ObjectiveCamptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP) and juvenile idiopathic arthritis (JIA) both feature joint effusions. This study aimed to identify preliminary MSUS-based criteria that may help discriminate children with CACP from those with polyarticular JIA.MethodsA retrospective multicentre analysis of MSUS images from children with genetically confirmed CACP or a diagnosis of active polyarticular JIA was performed. Joint and tendon findings were evaluated using qualitative B-mode (BM) and Doppler-mode (DM) assessment and graded semi-quantitatively (0–3) according to OMERACT definitions.ResultsAll four children with CACP showed symmetrical joint involvement, with effusion present in 46/46 scanned joints and no intrasynovial hypervascularity (median DM = 0). In the JIA cohort (n = 6) 16/42 joints had asymmetric effusions, of which 56% showed intrasynovial hypervascularity (median DM = 1). All 16/16 scanned tendons in the CACP group showed no DM signal, whereas hypervascularity was observed in 7/8 affected tendons in the JIA cohort. Hyperechoic foci, suggestive of increased synovial fluid viscosity, were present in 18/46 (39%) affected joints in the CACP group compared to 1/16 (6%) in the JIA cohort.ConclusionCACP is characterised by symmetrical large-joint effusions with hyperechoic foci and absence of intrasynovial DM signal, in contrast to inflammatory findings in JIA. These features may support early differentiation of CACP from JIA and therefore prompt earlier specific diagnostics, including genetic testing.

To identify serum biomarkers associated with the development of uveitis in a German juvenile idiopathic arthritis (JIA) cohort. A convenience sample, enriched for uveitis cases, was drawn from a prospectively followed inception cohort of newly diagnosed JIA patients (ICON). Baseline serum samples were biobanked, and each was tested for conventional and novel autoantibodies using multi-analyte array technologies. Associations between uveitis occurrence, disease outcomes, and autoantibody profiles were examined. Fifty-two patients with and 141 patients without uveitis were included in the analyses. At first uveitis documentation, 26

Objectives To determine the prevalence of depressive and anxiety symptoms among young people 7 years and 9 years after inclusion in the multicentre, prospective inception cohort (ICON) of newly diagnosed patients with juvenile idiopathic arthritis (JIA) in Germany, and to identify factors associated with mental health problems at study inclusion and in the course of the disease.Methods Patients and controls (healthy peers, eg, friends of the same age and sex) from the ICON cohort (both ≥13 years) were assessed for mental health using the Patient Health Questionnaire-9 and the Generalised Anxiety Disorder Scale-7 at 7-year and 9-year follow-ups. Demographic and clinical characteristics, treatments and health-related quality of life (HRQoL) (Pediatric Quality of Life Inventory (PedsQL)) were documented at baseline and follow-up visits. Cross-sectional (analysis of variance or χ² tests at 7-year/9-year follow-up) and longitudinal analyses (generalised linear mixed models for PedsQL in follow-up from baseline) were conducted, respectively.Results A total of 344 patients (age 18.7±3.5 years, disease duration 9.2±1.8 years, 42% polyarthritis) and 224 controls (age 18.2±3.6 years) were evaluated. Moderate to severe symptoms of depression and anxiety were present in 13% and 10% of patients, respectively, compared with 7% and 2% of controls. Patients with moderate to severe psychological distress did not exhibit significantly higher physician-reported disease activity at inclusion and follow-up but reported worse patient-reported outcomes. These patients already showed reduced emotional functioning 3 months after diagnosis (p<0.001) and reported lower physical and emotional functioning (p<0.001) after the first year of specialised care compared with those without relevant mental health problems at long-term follow-up.Conclusion Poor emotional functioning at the start of care for JIA may be an indicator of future mental health issues. Therefore, HRQoL should be routinely assessed at treatment initiation to identify at-risk patients early and provide targeted support.

