The Lancet Rheumatology

BackgroundJuvenile idiopathic arthritis (JIA) shows recognised sex differences, but their impact on treatment and early outcomes remains uncertain. This study assesses sex-specific patterns in onset, phenotype, treatment timing, and short- and medium-term outcomes in JIA. MethodsData were drawn from the Childhood Arthritis Prospective Study (CAPS), a UK multicentre inception cohort of 1,789 children presenting with a new episode of arthritis. Demographics, subtype distribution, clinical features, and 6- and 12-month outcomes were stratified by sex. Cox, Kaplan-Meier, and linear regression models assessed associations between sex and treatment initiation and 12-month outcomes. ResultsThe cohort was predominantly female (64.3%), with a median age at symptom onset of 6.8 years. Girls were younger than boys at onset (6.1 vs 7.8 years, p<0.0001) and diagnosis (7.0 vs 9.1 years, p<0.0001) and demonstrated a distinct bimodal age distribution. Diagnostic delay was short and comparable (median 4.4 months, p=0.8932). At diagnosis, girls had slightly higher active joint counts (p=0.0080, while inflammatory markers were similar except in psoriatic JIA, where females had higher ESR and CRP. After adjustment, sex was not associated with time to methotrexate (HR 0.89, 95% CI 0.74-1.06) or biologic initiation (HR 0.91, 95% CI 0.72-1.16). Outcomes at 6- and 12-month were largely comparable, with only ESR showing a modest male-favoured improvement at 12 months (p=0.0480). ConclusionsSex shaped age at onset and subtype distribution but did not independently influence treatment timing or early outcomes, underscoring the value of sex-aware analyses while confirming broadly comparable short-term trajectories in JIA. Evidence before this studyRecent evidence on sex effects in JIA is genuinely mixed: several cohorts have reported that girls, despite more severe onset, show greater resolution of objective inflammation, while a newer, large network analysis found females had poorer outcomes across composite disease activity and pain, pointing to potential inequities or phenotype-driven differences. In parallel, boys, especially in enthesitis-related arthritis (ERA), often exhibit more persistent activity and risk of damage. Overall, the picture is controversial: sex appears to shape biology, trajectory, and patient-reported burden in different ways across subtypes and settings, reinforcing the need for sex-stratified analyses, careful adjustment for confounders, and precision approaches that integrate biomarkers, subtype, and social context in JIA care. Added value of this studyThe study establishes that, although sex is closely linked to JIA subtype distribution and baseline clinical features, it does not independently determine the timing of methotrexate or biologic initiation within a UK inception cohort. By analysing one of Europes largest prospective multicentre datasets, it provides strong evidence that treatment decisions appear to be guided by disease characteristics rather than demographic bias. Within the context of the UK National Health Service (NHS), where universal access to paediatric rheumatology care is a core principle, this study provides important epidemiological evidence on sex and equity in JIA. Although clear sex differences were observed in age at onset, subtype distribution, and certain diagnostic features, these did not translate into disparities in treatment timing or medium-term disease burden. The absence of sex-based differences in 6 and 12-month outcomes, despite variation in baseline presentation, suggests that the NHS model of coordinated, guideline-driven care may help buffer against inequities that might otherwise emerge in systems with variable access. These findings reinforce the value of population-based cohorts in evaluating equity within healthcare delivery and highlight that, in this setting, sex does not appear to drive differential treatment or short-term clinical trajectories. Implications of all the available evidence.This study underscores sex as an important biological variable in JIA. Although treatment initiation was equitable and disease-driven, baseline phenotype differences and isolated effects on 12-month outcomes highlight how sex interacts with JIA subtype and initial disease burden. Prior work shows that females often present earlier with higher inflammatory burden, while males are more frequently affected by ERA, a subtype linked to treatment resistance and poorer long-term outcomes. Yet published findings remain inconsistent, with some cohorts reporting better resolution of inflammation in females and others suggesting poorer outcomes. Our findings suggest that coordinated and guideline-driven care may minimise sex-related disparities in JIA, even when underlying biological or phenotypic differences exist. The comparable medium-term trajectories observed across sexes support equitable paediatric rheumatology care in the UK and highlight the need to continue monitoring for structural or access-related inequities beyond clinical measures.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that causes joint destruction along with extra-articular morbidity and early mortality. Abatacept (CTLA-4 Ig), a blocker of lymphocyte co-stimulation, has become a well-accepted biologic treatment with proven efficacy in established-RA and for preventing disease onset in predisposed individuals. To investigate the immunologic implications of abatacept treatment, we conducted a prospective, open-label trial with multi-omic single-cell analyses of lymphocytes and BCR repertoire profiling at predefined intervals. Treatment-induced low-disease activity correlated with coordinated depletion of circulating peripheral helper cells (Tph), late-activated naive cells (late-aNAV), and of CD27-IgD- (Double negative, DN) Zeb2+CD11c+ T-box transcription factor 21 (Tbet+) DN2 unconventional memory B cells, implicated in the tertiary lymphoid structures responsible for the propagation of pathologic autoimmune responses and joint destruction. Among B-cell subsets, DN2 had the greatest representation of molecular machinery for antigen-uptake, processing, and presentation. Among memory B-cell subsets, DN2 had the lowest representation of somatically generated N-glycosylation sites and somatic hypermutation. Yet abatacept induced DN2 cells to express elevated CXCR4 levels, which normalized upon drug withdrawal, suggesting that abatacept treatment may cause these cells to traffic out of pathologic synovial infiltrates. In conclusion, we have documented that abatacept affects the circulating immune cellular drivers of disease activity, Tph, late-aNAV and DN2. Therapeutic depletion of these pathologic lymphocyte subsets is associated with clinical benefits that can persist after therapy cessation. Hence, levels of these subsets may serve as surrogates for the overall burden of disease and potential response to abatacept therapy. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=62 SRC="FIGDIR/small/26348386v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@b44131org.highwire.dtl.DTLVardef@241f4eorg.highwire.dtl.DTLVardef@18361f6org.highwire.dtl.DTLVardef@9470b7_HPS_FORMAT_FIGEXP M_FIG C_FIG One Sentence SummaryMulti-omics analyses showed costimulatory blockade depletes trafficking DN2 B cells and Tph cells that correlates with rheumatoid disease response.

