Juvenile idiopathic arthritis

Identification and validation of susceptibility modules and hub genes in polyarticular juvenile idiopathic arthritis using WGCNA and machine learning

BACKGROUND

Juvenile idiopathic arthritis (JIA), superseding juvenile rheumatoid arthritis (JRA), is a chronic autoimmune disease affecting children and characterized by various types of childhood arthritis. JIA manifests clinically with joint inflammation, swelling, pain, and limited mobility, potentially leading to long-term joint damage if untreated. This study aimed to identify genes associated with the progression and prognosis of JIA polyarticular to enhance clinical diagnosis and treatment.

METHODS

We analyzed the gene expression omnibus (GEO) dataset GSE1402 to screen for differentially expressed genes (DEGs) in peripheral blood single nucleated cells (PBMCs) of JIA polyarticular patients. Weighted gene co-expression network analysis (WGCNA) was applied to identify key gene modules, and protein-protein interaction networks (PPIs) were constructed to select hub genes. The random forest model was employed for biomarker gene screening. Functional enrichment analysis was conducted using David's online database, gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to annotate and identify potential JIA pathways. Hub genes were validated using the receiver operating characteristic (ROC) curve.

RESULTS

PHLDA1, EGR3, CXCL2, and PF4V1 were identified as significantly associated with the progression and prognosis of JIA polyarticular phenotype, demonstrating high diagnostic and prognostic assessment value.

CONCLUSION

These genes can be utilized as potential molecular biomarkers, offering valuable insights for the early diagnosis and personalized treatment of JIA polyarticular patients.

Vitamin D as a Modifiable Risk Factor for Juvenile Idiopathic Arthritis: A Systematic Review and Meta-analysis of Observational Studies Comparing Baseline Vitamin D in Children with JIA to Individuals Without

CONTEXT

The varying interactions contributing to the development of juvenile idiopathic arthritis (JIA) drive the struggle to understand its etiology. Among the environmental risk factors, vitamin D has been posited to have a component in disease progression, acting as an inflammatory mediator.

OBJECTIVE

To investigate the correlation between serum 25-hydroxyvitamin D [25(OH)D] levels, indicative of vitamin D, among patients diagnosed with JIA compared with control participants. The aim was to elucidate potential therapeutic implications of vitamin D in the management of JIA.

DATA SOURCES

A systematic search of 6 electronic databases (MEDLINE, Embase, Scopus, CINAHL, Web of Science, and Cochrane Library) was performed until February 2023. Inclusion criteria required participants to be <16 years old (either clinically diagnosed with JIA or a matched control participant), with vitamin D levels measured through serum laboratory methods. Exclusion criteria omitted studies in which participants used vitamin D supplementation or medications affecting vitamin D levels without corresponding statistical analyses on their association with vitamin D levels.

DATA EXTRACTION

Each article was reviewed by at least 2 independent reviewers to assess eligibility for analysis.

DATA ANALYSIS

Data were qualitatively analyzed to compare means of serum 25(OH)D levels (ng/mL) between patients with JIA and control participants, followed by a meta-analysis to obtain effect size.

RESULTS

Ten eligible studies were included qualitatively, and eight were included in the meta-analysis. Seven studies found a statistically significant difference in vitamin D levels between control participants and patients with JIA, with five of these reporting a lower mean vitamin D level in patients with JIA. A random-effects model using standardized mean difference found a statistically significant difference in vitamin D levels between control participants and patients with JIA (-0.49; 95% CI, -0.92 to -0.06).

CONCLUSIONS

The findings from the analysis indicate vitamin D levels were lower in patients with JIA as compared with healthy control participants at baseline. It is recommended that research into vitamin D supplementation and JIA should be conducted.

Central Nervous System Involvement in Pediatric Juvenile Idiopathic Arthritis: A Case Report of Cerebellitis and Literature Review

Autoimmune diseases are a heterogeneous group resulting from dysregulation or dysfunction of the immune system due to genetic predisposition and environmental triggers. It is common for these diseases to coexist. However, except for a single case secondary to varicella zoster virus infection, the association between juvenile idiopathic arthritis and acute cerebellitis has not been reported in the literature. A 9-year-old girl with juvenile idiopathic arthritis, initially presenting with symptoms of headache, nausea and vomiting, was diagnosed with diffuse bihemispheric acute cerebellitis by magnetic resonance imaging (MRI). Various tests were performed to determine the etiology of the disease. Infectious, metabolic, and autoimmune causes were excluded. This case report illustrates an ultra-rare association between juvenile idiopathic arthritis and acute cerebellitis, with a successful outcome following treatment and monitoring. There are 17 children, including our patient, who were followed with juvenile idiopathic arthritis and were found to have central nervous system disorders in the literature. Cerebral vasculitis and optic neuritis were the most commonly diagnosed neurologic disorders. Biologic agents have been implicated in some cases of optic neuritis and aseptic meningitis. Prompt treatment with corticosteroids and discontinuation of suspected biologic agents leads to favorable outcomes. This literature review highlights that early diagnosis and intervention can significantly improve outcomes.

Population-Based Big Data Analysis on Disease Patterns in Patients Identified With Juvenile Idiopathic Arthritis Using National Claims Data

BACKGROUND

This study aimed to identify epidemiologic data, including prevalence and incidence, of patients with juvenile idiopathic arthritis (JIA) in accordance with the diseases diagnostic code and Rare Intractable Disease Registration (RIDR) code from the claims data of the Health Insurance Review and Assessment Service (HIRA), the representative secondary data in Korea.

METHODS

We conducted a retrospective analysis of the national claims data of the HIRA. The study population included 1,728 patients with JIA who 1) had records with diagnostic codes in the format prescribed by the International Classification of Diseases, 10th Revision M08 and the RIDR code V133 between January 1, 2010, and December 31, 2019, and 2) were aged < 16 years as per the definition of JIA. We categorized the patients by age at diagnosis, annual prevalence, and incidence per 100,000 individuals for the study period. Moreover, the study population was stratified by age and gender for subgroup analysis.

RESULTS

The overall prevalence rate for the total, male, and female population was 15.9 (14.5-16.8), 15.4 (13.1-17.0), and 16.4 (15.9-16.9) per 100,000 individuals, respectively. Additionally, the overall incidence rate for the same populations was 2.2 (1.8-2.8), 2.3 (1.7-2.9), and 2.1 (1.8-2.6) per 100,000 individuals, respectively.

CONCLUSION

To the best of our knowledge, this is the first study presenting the epidemiologic data, including prevalence and incidence, of patients with JIA using population-based claims big data in Korea. The results of this study will aid in understanding the current status of JIA in Korea and Asia and in health care planning.

An update on the safety of biologic therapies for the treatment of polyarticular juvenile idiopathic arthritis

INTRODUCTION

An increasing number of patients with polyarticular course juvenile idiopathic arthritis are treated with biologics with great efficacy. Consequently, the importance regarding safety data in general as well as especially serious infections, incident autoimmune processes, or malignancies rises. In children, this is crucial concerning occurrences that manifest rarely and only after a prolonged latency period.

AREAS COVERED

This study aims to analyze safety under therapy with the five most commonly used biologicals for the treatment of juvenile idiopathic arthritis in Germany: abatacept, adalimumab, etanercept, golimumab, and tocilizumab, and a control cohort, who received methotrexate. For this, data from the Biologics in Pediatric Rheumatology (BiKeR) Registry were analyzed with a focus on potential adverse drug reactions like serious infections, autoimmune processes or malignancies.

EXPERT OPINION

Besides JIA category-specific differences, investigating side effects like severe infections and the development of additional autoimmune processes due to therapy is crucial. Future clinical randomized double-blinded studies are essential for direct drug comparisons, enabling optimal individualized therapy considering comorbidities and individual risks. Large patient data over a (life-)long period beyond childhood are particularly important, especially concerning the risk of malignancy after prolonged latency.

Quantifying and improving rheumatoid arthritis algorithm performance in biobank settings

OBJECTIVE

To quantify and improve the performance of standard rheumatoid arthritis (RA) algorithms in a biobank setting.

METHODS

This retrospective cohort study within the Mayo Clinic (MC) Biobank and MC Tapestry Study identified RA cases by presence of at least two RA codes OR positive anti-cyclic citrullinated peptide antibodies (CCP) plus disease-modifying anti-rheumatic drug (DMARD) prescription as of 7/18/2022. Rheumatology physicians manually verified all RA cases using RA criteria and/or rheumatology physician diagnosis plus DMARD use. All other biobank participants served as non-RA controls. We defined seropositivity as rheumatoid factor and/or anti-CCP positivity. We assessed rules-based and Electronic Medical Records and Genomics (eMERGE) RA algorithms using positive predictive value (PPV). Finally, we developed a novel RA algorithm using a LASSO-based machine learning approach with five-fold cross validation.

RESULTS

We identified 1,316 confirmed RA cases (968 MC Biobank, 348 Tapestry, 70 % seropositive) and 82,123 non-RA controls (mean age 65, 61 % female). The PPV of 3 RA codes was 43 %, codes plus DMARD was 54 %, and codes plus DMARD plus seropositivity was 85 %. The PPV of eMERGE was 77 %. Available in the MC Biobank, self-reported RA (PPV 10 %) only minimally improved algorithm performance (PPV from 83 % to 85 %), whereas family history of RA (PPV 3 %) worsened performance. At 90 % PPV, the novel RA algorithm incorporating key variables such as anti-CCP and DMARD use increased sensitivity by 4-11 % compared to eMERGE.

CONCLUSION

Rules-based and eMERGE RA algorithms had worse performance in biobank than administrative settings. Our novel RA algorithm outperformed these standard algorithms.

