Safety and effectiveness of abatacept in juvenile idiopathic arthritis: results from the PRINTO/PRCSG registry.

OBJECTIVE: To report the interim 5-year safety and effectiveness of abatacept in patients with juvenile idiopathic arthritis (JIA) in the PRINTO/PRCSG registry. METHODS: The Abatacept JIA Registry (NCT01357668) is an ongoing observational study of children with JIA receiving abatacept; enrolment started in January 2013. Clinical sites enrolled patients with JIA starting or currently receiving abatacept. Eligible patients were assessed for safety (primary end point) and effectiveness over 10 years. Effectiveness was measured by clinical 10-joint Juvenile Arthritis Disease Activity Score (cJADAS10) in patients with JIA over 5 years. As-observed analysis is presented according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. RESULTS: As of 31 March 2020, 587 patients were enrolled; 569 are included in this analysis (including 134 new users) with 1214.6 patient-years of safety data available. Over 5 years, the incidence rate (IR) per 100 patient-years of follow-up of serious adverse events was 5.52 (95% confidence interval [CI]: 4.27, 7.01) and of events of special interest was 3.62 (95% CI: 2.63, 4.86), with 18 serious infections (IR 1.48 [95% CI: 0.88, 2.34]). As early as month 3, 55.9% of patients achieved cJADAS10 low disease activity and inactive disease (20.3%, 72/354 and 35.6%, 126/354, respectively), sustained over 5 years. Disease activity measures improved over 5 years across JIA categories. CONCLUSION: Abatacept was well tolerated in patients with JIA, with no new safety signals identified and with well-controlled disease activity, including some patients achieving inactive disease or remission. TRIAL REGISTRATION: Clinicaltrials.gov, NCT01357668.

A clinical prediction model for estimating the risk of developing uveitis in patients with juvenile idiopathic arthritis.

OBJECTIVE: To build a prediction model for uveitis in children with JIA for use in current clinical practice. METHODS: Data from the international observational Pharmachild registry were used. Adjusted risk factors as well as predictors for JIA-associated uveitis (JIA-U) were determined using multivariable logistic regression models. The prediction model was selected based on the Akaike information criterion. Bootstrap resampling was used to adjust the final prediction model for optimism. RESULTS: JIA-U occurred in 1102 of 5529 JIA patients (19.9%). The majority of patients that developed JIA-U were female (74.1%), ANA positive (66.0%) and had oligoarthritis (59.9%). JIA-U was rarely seen in patients with systemic arthritis (0.5%) and RF positive polyarthritis (0.2%). Independent risk factors for JIA-U were ANA positivity [odds ratio (OR): 1.88 (95% CI: 1.54, 2.30)] and HLA-B27 positivity [OR: 1.48 (95% CI: 1.12, 1.95)] while older age at JIA onset was an independent protective factor [OR: 0.84 (9%% CI: 0.81, 0.87)]. On multivariable analysis, the combination of age at JIA onset [OR: 0.84 (95% CI: 0.82, 0.86)], JIA category and ANA positivity [OR: 2.02 (95% CI: 1.73, 2.36)] had the highest discriminative power among the prediction models considered (optimism-adjusted area under the receiver operating characteristic curve = 0.75). CONCLUSION: We developed an easy to read model for individual patients with JIA to inform patients/parents on the probability of developing uveitis.

Clinical Validation of Superficial Lip Injections Utilizing Cohesive Polydensified Matrix Hyaluronic Acid-Based Soft Tissue Fillers.

BACKGROUND: A combination of optimal injection technique and dermal filler choice is key for improving lip architecture with natural and long-lasting results. OBJECTIVE: To investigate the positioning of Cohesive Polydensified Matrix™ (CPM) hyaluronic acid (HA) fillers after superficial lip injections and document their tissue integration and effects on lip architecture and shape. METHODS: Eligible patients underwent lip contouring and volumization using a superficial direct tissue action technique. All injections were performed with CPM-HA lip fillers using a 30G needle and retrograde microthreading. Total injected volume was 0.8-1.2 mL. High-resolution ultrasound (US) imaging, 3D surface scanning, and Global Aesthetic Improvement Scale (GAIS) assessments were performed before, and 1, 3 and 6 months post-injection to define the anatomy, positioning, longevity and patient satisfaction. RESULTS: Sixteen patients were injected (mean age, 33.2 years). US measurements revealed an increased skin–orbicularis oris muscle distance up to 1 month post-injection after which measurements returned to baseline values. This observation correlated with complete product integration into the surrounding tissue visualized by US at 3 months. An increased dry mucosa thickness (vermilion body) remained at 6 months, and GAIS scores revealed 70% of patients continued to experience visible lip improvements. 3D analyses revealed significantly increased total lip surface area at 3 months with increased Cupid’s bow distance, philtral height, and anterior upper lip projection. CONCLUSION: Superficial injection of CPM-HA fillers offers an effective and safe tool for improving lip architecture and volume. Results showed homogeneous dermal integration of the product and aesthetic outcomes maintained up to 6 months. J Drugs Dermatol. 2021;20(9):940-945. doi:10.36849/JDD.6011.