BackgroundMonogenic diseases are considered rare, yet many remain underdiagnosed when clinical manifestations are heterogeneous. A20 haploinsufficiency (HA20) is an early-onset inborn error of immunity (IEI) caused by heterozygous germline TNFAIP3 variants, resulting in dysregulated inflammatory signaling and diverse immune phenotypes. MethodsWe analyzed variants in all human haploinsufficiency disease genes in gnomAD v4, applying refined loss-of-function predictors to estimate population frequencies. We assessed rare TNFAIP3 variants (allele frequency <0.01%) in All of Us (AoU), UK Biobank (UKBB), and gnomAD. Variants were classified as predicted loss-of-function (pLOF) or high predicted pathogenic missense (HPPM). Clinical associations were tested through phenome-wide association studies (PheWAS) and validated in a University of Pittsburgh referral cohort. FindingsHigh-confidence deleterious variants in human haploinsufficiency disease genes, including IEI haploinsufficiency genes, occur frequently at the population level despite strong constraint. Across datasets, TNFAIP3 pLOF variants corresponded to estimated prevalences of [~]1:14,400 (U.S.) and [~]1:23,700 (global); combined pLOF + HPPM prevalences were [~]1:2,800 (U.S.) and [~]1:4,900 (global). PheWAS linked rare TNFAIP3 variants to immune phenotypes with large effect sizes. In a referral cohort (18 patients, 9 families), missense variants conferred hypomorphism with intermediate immunophenotypes. InterpretationDeleterious TNFAIP3 variants are over 100-fold more common than reported cases suggest and are associated with immune dysregulation spanning variable expressivity and severity. These findings establish proof-of-concept that haploinsufficiency diseases may be pervasively underrecognized. Patients with early-onset or treatment-refractory autoimmune disease should be considered for genetic testing, as precision therapies are available and commercial panels already incorporate TNFAIP3. FundingThis work was supported by NIAID (T32-AI074490, T32-GM144300), the Jeffrey Modell Foundation, Rheumatology Research Foundation, Samuel and Emma Winters Foundation, University of Pittsburgh Competitive Medicine Research Fund, Sobi, and Eli Lilly. Research in Context Evidence before this studyPrior database analyses estimated that pathogenic variants in constrained haploinsufficiency genes may occur more frequently than case reports suggest, but these observations have not been validated clinically or for specific genetic diseases. Haploinsufficiency of A20 (HA20) is a monogenic immune disorder caused by deleterious variants in TNFAIP3, with fewer than 200 cases reported worldwide. Previous studies characterized clinical phenotypes and treatment responses but did not systematically assess population-level prevalence. Added value of this studyThis is the first study to establish that a monogenic immune disease is substantially underrecognized at the population level. We first show that predicted deleterious variants in haploinsufficiency disease genes, including inborn errors of immunity, occur at unexpectedly high frequencies in population databases. We then demonstrate that predicted and functionally validated deleterious TNFAIP3 variants occur at over 100-fold higher frequencies than reported case numbers suggest. We further validate this through phenome-wide association studies showing that variant carriers have significantly elevated rates of immunologic disease, and through deep phenotyping of a referral cohort. Implications of all the available evidenceThese findings indicate that HA20, and likely other haploinsufficiency diseases, represent a substantial burden of undiagnosed monogenic disease. Clinicians evaluating patients with early-onset or treatment-refractory autoimmune and autoinflammatory conditions should consider genetic testing for inborn errors of immunity including HA20. The high prevalence of pathogenic variants, combined with the availability of targeted therapies, underscores the clinical urgency of improved recognition and diagnosis.

Autoimmune diseases result from immune responses against self-antigens but exhibit marked phenotypic diversity shaped by genetic and environmental factors. Genome-wide association studies (GWAS) have identified susceptibility loci that inform polygenic scores (PGS) for risk prediction. This study integrates phenotypic and genetic data from the UK Biobank(UKB) to characterize disease overlap, genetic heterogeneity, and shared biological mechanisms across autoimmune conditions. Comorbidity patterns were further assessed using patient records from UKB and the TriNetX(TNX). Phenotypic data from 502,371 UKB participants were used to evaluate diagnostic overlap, with a subset of 104,544 individuals analyzed for PGS distributions. Significant variants were identified using genome-wide thresholds, allele frequency, and predicted impact, and shared genes were subsequently mapped to pathways using Hallmark gene sets. Comorbidity across rare and common autoimmune diseases was assessed in the UKB and TNX using ICD-10 codes, focusing on White individuals (71,069,654 in TNX; 502,371 in UKB). Odds ratios for 15 diseases were estimated, and cross-cohort comparisons evaluated reproducibility and cohort-specific differences. PGS analyses revealed both shared and distinct genetic architectures, indicating partial genetic overlap and supporting poly-autoimmunity. Integration of common, rare and impactful variants identified both known and novel gene associations, while pathway analysis highlighted systemic and tissue-specific immune dysregulation. Cross-dataset comparisons confirmed consistent comorbidity patterns but underscored the impact of dataset-specific factors, emphasizing the need for standardized approaches in autoimmune disease research.

