Predicting disease outcomes in juvenile idiopathic arthritis: challenges, evidence, and new directions

A lifelong journey: Long-term perspectives on Juvenile Idiopathic Arthritis

Juvenile Idiopathic Arthritis (JIA) represents a diverse group of chronic inflammatory conditions that begin in childhood or adolescence and continue into adulthood, with varying severity and outcomes. This review discusses the complexities of transitioning JIA patients emphasizing that inadequate transition from pediatric to adult care leads to loss of follow-up, treatment discontinuation, and increased disease activity. Furthermore, challenges in disease classification hinder continuity of care across lifespan. It is also pointed out that predicting long-term outcomes in JIA remains complex due to heterogeneity and evolving phenotypes. Factors such as disease category, joint involvement, and treatment influence disease activity, functional disability, and quality of life. Despite advancements in treatment strategies, a substantial proportion of patients experience long-term disability and joint damage. Finally, it is underscored that optimising long-term outcomes in adults with JIA requires a multifaceted approach encompassing structured transition processes, personalised treatment strategies, and comprehensive management of comorbidities. Further research is needed to refine predictive models, enhance disease monitoring tools, and understand the complex interplay between disease activity, treatment response, and long-term outcomes.

Caregiver burden in families of children with juvenile idiopathic arthritis in India

Juvenile Idiopathic Arthritis (JIA) causes caregiver burden on families with children affected with it. Our study aimed to explore this multifaceted burden in the Indian context. In this cross-sectional study, we administered the Hindi translated CAREGIVER questionnaire to adult caregivers in the families of JIA patients ≤ 18 years. The responses to the 28 items were used to calculate the burden scores in various dimensions. The relationship of the global burden scores with demographic and socioeconomic factors were analysed. Non parametric tests were used. Two hundred twenty-one caregivers participated with a median age of 39 years (IQR 32-45). This included 116 fathers, 50 mothers, 32 brothers, 18 uncles, three grandfathers, one sister, and one grandmother. The JIA patients had a median age of 15 (12-17) years, and the male-to-female ratio was 3.2:1. Enthesitis-related arthritis was the predominant subtype (72.4%). Most caregivers (70.6%) expressed sadness at diagnosis, and 29.9% continued to express sadness. Nearly two-thirds (65.6%) had to borrow money from others. More than half (59.3%) of the caregivers neglected their health, and 9.0% became sick. Male gender of the child, systemic JIA subtype, low socioeconomic status, high disease activity, extra-articular damage, high parent-reported disease activity and poor quality of life were associated with higher global caregiver burden. JIA has a significant emotional, social, economic, and labour impact on caregivers. Economic and psychosocial support needs to be given to family caregivers caring for children with 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.

Disease activity trajectories from childhood to adulthood in the population-based Nordic juvenile idiopathic arthritis cohort

OBJECTIVES

To identify long-term disease activity trajectories from childhood to adulthood by using the clinical Juvenile Arthritis Disease Activity Score (cJADAS10) in juvenile idiopathic arthritis (JIA). Second, to evaluate the contribution of the cJADAS10 components and explore characteristics associated with active disease at the 18-year follow-up.

METHODS

Patients with onset of JIA in 1997-2000 were followed for 18 years in the population-based Nordic JIA cohort. We used a discrete mixture model for longitudinal clustering of the cJADAS10 and its components. We assessed factors potentially associated with higher scores on the patient's global assessment of well-being (PaGA) by hierarchical clustering and correlation analysis.

RESULTS

Four disease activity trajectories were identified based on the cJADAS10 components among 427 patients. In trajectory-group 2, the PaGA and the physician's global assessment of disease activity (PhGA) increased significantly during the course, but not the active joint count. The increase in the PaGA was significantly higher than the increases in the PhGA and the active joint count (p<0.0001). A similar pattern was found among all the patients with active disease in the total cohort. Patients with higher PaGA scores had unfavourable scores on several other patient-reported outcomes.