Introduction:Juvenile idiopathic arthritis (JIA) is the commonest rheumatologic disease in children and frequently affects the knee joint. Synovial inflammation and tenosynovitis are key pathological features, and ultrasound plays an increasingly important role in their assessment. Superb Microvascular Imaging (SMI) is a novel Doppler technique with enhanced sensitivity to low-velocity microvascular flow, but evidence on its repeatability in JIA remains limited. This study aimed to evaluate intra- and inter-observer repeatability of knee SMI in children with JIA. Methods:In this prospective multicenter study (June 2023-October 2024), 76 children with JIA were examined (Hannover Medical School and St. Josef-Stift Sendenhorst). Each underwent three standardized SMI scans: two by the same and one by a different examiner. Synovial vascularity was graded using the Pediatric OMERACT scoring system. Intra- and inter-observer reliability measures were calculated using intra-class correlation coefficients (ICC). Agreement between longitudinal and transverse suprapatellar planes was assessed using weighted kappa statistics, and correlations with clinical disease activity were analyzed via logistic regression. Results:Intra-observer reliability was excellent (ICC = 0.972, 95% CI: 0.956-0.982). Inter-observer reliability was strong (ICC = 0.828-0.928), regardless of examiner experience. Agreement between imaging planes was substantial (κ = 0.72, p = 0.32). Synovial vascularity scores correlated significantly with clinical measures of active arthritis (OR = 1.182, p = 0.0004), particularly with swelling (OR = 1.249, p < 0.0001). Discussion:SMI demonstrates excellent repeatability for assessing synovial vascularity in JIA. Its reliability, examiner independence, and non-invasive nature support its use for routine monitoring and longitudinal disease evaluation in pediatric rheumatology.

OBJECTIVE:The objective of this study was to evaluate the novel Musculoskeletal Ultrasound Sum Score (MUSS) as a longitudinal marker of disease activity (DA) in patients with JIA within a treat-to-target management approach. METHODS:Demographics, clinical, laboratory and US (B Mode, BM; Power Doppler Ultrasound, PDU; scored 0-3, using the paediatric OMERACT score) findings were recorded over a 1-year follow-up in the PRO-KIND cohort. The US imaging of joints was individual to the patient, determined by the treating clinicians (unaware of the study aims) as routine. MUSS (a combination of the highest single BM grade of all examined joints + the highest single PDU grade of all examined joints) was calculated (maximum score 6). Spearman correlations with clinical activity measures and ROC-derived MUSS cut-offs for clinical inactive disease were calculated, using pooled visit-level data. RESULTS:Thirty-three JIA patients were included (oligoarthritis: n = 12, median age 4.4 years; polyarthritis: n = 21, 5.3 years). The median baseline MUSS was similar between subtypes. MUSS values decreased significantly over follow-up, paralleling improvements in JADAS-10 and global assessment scores. MUSS correlated strongly with JADAS-10, physician and parent/patient global scores (Ρ = 0.68-0.81; all P < 0.001) and with ESR in polyarthritis (Ρ = 0.57; P < 0.001). ROC analysis identified a MUSS cut-off of ≥1 as optimal for detecting active disease (specificity 100%, sensitivity 55%). CONCLUSION:MUSS is a promising, feasible sonographic score for longitudinal monitoring of disease activity in JIA, showing strong correlations with clinical measures and excellent specificity for active disease at a cut-off of ≥1. Validation in independent, prospective cohorts is warranted.

OBJECTIVES:Juvenile idiopathic arthritis (JIA) in infants is extremely rare, making diagnosis particularly challenging. This study examines the characteristics of JIA in infancy, including early symptoms, time to diagnosis, JIA categories, treatment approaches and clinical outcomes. METHODS:Infants diagnosed with JIA were included in the study if enrolled in the German National Pediatric Rheumatology Database (NPRD) between 2011 and 2020 and followed prospectively. NPRD data were retrospectively supplemented using a dedicated infant-onset JIA module. To analyse differences in disease presentation, the infant-onset cohort was matched with NPRD patients who developed JIA between the ages of >1 and <6 years (toddler-onset JIA). RESULTS:Ninety individuals (62% female) with infant-onset JIA were identified across 18 pediatric rheumatology centres in Germany, with disease onset at 9.5 ± 2.64 months. Compared with toddlers, infants were more frequently affected by systemic JIA. Time from symptom onset to first rheumatology consultation was significantly longer in infants than toddlers (3.1 vs 2.3 months, P = 0.025). At follow-up, disease-modifying anti-rheumatic drugs (DMARDs) were prescribed in 66% of patients with infant-onset JIA and 59% with toddler-onset JIA. Although both groups exhibited similar disease activity at enrolment, the infant-onset group had significantly higher disease activity at follow-up (cJADAS10: 3.0 vs 2.1; P = 0.034). CONCLUSION:Very early-onset JIA is often diagnosed late, delaying appropriate care. Our study underscores the need for improved awareness and earlier recognition of non-infectious arthritis in infants, along with timely initiation of effective treatment to minimize potential long-term consequences.