Population Incidence and Burden of Juvenile Idiopathic Arthritis on Australian Health System: Data Linkage Study

AIM

There is a lack of population-based information on patterns of healthcare for children with juvenile idiopathic arthritis (JIA). The aim of this study was to examine the population incidence of health service utilisation for children with JIA.

METHODS

We conducted a population-based data linkage study that examined children aged < 16 admitted to hospital with a diagnosis of JIA in New South Wales, Australia between 2002 and 2019. The annual incidence of JIA hospitalisations was calculated using population denominators. Health service utilisation and associated costs to the health system 12 months before and after the first JIA admission were examined using linked hospital admission, emergency department (ED) and outpatient datasets.

RESULTS

A total of 1433 children were admitted to hospital with a first diagnosis of JIA; the highest annual incidence was 7.2/100 000 children. In the year before the first JIA admission, 29% were admitted to hospital, 43% presented to the ED and 48% attended an outpatient clinic. In the year following the first JIA admission, inpatient/outpatient attendance increased: 44% had at least one inpatient admission, 61% attended ≥ 1 outpatient clinics. ED presentations remained stable. The unadjusted total cost to the health system in the year before the first JIA admission was $4422 per child diagnosed with JIA compared to $11 806 in the year following the first JIA admission.

CONCLUSION

Children with JIA have been demonstrated to be frequent users of hospital services, particularly just before and following their first admission for JIA, highlighting the impact of JIA both on the child and the health system.

Current Challenges in Yersinia Diagnosis and Treatment

Yersinia bacteria (Yersinia enterocolitica, Yersinia pseudotuberculosis) are commonly found in nature in all climatic zones and are isolated from food (mainly raw pork, unpasteurized milk, or contaminated water), soil, and surface water, rarely from contaminated blood. Yersinia infection occurs through sick or asymptomatic carriers and contact with the feces of infected animals. The invasion of specific bacterial serotypes into the host cell is based on the type 3 secretion system (T3SS), which directly introduces many effector proteins (Yersinia outer proteins-Yops) into the host cell. The course of yersiniosis can be acute or chronic, with the predominant symptoms of acute enteritis (rarely pseudo-appendicitis or septicemia develops). Clinical and laboratory diagnosis of yersiniosis is difficult. The infection requires confirmation by isolating Yersinia bacteria from feces or other biological materials, including lymph nodes, synovial fluid, urine, bile, or blood. The detection of antibodies in blood serum or synovial fluid is useful in the diagnostic process. The treatment of yersiniosis is mainly symptomatic. Uncomplicated infections (diarrhea and abdominal pain) usually do not require antibiotic therapy, which is indicated in severe cases. Surgical intervention is undertaken in the situations of intestinal necrosis. Given the diagnostic and therapeutic difficulties, this review discusses the prevalence of Y. enterocolitica and Y. pseudotuberculosis, their mechanisms of disease induction (virulence factors and host response), clinical manifestations, diagnostic and preventive methods, and treatment strategies in the context of current knowledge and available recommendations.

Dissecting immune-mediated pathways in rheumatoid arthritis: A multivariate mediation analysis of antibodies and circulating proteins

Rheumatoid arthritis (RA) is a chronic inflammatory disorder with complex etiologies involving immune responses and circulating proteins. This study investigates the causal relationships between antibody immune responses, plasma circulating proteins, and the development of RA using Mendelian Randomization (MR) analysis; A two-sample and multivariate MR analysis was conducted to explore the mediating causal relationship between 46 antibody immune responses and RA through 4,907 plasma circulating proteins. Genetic variations were utilized as instrumental variables (IVs) to infer causality, ensuring that they met the assumptions of relevance, independence, and exclusion restriction. Data were sourced from the FinnGen R10 dataset, UK Biobank, and the SomaScan platform, providing a robust foundation for the analysis. Statistical methods including IVW, weighted median, and mode-based approaches were employed, complemented by sensitivity analyses to ensure the robustness of the findings; The study identified significant causal relationships between six antibody immune responses and RA, with three specific responses-Epstein-Barr virus EBNA-1, Epstein-Barr virus ZEBRA, and Anti-polyomavirus 2 IgG seropositivity-showing strong associations. However, reverse causality was detected for EBNA-1 and ZEBRA, leading to their exclusion from further analysis. Additionally, 12 plasma circulating proteins were found to have significant causal relationships with RA, with KCNIP3 emerging as a key protective factor. Multivariate MR analysis revealed that KCNIP3 mediates the relationship between Anti-polyomavirus 2 IgG seropositivity and RA, suggesting a potential protective mechanism. This study highlights the intricate relationships between specific antibody responses, circulating proteins, and RA risk. The findings suggest that certain proteins, particularly KCNIP3, may mediate the effects of immune responses on RA development, offering potential targets for therapeutic intervention.

[Rheumatic shoulder joints in childhood]

Although the knee joint in children and adolescents is most frequently affected in cases of juvenile idiopathic arthritis (JIA), shoulder joint arthritis is only present in a small proportion of JIA patients at disease onset. Shoulder joint involvement is more frequently seen in polyarthritis or chronic JIA, which if not considered and left untreated can lead to substantial joint immobility and with a destructive course. In addition to the clinical examination, imaging methods help to verify an early involvement of the shoulder joint and imaging can also provide important information in a treat to target concept. The treatment of pediatric omarthritis is very often guided by the treatment algorithm for the appropriate JIA category. In this respect, in addition to local steroid injections, medications such as methotrexate, biologicals and also Janus kinase (JAK) inhibitors are used. In addition to the pharmacotherapy, physiotherapy also plays an important role.

Knee-ultrasound: reference values for the amount of joint fluid and synovial appearances in healthy children and adolescents

BACKGROUND

With increasing ultrasound use, data for the normal amount of joint fluid and synovial appearances are needed.

OBJECTIVE

To establish reference values for knee-ultrasound in healthy volunteers by age. To examine the association of joint fluid and synovial appearances with age, sex, and time spent in sports activities.

MATERIALS AND METHODS

Prospective, cross-sectional, including 3-17-year-old volunteers. Examinations were performed by one of two experienced radiologists after meticulous standardisation of the technique. Knees were examined in 30° flexion, in extension and during provocation.

RESULTS

One hundred twenty-seven volunteers (67 females), median age 10.9 years (percentile 2.5th-97.5th: 3.4-17.2), were included. With 30° knee flexion, the median amount of suprapatellar recess joint fluid (sagittal view) was 0.5 mm for females and 0.9 mm for males (P = 0.014), increasing to 1.9 mm and 2.4 mm (P = 0.031), respectively, during provocation. The amount of fluid during provocation increased with age for both sexes (P = 0.007 females; P = 0.012 males) and by time spent in sport-activities (P = 0.003). Further, there was a positive association between the presence of joint fluid speckles and sport-activities (P = 0.039). Median double-layered synovium was 1.5 mm in 3-6-year-olds, increasing to 2.1 mm in 7-9-year-olds and 2.0 mm in 10-17-year-olds (P = 0.024). No synovial Doppler signal was seen. Observers' agreement was excellent, with ICC values ≥ 0.9.

CONCLUSION

The majority of healthy children have measurable knee joint fluid, more so when examined with a flexed knee and under provocation. Speckles within the joint fluid are seen in one-fourth, especially in males, and the presence of speckles and joint fluid amount are associated with sports-activity.

Candidate Tear-Based Uveitis Biomarkers in Children with JIA Based on Arthritis Activity and Topical Corticosteroid Use

BACKGROUND

Uveitis is an inflammatory ocular disease secondary to disruption of the retinal pigmented epithelium (RPE) and blood retinal barrier (BRB). Known clinical factors do not accurately predict uveitis risk in Juvenile Idiopathic Arthritis (JIA). Tear fluid is easily obtained for biomarker study. We aim to identify tear-based markers associated with the presence of uveitis in children with JIA.

METHODS

In a cross-sectional comparative cohort study, tears were collected by Schirmer strips from children with oligoarticular JIA-associated uveitis (JIA-U) and JIA without uveitis (JIA-no-U). A tandem isotope tagging (iTRAQ and TMT) strategy was used for relative quantitation via nanoLC-MS/MS to quantify proteins in the affected eye. Log transformed relative protein abundance of protein levels was compared between groups using Wilcoxon exact test. We explored the influence of arthritis activity and topical corticosteroids (CS) use on protein levels. STRING analysis was performed.

RESULTS

Tear samples of 14 JIA-U and 14 JIA-no-U patients were analyzed. Thirteen proteins were differentially expressed between both groups. Stratified analysis based on arthritis activity (inactive arthritis) and topical CS (off CS) showed that alpha-2-macroglobulin (p = 0.012), apolipoprotein A1 (p = 0.036), S100A9 (p = 0.05), haptoglobin (p = 0.066), and transthyretin (p = 0.066) consistently differentiated between both groups. On STRING analysis, these proteins were associated with the RPE, BRB, and inflammation.

CONCLUSION

Importantly, we identified proteins involved in the RPE, BRB, and immune response that were differentially abundant in the tears of children with JIA-U compared to JIA-no-U, regardless of arthritis activity or topical CS. Candidate tear-based biomarkers may represent a non-invasive means to detect uveitis.

