A comparison of Juvenile Idiopathic Arthritis classification systems with the Research in Arthritis in Canadian Children, Emphasizing Outcomes (ReACCh-Out) cohort

Evaluation of ILAR and PRINTO classifications for juvenile idiopathic arthritis: oligoarticular JIA vs early-onset ANA-positive JIA

OBJECTIVES

The International League of Associations for Rheumatology (ILAR) juvenile idiopathic arthritis (JIA) classification was revisited by the Pediatric Rheumatology International Trials Organization (PRINTO) in 2018. Classifications should establish uniform groups to assist physicians in providing optimal care. Therefore, we evaluated changes proposed by PRINTO to highlight their impact on forming consistent groups regarding uveitis and treatment responses, particularly focusing on early-onset anti-nuclear antibody (ANA)-positive JIA.

METHODS

Pediatric patients diagnosed with JIA according to ILAR and PRINTO classification, with a minimum of 1-year of follow-up, were enrolled, excluding those meeting the exclusion criteria for both the oligoarticular JIA and the early-onset ANA-positive JIA groups.

RESULTS

Among the 139 enrolled patients, 110 (79.1%) had oligoarticular JIA, while 15 (10.8%) had early-onset ANA-positive JIA. The below-age-5 criterion demonstrated the strongest association with uveitis, while the below-age-7 provided similar associations without substantial exclusions (odds ratio (OR) 8.62 [2.50-29.81] vs 7.45 [2.37-26.66]). Patients with a single ANA positivity at a titer ≥ 1/160 and age of onset below 7 had a notably higher risk of new-onset uveitis and biologic DMARD requirement (OR 7.95 [2.37-26.66] and 3.6 [1.42-9.09], respectively).

CONCLUSION

The inclusion of age of disease onset and ANA positivity with a titer ≥ 1/160 has enhanced uniformity in uveitis risk and treatment response, including failure of conventional synthetic DMARDs. Additionally, a single ANA positivity at a ≥ 1/160 titer rather than requiring two instances yields similar consistency. However, the joint count criteria failed to form consistent groups. PRINTO's classification places a significant proportion of patients into the "other JIA" group, necessitating further classification for improved clinical utility. Key Points •Inclusion of age and ANA positivity criteria increased uniformity among the subgroups. •Single ANA positivity at a ≥ 1/160 titer can be sufficient instead of twice. •Early utilization of bDMARDs may be beneficial for early-onset ANA-positive JIA group. •PRINTO classification must further classify the "other JIA" before being implemented in clinical practice.

Pediatric Society of the African League Against Rheumatism juvenile idiopathic arthritis recommendations for enthesitis-related arthritis and juvenile psoriatic arthritis

The objective of this study is to develop evidence-based recommendations for the diagnosis and management of enthesitis-related arthritis (ERA) and juvenile psoriatic arthritis (JPsA) in the African context. The recommendations for ERA and JPsA were combined into a single document. The steering committee and task force identified 15 key questions and formulated 35 research questions. A comprehensive literature review, utilizing Medline and a manual search for African local data, was conducted to gather evidence. Following this synthesis, the task force developed draft recommendations and engaged in a Delphi process with an expert panel, including 17 African and three international experts, to reach a consensus and ensure alignment with global standards. The final recommendations were assigned a level of evidence and subsequently approved by the task force members, the expert panel, and the PAFLAR Board. Fifteen recommendations on the diagnosis and management of ERA and JPsA were developed, covering the role of the pediatric rheumatologist in multiple aspects of disease management, including diagnosis, monitoring of disease and extra-articular manifestations, determining treatment strategies, and guiding interventions. The level of evidence supporting these recommendations was variable, leading to the identification of a research agenda to address African particularities and answer pending questions. The final recommendations achieved a high level of agreement, with consensus ranging from 90 to 100%. These recommendations represent an important achievement for pediatric rheumatology in Africa, being the first of their kind, tailored specifically to the region. Developed through a rigorous methodology and collaboration between international and African experts, they aim to standardize care and address the unique challenges faced in African setting.

What have we learned from long-term studies in juvenile idiopathic arthritis? - Prediction, classification, transition

BACKGROUND

Research and management of juvenile idiopathic arthritis (JIA) are challenging due to its heterogeneous nature, chronicity, and unpredictable, multidimensional long-term outcomes.