Subcutaneous golimumab for children with active polyarticular-course juvenile idiopathic arthritis: results of a multicentre, double-blind, randomised-withdrawal trial.

OBJECTIVE: This report aims to determine the safety, pharmacokinetics (PK) and efficacy of subcutaneous golimumab in active polyarticular-course juvenile idiopathic arthritis (polyJIA). METHODS: In this three-part randomised double-blinded placebo-controlled withdrawal trial, all patients received open-label golimumab (30 mg/m2 of body surface area; maximum: 50 mg/dose) every 4 weeks together with weekly methotrexate during Part 1 (weeks 0-16). Patients with at least 30% improvement per American College of Rheumatology Criteria for JIA (JIA ACR30) in Part 1 entered the double-blinded Part 2 (weeks 16-48) after 1:1 randomisation to continue golimumab or start placebo. In Part 3, golimumab was continued or could be restarted as in Part 1. The primary outcome was JIA flares in Part 2; secondary outcomes included JIA ACR50/70/90 responses, clinical remission, PK and safety. RESULTS: Among 173 patients with polyJIA enrolled, 89.0% (154/173) had a JIA ACR30 response and 79.2%/65.9%/36.4% demonstrated JIA ACR50/70/90 responses in Part 1. At week 48, the primary endpoint was not met as treatment groups had comparable JIA flare rates (golimumab vs placebo: 32/78=41% vs 36/76=47%; p=0.41), and rates of clinical remission were comparable (golimumab vs placebo: 10/78=12.8% vs 9/76=11.8%). Adverse event and serious adverse event rates were similar in the treatment groups during Part 2. Injection site reactions occurred with <1% of all injections. PK analysis confirmed adequate golimumab dosing for polyJIA. CONCLUSION: Although the primary endpoint was not met, golimumab resulted in rapid, clinically meaningful, improvement in children with active polyJIA. Golimumab was well tolerated, and no unexpected safety events occurred. CLINICAL TRIAL REGISTRATION: NCT01230827; Results.

The German version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR).

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the German language. The reading comprehension of the questionnaire was tested in 10 JIA parents and patients. The participating centres were asked to collect demographic and clinical data along the JAMAR questionnaire in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the three Likert assumptions, floor/ceiling effects, internal consistency, Cronbach's alpha, interscale correlations, test-retest reliability, and construct validity (convergent and discriminant validity). A total of 319 JIA patients (2.8% systemic, 36.7% oligoarticular, 23.5% RF negative polyarthritis, and 37% other categories) and 100 healthy children were enrolled in eight centres. The JAMAR components discriminated well healthy subjects from JIA patients. All JAMAR components revealed good psychometric performances. In conclusion, the German version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and in clinical research.

Juvenile idiopathic arthritis - the role of imaging from a rheumatologist's perspective.

Alongside recent advances in treatment strategies for juvenile idiopathic arthritis (JIA), paediatric rheumatologists have taken increasing interest in the use of imaging. Magnetic resonance imaging (MRI) and musculoskeletal ultrasound, by providing more detailed information on disease activity than clinical examination and conventional radiography (CR), have become helpful diagnostic and managerial tools. The growing skeleton, however, with changing appearances over time, is still challenging in the establishment of valid scoring systems for pathological changes. Defining child- and age-specific reference standards is therefore a highly prioritized issue. The aim of this article is to raise awareness among radiologists of the substantial role that imaging can play to optimize the management of JIA patients and to describe the state-of-the-art validation process of imaging as an outcome measure. A closer collaboration between radiologists and pediatric rheumatologists is crucial to define a scheduled workflow for imaging in JIA.

Imaging of the knee in juvenile idiopathic arthritis.