Evaluation of the frequency of allergic diseases in pediatric patients with juvenile idiopathic arthritis

Objective: Allergic diseases are characterized by a T-helper type 2 (Th2) dominant immune response, whereas juvenile idiopathic arthritis (JIA) is an autoimmune condition attributed to the Th1 pathway of CD4+ T cells. Reciprocal inhibition between the Th1 and Th2 responses is proposed to result in mutual exclusion of their polarized immune responses and associated diseases. This study aimed to ascertain the frequency of allergic diseases among children with JIA. Methods: The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to assess symptoms of allergic diseases in children with JIA and a control group of children with no known autoimmune diseases. The presence of current wheezing, allergic rhinitis and/or rhinoconjunctivitis symptoms, eczema symptoms, and food allergy symptoms were assessed based on affirmative answers. Results: The ISAAC questionnaire was administered to 101 children with JIA and 99 healthy controls. The median (interquartile range [IQR]) age was 12.64 years (8.83-15.83 years) in the JIA group and 11.99 years (6.65-14.90 years) in the control group. Children with JIA had lower rates of current wheezing (p = 0.003), current allergic rhinitis (p < 0.001), current rhinoconjunctivitis (p = 0.006), current atopic dermatitis (p < 0.001), and current food allergy (p = 0.005) symptoms. In addition, ever having had allergic rhinitis, wheezing, and atopic dermatitis were less common in the JIA group. In the multivariate logistic regression model, the absence of autoimmune disease in the patient and the presence of any allergic disease in the mother emerged as independent risk factors for current wheezing symptoms and current rhinoconjunctivitis and/or rhinitis. Conclusion: The results of this study demonstrated that the frequency of allergic diseases was lower in the presence of JIA, an autoimmune disease. This offers further evidence of mutual opposition between diseases that involve the Th1 and Th2 pathways, but there remains no consensus on this matter. More comprehensive studies that delve into the molecular foundations of these diseases are still needed to reach more definitive conclusions.

Sarcopenia in Rheumatic Diseases: A Hidden Issue of Concern

Sarcopenia is characterized by a loss of muscle mass and function, with significant implications for the physical performance of the affected people. Although commonly associated with aging, disease-related sarcopenia is of great clinical importance, particularly as it impacts disease progression and outcomes. Individuals with rheumatic diseases (RDs), including rheumatoid arthritis, systemic sclerosis, spondyloarthritides, systemic lupus erythematosus, fibromyalgia, myositis, or vasculitis, exhibit a high prevalence of sarcopenia, which exacerbates their clinical symptoms and contributes to poorer disease outcomes. Chronic inflammation influences muscle tissue degradation, causing a decline in physical performance. Apart from the apparent clinical manifestations, patients with RDs also use pharmacological treatments that negatively impact muscle mass further, increasing the risk of sarcopenia. Nutrition (diet and dietary supplements) and exercise interventions have been recommended as protective measures for sarcopenia as they may mitigate its adverse events. The present narrative review seeks to explore the methods used to assess sarcopenia in patients with RDs, its prevalence among them, and the challenges faced by the affected individuals, while critically assessing the appropriateness and limitations of current sarcopenia assessment tools in the context of RDs.

Incidence and reasons for biologic and targeted synthetic DMARD switching in juvenile idiopathic arthritis: a real- life stratified analysis

BACKGROUND

Switching biologic and targeted synthetic DMARDs (b/tsDMARD) is common in juvenile idiopathic arthritis (JIA) patients, though information about how this switching is done is scarce. This study aimed to determine the incidence rate, reasons for switching, and risk factors associated with switching due to inefficacy across different JIA subtypes.

METHODS

A multi-hospital electronic health record (EHR) registry was used to identify JIA patients prescribed ≥ 1 b/tsDMARD between 2000 and 2024. Patients were categorized into four JIA subgroups: oligoarticular, polyarticular, juvenile spondyloarthritis (JSpA), and systemic JIA. The primary outcomes were switching rates and switching due to inefficacy. Incidence rates (IR) were calculated per 100 patients-year. Cox multivariate regression analyses were run to assess the risk of b/tsDMARDs switching due to inefficacy, expressed as hazard ratio (HR) and 95% CI.

RESULTS

In our JIA registry, a total of 213 patients received a b/tsDMARD, with a total of 321 courses. The mean age at onset was 6.03 ± 4.44 years and 66.20% were females. The oligoarticular course group included 69 patients (32.39%), the polyarticular group 76 patients (35.68%), the JSpA group 43 patients (20.19%), and the systemic group 25 patients (11.74%). We found a total of 100 b/tsDMARD switches, with 32.05% of patients switched at least once. The systemic JIA group was more likely to swapping (p ≤ 0.001). Through the study period, the overall switching incidence rate was 7.32 [6.01-8.90] per 100 patients-year. In the stratified analysis across JIA groups, the systemic JIA group exhibited the highest incidence (IR:17.01 [11.20-25.84]). Regarding switching due to inefficacy, global incidence was 4.53 [3.53-5.82] and again systemic JIA was the group with the highest incidence (IR: 9.28 [5.27-16.34]). Still, the adjusted multivariate final model confirms that systemic JIA needed more switching due to inefficacy (2.43 [1.01-5.89], p = 0.04).

CONCLUSION

This real-life study provides data on different switch patterns in various subtypes of JIA, confirming that patients with systemic JIA needed more switching, did more swapping strategies, and had more risk for switching due to inefficacy.

The interplay between pain and disease activity: personal models of pain beliefs and emotional representations in children and young people with juvenile idiopathic arthritis in a UK nationwide prospective inception cohort

OBJECTIVES

Juvenile idiopathic arthritis (JIA) is a group of childhood-onset inflammatory rheumatic conditions characterized by pain as one of the most common and distressing symptoms. This cross-sectional study aimed to investigate whether relationships between reported pain and disease activity in JIA affected beliefs about pain, known as "personal models."

METHODS

187 out of a possible 363 participants with JIA who completed questionnaires about function and pain perception were recruited through the Childhood Arthritis Prospective Study (CAPS). A pre-selected pain score threshold and validated disease activity score cut-offs were used to assign the participants into four groups: low pain/low disease, low pain/high disease, high pain/low disease, and high pain/high disease. Multivariable linear regressions examined associations between the groups and their "personal models."

RESULTS

Compared to participants with low pain/low disease, those with high pain/high disease and those with high pain/low disease were more likely to sense greater threat, have more negative emotional representations, and perceive less control over their pain. Participants with low pain/high disease had similar pain beliefs compared to those with low pain/low disease.

CONCLUSION

This is the first study to compare "personal models" of pain in JIA. Children and young people who experience high pain severity regardless of disease activity perceived high pain threat, low controllability, and negative emotional representations. This highlights the importance of considering and addressing personal models of pain at diagnosis, especially those who present high levels of pain.

Disease activity and treatment in patients with juvenile idiopathic arthritis before transfer to adult care: the first survey in China

Objectives

To analyze disease activity and treatment in patients with juvenile idiopathic arthritis (JIA) before transfer to adult care.

Methods

We retrospectively collected the clinical data of 230 JIA patients (range 14-18 years) in our center from January 2013 to December 2022. We evaluated the clinical features, disease activity, and medication use across various JIA subtypes.

Results

230 patients with JIA were included, and 144 (63%) were male. The distribution of JIA subtypes was dominated by enthesitis-related arthritis (32%), polyarthritis (31%), systemic JIA (27%), and oligoarthritis (10%). Disease activity assessment showed that 87 JIA (38%) were in active disease; while 143 JIA (62%) were in inactive disease, of which 59 patients achieved clinical remission on medicine and 13 patients achieved clinical remission off medicine. Conventional synthetic disease-modifying anti-rheumatic drugs were used in 83% of JIA patients, and biologics in 56%. Clinical characteristics and medication use differed between different subtypes of JIA. The oligoarthritis group had earlier disease onset (P = 0.020) and longer disease duration (P = 0.009) compared to other subtypes. Patients in the RF-positive polyarthritis group had a significantly lower rate of disease inactivity (39%, P = 0.004) than the other subtypes, and a relatively lower proportion of patients achieved clinical remission on medication or discontinuation of medication (18%, P = 0.024).

Conclusions

Some JIA patients were still in active disease before transfer to adult clinics, failing to achieve clinical remission and discontinuation of medication, and required continued treatment. Patients in the RF-positive polyarthritis group were less likely to achieve clinical remission.

Juvenile Idiopathic Arthritis and Spondylarthritis

Juvenile idiopathic arthritis (JIA) is a heterogeneous disorder affecting children < 16 years of age. The clinical heterogeneity translates to imaging, where no specific joint is affected. This article highlights a general imaging approach to JIA, using specific examples of the knee, hand, and wrist as the typical joints affected. We then focus on unique joints that are commonly affected by JIA: the temporomandibular joint, the joints of the upper cervical spine, and the sacroiliac joint. For these latter anatomical sites, regional anatomy and development, location-specific imaging considerations, and arthritis, treatment decision making, and potential differential considerations are reviewed. We highlight, where applicable, a multimodal approach to imaging using developed or developing standardized scoring systems.

Trends in New Use of Disease-Modifying Antirheumatic Drugs for Juvenile Idiopathic Arthritis Among Commercially Insured Children in the United States from 2001 to 2022

OBJECTIVE

The objective of this study is to describe recent trends in disease-modifying antirheumatic drug (DMARD) use for children with juvenile idiopathic arthritis (JIA) in the United States.

METHODS

We used commercial claims data (2000-2022) to perform a serial cross-sectional utilization study of children aged 1 to 18 that were diagnosed with JIA. Initiations of conventional synthetic DMARDs (csDMARDs), biologic DMARDs (bDMARDs), or targeted synthetic DMARDs (tsDMARDs) were identified after a ≥12-month baseline and expressed as a percentage of all new DMARD initiations per year, by category, class, and individual agent. Trends were evaluated using linear regression. We also examined the first bDMARDs and tsDMARDs initiated after csDMARD monotherapy.

