheumatology or Systemic Lupus International Collaborating Clinics criteria for SLE. Participants were purposefully selected for age, race, sex and nephritis history. All interviews were audio-recorded and transcribed. Data were analysed through episode profile and thematic analysis., Results: Through interviews with 42 patients with SLE, two patterns of Type 2 SLE emerged: Intermittent (n=18) and Persistent (n=24). Participants with Intermittent Type 2 SLE described feeling generally well when Type 1 is inactive; these participants were younger and had more internal SLE manifestations. Participants with Persistent Type 2 described always experiencing Type 2 symptoms despite inactive Type 1, although the severity may fluctuate. Participants with Persistent Type 2 SLE experienced traditional lupus symptoms of joint pain, hair loss and rash, but less often had severe organ system involvement., Conclusions: By listening to the stories of our patients, we found two underlying patterns of Type 2 SLE: Intermittent Type 2 symptoms that resolve in synchrony with Type 1 inflammatory symptoms, and Persistent Type 2 symptoms that continue despite remission of Type 1 symptoms., Competing Interests: Competing interests: AME reports grant support from Exagen to her institution outside the submitted work. JLR reports grant support from Exagen to her institution outside the submitted work; consulting fees from Eli Lilly, Immunovant and Exagen. AC reports grant support from UCB to her institution outside the submitted work. DSP reports consulting fees from Immunovant and participation on a Data Safety Monitoring Board or Advisory Board for Bristol Myers Squibb. LGC-S reports grant support from GlaxoSmithKline to her institution outside the submitted work; honorarium from Pennsylvania State University and the American College of Rheumatology. JD reports grant support from Pfizer outside the submitted work. MEBC reports grant support from Exagen, UCB and GlaxoSmithKline to her institution outside the submitted work; consulting fees from UCB, AstraZeneca and GlaxoSmithKline outside the submitted work. KM, MM and RES have no relevant competing interests to declare., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: None declared.

Antibodies to DNA (anti-DNA) are the serological hallmark of systemic lupus erythematosus, a prototypic autoimmune disease. These antibodies bind to conserved sites on single-stranded and double-stranded DNA and display variable region somatic mutations consistent with antigen selection. Nevertheless, the interaction of anti-DNA with DNA has unconventional features. Anti-DNA antibodies bind by a mechanism called monogamous bivalency, in which stable interaction requires contact of both Fab sites with determinants on the same extended DNA molecule; the size of this DNA can be hundreds to thousands of bases, especially in solid phase assays. This binding also requires the presence of the Fc portion of IgG, a binding mechanism known as Fc-dependent monogamous bivalency. As shown by the effects of ionic strength in association and dissociation assays, anti-DNA binding is primarily electrostatic. Like anti-DNA autoantibodies, anti-DNA antibodies that bind specifically to non-conserved sites on bacterial DNA, a type of anti-DNA found in otherwise healthy individuals, also interact by monogamous bivalency. The unconventional features of anti-DNA antibodies may reflect the highly charged and polymeric nature of DNA and the need for molecular rearrangements to facilitate monogamous bivalency; the Fc portion contributes to binding in an as yet unknown way.