In juvenile idiopathic arthritis (JIA), imaging is increasingly used in clinical practice. In this paper we discuss imaging of the knee, the clinically most commonly affected joint in JIA. In the last decade, a number of important steps have been made in the development of imaging outcome measures in children with JIA knee involvement. Ultrasound is undergoing a fast validation process, which should be accomplished within the next few years. The validation processes of MRI as an imaging biomarker for clinical trials in the JIA knee are at an advanced stage, with important data available on the feasibility, reliability and validity of the Juvenile Arthritis MRI Scoring system. Moreover, both US and MRI data are emerging on the normal appearance of the growing knee joint.

Imaging in juvenile idiopathic arthritis - international initiatives and ongoing work.

Imaging is increasingly being integrated into clinical practice to improve diagnosis, disease control and outcome in children with juvenile idiopathic arthritis. Over the last decades several international groups have been launched to standardize and validate different imaging techniques. To enhance transparency and facilitate collaboration, we present an overview of ongoing initiatives.

Imaging of temporomandibular joint abnormalities in juvenile idiopathic arthritis with a focus on developing a magnetic resonance imaging protocol.

Inflammation and damage in the temporomandibular joint (TMJ) often develop without clinical symptoms but can lead to severe facial growth abnormalities and impaired health-related quality of life, making early diagnosis of TMJ changes crucial to identify. Inflammatory and osteochondral changes detectable through magnetic resonance imaging (MRI) occur in TMJs of approximately 40% of children with juvenile idiopathic arthritis (JIA), and no other imaging modality or physical method of examination can reliably detect these changes. Therefore contrast-enhanced MRI is the diagnostic standard for diagnosis and interval monitoring of JIA. However the specific usage of MRI for TMJ arthritis is not standardized at present. There is a recognized need for a consensus effort toward standardization of an imaging protocol with required and optional sequences to improve detection of pathological changes and shorten study time. Such a consensus imaging protocol is important for providing maximum information with minimally necessary sequences in a way that allows inter-site comparison of results of clinical trials and improved clinical management. In this paper we describe the challenges of TMJ imaging and present expert-panel consensus suggestions for a standardized TMJ MRI protocol.

Proinflammatory stimuli induce galectin-9 in human mesenchymal stromal cells to suppress T-cell proliferation.

Human multipotent mesenchymal stromal cells (MSCs) are clinically applied to treat autoimmune diseases and graft-versus-host disease due to their immunomodulatory properties. Several molecules have been identified to mediate these effects, including constitutively expressed galectin-1. However, there are indications in the literature that MSCs exert enhanced immunosuppressive functions after interaction with an inflammatory environment. Therefore, we analyzed how inflammatory stimuli influence the expression of the galectin network in MSCs and functionally tested the relevance for the immunomodulatory effects of MSCs. We found that galectin-9 was strongly induced in MSCs upon interaction with activated PBMCs. Proinflammatory cytokines, such as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α), and also ligands of the Toll-like receptors (TLRs) TLR2, TLR3, and TLR4 elicited similar induction of galectin-9 in activated PBMCs. Galectin-9 was not only upregulated intracellularly, but also released by MSCs in significant amounts into the supernatant after exposure to proinflammatory stimuli. In proliferation assays, MSCs with a galectin-9 knockdown lost a significant portion of their antiproliferative effects on T cells. In conclusion, we found that unlike constitutively expressed galectin-1, galectin-9 is induced by several proinflammatory stimuli and released by MSCs. Thus, galectin-9 contributes to the inducible immunomodulatory functions of MSCs.

Systematic calibration reduces sources of variability for the preliminary OMERACT juvenile idiopathic arthritis MRI- sacroiliac joint score (OMERACT JAMRIS-SIJ).

OBJECTIVE: To determine whether systematic calibration enhances scoring proficiency of the OMERACT juvenile idiopathic arthritis MRI-Sacroiliac Joint score (JAMRIS-SIJ) and whether contrast-enhancement enhances its performance. METHODS: MRI SIJ scans of 50 cases with juvenile spondyloarthritis were scored by 7 raters after calibration with 3 different knowledge transfer tools. RESULTS: Calibrated readers achieved greater reliability for scoring certain inflammatory and structural lesions. Sensitivity and reliability for scoring inflammatory lesions was greater on fluid-sensitive compared to contrast-enhanced sequences. CONCLUSION: Systematic calibration should be implemented prior to the use of JAMRIS-SIJ for clinical trials. It is unlikely that contrast-enhanced MRI will improve the performance of this method.