RESULTS

We identified 20,258 new DMARD use episodes among 13,696 individuals (median age 14 years, 67.5% female). csDMARDs, although most used overall, declined from 89.5% of new use episodes to 43.2% (2001-2022, P < 0.001 for trend). In contrast, bDMARD use increased (10.5-50.0%, P < 0.001). For tumor necrosis factor inhibitors (TNFi), etanercept peaked at 28.3% in 2006 and declined to 4.2% in 2022 (P = 0.002). Meanwhile, adalimumab use doubled (7.0-14.0%, 2007-2008) after JIA approval, increasing further following a less painful formulation release (20.5% in 2022, P < 0.001). However, overall TNFi use has declined with increasing use of other bDMARDs and tsDMARDs, particularly ustekinumab, secukinumab, and tofacitinib. By 2022, adalimumab was the most common b/tsDMARD initiated first after csDMARDs (77.8%).

CONCLUSION

Among commercially insured children with JIA in the United States, new b/tsDMARD use is rising and new csDMARD use is declining. For b/tsDMARDs, adalimumab is most used and is the predominant b/tsDMARD initiated first after csDMARDs. Patterns in DMARD use for JIA have evolved relative to multiple factors, including regulatory approvals and tolerability.

Incidence and Genetic Risk of Juvenile Idiopathic Arthritis in Norway by Latitude

OBJECTIVE

We aimed to investigate the incidence of juvenile idiopathic arthritis (JIA) in the three geographic regions of Norway and whether potential regional incidence differences are explained by environmental or genetic factors across regions.

METHODS

We conducted a register-based cohort study including all Norwegian children born from 2004 to 2019, with follow-up throughout 2020. The JIA diagnosis, defined by at least two International Classification of Diseases, Tenth Revision codes for JIA, was validated against medical records. The incidence rate (IR) and hazard ratio (HR) for JIA were estimated for all Norway and for the North, Mid, and South regions. In a subsample from the Norwegian Mother, Father, and Child Cohort Study (MoBa), the genetic risk for JIA was assessed in the three regions.

RESULTS

After median 9.1 (range 0.3-16.0) years of follow-up, we identified 1,184 patients with JIA and 910,058 controls. The IR for JIA/100,000 person-years was 14.4 in all of Norway, 25.9 in the North region, 17.9 in the Mid region, and 12.5 in the South region. The HR (95% confidence interval [CI]) of JIA in the North region was 2.07 (1.77-2.43) and in the Mid region HR 1.43 (95% CI 1.23-1.67) compared with the South region. Adjustments for perinatal factors, socioeconomic status, and early antibiotic exposure did not change our estimates substantially. In MoBa (238 patients with JIA, 57,392 controls), the association between JIA and region of birth was no longer significant when adjusting for genetic factors.

CONCLUSION

We found a higher incidence of JIA with increasing latitude without evidence for available environmental factors explaining the observed gradient. In contrast, genetic factors modified the association, but further studies are warranted.

Whole-body Magnetic Resonance Imaging in Inflammatory Spine and Joint Disease

Whole-body magnetic resonance imaging (WB-MRI) can effectively diagnose rheumatologic diseases with systemic and multifocal characteristics, such as spondyloarthritis, chronic recurrent multifocal osteomyelitis, and synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, among others. Advances in rheumatic disease treatments have emphasized the importance of early diagnosis for effective management, function preservation, and improved quality of life. WB-MRI offers comprehensive imaging of the musculoskeletal system, detecting early and subtle disease changes that traditional methods might overlook. Initially used for spondyloarthritis, the technique has recently expanded to other rheumatic diseases and is becoming the gold standard for diagnosing and monitoring chronic nonbacterial osteomyelitis in pediatric patients. This review article presents the current status of WB-MRI in rheumatologic conditions.

The impact of BMI on disease activity and growth outcomes in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) presents with diverse phenotypes and can lead to significant morbidity. Obesity, affecting 5 to 23% of JIA patients, may exacerbate disease activity and complicate management. This study evaluates the impact of body mass index (BMI) on disease activity and the influence of joint involvement on BMI in JIA patients. Between January 2012 and June 2024, 225 JIA patients were reviewed, with 173 ultimately included based on specific inclusion and exclusion criteria. Treatments followed the American College of Rheumatology (ACR) recommendations. Data on demographics, BMI, JADAS-27 scores, joint involvement, and laboratory parameters were analyzed, with statistical significance defined as p < 0.05. Among 173 JIA patients, significant increases in weight and height SDS were observed (p < 0.05). Obese patients at baseline had higher JADAS-27 scores at 6 months (p < 0.05). A positive correlation was found between initial JADAS-27 and final BMI SDS (r = 0.170, p < 0.05). Patients with hip involvement had lower BMI at diagnosis and at the first-year follow-up (p < 0.0001, p = 0.049), while knee involvement was linked to lower height SDS at the second year (p = 0.041).

CONCLUSION

Our study revealed that baseline obesity is a significant risk factor for poorer disease control at the 6-month follow-up in JIA patients. We also observed that effective treatment led to improvements in growth, particularly in patients with hip involvement, who initially had lower BMI values. These findings underscore the importance of monitoring BMI in JIA patients to optimize disease management and long-term outcomes.

WHAT IS KNOWN

• Overweight and obesity are prevalent in children with JIA, with reported rates ranging from 5 to 23% in various studies. • The relationship between BMI and disease activity in JIA remains controversial, with previous studies reporting conflicting results on whether BMI impacts disease remission or activity.

WHAT IS NEW

• Baseline obesity in juvenile idiopathic arthritis (JIA) patients is associated with worse disease activity during follow-up, particularly evident at the 6-month visit. • Patients with hip involvement had significantly lower BMI values, indicating a potential correlation with more severe disease. • Improved linear growth was observed in JIA patients during follow-up, indicating that effective treatment positively impacts growth despite the chronic nature of the disease.

Clinical insights into heterogeneity of rheumatoid factor negative polyarticular juvenile idiopathic arthritis across the world

BACKGROUND

To our knowledge, limited information is available about the differences in the characteristics of rheumatoid factor (RF)-negative polyarticular juvenile idiopathic arthritis (JIA) throughout the world. This study was aimed to compare the demographic and clinical features of patients with RF-negative polyarthritis across the world.

METHODS

Patients were part of a multinational sample included in a study aimed to investigate the prevalence of disease categories, treatment regimens, and disease status in patients from different geographical areas (EPOCA Study). All patients underwent a retrospective assessment, based on the review of clinical chart, and a cross-sectional evaluation, which included assessment of physician- and parent-reported outcomes and collection of ongoing medications.

RESULTS

Among the 9081 patients enrolled in the EPOCA study, 2141 patients (23.6%) with RF-negative polyarthritis were included in the present analysis. The prevalence of RF-negative polyarthritis was highest in North America and lowest in Southeast Asia (12.7%). The age at disease onset was lower in Northern and Southern Europe, where the highest prevalence of uveitis was found. Uveitis was rare in Southeast Asia, Africa & Middle East and Latin America. Patients from Eastern Europe, Latin America and Africa and Middle East presented with the highest prevalence of active joints at the visit. The combination of early onset, ANA positivity, and uveitis was observed mainly in Southern Europe (39%).

CONCLUSIONS

Our results confirm the wide heterogeneity of the clinical presentation and outcome of children with RF-negative polyarticular JIA throughout the world. In particular, relevant differences in the onset age were observed across geographic areas. The group of children with early onset polyarthritis, ANA positivity, and risk of uveitis is remarkably frequent in Southern Europe.

Sex Differences in B Cells From the Joints of Children With Oligoarticular Juvenile Idiopathic Arthritis

OBJECTIVE

Disordered T peripheral helper (Tph)-B cell interactions have been implicated in several forms of inflammatory arthritis, including oligoarticular (oligo) juvenile idiopathic arthritis (JIA). We sought to evaluate the Tph-B cell axis in oligo JIA through an analysis of intra-articular B cells.

METHODS

B cells from the blood and synovial fluid (SF) of 44 children with oligo JIA were compared to those from the blood and tonsils of controls. Flow cytometry, B cell receptor (BCR) repertoire analysis, and autoantibody profiling were used to characterize B cells.

RESULTS

Memory B (Bmem) cells and heterogeneous subsets of CD21lo B cells were enriched in oligo JIA-SF versus blood of patients and controls. Compared to male patients, female patients with oligo JIA had greater proportions of intra-articular Tph cells that expressed B cell help factors as well as Bmem cells, plasmablasts, and age-/autoimmune-associated B cells. The sex differences in B cells were observed only in the joints and were not found in the blood or tonsil, nor were they explained by other disease features such as age at onset, antinuclear antibody status, or severity. Bmem cells in SF from female patients displayed characteristics of autoreactivity, including longer complementarity determining region 3 lengths and increased usage of autoreactive BCR gene segments, which were not found in blood Bmem cells. A diverse array of autoantibodies accumulated in the SF of female patients with oligo JIA compared to the blood of patients with JIA and controls.

CONCLUSION

These findings demonstrate prominent B cell dysregulation in oligo JIA and implicate sex as an important biologic factor in B cell responses in this disease.

Trajectories of physical, mental health and health satisfaction before and after arthritis diagnosis: a UK population-based study

BACKGROUND

Few longitudinal studies have explored changes in physical and mental health in individuals prior to and after arthritis diagnosis. This is important for understanding timing of diagnosis in relation to symptoms and their broader health impacts.