CONCLUSIONS

We have identified groups of patients based on long-term disease activity trajectories. In our study the PaGA was the most important driver of disease activity into adulthood assessed by cJADAS10. We need to better understand how our patients interpret global well-being and implement strategies to achieve inactive disease perceived both by the patient and the physician.

Patterns and determinants of response to novel therapies in juvenile and adult-onset polyarthritis

Biologic and targeted synthetic DMARDs (b/tsDMARDs) have revolutionized the management of multiple rheumatic inflammatory conditions. Among these, polyarticular JIA (pJIA) and RA display similarities in terms of disease pathophysiology and response pattern to b/tsDMARDs. Indeed, the therapeutic efficacy of novel targeted drugs is variable among individual patients, in both RA and pJIA. The mechanisms and determinants of this heterogeneous response are diverse and complex, such that the development of true 'precision'-medicine strategies has proven highly challenging. In this review, we will discuss pathophysiological, patient-specific, drug-specific and environmental factors contributing to individual therapeutic response in pJIA in comparison with what is known in RA. Although some biomarkers have been identified that stratify with respect to the likelihood of either therapeutic response or non-response, few have proved useful in clinical practice so far, likely due to the complexity of treatment-response mechanisms. Consequently, we propose a pragmatic, patient-centred and clinically based approach, i.e. personalized instead of biomarker-based precision medicine in JIA.

Towards stratified treatment of JIA: machine learning identifies subtypes in response to methotrexate from four UK cohorts

BACKGROUND

Methotrexate (MTX) is the gold-standard first-line disease-modifying anti-rheumatic drug for juvenile idiopathic arthritis (JIA), despite only being either effective or tolerated in half of children and young people (CYP). To facilitate stratified treatment of early JIA, novel methods in machine learning were used to i) identify clusters with distinct disease patterns following MTX initiation; ii) predict cluster membership; and iii) compare clusters to existing treatment response measures.

METHODS

Discovery and verification cohorts included CYP who first initiated MTX before January 2018 in one of four UK multicentre prospective cohorts of JIA within the CLUSTER consortium. JADAS components (active joint count, physician (PGA) and parental (PGE) global assessments, ESR) were recorded at MTX start and over the following year. Clusters of MTX 'response' were uncovered using multivariate group-based trajectory modelling separately in discovery and verification cohorts. Clusters were compared descriptively to ACR Pedi 30/90 scores, and multivariate logistic regression models predicted cluster-group assignment.

FINDINGS

The discovery cohorts included 657 CYP and verification cohorts 1241 CYP. Six clusters were identified: Fast improvers (11%), Slow Improvers (16%), Improve-Relapse (7%), Persistent Disease (44%), Persistent PGA (8%) and Persistent PGE (13%), the latter two characterised by improvement in all features except one. Factors associated with clusters included ethnicity, ILAR category, age, PGE, and ESR scores at MTX start, with predictive model area under the curve values of 0.65-0.71. Singular ACR Pedi 30/90 scores at 6 and 12 months could not capture speeds of improvement, relapsing courses or diverging disease patterns.

INTERPRETATION

Six distinct patterns following initiation of MTX have been identified using methods in artificial intelligence. These clusters demonstrate the limitations in traditional yes/no treatment response assessment (e.g., ACRPedi30) and can form the basis of a stratified medicine programme in early JIA.

FUNDING

Medical Research Council, Versus Arthritis, Great Ormond Street Hospital Children's Charity, Olivia's Vision, and the National Institute for Health Research.

Musculoskeletal Ultrasound in Childhood Arthritis Limited Examination: A Comprehensive, Reliable, Time-Efficient Assessment of Synovitis

OBJECTIVE

To develop and initially validate a comprehensive pediatric musculoskeletal ultrasound (MSUS) joint-specific scoring system, and to determine the minimum number of joints needed to identify active disease.