Reliability assessment of the OMERACT whole-body magnetic resonance imaging scoring system for juvenile idiopathic arthritis.

Inter-reader reliability of a new scoring system for evaluating joint inflammation and enthesitis in whole body MRI (WBMRI) in juvenile idiopathic arthritis was tested. The scoring system grades 732 item-region combinations of bone marrow and soft tissue changes for commonly involved joints and entheseal sites. Five radiologists rated 17 WBMRI scans through an online rating platform. Item-wise reliability was calculated for 117 items with non-zero scores in >10 % of readings. Interquartile ranges of the five-reader Kappa reliability coefficients were 0.58-0.73 (range: 0.36-0.88) for the joints, 0.65-0.81 (range: 0.39-0.95) for the entheses, and 0.62-0.75 (range: 0.60-0.76) for chronic nonbacterial osteomyelitis-like lesions.

Long-Term Maintenance of Clinical Responses by Individual Patients With Polyarticular-Course Juvenile Idiopathic Arthritis Treated With Abatacept.

OBJECTIVE: To investigate the frequency and trajectories of individual patients with polyarticular-course juvenile idiopathic arthritis (JIA) achieving novel composite end points on abatacept. METHODS: Data from a clinical trial of subcutaneous abatacept (NCT01844518) and a post hoc analysis of intravenous abatacept (NCT00095173) in patients with polyarticular-course JIA were included. Three end points were defined and evaluated: combined occurrence of low disease activity (LDA) measured by the Juvenile Arthritis Disease Activity Score; 50% improvement in American College of Rheumatology criteria for JIA (ACR50); and patient-reported outcomes. Patient-reported outcomes included visual analog scale score of minimal pain (pain-min) and Childhood Health Assessment Questionnaire disability index score of 0 (C-HAQ DI0). In this post hoc analysis, maintenance of month 13 and 21 end points (LDA+pain-min, LDA+C-HAQ DI0, and ACR50+pain-min) in those who achieved them at month 4 was determined. RESULTS: Composite end points (LDA+pain-min, LDA+C-HAQ DI0, and ACR50+pain-min) were achieved at month 4 (44.7%, 19.6%, and 58.9% of the 219 patients treated with subcutaneous abatacept, respectively). Of those who achieved LDA+pain-min at month 4, 84.7% (83 of 98) and 65.3% (64 of 98) maintained LDA+pain-min at months 13 and 21, respectively. The proportions of patients meeting LDA+pain-min outcomes increased from 44.7% (98 of 219) at month 4 to 54.8% (120 of 219) at month 21. The frequency of patients who met an LDA+C-HAQ DI score of 0 increased from 19.6% (43 of 219) at month 4 to 28.8% (63 of 219) at month 21. CONCLUSION: Among individual patients with polyarticular-course JIA treated with abatacept who achieved 1 of the combined clinical and patient-reported outcomes composite end points, many maintained them over 21 months of abatacept treatment.

Determination of Relative Weightings for Sacroiliac Joint Pathologies in the OMERACT Juvenile Arthritis Magnetic Resonance Imaging Sacroiliac Joint Score.

This study aims to determine the relative weights (point value) of items of the juvenile idiopathic arthritis magnetic resonance imaging-sacroiliac joint scoring system (JAMRIS-SIJ). An adaptive multicriteria decision analysis was performed using the 1000Minds web application to determine the relative weights of the items in the JAMRIS-SIJ inflammation and damage domains. Experts in imaging and rheumatology independently completed a conjoint analysis survey (CAS) to determine the point value of the measurement items of the JAMRIS-SIJ. Each CAS survey question asked the expert to compare two hypothetical patient profiles, which were otherwise similar but different at two items at a time, and to select which item showed a more severe stage of inflammation or osteochondral damage. In addition, experts ranked 14 JAMRIS-SIJ grade only or image + grade patient vignettes while blinded to the CAS-derived weights. The validity of the weighted JAMRIS-SIJ was tested by comparing the expert CAS-weighted score and the image + grade ranking method. Seventeen experts completed the CAS (11 radiologists and 6 rheumatologists). Considering the point value for inflammation domain items, osteitis (24.7%) and bone marrow edema (24.3%) had higher group-averaged percentage weights compared to inflammation in erosion cavity (16.9%), joint space enhancement (13.1%), joint space fluid (9.1%), capsulitis (7.3%), and enthesitis (4.6%). Similarly, concerning the damage domain, ankylosis (41.3%) and erosion (25.1%) showed higher group-averaged weights compared to backfill (13.9%), sclerosis (10.7%), and fat metaplasia lesion (9.1%). The Spearman correlation coefficients of the CAS-weighted vignette order and unweighted JAMRIS-SIJ grade only order vignettes for all experts were 0.79 for inflammation and 0.80 for damage. The correlations of image vignettes among imaging experts to CAS were 0.75 for inflammation and 0.90 for damage. The multicriteria decision analysis identified differences in relative weights among the JAMRIS-SIJ measurement items. The determination of the relative weights provided expert-driven score scaling and face validity for the JAMRIS-SIJ, enabling the future evaluation of its longitudinal construct validity.