Juvenile idiopathic arthritis-associated uveitis (JIAU) typically takes a chronic course, frequently leading to ocular complications and often requiring long-term treatment. The present study assesses the 5-years outcome of JIAU by analyzing data from a prospective study initiated in 2010. Data from 75 patients with onset of uveitis after study enrollment, and with a documentation at 5-years follow-up (5yFU) were available for analysis of uveitis characteristics, frequency and predictors of „inactivity on medication “ (defined as inactive uveitis for ≥ 6 months) and „inactivity off medication “ (defined as inactive uveitis for ≥ 6 months off medication). At the 5yFU, visual acuity remained good in the majority of eyes (LogMAR < 0.1 in 65.5

Whilst musculoskeletal ultrasound (MSUS) normal values for examination of the hip joint have been established for healthy children, equivalent values for patients with juvenile idiopathic arthritis (JIA), as well as internationally validated MSUS protocols for the optimal evaluation of synovitis are lacking. This study aimed to develop and validate the most sensitive MSUS protocol for the detection of hip synovitis in JIA. In consecutive JIA patients with ≥ 1 clinically affected hip joint, affected and unaffected hips underwent MSUS. Disease, demographic and clinical findings were recorded. Synovitis was graded using the pediatric OMERACT score for B-Mode (BM) and power-Doppler Mode (PD) in the longitudinal and transverse scans and the sensitivity and specificity was analyzed. Additionally anterior recess size (bone to capsula distance), capsula thickness and femoral head cartilage thickness (transverse view) were measured. Published data provided further control data for anterior recess size (children without JIA). Interobserver reliability of BM and PD was tested using Fleiss-Kappa. 60 patients were enrolled who had 76 hips with and 32 without clinical arthritis. BM was positive (grade ≥ 1) in 74/76 of hips with clinical arthritis (97

Die zunehmende Bedeutung der Ultraschalltechnik in der Kinderrheumatologie spiegelt sich in vielen wissenschaftlichen Projekten, in zunehmenden Weiterbildungsangeboten sowie im alltäglichen Einsatz wider. Mehrere internationale Arbeitsgruppen haben sich innerhalb der letzten Jahre darum bemüht, standardisierte Untersuchungsprotokolle für die Gelenksonographie zu entwickeln. Der Artikel fasst die aktuellen Fortschritte der Ultraschalldiagnostik bei Kindern und Jugendlichen mit rheumatischen Erkrankungen zusammen und geht dabei auf technische Entwicklungen, verbesserte Weiterbildungsmöglichkeiten, die Implementierung in das Treat-to-target-Management sowie die Ausweitung auf weitere Anwendungsgebiete in der Kinderrheumatologie ein. Zur Bestimmung der Krankheitsaktivität und Beschreibung von pathologischen Befunden wurden unter Berücksichtigung der altersabhängigen Veränderungen am Bewegungsapparat sonographische Definitionen abgestimmt und erste pädiatrische Scoringsysteme in Validierungsstudien überprüft. Mehrere Publikationen der vergangenen Jahre haben gezeigt, dass der Gelenkultraschall der klinischen Untersuchung in bestimmten Gelenkregionen überlegen ist. Mehrere Arbeiten konnten auch die wichtige Rolle im Therapie- und Verlaufsmonitoring darlegen. Auch außerhalb der Gelenkregionen, wie z. B. bei der Darstellung von Speicheldrüsen oder Muskulatur, gewinnt der Ultraschall eine zunehmende Bedeutung in der Kinder- und Jugendrheumatologie. Fortschritte in der technischen Entwicklung und Expertise auf dem Gebiet des Ultraschalls haben dazu geführt, dass der Ultraschall eine wichtige Bedeutung in der Versorgung von Kindern und Jugendlichen mit rheumatischen Erkrankungen gewonnen hat.

Children and adolescents with juvenile idiopathic arthritis (JIA) are at increased risk for long-term physical and psychosocial complications, making physical activity (PA) and sedentary behaviour (SB) key modifiable lifestyle factors. Although increasingly acknowledged as relevant, data on the daily distribution of these behaviours in JIA remain scarce. This study aimed to (1) describe the time-use composition of SB and PA intensities in young people with JIA, (2) identify correlates of greater relative time spent in SB, and (3) compare movement behaviour patterns to matched population controls using a compositional data analysis (CoDA) approach. Patients aged 10–20 years with JIA and individually matched population controls wore hip-worn accelerometers (ActiGraph wGT3X-BT) for eight consecutive days. Movement behaviours were categorized into SB, light-intensity PA, and moderate-to-vigorous PA (MVPA) using validated, age-specific cut-points. CoDA with log-ratio transformations was used to model associations and compare groups. Diifferences in movement composition were assessed using adjusted multivariate analysis of variance (MANOVA). Data from 126 matched pairs (mean age: 15.0 ± 2.1 years; 67

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.

