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

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.