Impaired suppression of synovial fluid CD4+CD25- T cells from patients with juvenile idiopathic arthritis by CD4+CD25+ Treg cells.

OBJECTIVE: Natural CD4+CD25+FoxP3+ Treg cells play a crucial role in maintaining immune homeostasis and controlling autoimmunity. In patients with juvenile idiopathic arthritis (JIA), inflammation occurs despite the increased total numbers of Treg cells in the synovial fluid (SF) compared to the peripheral blood (PB). This study was undertaken to investigate the phenotype of CD4+ T cells in PB and SF from JIA patients, the function of synovial Treg cells, and the sensitivity of PB and SF CD4+CD25- effector T cells to the immunoregulatory properties of Treg cells, and to study the suppression of cytokine secretion from SF effector T cells by Treg cells. METHODS: The phenotypes of effector T cells and Treg cells of PB and SF from JIA patients and healthy donors were determined by flow cytometry. The functionality of isolated Treg cells and effector T cells was quantified in (3) H-thymidine proliferation assays. Cytokine levels were analyzed using Bio-Plex Pro assay. RESULTS: Compared to PB, SF showed significantly elevated numbers of activated and differentiated CD4+CD45RO+ T cells. Sensitivity of SF effector T cells to the suppressive effects of Treg cells from both PB and SF was impaired, correlating inversely with the expression of CD69 and HLA-DR. However, SF effector T cell cytokine secretion was partly suppressed by SF Treg cells. CONCLUSION: Our findings indicate that regulation is impaired in the SF of patients with JIA, as shown by the resistance of effector T cells to immunoregulation by functional Treg cells. This resistance of the SF effector T cells might be due to their activated phenotype.

Advances in Musculoskeletal Imaging in Juvenile Idiopathic Arthritis.

Over the past decade, imaging of inflammatory arthritis in juvenile arthropathies has significantly advanced due to technological improvements in the imaging modalities and elaboration of imaging recommendations and protocols through systematic international collaboration. This review presents the latest developments in ultrasound (US) and magnetic resonance imaging (MRI) of the peripheral and axial joints in juvenile idiopathic arthritis. In the field of US, the ultra-wideband and ultra-high-frequency transducers provide outstanding spatial resolution. The more sensitive Doppler options further improve the assessment and quantification of the vascularization of inflamed tissues, and shear wave elastography enables the diagnosis of tissue stiffness. Concerning MRI, substantial progress has been achieved due to technological improvements in combination with the development of semiquantitative scoring systems for the assessment of inflammation and the introduction of new definitions addressing the pediatric population. New solutions, such as superb microflow imaging, shear wave elastography, volume-interpolated breath-hold examination, and MRI-based synthetic computed tomography open new diagnostic possibilities and, at the same time, pose new challenges in terms of clinical applications and the interpretation of findings.

Discrete Choice Experiment on a Magnetic Resonance Imaging Scoring System for Temporomandibular Joints in Juvenile Idiopathic Arthritis.