METHODS

A semiquantitative scoring system was developed by consensus and initially validated by interrater reliability using intraclass correlation coefficients (ICCs). Subsequently, newly diagnosed juvenile idiopathic arthritis patients with an active joint count of >4 had a 42-joint MSUS performed at baseline and 3 months using this protocol. A minimum set of joints needed to identify all patients with synovitis on MSUS was obtained through a data reduction process. Spearman's correlation (rs ) was calculated to determine the association between MSUS findings and clinical Juvenile Arthritis Disease Activity Score in 10 joints (cJADAS10). Standardized response means (SMRs) were used to assess change over time.

RESULTS

The final joint-specific scoring system revealed an excellent interrater reliability (ICC 0.81-0.96) for all joints. Thirty patients were enrolled. Scanning 5 joints bilaterally (wrists, second and third metacarpophalangeal joints, knees and ankles) captured 100% of children with B-mode synovitis and had moderate correlation with the cJADAS10 at baseline (rs  = 0.45). Mean ultrasound scores at baseline and follow-up were 28.3 and 22.3, with an SRM of 0.69 (P = 0.002) for 42 joints, and 36 and 27.7, with an SRM of 0.76 (P = 0.003) for the reduced joints, respectively.

CONCLUSION

A limited MSUS examination called musculoskeletal ultrasound in childhood arthritis limited examination (MUSICAL) captures all patients with active synovitis, and our new joint-specific scoring system is highly reliable and sensitive to change.

The Role of Serum Calprotectin in Defining Disease Outcomes in Non-Systemic Juvenile Idiopathic Arthritis: A Pilot Study

Serum calprotectin (MRP8/14) is currently being studied as a promising biomarker of disease activity and outcome in patients with juvenile idiopathic arthritis (JIA) but the data in the literature are conflicting. The aim of our study was to investigate the potential role of serum calprotectin as biomarker of disease activity and flare/remission in a group of nsJIA patients during a follow-up period of 18 months. In this prospective longitudinal study, two groups of patients with ns-JIA (55 active patients and 56 patients in remission according to Wallace's criteria) and a control group (50 children) were recruited at baseline from January 2020 to September 2021. JIA patients were followed for up to 18 months at four timepoints: 3 months (T1), 6 months (T2), 12 months (T3) and 18 months (T4). At each timepoint, the following were recorded: JADAS27, blood counts, ESR, CRP, albumin, ferritin and serum calprotectin. To illustrate the performance of calprotectin, Kaplan-Meier curves were constructed from baseline to relapse/remission, dichotomizing patients at baseline in positive/negative on the basis progressive calprotectin cut-offs. Associations between baseline factors and relapse were determined using Cox regression models. Multivariate models were constructed to analyze the effect of covariates. Comparing baseline clinical and laboratory data of the three groups (active vs. inactive JIA vs. controls), only serum calprotectin reached statistical significance (active patients vs. inactive (p = 0.0016) and vs. controls (p = 0.0012)). In the inactive group, during the 18 months of follow up, 31 patients (55.3%) had a relapse. Comparing the baseline data of relapsers vs. non-relapsers, serum calprotectin showed higher levels (p = 0.001) in relapsers. In survival analysis, a log rank test showed significant differences of up to 12 ng/mL (p = 0.045). Multivariate Cox regression confirmed that only baseline calprotectin levels were independently associated with disease recurrence. In the active group, in the 12 months of follow-up, 19 patients (38%) entered remission of the disease. In addition, in this group, the only statistical difference at the baseline was the value of MPR8/14 (p = 0.0001). Log rank test showed significant differences up to 10 ng/mL (p = 0.003). In the multivariate Cox regression, serum calprotectin levels at baseline were independently associated with remission. In conclusion, our study would suggest a dual role for calprotectin in predicting future relapse and treatment response in patients with nsJIA, thus influencing therapeutic decisions and management of these patients during follow up.