MAIN BODY

Long-term studies have consistently shown that a majority of children with JIA reach adulthood with ongoing disease activity, on medication, or with recurrent flares. The heterogeneity is evident both between and within the present JIA categories based on The International League of Associations for Rheumatology (ILAR) JIA classification system. Several baseline predicting factors are known, but prediction modelling is only in the initial phase, and more models need to be tested in independent cohorts and possibly also supplemented with new biomarkers. Many have criticized the ILAR classification system, but new or updated classification systems have not yet been validated and proved their superiority. The lack of prediction possibilities for long-term outcomes and the limited alignment between JIA classification categories and adult rheumatic conditions are challenges for research, may limit the accessibility to treatment, and hamper a smooth transition to adult care.

CONCLUSION

We need more prospective, long-term studies based on unselected JIA cohorts with disease onset in the biologic era that can aid decision-making for individualized early treatment, suggest intervention studies, and ensure our patients the best possible transition to adulthood and the best likelihood of optimal health and quality of life.

Do the Provisional Paediatric Rheumatology International Trials Organisation Enthesitis/Spondylitis-Related Juvenile Idiopathic Arthritis Criteria Capture Youth With Axial Spondyloarthritis?

OBJECTIVE

The Paediatric Rheumatology International Trials Organisation (PRINTO) recently undertook an effort to better harmonize the pediatric and adult arthritis criteria. These provisional criteria are being refined for optimal performance. We aimed to investigate differences between patients who did and did not fulfill these PRINTO criteria among youth diagnosed with juvenile spondyloarthritis (SpA) that met axial juvenile SpA (axJSpA) classification criteria.

METHODS

This was a retrospective cross-sectional sample of youth diagnosed with juvenile SpA who met the axJSpA classification criteria. Demographics, clinical manifestations, and physician and patient-reported outcomes were abstracted from medical records. Magnetic resonance imaging (MRI) scans underwent central imaging review by at least two central raters. Differences between groups were compared using Wilcoxon signed-rank test or chi-square test, as appropriate.

RESULTS

Of 158 patients who met axJSpA criteria, 107 patients (68%) met the PRINTO provisional criteria for enthesitis/spondylitis-related arthritis. A total of 41 patients (26%) did not fulfill any of the three major PRINTO criteria due to lack of peripheral disease manifestations. Demographics, prevalence of inflammatory or structural lesions on MRI, family history of SpA, and duration of pain were not statistically different between those who did and did not meet PRINTO criteria. Those who fulfilled the PRINTO criteria had significantly more peripheral arthritis, enthesitis, and HLA-B27 positivity but reported less sacral/buttock pain.

CONCLUSION

Phenotypic differences of children with axJSpA between those who were and were not classified by the PRINTO criteria were primarily due to peripheral disease manifestations and HLA-B27 positivity. Modification of the PRINTO provisional criteria may facilitate capture of youth with primarily axial disease.

Application of the new classification proposal for juvenile idiopathic arthritis of the pediatric rheumatology international trials organization in a group of Mexican patients

Objective

Apply the PRINTO classification proposal for diagnosing Juvenile Idiopathic Arthritis (JIA) to Mexican patients, analyzing demographic, clinical, and laboratory characteristics.

Material and methods

Cross-sectional study analyzing patients diagnosed with JIA using International League of Associations for Rheumatology (ILAR 2001) criteria over two years at a national rheumatic disease center. Reclassification was done using the Pediatric Rheumatology International Trials Organization (PRINTO) proposal. Comparisons were made between antinuclear antibodies (ANAs) positive vs. negative and rheumatoid factor (RF) positive vs. negative patients.

Results

Seventy-six patients were analyzed, mostly female. Median age was lower in systemic JIA (sJIA) and early onset JIA with positive ANAs (eoANA JIA). ANAs was present in 78.6% of patients. Reclassification according to PRINTO disorders showed RF positive polyarticular JIA, sJIA, and enthesitis-related JIA (ER JIA) reclassified to RF JIA, sJIA, and enthesitis/spondylitis-related JIA (ESR JIA) by 100%, 94.7%, and 80%, respectively. The ILAR category with the most variation was RF negative polyarticular JIA. Early disease onset was associated with a lower probability of positive RF after adjusting for sex, age, and ANAs. No association was found between ANAs positive vs. negative in adjusted multivariate analysis.