Objective: We developed a model that categorizes systemic lupus erythematosus (SLE) activity into two dimensions: Type 1 SLE consists of inflammatory activity, including arthritis, nephritis, and rashes; Type 2 SLE includes fatigue, myalgia, mood disturbance, and cognitive dysfunction. Patient-reported outcome (PRO) measures have received attention as a way to capture symptomatology of SLE. The objective of this study was to explore the use of existing PRO measures to classify Type 1 and 2 SLE activity., Methods: Systemic lupus erythematosus patients completed three questionnaires: Systemic Lupus Activity Questionnaire (SLAQ), Polysymptomatic Distress Scale (PSD), and Patient Health Questionnaire (PHQ-2). SLE Disease Activity Index (SLEDAI) and physician global assessments (PGA; 0-3) for Type 1 and Type 2 activity were also recorded. High Type 1 SLE activity was defined as cSLEDAI ≥4 (scored without labs), SLEDAI ≥6, active nephritis, or Type 1 PGA ≥1.0. High Type 2 SLE activity was defined as Type 2 PGA ≥1.0. Patients with both high Type 1 and 2 activity were defined as Mixed SLE, and patients with low Type 1 and 2 activity were defined as Minimal SLE. Data were reduced with a factor analysis. Using a reduced set of 13 variables, multinomial logistic regression models estimated the probability of Minimal, Type 1, Type 2, and Mixed SLE classification., Results: The study included 208 patients with SLE. The model accurately predicted the clinician-based Type 1 and 2 SLE classification in 63% of patients; 73% of patients had their Type 1 SLE activity accurately predicted; and 83% had their Type 2 SLE activity accurately predicted. Performance varied by group: 87% of Minimal patients were correctly predicted to be in the Minimal SLE group, yet only about one-third of patients in the Type 1 group were correctly predicted to be in the Type 1 group., Conclusions: Our findings indicate Type 2 SLE activity can be identified by patient-reported data. The use of PROs was not as accurate at predicting Type 1 activity. These findings highlight the challenges of using PROs to categorize and classify SLE symptoms since some manifestations of Type 1 activity (e.g., nephritis) may be essentially clinically silent while other Type 1 manifestations may cause severe symptoms.

Objectives: The goals of these studies were to elucidate the inter-relationships of specific anti-nuclear antibody (ANA), complement, and the interferon gene signature (IGS) in the pathogenesis of systemic lupus erythematosus (SLE)., Methods: Data from the Illuminate trials were analysed for antibodies to dsDNA as well as RNA-binding proteins (RBP), levels of C3, C4 and various IGS. Statistical hypothesis testing, linear regression analyses and classification and regression trees analysis were employed to assess relationships between the laboratory features of SLE., Results: Inter-relationships of ANAs, complement and the IGS differed between patients of African Ancestry (AA) and European Ancestry (EA); anti-RNP and multiple autoantibodies were more common in AA patients and, although both related to the presence of the IGS, relationships between autoantibodies and complement differed. Whereas, anti-dsDNA had an inverse relationship to C3 and C4, levels of anti-RNP were not related to these markers. The IGS was only correlated with anti-dsDNA in EA SLE and complement was more correlated to the IGS in AA SLE. Finally, autoantibodies occurred in the presence and absence of the IGS, whereas the IGS was infrequent in anti-dsDNA/anti-RBP-negative SLE patients., Conclusion: There is a complex relationship between autoantibodies and the IGS, with anti-RNP associated in AA and both anti-dsDNA and RNP associated in EA. Moreover, there was a difference in the relationship between anti-dsDNA, but not anti-RBP, with complement levels. The lack of a relationship of anti-RNP with C3 and C4 suggests that anti-RNP immune complexes (ICs) may drive the IGS without complement fixation, whereas anti-dsDNA ICs involve complement consumption., Competing Interests: Competing interests: The authors have no competing interests to disclose. ELH and PEL are salaried employees of AMPEL BioSolutions, LLC., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To perform an exploratory study to identify a JDM serum metabolic profile that differs from healthy controls (HCs) and responds to immunosuppressive treatment., Methods: Blood was collected from 9 HCs and 10 patients diagnosed with probable (n = 4) or definite (n = 6) JDM based on the criteria of Bohan and Peter for myositis, with 7 of the 10 providing longitudinal samples following initiation of treatment; these patients comprised the treatment-naïve cohort. Sera underwent mass spectroscopy-based measurements of targeted metabolic intermediates, including 15 amino acids, 45 acylcarnitines (ACs), 15 ceramides and 29 sphingomyelins. Principal components analysis reduced metabolites into smaller sets of factors each comprised of correlated metabolic intermediates. Factor scores and metabolite concentrations were compared with HCs using two-sample t-tests while treatment effects were evaluated using paired t-tests., Results: Of eight principal components analysis-derived metabolite factors (one AC, two amino acids, three sphingosine and two ceramide), two were significantly associated with JDM: one AC factor containing mostly long-chain ACs (P = 0.049) and one ceramide factor (P < 0.01). For 12 individual ACs, mostly long chain, and three ceramides, concentrations were significantly greater for JDM than HCs. Factors based on these individual metabolites showed decreasing scores with treatment (P = 0.03 and P < 0.01, respectively)., Conclusion: While additional validation is needed, these lipids have potential as JDM serum diagnostic and/or treatment biomarkers. Additionally, the significant association of long-chain ACs and ceramides with JDM offers insights regarding pathogenesis, implicating dysregulation of mitochondrial fatty acid β-oxidation., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Abs to DNA (anti-DNA) are a unique population of Abs that bind structural determinants on the DNA molecule. In systemic lupus erythematosus (SLE), anti-DNA Abs bind to conserved antigenic determinants, with the phosphodiester backbone being the most likely. In contrast, otherwise healthy subjects (HS) express anti-DNA that bind selectively to nonconserved sites on certain bacterial and viral DNA. As shown previously, SLE anti-DNA bind by a mechanism termed Fc-dependent monogamous bivalency. In this mechanism, both Fab sites interact with determinants on the same extended DNA molecule, reflecting the low affinity of each Fab site; the requirement for the Fc region suggests some contribution of the C region to increase avidity. In this study, we investigated whether anti-DNA from HS also bind to bacterial DNA by Fc-dependent monogamous bivalency. For this purpose, we compared the activity of intact IgG with Fab and F(ab') 2 fragments prepared from the plasmas of SLE patients and HS using ELISAs with DNA from calf thymus or Micrococcus luteus These studies showed that Fab fragments from all plasmas tested, both SLE and HS, failed to bind significantly to DNA compared with intact IgG. By contrast, some, but not all, F(ab') 2 preparations from both SLE patients and HS showed binding to M. luteus DNA; F(ab') 2 fragments from SLE plasmas, however, did not bind significantly to calf thymus DNA. Together, these findings suggest that although anti-DNA Abs, whether from SLE or HS, bind by monogamous bivalency, binding to bacterial DNA does not require the Fc region., (Copyright © 2021 The Authors.)