Conventional dendritic cells type 1 are strongly enriched, quiescent and relatively tolerogenic in local inflammatory arthritis

Introduction

Dendritic cells (DC) are crucial for initiating and shaping immune responses. So far, little is known about the functional specialization of human DC subsets in (local) inflammatory conditions. We profiled conventional (c)DC1, cDC2 and monocytes based on phenotype, transcriptome and function from a local inflammatory site, namely synovial fluid (SF) from patients suffering from a chronic inflammatory condition, Juvenile Idiopathic Arthritis (JIA) as well as patients with rheumatoid arthritis (RA).

Methods

Paired PB and SF samples from 32 JIA and 4 RA patients were collected for mononuclear cell isolation. Flow cytometry was done for definition of antigen presenting cell (APC) subsets. Cell sorting was done on the FACSAria II or III. RNA sequencing was done on SF APC subsets. Proliferation assays were done on co-cultures after CD3 magnetic activated cell sorting (MACS). APC Toll-like receptor (TLR) stimulation was done using Pam3CSK4, Poly(I:C), LPS, CpG-A and R848. Cytokine production was measured by Luminex.

Results

cDC1, a relatively small DC subset in blood, are strongly enriched in SF, and showed a quiescent immune signature without a clear inflammatory profile, low expression of pathogen recognition receptors (PRRs), chemokine and cytokine receptors, and poor induction of T cell proliferation and cytokine production, but selective production of IFNλ upon polyinosinic:polycytidylic acid exposure. In stark contrast, cDC2 and monocytes from the same environment, showed a pro-inflammatory transcriptional profile, high levels of (spontaneous) pro-inflammatory cytokine production, and strong induction of T cell proliferation and cytokine production, including IL-17. Although the cDC2 and monocytes showed an overlapping transcriptional core profile, there were clear differences in the transcriptional landscape and functional features, indicating that these cell types retain their lineage identity in chronic inflammatory conditions.

Discussion

Our findings suggest that at the site of inflammation, there is specific functional programming of human DCs, especially cDC2. In contrast, the enriched cDC1 remain relatively quiescent and seemingly unchanged under inflammatory conditions, pointing to a potentially more regulatory role.

No evidence that genetic predictors of susceptibility predict changes in core outcomes in JIA

OBJECTIVES

The clinical progression of JIA is unpredictable. Knowing who will develop severe disease could facilitate rapid intensification of therapies. We use genetic variants conferring susceptibility to JIA to predict disease outcome measures.

METHODS

A total of 713 JIA patients with genotype data and core outcome variables (COVs) at diagnosis (baseline) and 1 year follow-up were identified from the Childhood Arthritis Prospective Study (CAPS). A weighted genetic risk score (GRS) was generated, including all single nucleotide polymorphisms (SNPs) previously associated with JIA susceptibility (P-value < 5×10-08). We used multivariable linear regression to test the GRS for association with COVS (limited joint count, active joint count, physician global assessment, parent/patient general evaluation, childhood HAQ and ESR) at baseline and change in COVS from baseline to 1 year, adjusting for baseline COV and International League of Associations of Rheumatology (ILAR) category. The GRS was split into quintiles to identify high (quintile 5) and low (quintile 1) risk groups.

RESULTS

Patients in the high-risk group for the GRS had a younger age at presentation (median low risk 7.79, median high risk 3.51). No association was observed between the GRS and any outcome measures at 1 year follow-up or baseline.

CONCLUSION

For the first time we have used all known JIA genetic susceptibility loci (P=<5×10-08) in a GRS to predict changes in disease outcome measured over time. Genetic susceptibility variants are poor predictors of changes in core outcome measures, it is likely that genetic factors predicting disease outcome are independent to those predicting susceptibility. The next step will be to conduct a genome-wide association analysis of JIA outcome.

Economic impact of Juvenile Idiopathic Arthritis: a systematic review

BACKGROUND

Juvenile Idiopathic Arthritis (JIA) requires complex care that generate elevated costs, which results in a high economic impact for the family. The aim of this systematic review was to collect and cluster the information currently available on healthcare costs associated with JIA after the introduction of biological therapies.