Conclusions

We found compatibility of sJIA, RF positive polyarticular JIA, and RE JIA categories with sJIA, RF JIA, and ESR JIA disorders, respectively. Differences were noted in variables such as sex and the number of affected joints. There was high ANAs positivity; however, few patients were classified into eoANA JIA disorder, with only one presenting uveitis. Most patients were classified as other JIA.

Overlap of International League of Associations for Rheumatology and Preliminary Pediatric Rheumatology International Trials Organization Classification Criteria for Nonsystemic Juvenile Idiopathic Arthritis in an Established UK Multicentre Inception Cohort

OBJECTIVE

The goal was to assess the degree of overlap between existing International League of Associations for Rheumatology (ILAR) and preliminary Paediatric Rheumatology International Trials Organisation (PRINTO) classification criteria for juvenile idiopathic arthritis (JIA).

METHODS

Participants from the Childhood Arthritis Prospective Study, a multicenter UK JIA inception cohort, were classified using the PRINTO and ILAR classification criteria into distinct categories. Systemic JIA was excluded because several classification items were not collected in this cohort. Adaptations to PRINTO criteria were required to apply to a UK health care setting, including limiting the number of blood biomarker tests required. The overlap between categories under the two systems was determined, and any differences in characteristics between groups were described.

RESULTS

A total of 1,223 children and young people with a physician's diagnosis of JIA were included. Using PRINTO criteria, the majority of the patients had "other JIA" (69.5%). There was a high degree of overlap (91%) between the PRINTO enthesitis/spondylitis- and ILAR enthesitis-related JIA categories. The PRINTO rheumatoid factor (RF)-positive category was composed of 48% ILAR RF-positive polyarthritis and 52% undifferentiated JIA. The early-onset antinuclear antibodies-positive PRINTO category was largely composed of ILAR oligoarthritis (50%), RF-negative polyarthritis (24%), and undifferentiated JIA (23%). A few patients were unclassified under PRINTO (n = 3) and would previously have been classified as enthesitis-related JIA (n = 1) and undifferentiated JIA (n = 2) under ILAR.

CONCLUSION

Under the preliminary PRINTO classification criteria for childhood arthritis, most children are not yet classified into a named category. These data can help support further delineation of the PRINTO criteria to ensure homogenous groups of children can be identified.

Pathways of sleep disturbances in juvenile idiopathic arthritis and recommendations for clinical management approaches: A critical review

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease affecting young people. It has a profound impact on their physical, mental and social lives, leading to long-term disability. With the growing awareness of the importance of sleep in all areas of functioning in young people, an emerging literature has drawn attention to the role of sleep in the pathogenesis of JIA. Sleep disturbances in children and adolescents with JIA arise from a wide range of symptoms and pathways, leading to a vicious cycle that exacerbates subclinical inflammation, symptoms and disease progression. Putative factors contributing to sleep disturbances include chronic inflammation, JIA-associated sleep disorders, JIA symptoms (e.g. pain), psychological comorbidities and potential circadian disruption, which may be exacerbated by the transition to adolescence. Here, we review these pathways and advocate key strategies and alternatives for sleep management in young people with JIA in clinical settings. We identify gaps in knowledge and suggest future directions to improve our understanding of JIA sleep disorders, including clinical trials investigating potential strategies to improve sleep health in this young population.

Application of the new PRINTO classification criteria for juvenile idiopathic arthritis in a sample of Portuguese patients

BACKGROUND

The International League of Associations for Rheumatology (ILAR) classification system for juvenile idiopathic arthritis (JIA) does not depict homogenous subgroups of disease. As to unify our language with the adult rheumatic diseases, the Pediatric Rheumatology International Trials Organization (PRINTO) is attempting to revise these criteria.

OBJECTIVE

To reclassify a JIA sample according to the new provisional PRINTO subsets: systemic JIA (sJIA), RF-positive JIA (RF-JIA), early-onset ANA-positive JIA (eoANA-JIA), enthesitis/spondylitis-related JIA (ESR-JIA), "other JIA" and "unclassified JIA".

METHODS

Retrospective study including JIA patients followed in a Pediatric Rheumatology Unit at a university hospital. Medical records were reviewed, and patients were reclassified as per the provisional PRINTO criteria.