Objective The potential involvement of adaptive immunity in systemic juvenile idiopathic arthritis (sJIA) pathophysiology remains an intriguing question. Here, we investigated whether and how the inflammatory environment in sJIA versus JIA synovial fluid (SF) may differentially impact T helper (Th) cell polarization and activation. Methods SF samples from sJIA and JIA patients (both n=7) were tested in various cell culture setups, with or without recombinant cytokines or cytokine-blocking drugs, to assess their effects on healthy donor Th cell activation. We analyzed cellular surface marker, transcription factor, and effector molecule expression using flow cytometry, Luminex, ELISA, and qRT-PCR. Results Both sJIA and JIA SF revealed highly pro-inflammatory profiles. Compared to JIA, sJIA SF demonstrated markedly elevated IL-1β, IL-18, GM-CSF, S100A9, and MPO levels, while JIA SF showed trends toward higher soluble FasL and IL-17A concentrations. Notably, sJIA SF significantly increased CD4 T cell ICOS expression and expanded CXCR3posCCR6pos Th cells, whereas JIA SF favored expansion of CXCR3negCCR6pos Th cells and CCR6pos Th cell expansion was sensitive to IL-1 blockade. Systemic JIA SF selectively sustained a IFNγ/IL-21 expressing T peripheral helper (Tph) phenotype, particularly associated with IL-1β, IL-18, and GM-CSF SF levels. Spiking JIA SF with a cocktail of these cytokines recapitulated some T cellular phenotypic features observed in sJIA SF cultures. Conclusion JIA and sJIA SF drive distinct Th cell polarization, including differential and sustained Tf/ph cell activation. These findings complement our earlier observations in sJIA peripheral blood and demonstrate the impact of the SF inflammatory matrix on immune cell activation. What is already known on this topic What this study adds How this study might affect research, practice or policy ### Competing Interest Statement CB received consultancy fees from Sobi and Novartis and speaker fees from GSK. MP received consultancy fees from Sobi and Novartis. CH has received honoraria (lecture fees) from Novartis; HW has received honoraria (lecture fees) from Novartis and Takeda, and travel support from Octapharma and CSL-Behring; DF received speaker fees/honoraria from Chugai-Roche, Novartis and SOBI as well as research support from Novartis, Pfizer and SOBI. HM received honoraria (lectures fees) and travel support from Novartis. No other disclosures relevant to this article were reported. CK has received consulting fees from Novartis and Swedish Orphan Biovitrum (SOBI) (< $10,000 each) and received research support from Novartis (> $10,000). Interdisciplinary Center for Clinical Research (IZKF) Wuerzburg, Z-3/BC-13 Italian Ministry of Health Federal Ministry of Education and Research (BMBF), 01EO2108 German Research Foundation (DFG), MO 2160/4-1, KE 2026 1/3

Das Hüftgelenk gehört im Kindesalter mit der Coxitis fugax zu den am häufigsten von einer Gelenkentzündung betroffenen anatomischen Regionen. Hinter einem Erguss im kindlichen Hüftgelenk kann sich jedoch auch ein vielfältiges Spektrum kindlicher Arthritiden einschließlich anderer wichtiger Differenzialdiagnosen verbergen. In Ergänzung zum klinischen Befund nimmt der Gelenkultraschall in der Diagnostik und Abklärung dieser Region eine zentrale Rolle ein. Mit zunehmendem Einsatz des Gelenkultraschalls verbessern sich die diagnostischen Möglichkeiten sowohl bei der Diagnosestellung und Abgrenzung als auch im Verlaufsmonitoring einer kindlich rheumatischen Hüftbeteiligung. Neben den typischen sonografischen Zeichen einer Gelenkentzündung lassen sich im Bereich der Hüftgelenke auch rheumatische Sehnenansatzentzündungen, Schleimbeutelentzündungen oder Knochenläsionen nachweisen. Wichtige Differenzialdiagnosen können sonografisch ausgeschlossen oder bestätigt werden. Die zunehmende Standardisierung erhöht die Zuverlässigkeit dieser bedienerabhängigen Bildgebungstechnik und hilft bei der praktischen Durchführung, Beurteilung und Quantifizierung der pathologischen Befunde.