METHODS

We comprehensively searched in MEDLINE, EMBASE, Web of Science, Scopus, and Cochrane Databases for studies from January 2000 to March 2021. Reviewers working independently and in duplicate appraised the quality and included primary studies that report total, direct and/or indirect costs related to JIA for at least one year. The costs were converted to United States dollars and an inflationary adjustment was made.

RESULTS

We found 18 eligible studies including data from 6,540 patients. Total costs were reported in 10 articles, ranging from $310 USD to $44,832 USD annually. Direct costs were reported in 16 articles ($193 USD to $32,446 USD), showing a proportion of 55 to 98 % of total costs. Those costs were mostly related to medications and medical appointments. Six studies reported indirect costs ($117 USD to $12,385 USD). Four studies reported costs according to JIA category observing the highest in polyarticular JIA. Total and direct costs increased up to three times after biological therapy initiation. A high risk of reporting bias and inconsistency of the methodology used were found.

CONCLUSION

The costs of JIA are substantial, and the highest are derived from medication and medical appointments. Indirect costs of JIA are underrepresented in costs analysis.

Novel biomarkers for prediction of outcome and therapeutic response in juvenile idiopathic arthritis

INTRODUCTION

The search for biomarkers in juvenile idiopathic arthritis (JIA) is a promising and rapidly expanding field of investigation. The biomarkers identified so far may help to dissect the clinical heterogeneity of the illness, measure the level of disease activity, predict clinical remission, relapse, response to medications, course over time, complications, and forestall disease flares.

AREAS COVERED

We provide a summary of the most recent advances in the development and application of biomarkers in JIA. We performed a PubMed search for significant articles combining predetermined keywords related to biomarkers in non-systemic and systemic JIA, chronic uveitis, and macrophage activation syndrome (MAS). The biomarkers available or under study are presented and discussed separately for non-systemic and systemic subtypes and for the two main disease complications, uveitis and MAS.

EXPERT OPINION

The incorporation of valid and reliable biomarkers in standard clinical care may help to design better patient-tailored treatment regimens and to improve the therapeutic strategies based on the treat-to-target approach. The establishment of biomarkers that predict the risk of disease flare may lead to define the optimal modalities for treatment discontinuation after the achievement of clinical remission.

Familial aggregation of juvenile idiopathic arthritis with other autoimmune diseases: Impact on clinical characteristics, disease activity status and disease damage

OBJECTIVES

To evaluate the impact of family history of autoimmune diseases (FHADs) on the clinical characteristics and outcome of juvenile idiopathic arthritis (JIA).

METHODS

We retrospectively reviewed children with JIA seen in 7 pediatric rheumatology clinics from 6 Arab countries. All included patients met the International League of Associations for Rheumatology classification criteria for JIA and had a disease duration greater than 1 year. Data were collected at the last follow-up visit and comprised clinical findings, including FHADs. Disease activity and disease damage were assessed by Juvenile Arthritis Multidimensional Assessment Report, and juvenile arthritis damage index (JADI) respectively. Disease activity was categorized as remission off treatment, remission on treatment, or active disease.

RESULTS

A total of 349 (224 females) JIA patients with a disease duration of 5 (interquartile range 2.9-7.5) years were included. The most frequent JIA categories were polyarticular JIA and oligoarticular JIA, followed by systemic JIA. There were 189 patients with FHADs and 160 patients without FHADs. The most frequent FHADs were diabetes mellitus (21.2%), JIA (18.5%), rheumatoid arthritis (12.7%). Among patients with FHADs, 140/189 (74.1%) achieved clinical remission, while 131/160 (81.9%) patients without FHDs had clinical remission (odds ratio [OR] = 1.2, 95% CI 0.97-1.5). Rate of consanguinity, enthesitis-related arthritis (ERA) and psoriatic arthritis were higher in patients with FHADs (OR = 0.6, 95% CI 0.4-0.9 and OR = 1.2, 95% CI 1.1-1.4). Also, articular JADI correlated significantly with presence of FHADs (OR = 1.1, 95% CI 1.0-1.1).