METHODS

Adults (≥ 16 years) reporting new diagnoses of arthritis between 2010 and 2023 in the UK Household Longitudinal Study (UKHLS) were included in the study (N = 5,258), along with a 1:1 matched sample of arthritis-free individuals. Trajectories of physical health (assessed using the SF-12 physical component summary), mental health (General Health Questionnaire (GHQ-12)) and satisfaction with health were constructed from 8 years prior to 8 years after diagnosis using growth curve models with linear splines. Difference in difference analysis was used to test whether changes in health measures following diagnosis were attributable to arthritis diagnosis.

RESULTS

Physical health decreased from 8 years prior to diagnosis, but began to show a steeper decline from 4 years before diagnosis. There was a small recovery in the year following diagnosis, followed by a continued decline from 4 years post diagnosis. Mental health worsened at 2 years prior to diagnosis and then remained relatively stable. Health satisfaction also decreased around 2 years prior to diagnosis, showing a gradual increase in the 3 years following diagnosis and then remaining stable. Patterns of change were similar by sex, neighbourhood deprivation and living situation. There was some evidence that changes in mental health and health satisfaction were larger and occurred earlier in individuals diagnosed at younger ages (16-49 year olds). Difference in difference models showed consistent findings, with deteriorations across all three outcomes in the arthritis group relative to their matched controls.

CONCLUSIONS

Detectable changes in physical and mental health several years prior to diagnosis suggest the need to improve pathways to diagnosis. Persistence of worse mental health, particularly amongst younger people, highlights the importance of considering both physical and mental health in the years following diagnosis.

Transition-related outcomes among a cohort of patients with juvenile idiopathic arthritis

A major goal in juvenile idiopathic arthritis (JIA) long-term management is to ensure a successful transition to adult age. This study aims to assess transition outcomes in a group of JIA patients during their passage from pediatric to adult healthcare assistance at a single center. This is a cross-sectional study. All patients with JIA undergoing a transition from the Pediatric Rheumatology Service of the IRCCS "Burlo Garofolo" Hospital, Trieste, to the adult Rheumatology Service of "Santa Maria della Misericordia" Hospital, Udine, between 2017 and 2022, were enrolled. Clinical and laboratory data were collected. A semi-structured survey exploring patients' satisfaction was distributed through email. Numerical variables were compared using Student's t-test or Mann-Whitney test. Categorical variables were compared with Fisher's exact test. We recruited 36 patients (26 female, 72.2%): 9 with polyarticular course JIA, 13 oligoarticular, 8 psoriatic arthritis, 3 systemic JIA, and 3 enthesitis-related arthritis. The mean age at transition was 18.6 (Q1-Q3, 18.3-19.1). JADAS-27 score significantly decreased after the transition, with a mean difference of 2.6 (p = 0.014). No patients were lost to follow-up, and in 8 out of 36 (22.2%), a step-up therapy was needed within the first 12 months. Among these, no correlation was found with the JIA subtype, age at onset, type of involved joints, and other variables explored. Finally, the 15 patients who answered the survey (response rate 50%) were satisfied about the transition process. This study described a real-life transition experience from pediatric to adult rheumatology care, showing good transition outcome measures, with no patients lost to follow-up and a reduction of JADAS-27 score after completing the process.

Measurable Outcomes of an Ophthalmology and Rheumatology Coordinated Care Clinic

OBJECTIVE

We evaluated the impact of an Ophthalmology/Rheumatology multidisciplinary clinic for patients with anterior uveitis by comparing outcomes between those who received traditional care (TC) versus coordinated care (CC).

METHODS

We conducted a retrospective cohort study of children with anterior uveitis from a pediatric tertiary care center between 2013 and 2022. Standard descriptive statistics were used; survival analyses explored differences in cohort disease activity and biologic disease-modifying antirheumatic drug (DMARD) treatment. Steroid treatment by cohort was compared using generalized estimating equation model with Poisson distribution and log link. Complications were compared using logistic regression. Number of visits in each cohort were assessed using Poisson generalized estimating equation model adjusted for complications.

RESULTS

We studied 215 patients with anterior uveitis; 66% were female, 53% had juvenile idiopathic arthritis, and 23% were idiopathic, with a median age at diagnosis of 8 years old (interquartile range 5-12). CC was associated with a 60% higher hazard of reaching disease control (hazard ratio 1.6; P < 0.01) when controlling for time since diagnosis and anterior chamber cell counts at the beginning of disease activity. CC was associated with starting biologic DMARDs earlier than TC (P < 0.01). Compared with the group who received TC, the group who received CC had a 96% lower rate of glucocorticoid reception per appointment within the first year (P < 0.01). The visit rate was 64% lower for the group who received CC when controlling for total complications per patient.

CONCLUSION

Patients who received multidisciplinary care had better outcomes than patients who received TC. Limitations include different cohort start times and absence of defined criteria for CC referral.

From gut to kidney: microbiota modulates stone risk through inflammation-a mediated Mendelian randomization study

The gut microbiota (GM) can affect the immune system, which can lead to a variety of diseases, as confirmed by many studies. However, the exact mechanism by which GM affects kidney stone incidence through the immune system remains unclear. This study used a two-step, two-sample Mendelian randomization (MR) analysis by inverse variance weighting (IVW) method as well as Bayesian weighting (BWMR) to find out how the gut microbiota and inflammatory cytokines contribute to kidney stones, followed by a mediated MR analysis to exploreHow inflammatory cytokines are involved in the connection with the gut microbiota and kidney stones. MR analysis revealed that seven intestinal flora were protective against kidney stones, including family. Actinomycetaceae, family.Clostridiaceae1, genus.Clostridiumsensustricto1, genus. Hungatella, genus.LachnospiraceaeUCG001, genus.LachnospiraceaeUCG008 and order. Actinomycetales, while four intestinal flora, including genus. Haemophilus, genus. RuminococcaceaeUCG010, order.Rhodospirillales and phylum.Actinobacteria may increase the risk of kidney stones. In addition, it was confirmed that seven Inflammatory cytokines DNER, IL-18, IL-1α, SLAMF1, STAMPB, CST5 and FGF-5 in association with kidney stones. Notably, the mediating MR indicated the causal effect of phylum. Actinobacteria and order. Rhodospirillales gut group on kidney stones was mainly modulated by IL-18 levels, with mediating effects accounting for 15.8% and 12.8% of the total effect, respectively. The present study demonstrates this phylum. Actinobacteria and order. Rhodospirillales flora have an important role in reducing the risk of kidney stones and act mainly by modulating IL-18 levels.

Safety and effectiveness of intravenous abatacept for polyarticular-course juvenile idiopathic arthritis: An all-case postmarketing surveillance study

BACKGROUND

In 2018, intravenous abatacept was approved for the treatment of refractory polyarticular-course juvenile idiopathic arthritis (JIA) in Japan. However, reports describing the effectiveness and safety of abatacept in clinical practice in Japanese patients with refractory polyarticular-course JIA are limited. Therefore, this postmarketing surveillance study aimed to evaluate the real-world safety and effectiveness of abatacept in Japanese pediatric patients with refractory polyarticular-course JIA.

METHODS

This study evaluated patients included in an all-case postmarketing surveillance study between February 2018 and August 2020 who were treated with intravenous abatacept. Data on the safety and effectiveness of the registered patients were collected during the 52-week follow-up period. Disease activities were evaluated using Juvenile Arthritis Disease Activity Score 27 (JADAS-27). The effect of abatacept on a child's growth was assessed using the height and weight standard deviation scores (SDS).

RESULTS

A total of 82 patients were registered in this study, of whom 14.6% and 85.4% were males and females, respectively. The proportion of patients with oligoarticular, rheumatoid factor (RF)-negative polyarticular, and RF-positive polyarticular JIA was 12.2, 28.0, and 54.9%, respectively. The incidence of adverse drug reactions (ADRs) and serious ADRs was 22.0% and 2.4%, respectively. During the study period, 64.7% of the patients achieved JADAS-27 low disease activity or less. A significant difference in JADAS-27 scores in patients with RF-positive polyarticular JIA was observed between baseline and 24 or 52 weeks after abatacept administration. The height and weight SDS tended to improve during abatacept treatment.

CONCLUSIONS

Abatacept is effective in polyarticular-course JIA, particularly in RF-positive patients, and in restoring a child's growth. Additionally, the incidence of ADRs is similar to that observed in the clinical trial. The results of the study suggest that abatacept is a useful therapeutic option for treating refractory polyarticular-course JIA in real-world settings in Japan.

Clinical implications of human Parvovirus B19 infection on autoimmunity and autoimmune diseases

Parvovirus B19 (B19V) is a human pathogen from the Parvoviridae family that primarily targets and replicates in erythroid progenitor cells (EPCs). While its symptoms are typically self-limiting in healthy individuals, B19V can cause or exacerbate autoimmune diseases in vulnerable patients. This review integrates the involvement of B19V in the development and worsening of several autoimmune diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), hematological disorders (thalassemia, anemia, and thrombocytopenia), vasculitis, antiphospholipid syndrome (APS), dermatological disease (systemic sclerosis, psoriasis), autoimmune thyroid disease, myocarditis, and myasthenia gravis, and autoinflammatory disease of adult-onset Still's disease (AOSD). B19V contributes to autoimmunity and autoimmune disease onset and progression through mechanisms such as molecular mimicry, immune system disruption, and chronic infection. By summarizing findings from in vitro experiments, clinical case studies, seroprevalence data, and biopsy results, this review highlights the critical connection between B19V and autoimmune disease development. Recognizing the role of B19V in the early diagnosis and management of these conditions is essential, as its presence may influence the disease course and severity. Greater awareness among healthcare professionals and the public is necessary to address the impact of B19V, leading to more accurate diagnoses and better-informed treatment approaches for autoimmune diseases linked to the virus.