Antibodies to DNA (anti-DNA) are the serological hallmark of systemic lupus erythematosus. Previous studies have indicated that the phosphodiester backbone is the main antigenic target, with electrostatic interactions important for high avidity. To define further these interactions, the effects of ionic strength on anti-DNA binding of SLE plasmas were assessed in association and dissociation assays by ELISA. As these studies demonstrated, increasing ionic strength to a concentration of 1000 mM NaCl reduced antibody binding although the extent of the reduction varied among samples. In dissociation assays, differences among plasmas were also observed. For one of the plasmas, binding to DNA displayed resistance to dissociation by increasing ionic strength even though these concentrations limited binding in association assays. Time course studies showed a gradual change in binding interactions. These studies indicate that anti-DNA binding can involve both electrostatic and non-electrostatic interactions, with binding in some plasmas showing evidence of hysteresis., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Source Citation: Yang W, Sun C, He SQ, et al. The efficacy and safety of disease-modifying osteoarthritis drugs for knee and hip osteoarthritis-a systematic review and network meta-analysis. J Gen Intern Med. 2021;36:2085-93. 33846938.

DNA is a polymeric macromolecule that can display a variety of backbone conformations. While the classical B-DNA is a right-handed double helix, Z-DNA is a left-handed helix with a zig-zag orientation. The Z conformation depends upon the base sequence, base modification and supercoiling and is considered to be transient. To determine whether the presence of Z-DNA can be detected immunochemically, the binding of monoclonal and polyclonal anti-Z-DNA antibodies to a panel of natural DNA antigens was assessed by an ELISA using brominated poly(dG-dC) as a control for Z-DNA. As these studies showed, among natural DNA tested ( Micrococcus luteus, calf thymus, Escherichia coli , salmon sperm, lambda phage), micrococcal (MC) DNA showed the highest binding with both anti-Z-DNA preparations, and E. coli DNA showed binding with the monoclonal anti-DNA preparation. The specificity for Z-DNA conformation in MC DNA was demonstrated by an inhibition binding assay. An algorithm to identify propensity to form Z-DNA indicated that DNA from Mycobacterium tuberculosis could form Z-DNA, a prediction confirmed by immunoassay. Together, these findings indicate that anti-Z-DNA antibodies can serve as probes for the presence of Z-DNA in DNA of various species origin and that the content of Z-DNA varies significantly among DNA sources.

Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.