BackgroundDespite advances in therapy, optimal management of juvenile idiopathic arthritis (JIA) remains challenging. The ability to predict disease progression in JIA can improve personalized treatment decisions, but few reliable clinical predictors have been identified. We developed machine learning approaches to predict disease trajectories in children with JIA. MethodsUsing data from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry (years 2015-2024), we developed machine learning models to predict attainment of inactive disease in children with non-systemic JIA. We applied Dynamic Bayesian Networks (DBN) to model temporal dependencies and causal relationships, and Convolutional Neural Networks (CNN) to capture complex non-linear patterns. Model input included demographic factors, longitudinal clinical factors, and medication use in the preceding 12 months. FindingsA total of 8,093 participants were included. When tested on an independent test cohort, both DBN (AUC:0.76; precision:0.73; recall:0.83; F1-score:0.78; accuracy:0.71) and CNN (AUC:0.76; precision:0.71; recall:0.63; F1-score:0.67; accuracy:0.70) models achieved comparable performance in predicting inactive disease. Disease activity levels in the preceding 12 months, presence of enthesitis and uveitis were the strongest predictors. Causal relationships captured in the DBN model revealed suboptimal care patterns, likely shaped by insurance constraints and a predominantly reactive approach to JIA management. InterpretationOur study demonstrates that machine learning approaches can predict disease trajectories in JIA with good discriminative performance. Unlike prior studies that predict outcomes at single timepoints, our models are the first to predict inactive disease longitudinally. However, suboptimal care patterns in retrospective data limit models capacity to learn treatment-outcome relationships, underscoring critical opportunities to improve JIA care and the need for prospective comparative studies to better inform prediction models. FundingPatient-Centered Outcomes Research Institute (PCORI) Award (ME-2022C2-25573-IC). RESEARCH IN CONTEXT Evidence before this studyNumerous studies have sought to identify clinical predictors of JIA progression and outcomes. However, few reliable predictors have emerged and existing prediction models demonstrate limited performance. As a result, our ability to personalize treatment decisions based on individual risk of severe disease course remains limited. Added value of this studyWe developed novel machine learning models that predict individualized disease trajectories in children with polyarticular and oligoarticular JIA using data from their preceding 12-month clinical course. These models demonstrated strong discriminative performance and outperformed previously published machine learning approaches in JIA. Unlike prior studies limited to single time-point predictions, our models are the first to predict inactive disease longitudinally, enabling a patient-specific projection of disease progression over time. Importantly, our findings also bright to light patterns of suboptimal care, likely driven by insurance constraints and a reactive treatment paradigm, underscoring critical opportunities to improve JIA management. Implications of all the available evidenceOur models have the potential to support clinical decision-making by enabling early identification of children with JIA at risk for unfavorable disease trajectories. In addition, the suboptimal care patterns and systems-level barriers identified through our analyses highlight priority areas for quality improvement initiatives and policy interventions to reduce gaps in JIA care delivery.

Background. Polypharmacy is common in autoimmune rheumatic diseases (ARDs) and increases adverse drug events (ADEs), but comparative evidence across diseases is limited. We aimed to quantify ADE burden and identify medications associated with ADE risk across six ARDs, and to examine shared and disease specific patterns across diseases. Methods. We conducted a retrospective cohort study at a tertiary medical center (2010 to 2024). Adults with ankylosing spondylitis (AS), psoriatic arthritis (PsA), rheumatoid arthritis (RA), Sjogren's disease (SjD), systemic lupus erythematosus (SLE), or systemic sclerosis (SSc) were identified using diagnostic codes. ADEs were ascertained using validated case definitions. Medications were mapped to Anatomical Therapeutic Chemical classes; active exposure was defined within 30 days before the index date. Polypharmacy was defined as more than 5 concurrent medications (minor 5 to 10; major >10). Within each ARD, nested case control analyses matched on encounter type (1:4) were performed, and adjusted odds ratios (aORs) were estimated using conditional logistic regression. Findings. Among 10,578 patients, 3,154 (29.8%) experienced at least one ADE. ADE burden varied across diseases, with the highest prevalence observed in SSc (35.9%). Polypharmacy was common (57.3% minor, 39.4% major) and medication burden was consistently higher in ADE cases across encounter types (eg, SLE outpatient median 12 vs 6; inpatient 20 vs 10; emergency 17 vs 8). Across ARDs, the strongest associations with ADEs were observed for supportive and symptom directed therapies (acid suppressors, pain adjuncts, and sedative hypnotic/psychotropic medications), whereas conventional disease-modifying antirheumatic drugs (DMARDs) showed weaker associations. Disease-specific signatures included gastrointestinal agents in SSc (metoclopramide aOR 12.32), antibiotics and respiratory agents in AS (ciprofloxacin aOR 13.71, fluticasone aOR 8.88). Interpretation ADEs affect nearly one third of ARD patients and increase with medication burden. Risk concentrates in supportive and symptom directed therapies rather than DMARDs, with both shared and disease-specific patterns. Optimizing prescribing, particularly for pain management and corticosteroid use, can reduce medication-related harm.