CONCLUSION

This study shows that autoimmune diseases cluster within families of patients with JIA with a high proportion of ERA and psoriatic arthritis. JIA patients with FHADs are likely to have more disease damage.

Future Biomarkers for Infection and Inflammation in Febrile Children

Febrile patients, suffering from an infection, inflammatory disease or autoimmunity may present with similar or overlapping clinical symptoms, which makes early diagnosis difficult. Therefore, biomarkers are needed to help physicians form a correct diagnosis and initiate the right treatment to improve patient outcomes following first presentation or admittance to hospital. Here, we review the landscape of novel biomarkers and approaches of biomarker discovery. We first discuss the use of current plasma parameters and whole blood biomarkers, including results obtained by RNA profiling and mass spectrometry, to discriminate between bacterial and viral infections. Next we expand upon the use of biomarkers to distinguish between infectious and non-infectious disease. Finally, we discuss the strengths as well as the potential pitfalls of current developments. We conclude that the use of combination tests, using either protein markers or transcriptomic analysis, have advanced considerably and should be further explored to improve current diagnostics regarding febrile infections and inflammation. If proven effective when combined, these biomarker signatures will greatly accelerate early and tailored treatment decisions.

Recent progress in the treatment of non-systemic juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease affecting the joints and other organs that occurs in 1 in 1,000 children in the United States. Given the various categories of JIA, interpretation of the literature can be difficult. In this review, new developments in understanding non-systemic JIA and its treatment will be covered. Recent advances in the journey toward personalized treatment in JIA will be highlighted, including a review of currently available biologic modifiers. Uveitis and the temporomandibular joint will be discussed as particularly challenging treatment issues. Recent guideline updates and literature-guided treatment decisions will be reviewed.

Biomarkers of Response to Biologic Therapy in Juvenile Idiopathic Arthritis

Background: Juvenile idiopathic arthritis (JIA) is the most common chronic inflammatory arthritis of childhood, characterized by various clinical phenotypes associated with variable prognosis. Significant progress has been achieved with the use of biologic treatments, which specifically block pro-inflammatory molecules involved in the disease pathogenesis. The most commonly used biologics in JIA are monoclonal antibodies and recombinant proteins targeting interleukins 1 (IL-1) and 6 (IL-6), and tumor necrosis factor α (TNF-α). Several biomarkers have been investigated in JIA. Aims: To assess the level of evidence available regarding the role of biomarkers in JIA related to guiding clinical and therapeutic decisions, providing disease prognostic information, facilitating disease activity monitoring and assessing biologic treatment response in JIA, as well as propose new strategies for biologic therapy-related biomarker use in JIA. Methods: We searched PubMed for relevant literature using predefined key words corresponding to several categories of biomarkers to assess their role in predicting and assessing biologic treatment response and clinical remission in JIA. Results: We reviewed serological, cellular, genetic, transcriptomic and imaging biomarkers, to identify candidates that are both well-established and widely used, as well as newly investigated in JIA on biologic therapy. We evaluated their role in management of JIA as well as identified the unmet needs for new biomarker discovery and better clinical applications. Conclusion: Although there are no ideal biomarkers in JIA, we identified serological biomarkers with potential clinical utility. We propose strategies of combining biomarkers of response to biologics in JIA, as well as routine implementation of clinically acceptable imaging biomarkers for improved disease assessment performance.

Patient-reported wellbeing and clinical disease measures over time captured by multivariate trajectories of disease activity in individuals with juvenile idiopathic arthritis in the UK: a multicentre prospective longitudinal study

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a heterogeneous disease, the signs and symptoms of which can be summarised with use of composite disease activity measures, including the clinical Juvenile Arthritis Disease Activity Score (cJADAS). However, clusters of children and young people might experience different global patterns in their signs and symptoms of disease, which might run in parallel or diverge over time. We aimed to identify such clusters in the 3 years after a diagnosis of JIA. The identification of these clusters would allow for a greater understanding of disease progression in JIA, including how physician-reported and patient-reported outcomes relate to each other over the JIA disease course.