The beauty of pediatric musculoskeletal ultrasound

Ultrasound is a powerful technique in pediatric imaging and musculoskeletal (MSK) imaging in many specific clinical scenarios. This article will feature some common and less common spot diagnoses in pediatric musculoskeletal ultrasound.Cases were collected by members of the Educational Committee of the ESSR (European Society of musculoSkeletal Radiology) and the Pediatric Subcommittee of the ESSR with expertise in musculoskeletal ultrasound.Fifteen clinical entities are discussed based on the features that allow diagnosis by ultrasound.Clinical history, location, and ultrasound appearance are the keys to spot diagnoses when performing pediatric musculoskeletal ultrasound. · Ultrasound in pediatric musculoskeletal imaging can achieve a diagnosis in specific clinical settings.. · Clinical history, location, and ultrasound appearance are keys to spot diagnoses.. · Knowledge of spot diagnoses in pediatric musculoskeletal ultrasound facilitates daily clinical practice.. · Drakonaki EE, Adriaensen M, Simoni P et al. The beauty of pediatric musculoskeletal ultrasound. Rofo 2025; 197: 172-185.

Assessment of choroidal vascularity index in juvenile idiopathic arthritis: implications for disease monitoring

PURPOSE

Juvenile Idiopathic Arthritis (JIA) can affect ocular structures, but choroidal involvement is not well understood. This study investigates the Choroidal Vascularity Index (CVI) in JIA patients compared to healthy controls and explores its relationship with disease activity.

METHODS

In this cross-sectional study, 35 JIA patients and 40 healthy controls underwent comprehensive ophthalmic examination and swept-source optical coherence tomography (SS-OCT). CVI, central macular thickness (CMT), and subfoveal choroidal thickness (SFCT) were measured. The Juvenile Arthritis Disease Activity Score (JADAS) was calculated for JIA patients. Statistical analysis included comparison between groups and correlation analysis.

RESULTS

JIA patients showed significantly lower CVI compared to controls (68.3 ± 2.5% vs. 72 ± 4.6%, p < 0.001). No significant difference was found in SFCT. CVI demonstrated a moderate negative correlation with JADAS (r = -0.368, p < 0.05). However, receiver operating characteristic (ROC) analysis revealed poor diagnostic performance of CVI for detecting JIA (AUC = 0.25).

CONCLUSION

The study reveals reduced choroidal vascularity in JIA patients and a correlation between CVI and disease activity. While CVI shows limited diagnostic utility, it may serve as a potential marker for monitoring inflammatory burden and treatment response in JIA. Further research is needed to establish its clinical utility fully.

The Limitation of HLA Diversity as a Risk Factor for Pediatric-Onset Autoimmune Rheumatic Disease

Background: HLA homozygosity of specific alleles at a single locus is associated with increased risk for autoimmunity and/or more severe clinical phenotypes. However, the contribution of the overall limitation of HLA diversity across multiple loci to autoimmunity risk remains to be determined. Methods: We conducted a proof-of-concept case-control study of 413 individuals (279 cases with pediatric-onset autoimmune rheumatic diseases, 134 matched controls) examining the "Limitation of HLA Diversity" (LoHLAD) across multiple loci as an allele-independent risk factor for autoimmunity. We examined the association of LoHLAD with pediatric-onset autoimmune rheumatic diseases at five HLA loci (A, B, DQB1, DRB1, DRB3/4/5). LoHLAD was defined as (1) homozygosity at any of the examined loci, and/or (2) the presence of a single allele or the complete lack of an allele at the HLA-DRB3/4/5 locus. Results: The frequency of LoHLAD at any locus was significantly higher in cases compared to controls (65.95% vs. 30.60%, OR 4.39 [2.82-6.84], p < 0.0001). Higher frequencies of LoHLAD in cases compared to controls were observed at both class I (19.35% vs. 10.45%, OR 2.06 [1.10-3.86], p = 0.031) and class II (54.48% vs. 20.15%, OR 4.74 [2.92-7.69], p < 0.0001) loci. Specifically, significant differences between cases and controls were observed at the B (OR 8.63 [1.14-65.55], p = 0.016), DQB1 (OR 3.34 [1.27-8.78], p = 0.016), and DRB3/4/5 (OR 4.64 [2.77-7.75], p < 0.0001) loci. Multiple logistic regression models confirmed the ability of LoHLAD to positively predict autoimmunity. Conclusions: LoHLAD is a significant allele-independent risk factor for pediatric-onset autoimmune rheumatic disease.

Exploring nutritional risks of the specific carbohydrate diet: food and nutrient intake in children with juvenile idiopathic arthritis

Diet is considered a key research priority for juvenile idiopathic arthritis (JIA), garnering considerable interest from affected families. Despite this, research studies focusing on dietary interventions remain scarce. The specific carbohydrate diet (SCD) has shown potential, however, its nutritional consequences and risks are not well understood. This study aims to describe and evaluate food and nutrient intakes in children with JIA adhering to the SCD and contextualize the results relative to recommendations and intakes in the general population. In a secondary analysis, food and nutrient intakes from three-day dietary records of ten children, following a four-week SCD intervention, were evaluated against the Nordic Nutrition Recommendations 2023 and Riksmaten Adolescents data (RMA) (n = 1282). All children following the SCD met the recommended minimum intake of fruit and vegetables of 500g/day, a stark contrast to the 6% in RMA. Median dietary fibre intake for the SCD was 26g/d, (IQR 21-33), compared to 16g/d (IQR 12-22) in RMA. Elevated saturated fatty acid (SFA) intake was observed in both groups, with the SCD group also consuming high amounts of red meat. Calcium was the sole nutrient for which the standard diet surpassed the SCD, as 9 out of 10 participants had inadequate intake. While children on the SCD showed a lower likelihood of nutrient inadequacy compared to the general population, inadequate calcium intake and elevated SFA and red meat consumption are concerning given known comorbidities in JIA. These results highlight the importance of disease-specific dietary guidance to ensure optimal support for patients and parents.

Juvenile Idiopathic Arthritis Associated Uveitis. Current Status: Epidemiology, Pathogenesis, and Clinical Issues

Uveitis is the most common extraarticular manifestation of juvenile idiopathic arthritis (JIA) and with no adequate management results in serious eye complications such as cataracts, secondary glaucoma, retinal detachment, and linear corneal dystrophy. This pathology reduces patients’ quality of life and can lead to significant social and economic losses, both due to direct health costs and due to disability (total loss of sight). Childhood uveitis accounts for approximately 5–10% of all uveitis in global population, however their prevalence has been increasing in recent years. The etiology and pathogenesis of JIA-associated uveitis remains poorly studied despite the well-known correlation of uveitis with JIA. Uveitis in children is difficult to diagnose in routine pediatric practice, both due to its course (asymptomatic/mild), and due to challenging verbal communication and examination (young children), which poses significant clinical problem. This article presents current data on the epidemiology, pathogenesis, clinical manifestations, and terminology of JIA-associated uveitis.

Juvenile idiopathic arthritis and associated uveitis: A review of pathogenesis, diagnosis, and management

Juvenile idiopathic arthritis (JIA) is the most common rheumatologic disorder in children, posing significant physical and emotional challenges due to its chronic nature and the need for prolonged immunosuppressive therapies. Uveitis is the most common extra-articular manifestation of JIA, and it can be a sight-threatening condition. Despite advances in biologic treatments, JIA continues to present substantial therapeutic challenges, necessitating multiple treatment attempts and close monitoring for secondary failures. JIA-associated uveitis remains one of the most challenging and aggressive types of uveitis, particularly in children, due to its early onset, chronicity, and limited therapeutic responses despite new treatments. Early recognition and prompt treatment of both arthritis and uveitis are essential for achieving sustained remission and preventing complications. Effective management of JIA-uveitis requires a collaborative approach between pediatric rheumatologists and ophthalmologists to ensure timely assessments, regular screenings, and necessary therapy adjustments. This integrated care approach is crucial for achieving optimal outcomes. Therefore, this review aims to extensively analyze the pathogenesis, diagnosis, and therapy of JIA and its associated uveitis.

Genetic analysis uncovers potential mechanisms linking juvenile ldiopathic arthritisto breast cancer: A Bioinformatic Pilot study

BACKGROUND

In recent years, concerns have emerged regarding the potential link between Juvenile idiopathic arthritis (JIA) and an elevated risk of developing breast cancer. However, the potential relationship between JIA and breast cancer is currently unclear. The objective of this study is to investigate the mechanism of JIA on cancer risk.

METHODS

Use the Bulk-seq data related to JIA, selected from the GEO database, to explore potential candidate genes using methods such as WGCNA and consensus machine learning labeling. Verify using breast cancer Bulk-seq data from TCGA and scRNA-seq analyses.

RESULTS

A total of 2050 genes potentially related to JIA were identified by WGCNA, and after merged with differentially expressed genes, 43 potential candidate genes were found. Subsequently, consensus machine learning label analysis was conducted on the aforementioned genes, and a total of 6 genes closely related to JIA were identified. In breast cancer, we found that PRRG4, NCR3 and CREB5 also had significant differences in TCGA. And it is closely related to prognosis. ScRNA-seq analysis showed that the expression of PRRG4 was different in T cells in JIA, and PRRG4 was mainly expressed in T cells in breast cancer.

CONCLUSIONS

The findings of this study support a mechanism between JIA and an increased risk of breast cancer.