Background: Rheumatoid arthritis (RA) has a preclinical period characterised by elevations in serum autoantibodies. Identifying the timing and magnitude of autoantibody trajectory changes may inform screening strategies and preventative interventions. Methods: Using a Bayesian multivariate segmented regression, we jointly modelled longitudinal autoantibody trajectories from two Department of Defense Serum Repository cohorts (Sample A: 209 matched case-control pairs, 1566 samples, six biomarkers; Sample B: 309 cases with two matched controls each, 2758 samples, eight biomarkers). Change-points and magnitudes of change were estimated simultaneously under a multivariate likelihood with an unstructured residual correlation matrix. Results: In Sample A, five of six biomarkers exhibited pre-diagnostic trajectory shifts with 95% highest posterior density intervals excluding zero. RF-IgM demonstrated the earliest change-point at 8.10 years before diagnosis (95% HPDI: -10.47, -5.73), followed by ACPA-IgG at 7.43 years (95% HPDI: -9.33, -5.76). In Sample B, only the four IgG isotypes showed pre-diagnostic shifts, with anti-CCP3 (IgG) earliest at 7.00 years (95% HPDI: -8.48, -5.29). A composite metric integrating timing and magnitude reordered rankings. Conclusions: This Bayesian framework enables simultaneous estimation of change-points and magnitudes across correlated autoantibodies while fully characterising uncertainty, offering a complementary approach to prior divergence-based methods for understanding preclinical RA autoimmunity.

Background Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease which can lead to progressive disability and damage to multiple organs. Obesity is associated with higher disease activity in RA and inadequate long-term outcomes, so better understanding of mechanisms linking adiposity to immune dysregulation might help to refine optimal treatments. Monocytes are important contributors to immune activation in RA through antigen presentation and costimulatory signaling. We hypothesized that adiposity enhances monocyte costimulatory programming in RA, thereby promoting adaptive immune activation. Methods Single-cell RNA sequencing was performed using the 10x Genomics Flex platform on purified circulating monocytes from 31 donors (16 RA participants fulfilling 2010 ACR/EULAR classification criteria and 15 non-RA controls) generating transcriptomic profiles for approximately 135,599 monocytes. Donor-level pathway enrichment scores were calculated for predefined immune activation pathways including antigen processing and presentation, interferon signaling, and regulation of T-cell costimulation. Analyses were performed at the donor level to avoid cell-level pseudoreplication. Associations with disease status and body mass index were evaluated using factorial linear models and Spearman correlation analyses. Results Single-cell transcriptomic profiling identified classical, intermediate-like, non-classical, and interferon-responsive monocyte populations. RA was associated with enrichment of antigen processing and presentation programs in circulating monocytes (p=0.0106), indicating a primed antigen-presenting state. In contrast, regulation of T-cell costimulation pathway enrichment did not differ by RA status alone. However, within RA participants, higher BMI was associated with increased enrichment of monocyte T-cell costimulatory pathways (Spearman {rho}=0.56, p=0.0248), unlike in non-RA controls. Gene-level analyses demonstrated strong baseline expression of CD86, while ICOSLG and TNFSF4 transcripts were expressed at low levels overall, consistent with inducible costimulatory signaling programs. Conclusions These findings support a model in which metabolic dysregulation amplifies monocyte-mediated immune activation and may contribute to worsened disease outcomes in RA.

Rheumatoid arthritis is a prototypical autoimmune disease, characterised by prolonged systemic autoimmunity prior to organ-specific tissue inflammation. To achieve the contemporary goal of autoimmune disease prevention, a nuanced understanding of the transition from systemic autoimmunity to tissue-specific inflammation is critical. Here, we sought to identify immune signatures associated with the transition to subclinical joint inflammation detected by multi-joint ultrasound in anti-citrullinated protein antibodies (ACPA+)-positive individuals who imminently progress to RA. To achieve this, we performed single-cell transcriptomic and proteomic profiling on prospectively collected blood samples from high-risk ACPA+ imminent progressors, who were further stratified by the presence or absence of ultrasound (US)-detectable subclinical synovitis and compared them with ACPA+ non-progressors. We found type-1 interferon (IFN-I) activation in circulating CD14+ classical monocyte and GZMK+ CD8+ T cells preceding subclinical joint inflammation in ultrasound-negative (USneg) future progressors. In contrast, US-positive (USpos) future progressors exhibited a phenotypic shift in CD14+ classical monocytes towards IL1B+ expression and clonal expansion of GZMB+ cytotoxic CD8+ T cells at the onset of subclinical synovitis. Plasma proteomics also revealed a shift from Toll-like receptor-associated innate pathways in USneg future progressors toward effector and tissue-remodeling signatures in USpos future progressors. These findings suggest IFN-I-driven immune priming in specific immune subsets precedes the onset of subclinical joint inflammation, whereas tissue-directed inflammatory and cytotoxic programmes emerge at the onset of joint inflammation when clinical RA is imminent.