METHODS

In this multicentre prospective longitudinal study, we included children and young people recruited before Jan 1, 2015, to the Childhood Arthritis Prospective Study (CAPS), a UK multicentre inception cohort. Participants without a cJADAS score were excluded. To assess groups of children and young people with similar disease patterns in active joint count, physician's global assessment, and patient or parental global evaluation, we used latent profile analysis at initial presentation to paediatric rheumatology and multivariate group-based trajectory models for the following 3 years. Optimal models were selected on the basis of a combination of model fit, clinical plausibility, and model parsimony.

FINDING

Between Jan 1, 2001, and Dec 31, 2014, 1423 children and young people with JIA were recruited to CAPS, 239 of whom were excluded, resulting in a final study population of 1184 children and young people. We identified five clusters at baseline and six trajectory groups using longitudinal follow-up data. Disease course was not well predicted from clusters at baseline; however, in both cross-sectional and longitudinal analyses, substantial proportions of children and young people had high patient or parent global scores despite low or improving joint counts and physician global scores. Participants in these groups were older, and a higher proportion of them had enthesitis-related JIA and lower socioeconomic status, compared with those in other groups.

INTERPRETATION

Almost one in four children and young people with JIA in our study reported persistent, high patient or parent global scores despite having low or improving active joint counts and physician's global scores. Distinct patient subgroups defined by disease manifestation or trajectories of progression could help to better personalise health-care services and treatment plans for individuals with JIA.

FUNDING

Medical Research Council, Versus Arthritis, Great Ormond Street Hospital Children's Charity, Olivia's Vision, and National Institute for Health Research.

Outcomes and predictors of juvenile idiopathic arthritis in Southeast Asia: a Singapore longitudinal study over a decade

OBJECTIVE

To assess short- and long-term outcomes and predictors of juvenile idiopathic arthritis (JIA) children treated with contemporary therapy and compare those with reports elsewhere.

METHODS

Children with JIA were recruited from our web-based REgistry for Childhood Onset Rheumatic Diseases (RECORD) from 1997 to 2015. Disease status was defined using modified Wallace criteria. Nonparametric statistics described the data. Kaplan-Meier survival and logistic regression analyses were used to estimate probabilities and to determine predictors of outcomes.

RESULTS

A total of 251 children with JIA (62% males, 71% Chinese) were included. Median follow-up duration was 2.9 years (range 0.1-17.5). Short-term clinical inactive disease (CID) was attained in 37% with 62% systemic JIA (sJIA) and 47% persistent oligoarthritis (oJIA). Methotrexate (OR 0.34) decreased but sJIA (OR 3.25) increased chance of attaining CID at 6 months. Overall, 79% of patients achieved CID within 2 years (sJIA 92%, the highest, and RF+ polyarthritis 50%, the lowest probability). Biologics were associated with CID attainment (OR 2.73). One-half of patients flare after CID, median 1.2 years (IQR 0.71-1.97). Late CID achievement predicted flare (OR 2.15). Only 15% had clinical remission off medication (none RF+ polyarthritis and 7% ERA). Only 13% of patients had active arthritis as young adults and 22% had active arthritis at last visit.

CONCLUSION

Despite high proportion of JIA patients attaining CID, only one-fourth could stop all medications for at least 1 year. Persistent oJIA patients were less likely to achieve clinical remission on medication and ERA patients had the least chance stopping medications. One-tenth of patients had active arthritis as young adults. Key Points • Majority of Asian children with JIA attained inactive disease within 2 years after diagnosis. • Outcome predictors were different from reports from the West. • Despite high inactive disease numbers, only one-in-four JIA patients discontinued treatment within 5 years.