Radiographs in Pediatric Rheumatology: Where Do We Stand?

Rheumatic disorders in children include inflammatory arthritis, inflammatory bone disorders such as chronic nonbacterial osteomyelitis (CNO), connective tissue disorders, and vasculitides (juvenile dermatomyositis, scleroderma). The diagnosis in these children is based on a combination of history, clinical examination, and laboratory investigations. Radiographs play an important role in children with arthritis, who have atypical presentation or for assessment of disease-related damage and differentiation from mimics. Further, radiographs also have an ancillary role in the assessment of musculoskeletal disorders such as dermatomyositis and hemophilia. This review seeks to present a detailed analysis of the specific indications and advantages of radiographs in the situations. Further, a structured reporting format for assessment of radiographs in pediatric rheumatic disorders has also been presented for the reader's reference.

The plasma metabolome of juvenile idiopathic arthritis varies according to subtype and underlying inflammatory status

BACKGROUND

Juvenile idiopathic arthritis (JIA) is challenging to classify and effectively monitor due to the lack of disease- and subtype-specific biomarkers. A robust molecular signature that tracks with specific JIA features over time is urgently required, and targeted plasma metabolomics may reveal such a signature. The primary aim of this study was to characterise the differences in the plasma metabolome between JIA patients and non-JIA controls and identify specific markers of JIA subtype. We also assessed the extent to which these signatures are due to underlying inflammation as assessed by glycoprotein acetyls (GlycA) and high-sensitivity C-Reactive Protein (hsCRP) levels.

METHODS

Targeted nuclear magnetic resonance (NMR) metabolomic profiles of plasma of 72 children with JIA and 18 controls were assessed cross-sectionally. Associations between 71 metabolomic biomarkers and JIA, JIA subtype, disease activity status, and inflammation markers (GlycA and hsCRP) were assessed using multivariable linear regression models.

RESULTS

JIA was associated with higher GlycA (mean difference = 0.93 standard deviations, 95% confidence interval = [0.370, 1.494], Padj = 0.039) and docosahexaenoic acid (1.06, [0.51, 1.60], Padj = 0.021), and lower acetate (-0.92, [-1.43, -0.41], Padj = 0.024) relative to controls. This variation was largely driven by systemic JIA (sJIA), with 24 of 71 total biomarkers significantly different (Padj <0.05) relative to controls. There were no specific differences identified in oligoarticular (oJIA) or polyarticular (rheumatoid factor positive or negative) JIA relative to controls. Despite being generally highly correlated with hsCRP (r > 0.70), GlycA, but not hsCRP, was positively associated with active disease in sJIA (0.22, [-0.40, -0.04], Padj = 0.018), and 6 of 24 sJIA-associated markers were associated with GlycA levels. Only 1 sJIA-associated biomarker, histidine, was associated with hsCRP levels.

CONCLUSION

Differences in the plasma NMR metabolomic profiles are apparent in children with sJIA, but not other JIA subtypes, relative to non-JIA controls. These findings suggest a potential utility for classifying and monitoring JIA through metabolomic profiling, with chronic inflammation, measured by GlycA, potentially playing a role in at least some of these metabolomic differences.

Efficacy and safety of abatacept for systemic juvenile idiopathic arthritis: A systematic review

OBJECTIVES

This systematic review assessed the efficacy and safety of abatacept in patients with systemic juvenile idiopathic arthritis (JIA).

METHODS

Studies published between 2000 and 2021 were searched using PubMed, Embase, Cochrane, Ichushi-Web, and clinical trial registries. The risk of bias was assessed according to the manual for development clinical practice guidelines by Minds, a project to promote evidence-based medicine in Japan.

RESULTS

Seven observational studies were included. American College of Rheumatology pediatric 30/50/70 responses at 3, 6, and 12 months were 64.8%/50.3%/27.9%, 85.7%/71.4%/42.9%, and 80.0%/50.0%/40.0%, respectively. Outcomes on systemic symptoms, joint symptoms, and activities of daily living were not obtained. No macrophage activation syndrome or infusion reaction occurred. Serious infection occurred in 2.6% of cases.

CONCLUSIONS

Abatacept improved the disease activity index. In addition, abatacept was as safe as interleukin-6 (IL-6) and IL-1 inhibitors. However, both the efficacy and safety data in this systematic review should be reviewed with caution because their quality of evidence is low or very low. Further studies are needed to confirm the efficacy and safety of abatacept for systemic JIA, especially its efficacy on joint symptoms.

Efficacy and safety of tumor necrosis factor inhibitors for systemic juvenile idiopathic arthritis: A systematic review

OBJECTIVES

This systematic review assessed the efficacy and safety of tumor necrosis factor (TNF) inhibitors in patients with systemic juvenile idiopathic arthritis (JIA).

METHODS

Studies were searched using PubMed, Embase, Cochrane, Ichushi-Web, and clinical trial registries (from 2000 to 2021). The risk of bias was assessed using the Cochrane Risk of Bias version 2 for randomized controlled trials (RCTs) and the manual of Minds for observational studies.

RESULTS

One RCT and 22 observational studies were included. In the RCT on infliximab, the American College of Rheumatology pediatric (ACR Pedi) 30/50/70 responses at 14 weeks were 63.8%/50.0%/22.4%, with relative risks of 1.30 [95% confidence interval (CI): 0.94-1.79]/1.48 (95% CI: 0.95-2.29)/1.89 (95% CI: 0.81-4.40), respectively. In the observational studies, ACR Pedi 30/50/70 responses for etanercept at 12 months were 76.7%/64.7%/46.4%, respectively. Infliximab treatment caused anaphylaxis in 17% and an infusion reaction in 23% of patients. The incidence of macrophage activation syndrome, serious infection, and malignancy caused by TNF inhibitors was 0-4%.

CONCLUSIONS

Thus, although TNF inhibitors were relatively safe, they were unlikely to be preferentially administered in patients with systemic JIA because of their inadequate efficacy. Further studies, especially well-designed RCTs, are needed to accumulate clinical data.

Maximal mouth opening is a simple method to evaluate the treatment outcome of temporomandibular joint arthritis in patients with juvenile idiopathic arthritis

OBJECTIVE

Temporomandibular joint (TMJ) arthritis is a common finding in juvenile idiopathic arthritis (JIA) patients. TMJ arthritis can cause significant disturbances in TMJ function and growth without treatment. Our aim was to evaluate the effectiveness of medical treatments used to manage TMJ arthritis and how to evaluate the outcome of the treatment. Furthermore, this study aimed to ascertain the prevalence of TMJ arthritis in JIA patients and investigate the potential impact of specific factors.

MATERIAL AND METHODS

Between 2015 and 2019, a total of 194 JIA patients who received treatment at the Department of Oral and Maxillofacial Diseases, Helsinki University Hospital, Finland were included in the study. We retrospectively screened the patient records and imaging studies to find out how many patients had TMJ arthritis and what medication was used to treat it.

RESULTS

Maximal incisal mouth opening (MIO) increased significantly with patients whose TMJ arthritis was successfully treated with intra-articular corticosteroid injection (IACI). Almost all patients with TMJ arthritis were treated with an IACI at some point during their treatment. Overall, 99 patients (51%) had been diagnosed with TMJ arthritis. No statistical difference was found between the prevalence of TMJ arthritis and different JIA subtypes, JIA onset time, gender, or immunological factors.

CONCLUSION

MIO is an easy way to evaluate the treatment outcome and possible disease activation of TMJ arthritis. The prevalence of TMJ arthritis is high among JIA patients. In our study, we could not find any parameters that predict TMJ arthritis, and despite systemic medication, TMJ arthritis might occur.

Consensus on transition care for juvenile idiopathic arthritis: a Delphi study with youth, caregivers, and health professionals

BACKGROUND

The field of transitional care for chronic conditions in adolescents, notably juvenile idiopathic arthritis (JIA), is rapidly growing. Transitioning these patients to adult healthcare systems presents significant challenges in practical implementation. Consequently, it would be appropriate for each country to develop a transition program tailored to its specific infrastructure. To pursue this goal, a Delphi study was conducted to identify the key components of transitional care in JIA.

METHODS

Three panels and two rounds were held consisting of adolescents and young adults, parents, and clinicians (pediatric or adult rheumatologists). As a result, feedback on acceptance of the key statements of transitional care was obtained using the Delphi method.

RESULTS

Out of 102 contacted, 88 (86.3%) participants responded to the Round 1 survey, which included 48 clinicians, 20 youths, and 20 parents. In Round 2, the number of clinicians dropped to 29, while the number of youths and parents remained constant. Based on expert opinions, 29 statements were selected for the first round. Statements that received ≥ 70% approval in the first round advanced to the next round. Sixteen statements did not achieve ≥ 70% approval. Of the remaining, 12 were reviewed in the second round, while four were excluded.

CONCLUSION

Although consensus has been reached on the basic transitional care issues for JIA patients, several issues still need to be agreed upon. Acceptance and applicability of the final 20-item checklist in clinical practice are critical for advancing JIA transition care in Turkey.