Background: immune dysregulation underlies cardiovascular risk excess in systemic autoimmune diseases, such as rheumatoid arthritis (RA) and Sjogren disease (SjD). However, exact mediators are unknown. Regulatory autoantibodies targeting G protein coupled receptors, including CXCR3, have emerged as modulators of immune and vascular homeostasis, but their role in autoimmunity remains ill defined. Our aim was to evaluate antiCXCR3 levels in systemic autoimmunity and their potential value as biomarkers. Methods: antiCXCR3 IgG serum levels were quantified in early RA (n=84), clinically suspect arthralgia (n=12), and controls (n=65). Established RA (n=103) and SjD (n=44) were recruited for validation. Atherosclerosis was assessed by carotid ultrasound. Cytokines were measured by multiplex immunoassays. Cardiometabolic related proteins were evaluated using high-throughput targeted proteomics. Publicly available datasets were used for validation. Results: antiCXCR3 antibodies were significantly reduced in early RA and arthralgia compared with controls, independently of disease activity, autoantibodies, or systemic inflammation. This finding was confirmed in validation cohorts. AntiCXCR3 were negatively associated with good therapeutic outcomes upon csDMARD at 6 and 12 months. Lower anti-CXCR3 levels were independently associated with atherosclerosis occurrence and extent across conditions. Incorporating antiCXCR3 into mSCORE improved risk stratification. AntiCXCR3 were related to proteomic signatures linked to immune activation and to apoptosis, chemotaxis, and cell adhesion in an atherosclerosis dependent manner. Transcriptomic analyses indicated compartment specific CXCR3 dysregulation. Conclusion: reduced antiCXCR3 antibodies represent a shared hallmark bridging systemic autoimmunity and atherosclerosis burden, shaping our understanding on the regulatory role of antibodies at the vascular immune interface. Clinical translation of anti-CXCR3 antibodies hold promise to improve risk stratification.

Introductory ParagraphRheumatoid arthritis (RA) is a heritable and common autoimmune condition. To date, most genetic associations were derived from individuals with either European or East Asian ancestries. Here, we applied a multimodal automated phenotyping strategy to define RA and performed a genome-wide association study (GWAS) of RA in the Million Veteran Program (MVP), including underrepresented African American (AFR) and Admixed American (AMR) populations. Meta-analyses with previous RA cohorts identified 152 autosomal genome-wide significant loci, of which 31 were novel. Inclusion of multi-ancestry data dramatically improved fine-mapping resolution. Functional characterization of these loci using single-cell transcriptomic and chromatin data suggested new RA genes such as CHD7 and CD247. We identified underappreciated functional roles of fine-grained immune cell states other than T cells, such as B cell and myeloid cell states. We observed that multi-ancestry polygenic risk scores using our data demonstrated better predictive ability, especially for AFR and AMR populations.

Patients with myasthenia gravis (MG) may produce autoantibodies neutralizing type I interferons (AAN-I-IFN), which have been shown to underlie severe viral diseases, including critical COVID-19 pneumonia, in patients without MG. We studied an international cohort of 85 unvaccinated SARS-CoV-2-infected MG patients with no antiviral treatment. Hypoxemic pneumonia occurred in 48 of these patients, including 22 (45.8%) with AAN-I-IFN, which neutralized both IFN-2 and IFN-{omega} in 14 (29.2%) patients. Six (16.2%) of the remaining 37 patients had AAN-I-IFN, which neutralized both IFN-2 and IFN-{omega} in three patients. The risk of hypoxemic pneumonia was greater in MG patients with AAN-I-IFN neutralizing 10 ng/mL of both IFN-2 and IFN-{omega} (odds ratio and 95% confidence interval (OR [95% CI]): 12.7 [2.1-78.9], p=0. 0010) or IFN-2 at any dose (4.7 [1.5-15.0], p=0.0054) than in those without such autoantibodies. The risk of AAN-I-IFN production was much higher in MG patients than in the general population (28.9 [10.8-77.7], p=4.9x10-27). Fourteen patients had thymoma, which increased the risk of AAN-I-IFN (64% versus 27%, (OR [95% CI]: 5.6 [1.6-19.4], p=0.0050) and hypoxemic pneumonia (9.2 [1.9-44.2]; p=0.0019). Thymoma is, thus, associated with a higher risk of producing AAN-I-IFN, and these autoantibodies are associated with a higher risk of developing life-threatening COVID-19 pneumonia in patients with MG.