OBJECTIVE: To determine the relative importance weights of items and grades of a newly developed additive outcome measure called the juvenile idiopathic arthritis (JIA) magnetic resonance imaging (MRI) scoring system for the temporomandibular joint (TMJ) (JAMRIS-TMJ). METHODS: An adaptive partial-profile, discrete choice experiment (DCE) survey using the 1000Minds platform was independently completed by members of an expert group consisting of radiologists and non-radiologist clinicians to determine the group-averaged relative weights for the JAMRIS-TMJ. Subsequently, an image-based vignette ranking exercise was done, during which experts individually rank ordered 14 patient vignettes for disease severity while blinded to the weights and unrestricted to JAMRIS-TMJ assessment criteria. Validity of the weighted JAMRIS-TMJ was tested by comparing the consensus-graded, DCE-weighted JAMRIS-TMJ score of the vignettes with their unrestricted image-based ranks provided by the experts. RESULTS: Nineteen experts completed the DCE survey, and 21 completed the vignette ranking exercise. Synovial thickening and joint enhancement showed higher weights per raw score compared to bone marrow items and effusion in the inflammatory domain, while erosions and condylar flattening showed nonlinear and higher weights compared to disk abnormalities in the damage domain. The weighted JAMRIS-TMJ score of the vignettes correlated highly with the ranks from the unrestricted comparison method, with median Spearman's ρ of 0.92 (interquartile range [IQR] 0.87-0.95) for the inflammation and 0.93 (IQR 0.90-0.94) for the damage domain. CONCLUSION: A DCE survey was used to quantify the importance weights of the items and grades of the JAMRIS-TMJ. The weighted score showed high convergent validity with an unrestricted, holistic vignette ranking method.

Absence of Association Between Abatacept Exposure and Initial Infection in Patients With Juvenile Idiopathic Arthritis.

OBJECTIVE: To assess the relationship between infection risk and abatacept (ABA) exposure levels in patients with polyarticular-course juvenile idiopathic arthritis (pJIA) following treatment with subcutaneous (SC) and intravenous (IV) ABA. METHODS: Data from 2 published studies (ClinicalTrials.gov: NCT01844518, NCT00095173) of ABA treatment in pediatric patients were analyzed. One study treated patients aged 2-17 years with SC ABA and the other treated patients aged 6-17 years with IV ABA. Association between serum ABA exposure measures and infection was evaluated using Kaplan-Meier plots of probability of first infection vs time on treatment by ABA exposure quartiles and log-rank tests. Number of infections by ABA exposure quartiles was investigated. RESULTS: Overall, 343 patients were included in this analysis: 219 patients received SC ABA and 124 patients received IV ABA. Overall, 237/343 (69.1%) patients had ≥ 1 infection over 24 months. No significant difference in time to first infection across 4 quartiles of ABA exposure levels was observed in the pooled (P = 0.45), SC (2-5 yrs: P = 0.93; 6-17 yrs: P = 0.48), or IV (P = 0.50) analyses. Concomitant use of methotrexate and glucocorticoids (at baseline and throughout) with ABA did not increase infection risk across the ABA exposure quartiles. There was no evidence of association between number of infections and ABA exposure quartiles. No opportunistic infections related to ABA were reported. CONCLUSION: In patients aged 2-17 years with pJIA, no evidence of association between higher levels of exposure to IV ABA or SC ABA and incidence of infection was observed.

Reliability of the Preliminary OMERACT Juvenile Idiopathic Arthritis MRI Score (OMERACT JAMRIS-SIJ).

This study reports the reliability of the juvenile idiopathic arthritis magnetic resonance imaging scoring system (JAMRIS-SIJ). The study comprised of eight raters-two rheumatologists and six radiologists-and 30 coronal T1 and Short-Tau Inversion Recovery (STIR) MRI scans of patients with enthesitis-related juvenile spondylarthritis. The median age of patients was 15 years with a mean disease duration of 5 years and 22 (73.3%) of the sample were boys. The inter-rater agreement of scores for each of the JAMRIS-SIJ items was calculated using a two-way random effect, absolute agreement, and single rater intraclass correlation coefficient (ICC 2.1). The ICC was interpreted together with kurtosis, since the ICC is also affected by the distribution of scores in the sample. The eight-rater, single measure inter-rater ICC (and kurtosis) values for JAMRIS-SIJ inflammation and damage components were the following: bone marrow edema (BME), 0.76 (1.2); joint space inflammation, 0.60 (1.8); capsulitis, 0.58 (9.2); enthesitis, 0.20 (0.1); ankylosis, 0.89 (35); sclerosis, 0.53 (4.6); erosion, 0.50 (6.5); fat lesion, 0.40 (21); backfill, 0.38 (38). The inter-rater reliability for BME and ankylosis scores was good and met the a priori set ICC threshold, whereas for the other items it was variable and below the selected threshold. Future directives should focus on refinement of the scores, definitions, and methods of interpretation prior to validation of the JAMRIS-SIJ through the assessment of its measurement properties.