Clinical outcomes of tocilizumab therapy in polyarticular and systemic juvenile idiopathic arthritis: a single-center analysis (2018-2022)

This single-center retrospective study aimed to evaluate the safety and efficacy of Tocilizumab (TOC) in children with polyarticular (pJIA) and systemic juvenile idiopathic arthritis (sJIA) who exhibited inadequate responses to disease-modifying antirheumatic drugs (DMARDs) and biological modifiers (bDMARDs). Conducted at the Department of Pediatric Rheumatology, National Institute of Geriatrics, Rheumatology, and Rehabilitation in Warsaw, Poland, between 2018 and 2022, the study enrolled 29 patients diagnosed with JIA based on International League of Associations for Rheumatology (ILAR) criteria. The cohort comprised 13 sJIA and 16 pJIA patients, aged 2-18 years, receiving TOC treatment for 24 months. Safety and efficacy assessments included analysis of medical documentation, laboratory tests (CRP, ESR, WBC), and Juvenile Disease Activity Score (JADAS) 71 at baseline, 3, 6, 12, and 24 months post-treatment initiation. Significant reductions in CRP and ESR levels were observed within three months, with sustained improvement in JADAS71 scores over the 24-month treatment period. A substantial majority, 73.07% of patients, achieved inactive disease status or low disease activity, highlighting T0C's effectiveness. Adverse effects were manageable, predominantly involving mild to moderate infections, with no serious adverse events or instances of macrophage activation syndrome (MAS). The study also noted a steroid-sparing effect of TOC, with a reduction in glucocorticoid usage among the cohort. Tocilizumab demonstrates substantial efficacy in reducing disease activity and improving clinical outcomes in patients with pJIA and sJIA, coupled with a favorable safety profile. These findings reinforce the role of TOC as a critical component of the therapeutic arsenal for JIA, offering hope for improved quality of life and disease management in this patient population.

Intraarticular corticosteroid injections in pediatric rheumatology: insights from specialists

Juvenile idiopathic arthritis (JIA) refers to various types of arthritis appearing before age 16, categorized into seven subtypes by ILAR. Treatments target disease control, growth support, and quality of life, utilizing NSAIDs, DMARDs, and intraarticular corticosteroid injections (IACIs). Despite IACIs' efficacy for oligoarticular JIA, their usage and techniques vary due to anecdotal evidence. This study compares IACI strategies among pediatric rheumatologists in Turkey and India as part of a PReS Sister Center activity. A cross-sectional survey via Google Forms gathered IACI practice data from pediatric rheumatologists in Turkey and India. The 33-item questionnaire covered demographics, JIA subtypes treated with IACIs, preferred agents/dosages, injection sites, follow-up, complications, anesthesia, and post-IACI treatments. Seventy clinicians' responses were analyzed, with ethical approval from Gazi University's Ethics Committee. Seventy participants, with a mean age of 39.75 (±8.80) years responded, mostly clinical fellows (38.6%) at university hospitals (58.6%). All utilized IACIs, primarily for oligoarticular JIA (100%), with 20% exclusively using them for this subtype. Triamcinolone hexacetonide (TH) was preferred (74.3%), mainly targeting knee joints (15.7%). Initial side effect follow-up was 1-2 weeks post-IACI (65.7%), with ultrasound guidance used by 17.1%. Common complications included cutaneous hypopigmentation (38.6%) and subcutaneous atrophy (38.6%). Ketamine was the favored anesthesia (44.2%). Post-IACI, 21.4% did not add treatment for new-onset oligoarticular JIA, while NSAIDs and methotrexate were common for polyarticular JIA (51.4%).

CONCLUSION

IACIs are widely utilized in pediatric rheumatology for oligoarticular JIA, yet practice variability exists. Standardized protocols through randomized studies can enhance IACI efficacy and patient outcomes.

WHAT IS KNOWN

• Intraarticular corticosteroid injections (IACIs) are a widely utilized and effective treatment modality in managing oligoarticular and polyarticular juvenile idiopathic arthritis (JIA), offering rapid symptom relief and the potential to prevent long-term joint deformities. • Despite their widespread use, there is significant variability in the indications, techniques, and anesthetic methods employed for IACI administration among pediatric rheumatologists, and much of the supporting evidence remains anecdotal.

WHAT IS NEW

• This study highlights the diverse clinical practices and preferences regarding IACI use in pediatric rheumatology across two different countries, revealing considerable variations in the use of ultrasound guidance, anesthetic approaches, and corticosteroid formulations. • The findings underscore the need for standardized treatment protocols and further research to optimize IACI procedures, aiming to reduce variability and improve outcomes in the management of JIA.

Validation of the ankle-specific pediatric arthritis ultrasound scoring system in children with juvenile idiopathic arthritis

OBJECTIVE

To validate the ankle-specific Pediatric Arthritis Ultrasound Scoring System (PAUSS-ankle) in children with juvenile idiopathic arthritis (JIA).

METHODS

Patients with a diagnosis of JIA prospectively underwent a standard clinical assessment and musculoskeletal ultrasound (MSUS) of one or both ankles. B-mode and Power-Doppler mode MSUS images were acquired and scored according to the PAUSS-ankle protocol. A subset of patients received a contrast-enhanced MRI (ceMRI) of the affected ankle. ceMRI scoring for synovitis was performed according to the Rheumatoid Arthritis MRI System (RAMRIS). Test characteristics of the PAUSS-ankle scores were evaluated with ceMRI as reference. Associations between the findings on physical examination, PAUSS-ankle, and RAMRIS were investigated.

RESULTS

Thirty-two patients with JIA contributed 63 MSUS and 15 ceMRIs of the ankles. The PAUSS-ankle total B-mode score had a moderate correlation with physical examination findings (correlation (r)=0.43, p < 0.001). The PAUSS-ankle B-mode score ≥1 exhibited a sensitivity of 79 % and specificity of 100 %, demonstrating excellent diagnostic accuracy with an area under the curve (AUC)= 0.89 (confidence intervals, CI, 0.78-1.00) while clinical assessment had a sensitivity of 57 % and AUC= 0.71 (CI: 0.58-0.85). The PAUSS-ankle B-mode score had significant strong correlations (r = 0.68-0.90, p < 0.005) with the RAMRIS for the assessment of disease severity for each joint area and the ankle joint as a whole.

CONCLUSION

Our findings demonstrate excellent diagnostic accuracy of the PAUSS-ankle in detecting the presence and severity of ankle synovitis when compared to ceMRI. The PAUSS-ankle holds significant promise as an accurate measurement that may complement current clinical standards.

Integrated analysis of multi-omics data for the discovery of biomarkers and therapeutic targets for juvenile idiopathic arthritis

Background

Juvenile idiopathic arthritis (JIA) is a prevalent chronic rheumatic disease affecting children. Current medications merely alleviate symptoms rather than curing the disease. Hence, the identification and development of novel drug targets and biomarkers for JIA are imperative for enhancing treatment efficacy.

Methods

We employed two-sample Mendelian randomization (MR) analysis to investigate the causal effects of plasma proteins on JIA. Additionally, colocalization, bulk RNA-seq, and single-cell RNA-seq analyses were conducted to further investigate and validate the potential of candidate proteins as drug targets.

Results

Through MR analysis, we successfully identified five plasma proteins that are causally linked to JIA. Genetically inferred lower levels of AIF1, TNF, and TNFSF11 were associated with an elevated risk of JIA, while higher levels of AGER and GP1BA proteins were positively correlated with JIA risk. Colocalization analysis further supported our findings on GP1BA (OR = 9.26, 95 % CI: 2.30-37.20) and TNFSF11 (OR = 0.18, 95 % CI: 0.07-0.45). Based on this evidence, we classified these five proteins into two tiers. Finally, we conducted a systematic evaluation of the druggability and current drug development progress for these identified candidate proteins.

Conclusions

This study employed MR analysis to reveal causal relationships between plasma proteins and JIA, identifying five potential candidate proteins as promising drug targets for JIA, particularly focusing on GP1BA and TNFSF11.

Causal Effects of Rheumatoid Arthritis, Ankylosing Spondylitis, Juvenile Idiopathic Arthritis on Psoriasis: A Mendelian Randomization Study

Background

It is well-documented that rheumatoid arthritis (RA), ankylosing spondylitis (AS), and juvenile idiopathic arthritis (JIA) often exhibit skin manifestations, with psoriasis typically occurring around the time of diagnosis. Thus, it is essential to investigate the potential causal relationship between these forms of arthritis and psoriasis.

Methods

The OpenGWAS provided traitIDs for exposure factors (RA (bbj-A-74), AS (ebi-A-GCST005529), and JIA (finn-b-JUVEN-ARTHR)) and outcome (psoriasis, finn-b-L12-PSORIASIS). bbj-A-74 had 19,190 samples (9,739,303 SNPs), ebi-A-GCST005529 had 22,647 samples (99,962 SNPs), finn-b-JUVEN-ARTHR had 173,622 samples (16,380,296 SNPs), and psoriasis had 216,752 samples (16,380,464 SNPs). Initially, 57 RA SNPs, 25 AS SNPs, and 5 JIA SNPs were acquired. Causal links were explored via univariate Mendelian Randomization (UVMR) analysis, with sensitivity analyses ensuring reliability. Additionally, multivariate MR (MVMR) analysis was conducted to further estimate the effect of each exposure factor on psoriasis.

Results

Significant causal links (P < 0.05, OR > 1) were found between bbj-A-74, ebi-A-GCST005529, finn-b-JUVEN-ARTHR, and finn-b-L12-PSORIASIS, indicating associations of RA, AS, and JIA with psoriasis. Sensitivity analyses ensured the reliability of these finding, showing no heterogeneity, horizontal pleiotropy, or SNP locus oversensitivity in UVMR results. Furthermore, MVMR analysis revealed AS and JIA as psoriasis risk factors, while RA showed non-significant protective effects. This suggests AS and JIA may contribute to psoriasis onset or exacerbation when coexisting.

Conclusion

MR analyses were conducted to investigate the causal links between RA, AS, JIA, and psoriasis, enhancing our grasp of the underlying mechanisms of psoriasis.