Objectives: Juvenile systemic lupus erythematosus (JSLE) and juvenile dermatomyositis (JDM) are systemic autoimmune rheumatic diseases (RMDs) with childhood-onset associated with increased risk of damage accumulation and cardiovascular disease (CVD) over the life course. Methods: Damage associated with JSLE and JDM has been assessed using validated outcome measures in a longitudinal single-centre cohort study with long-term follow-up, involving data collected both retrospectively and prospectively. Descriptive statistics, sensitivity and regression analyses have been used to evaluate predictors of damage and CVD-risk. Results: We assessed comparatively a JSLE cohort (n=76), with a mean age of 24.3 +/- 4.2 years and a JDM cohort (n=79) with a mean 20.1 +/-5.0 years (p<0.001), with matched duration of follow-up (10.0 +/- 4.2 vs. 11.0 +/- 5.1, respectively, p=0.68). Traditional CVD-risk factors, including hypertension (p=0.02), dyslipidaemia (p=0.0005), and higher total cholesterol (p=0.01) and LDL-cholesterol (p=0.02) levels at the last assessment were higher in JSLE vs. JDM. Over the disease course, 39 (51.3%) AYA with JSLE vs. 47 (59.4%) AYA with JDM accumulated damage (p=0.307), which was independently predicted by the body mass index in both cohorts (p=0.038 and p=0.026, respectively). The PDAY score was the only tool able to stratify AYA based on CVD-risk (median = 5 (4-13) points in JSLE vs. 0 (0-3) points in JDM, p=0.0001), as all the adult CVD-risk scores were very low in both cohorts. Conclusions: This is the first comparative evaluation of JSLE vs. JDM in adulthood, which highlighted increased damage burden and CVD-risk in JSLE that warrants further investigation.

ObjectivesPatients with osteoarthritis (OA) affecting multiple joints have poorer health outcomes than those without, yet most research examines isolated joints, leaving a gap in multi-joint disease. This study aimed to describe radiographically defined hip (rHOA) and knee OA (rKOA) within UK Biobank (UKB), exploring interrelationships across joints, and associations with joint pain, obesity, race and deprivation. MethodsAutomated machine learning was applied to left and right hip and knee dual-energy X-ray absorptiometry scans. Radiographic OA (rOA) was defined as custom grades [&ge;]2. Joint pain was assessed through self-reported questionnaires. Descriptive statistics summarised the population characteristics. Logistic regression models examined bilateral and cross-joint associations, as well as associations with joint pain. Adjustments were made for age, sex, race, height, weight and deprivation. Other models examined the associations between body size and OA. ResultsAmong 59,475 individuals (mean age 65 years; 52.8% female), rHOA prevalence was 4,098 (6.9%)) and 4,841 (8.1%) for the right and left joints, respectively. The corresponding estimates for rKOA were 3,750 (6.3%) and 4,220 (7.1%). Overall, increasing grades of rOA and number of joints affected were more strongly associated with joint pain. Regarding joint-interrelationships, bilateral associations were stronger at the knee, whereas cross-joint associations (hip-knee) were weaker. Associations with BMI and height differed between the hip and knee. ConclusionsRadiographic hip and knee OA exhibit distinct patterns of interrelationship, associations with symptoms and risk factors, suggesting heterogeneity in disease process and the need for joint-specific treatment. Key MessagesO_ST_ABSWhat is already known on this topic?C_ST_ABSO_LIOsteoarthritis (OA) commonly affects the hip and knee and is associated with pain and disability, with recognised risk factors such as age, obesity and deprivation. C_LIO_LIIncreasing interest in multi-joint OA challenges the traditional concept of lower-limb OA as a monoarthritis, but most research examines joints in isolation. C_LIO_LIGenetic evidence suggests that hip and knee OA may differ in underlying mechanisms, yet population-scale comparisons are limited. C_LI What this study adds?O_LIAmong 59,574 individuals, this study identifies that radiographic OA captures structurally and clinically relevant disease with increasing severity and greater number of joints affected, positively associated with chronic joint pain. C_LIO_LIRadiographic hip and knee OA demonstrated strong bilateral but weaker cross-joint associations, indicating preferential within-joint symmetry. C_LIO_LIRisk factors differed by anatomical site with BMI and weight strongly associated with knee OA and weakly associated with hip OA. Height showed the opposite associations. C_LI How this study might affect research, practice or policy?O_LIThese findings support that hip and knee OA may partially represent different disease processes rather than a single condition. C_LIO_LIClinical practice should consider cumulative joint involvement and joint-specific risk factors. C_LIO_LIFuture research should consider the development of more targeted treatment to prevent multi-joint progression. C_LI