RESULTS

Of a total of 104 patients, 41 (39.4%) were reclassified as "other JIA", 36 (34.6%) as eoANA-JIA, 15 (14.4%) as ESR-JIA, 8 (7.7%) as sJIA and 4 (3.8%) as RF-JIA. More than 90% of the oligoarticular JIA were reclassified into either eoANA-JIA or "other JIA". Only one negative RF polyarticular JIA converted to RF-JIA due to the presence of a positive anti-citrulinated peptide antibody (ACPA). The psoriatic arthritis (PsA) subgroup disappeared into eoANA-JIA (25%), ESR-JIA (25%) or "other JIA" (50%). There were significant differences in age of onset, but not on the gender ratio or uveitis presence. Antinuclear antibody was more frequent in females (p=0.035) and younger patients (p<0.001).

CONCLUSION

The number of affected joints and PsA features elapsed in favour of laboratory RF, ACPA and ANA traits. PsA and oligoarticular JIA were abolished. The "other JIA" entity is heterogenous and prevalent, claiming reformulation.

Towards molecular-pathology informed clinical trials in childhood arthritis to achieve precision medicine in juvenile idiopathic arthritis

In childhood arthritis, collectively known as Juvenile idiopathic arthritis (JIA), the rapid rise of available licensed biological and targeted small molecule treatments in recent years has led to improved outcomes. However, real-world data from multiple countries and registries show that despite a large number of available drugs, many children and young people continue to suffer flares and experience significant periods of time with active disease for many years. More than 50% of young people with JIA require ongoing immune suppression well into adult life, and they may have to try multiple different treatments in that time. There are currently no validated tools with which to select specific treatments, nor biomarkers of response to assist in such choices, therefore, current management uses essentially a trial-and-error approach. A further consequence of recent progress is a reducing pool of available children or young people who are eligible for new trials. In this review we consider how progress towards a molecular based approach to defining treatment targets and informing trial design in JIA, combined with novel approaches to clinical trials, could provide strategies to maximise discovery and progress, in order to move towards precision medicine for children with arthritis.

Synovial fluid mesenchymal progenitor cells from patients with juvenile idiopathic arthritis demonstrate limited self-renewal and chondrogenesis

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of inflammatory diseases affecting joints with a prevalence of one in a thousand children. There is a growing body of literature examining the use of mesenchymal stem/progenitor cells (MPCs) for the treatment of adult and childhood arthritis, however, we still lack a clear understanding of how these MPC populations are impacted by arthritic disease states and how this could influence treatment efficacy. In the current study we examined the immunophenotyping, self-renewal ability and chondrogenic capacity (in vitro and in vivo) of synovial derived MPCs from normal, JIA and RA joints. Synovial MPCs from JIA patients demonstrated reduced self-renewal ability and chondrogenic differentiation capacity. Furthermore, they did not induce cartilage regeneration when xenotransplanted in a mouse cartilage injury model. Synovial MPCs from JIA patients are functionally compromised compared to MPCs from normal and/or RA joints. The molecular mechanisms behind this loss of function remain elusive. Further study is required to see if these cells can be re-functionalized and used in cell therapy strategies for these JIA patients, or if allogenic approaches should be considered.

Emerging therapies for juvenile arthritis: agents in early clinical trials

INTRODUCTION

Juvenile idiopathic arthritis (JIA) is the most common chronic inflammatory rheumatic condition in childhood. The management of JIA has been revolutionized thanks to the development of new powerful drugs and the possibility to conduct controlled clinical trials with support from legislative initiatives and availability of international collaborative networks. Trials are still needed in children because we now have new drugs related to specific JIA category.

AREAS COVERED

The review is centered on the latest achievements in the field, focusing on new investigational drugs which are currently or have been recently tested for JIA treatment, encompassing agents in early phase of clinical development.

EXPERT OPINION

Despite the tremendous improvement witnessed in the field of JIA treatment in the past 20 years, there are still many unmet needs to be prioritized. Studies on disease pathogenesis will hopefully help in the identification of new treatment targets for individual JIA categories, that could possibly favor a stricter disease control and contribute to solve the issue of refractory JIA. Novel strategies aimed at the prevention of the risk of long-term joint damage are also desirable, as well as the discovery of predictive biomarkers for treatment efficacy and safety in the individual patient.