ImportanceCardiovascular disease (CVD) is a major cause of morbidity/mortality in juvenile-onset systemic lupus erythematosus (JSLE), yet no reliable tools exist to stratify CVD-risk. ObjectiveTo identify serum biomarkers associated with atherosclerosis progression and response to atorvastatin. Design/SettingWe used data/samples from a sub-cohort of the APPLE trial (2009) which investigated atorvastatin vs. placebo to reduce atherosclerosis progression in JSLE, measured by change in carotid intima-media thickness (CIMT), and conducted a baseline autoantibody diagnostic-accuracy biomarker study. Participants/ExposureAPPLE trial participants (randomized 1:1 to atorvastatin vs. placebo) with matched baseline serum samples and stratified based on 36-month CIMT progression were included in the analysis. Main Outcomes and MeasuresBaseline serum autoantibodies were profiled using a functional proteomic platform (Sengenics, N=94). Empirical Bayes moderated t-test and Receiver Operating Characteristic (ROC) based logistic regression were applied to identify autoantibody signatures predictive of high vs. low atherosclerosis progression. ResultsNinety-four children and young people with JSLE (age mean [SD] =15.3 [2.4] years; 73 [78%] female, 8 [8.5%] Asian, 23 [24.5%] Black, 43 [45.7%] White, and 20 [21.3%] Other) were evaluated. Autoantibody levels against six novel autoantigens (STK24, RAD23B, HDAC4, STAT4, SEPTIN9, NFIA) classified high vs. low CIMT progression in the placebo arm (combined AUC 0.87, 95% CI -0.75 to 0.96). In the atorvastatin arm, autoantibodies to eight autoantigens (ABI1, ATP5B, CSNK2A2, NRIP3, PRKAR1A, PDK4, BATF, NUDT2), distinguished the statin responders vs. non-responders (combined AUC 0.96, 95% CI -0.88 to 1). An additional 27-autoantibody signature predicted response/partial response to atorvastatin (AUC 0.88, 95% CI - 0.76 to 0.97). Protein-protein interaction analysis identified endothelial disruption and lipid infiltration as key atherosclerosis mechanisms in atorvastatin non-responders. Combining the autoantibody prediction models with disease parameters and a metabolic signature did not increase model performance in either placebo (AUC 0.81, 95% CI - 0.68 to 0.94 vs. 0.87, 95% CI -0.75 to 0.96) or sttin arms (AUC 0.84, 95% CI -0.73 to 0.95 vs. 0.88, 95% CI -0.76 to 0.97). Conclusions and RelevanceThis study identified novel autoantibody signatures for atherosclerosis progression and statin response in JSLE, with potential utility for precision medicine approaches for CVD-risk management. Key PointsO_ST_ABSQuestionC_ST_ABSCan functional proteomic analyses identify autoantibody signatures predictive of atherosclerosis progression and response to statin treatment in children and young people with juvenile-onset systemic lupus erythematosus? FindingsUsing baseline samples from the APPLE trial (1:1 RCT of atorvastatin vs placebo), we identified novel autoantibody profiles that accurately distinguished individuals with high versus low carotid intima-media thickness progression over three years in both placebo (AUC 0.87, 95% CI-0.75 to 0.96) and atorvastatin groups (AUC 0.96, 95% CI-0.88 to 1). MeaningAutoantibody signatures show strong potential for early risk stratification and for identifying those most likely to benefit from statin therapy.

Red blood cell (RBC) alloimmunization is a clinically significant complication in transfused patients whose immunological determinants remain incompletely understood. Type I interferon (IFN-I) signaling drives RBC alloimmunization in murine models, and systemic lupus erythematosus (SLE) is characterized by constitutive IFN-I hyperactivation alongside elevated alloimmunization rates. We analyzed three publicly available SLE RNA-seq cohorts (GSE72509, GSE112087, GSE122459; whole blood and PBMC; total n = 150 SLE) in a pre-specified discovery-replication-validation design. A 14-gene IFN-I signature score was computed per sample; differential expression, gene set enrichment analysis, and Spearman correlation were performed independently per cohort. IFN-I scores were significantly elevated in SLE versus healthy controls in all three cohorts (p < 0.01 each). IFN-high SLE patients showed 665 differentially expressed genes, with enrichment of alloimmunization-associated and plasmablast differentiation gene sets confirmed by GSEA. The alloimmunization signature score correlated significantly with IFN-I score across all three independent cohorts ({rho} = +0.77, +0.51, +0.60; all FDR q < 0.05); Tfh differentiation showed no association in any cohort. To our knowledge, this represents the first human transcriptomic evidence that IFN-I pathway activity in SLE is coupled to alloimmunization-associated immune programs in vivo. These findings identify IFN-I score as a candidate biomarker of alloimmunization susceptibility in SLE and provide translational rationale for prospective studies incorporating transfusion outcome data.

BackgroundAntiphospholipid syndrome (APS) complicating pregnancy carries significant obstetric morbidity. Secondary APS, arising in the context of systemic autoimmune disease, may confer worse outcomes than primary APS due to additional inflammatory and immunological mechanisms. This study aimed to compare pregnancy outcomes between autoimmune rheumatic disease-associated secondary APS and primary APS managed at a quaternary care hospital in Chennai. MethodsA retrospective observational study analysed 82 pregnancies (secondary APS n=46; primary APS n=36) managed between January 2025 and March 2026. Outcomes including live birth rate, miscarriage, fetal death, preterm birth, pre-eclampsia, and intrauterine growth restriction (IUGR) were compared using chi-square test, Fisher exact test, and independent t-test. Multivariable logistic regression identified independent predictors of adverse outcomes. ResultsLive birth rate was significantly lower in secondary APS compared to primary APS (69.6% vs 86.1%; p=0.048). Triple antiphospholipid antibody positivity was more prevalent in secondary APS (47.8% vs 25.0%; p=0.032). On multivariable analysis, secondary APS (aOR 2.71; 95% CI 1.08-6.81; p=0.033), triple positivity (aOR 3.45; 95% CI 1.39-8.57; p=0.007), and lupus anticoagulant (aOR 2.62; 95% CI 1.01-6.76; p=0.047) independently predicted adverse outcomes. Hydroxychloroquine (aOR 0.39; p=0.038) and combination aspirin plus low-molecular-weight heparin (aOR 0.31; p=0.019) were independently protective. ConclusionSecondary APS is associated with significantly worse pregnancy outcomes than primary APS. Triple antiphospholipid positivity and lupus anticoagulant independently increase obstetric risk. Hydroxychloroquine and combination antithrombotic therapy significantly improve live birth rates. Early rheumatology referral and multidisciplinary obstetric management are essential.

IntroductionPublic and regulatory scrutiny of immunization safety has intensified in recent years. The COVID-19 pandemic has been instrumental in this. The accelerated timeline of COVID-19 vaccine development combined with the amplification of resultant side effects have proven corrosive to confidence. Unsurprisingly, COVID-19 vaccine uptake has declined year-on-year. This conflicts with the threat that infection still presents: predictors and prognoses of post-acute complications remain uncertain. Restoring public trust in these technologies will require meaningful progress in the availability and accessibility of clinical safety and pharmacovigilance data. MethodsExpanding upon recent comparisons of COVID-19 vaccine reactogenicity, we present a post-hoc safety analysis of adintrevimab, an intramuscular (IM) anti-SARS-CoV-2 spike recombinant investigational monoclonal antibody (mAb) for the pre-exposure and post-exposure prophylaxis of COVID-19, as assessed by the multi-center, double-blind, Phase 2/3 randomized placebo-controlled EVADE study (NCT04859517). Exploratory endpoints included the incidence of [&ge;]1 systemic symptoms within 7 days of study drug administration as well as symptom number, duration and severity. Safety reporting encompassed solicited and unsolicited treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), vital signs, and clinical laboratory assessments. ResultsEVADE study participants (n=2582) were randomized between April 2021 - January 2022. Baseline characteristics were balanced across treatment groups. Within the 7 day post-dose period, 25/1241 (2.0%) of adintrevimab recipients and 12/1242 (1.0%) of placebo recipients reported at least one systematic TEAE. Multiple systemic TEAEs were less prevalent, with 0.3% and 0.1% reporting two systemic TEAEs, and 0.1% and 0.1% reporting three TEAEs in adintrevimab and placebo groups, respectively. The majority of TEAEs reported were mild to moderate in severity, primarily involving headache (0.4% adintrevimab, 0.8% placebo), fatigue (adintrevimab 0.4%, placebo 0.2%), and nausea/vomiting (adintrevimab 0.4%, placebo 0.1%). For those participants who experienced any TEAEs in the 7 day post-dose period, mean (+/-standard deviation) number of systemic symptoms was 1.2 (0.5) for adintrevimab and 1.3 (0.6) for placebo with symptoms consistently resolving within 3 days. ConclusionsIncreased expectations for pharmaceutical safety data generation are to be welcomed, offering patients the information they need to appropriately weigh the benefits and risks of any novel therapeutic. These analysis results support the high tolerability of IM-administered adintrevimab, with reactogenicity data broadly comparable to placebo. While the co-administration of vaccines and monoclonal antibodies limit direct comparisons between historical safety reports, findings such as these demonstrate the potential clinical value of controlled head-to-head studies such as the anticipated LIBERTY trial.

Background: Rheumatoid arthritis is a chronic inflammatory disorder in which exercise is increasingly recognized as an important component of long-term management. Yet, most reviews in this field evaluate the effects of single exercise modalities, while bibliometric studies primarily identify publication trends and research hotspots without showing whether highly visible themes also represent coherent and comparatively mature evidence domains. Methods: We searched the Web of Science Core Collection for publications on exercise interventions in rheumatoid arthritis from 2016 to 2025. CiteSpace (6.4.1) and VOSviewer (1.6.20) were used to analyze publication growth, collaboration networks, keyword co-occurrence, thematic clusters, and burst terms. We then applied structured content coding in Excel 2021 to classify exercise modalities, outcome domains, and mechanistic topics, and integrated these findings into a visual evidence-distribution profile. Results: Publication output increased from 16 studies in 2016 to 37 in 2025. The United States led in productivity, Karolinska Institutet was the most prolific institution, and Kitas, Duda, and Metsios were among the most influential authors. Keyword analyses identified a shift from function- and disease-focused themes toward quality of life, risk factors, and comprehensive management. The integrated analysis revealed an uneven evidence structure: aerobic and resistance training accounted for the most concentrated and recurrently studied exercise-outcome domains, whereas mind-body and water-based interventions formed visible but methodologically heterogeneous clusters. Newer modalities, including blood flow restriction training and high-intensity interval training, showed growing prominence but limited depth of evidence. Conclusion:Exercise research in rheumatoid arthritis has evolved toward broader and more patient-centered management targets, but the field remains imbalanced across intervention types and outcome domains. This study demonstrates the value of combining bibliometric mapping with structured content analysis to distinguish thematic visibility from evidentiary coherence in heterogeneous intervention fields and may offer a transferable analytical framework for research evaluation beyond rheumatoid arthritis. Keywords: Rheumatoid Arthritis; Exercise Intervention; Bibliometrics; Content Analysis; Rehabilitation

Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious condition associated with pediatric SARS-CoV-2 infection. While COVID-19 vaccines prevent infection and reduce severity, less conclusive evidence exists regarding their role in preventing MIS-C during breakthrough infections. This systematic review assessed the impact of SARS-CoV-2 vaccination on MIS-C risk during breakthrough infection. Cross-sectional studies, surveillance studies, and cohort studies were included. Of the 944 studies identified, 6 were included. A significant protective effect was seen in patients who received two doses of SARS-CoV-2 vaccination after exclusion of a biased sample (d= 0.71 [95% CI 0.07 to 1.35; p=0.03]). A trend towards a protective effect was seen after one dose of vaccination, but this effect was not statistically significant. Current literature supports a protective effect of two doses of SARS-CoV-2 vaccination against development of MIS-C in breakthrough COVID-19. The evidence supports clinician advocacy for continued vaccination of children against SARS-CoV-2.