Methotrexate withdrawal at 6 vs 12 months in juvenile idiopathic arthritis in remission: a randomized clinical trial

Methotrexate for juvenile idiopathic arthritis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. Methotrexate has broad immunomodulatory properties and is the most commonly used disease-modifying antirheumatic drug (DMARD). This is an update of a 2001 Cochrane review. It supports a living guideline for children and young people with JIA.

OBJECTIVES

To assess the benefits and harms of methotrexate for children and young people with juvenile idiopathic arthritis.

SEARCH METHODS

The Australian JIA Living Guideline Working Group created a registry of all randomised controlled trials (RCTs) of JIA by searching CENTRAL, MEDLINE, Embase, and trials registries. The date of the most recent search of online databases was 1 February 2023.

SELECTION CRITERIA

We searched for RCTs that compared methotrexate with placebo, no treatment, or another DMARD (with or without concomitant therapies) in children and young people (aged up to 18 years) with JIA.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. The main comparison was methotrexate versus placebo. Our outcomes were treatment response, sustained clinically inactive disease, function, pain, participant global assessment of well-being, serious adverse events, and withdrawals due to adverse events. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified three new trials in this update, bringing the total number of included RCTs to five (575 participants). Three trials evaluated oral methotrexate versus placebo, one evaluated methotrexate plus intra-articular glucocorticoid (IAGC) therapy versus IAGC therapy alone, and one evaluated methotrexate versus leflunomide. Doses of methotrexate ranged from 5 mg/m2/week to 15 mg/m2/week in four trials, and participants in the methotrexate group of the remaining trial received 0.5 mg/kg/week. Trial size varied from 31 to 226 participants. The average age of participants ranged from four to 10 years. Most participants were females and most had nonsystemic JIA. The study that evaluated methotrexate plus IAGC therapy versus IAGC therapy alone recruited children and young people with the oligoarticular disease subtype of JIA. Two placebo-controlled trials and the trial of methotrexate versus leflunomide were adequately randomised and blinded, and likely not susceptible to important biases. One placebo-controlled trial may have been susceptible to selection bias due to lack of adequate reporting of randomisation methods. The trial investigating the addition of methotrexate to IAGC therapy was susceptible to performance and detection biases. Methotrexate versus placebo Methotrexate compared with placebo may increase the number of children and young people who achieve treatment response up to six months (absolute difference of 163 more per 1000 people; risk ratio (RR) 1.67, 95% confidence interval (CI) 1.21 to 2.31; I2 = 0%; 3 trials, 328 participants; low-certainty evidence). However, methotrexate compared with placebo may have little or no effect on pain as measured on an increasing scale of 0 to 100 (mean difference (MD) -1.10 points, 95% CI -9.09 to 6.88; 1 trial, 114 participants), improvement in participant global assessment of well-being (absolute difference of 92 more per 1000 people; RR 1.23, 95% CI 0.88 to 1.72; 1 trial, 176 participants), occurrence of serious adverse events (absolute difference of 5 fewer per 1000 people; RR 0.63, 95% CI 0.04 to 8.97; 3 trials, 328 participants), and withdrawals due to adverse events (RR 3.46, 95% CI 0.60 to 19.79; 3 trials, 328 participants) up to six months. We could not estimate the absolute difference for withdrawals due to adverse events because there were no withdrawals in the placebo group. All outcomes were reported within six months of randomisation. We downgraded the certainty of the evidence to low for all outcomes due to indirectness (suboptimal dosing of methotrexate and diverse outcome measures) and imprecision (few participants and low event rates). No trials reported function or the number of participants with sustained clinically inactive disease. Serious adverse events included liver derangement, abdominal pain, and inadvertent overdose. Methotrexate plus intra-articular corticosteroid therapy versus intra-articular corticosteroid therapy alone Methotrexate plus IAGC therapy compared with IAGC therapy alone may have little or no effect on the probability of sustained clinically inactive disease or the rate of withdrawals due to adverse events up to 12 months in children and young people with the oligoarticular subtype of JIA (low-certainty evidence). We could not calculate the absolute difference in withdrawals due to adverse events because there were no withdrawals in the control group. We are uncertain if there is any difference between the interventions in the risk of severe adverse events, because none were reported. The study did not report treatment response, function, pain, or participant global assessment of well-being. Methotrexate versus an alternative disease-modifying antirheumatic drug Methotrexate compared with leflunomide may have little or no effect on the probability of treatment response or on function, participant global assessment of well-being, risk of serious adverse events, and rate of withdrawals due to adverse events up to four months. We downgraded the certainty of the evidence for all outcomes to low due to imprecision. The study did not report pain or sustained clinically inactive disease.

AUTHORS' CONCLUSIONS

Oral methotrexate (5 mg/m2/week to 15 mg/m2/week) compared with placebo may increase the number of children and young people achieving treatment response but may have little or no effect on pain or participant global assessment of well-being. Oral methotrexate plus IAGC injections compared to IAGC injections alone may have little or no effect on the likelihood of sustained clinically inactive disease among children and young people with oligoarticular JIA. Similarly, methotrexate compared with leflunomide may have little or no effect on treatment response, function, and participant global assessment of well-being. Serious adverse events due to methotrexate appear to be rare. We will update this review as new evidence becomes available to inform the living guideline.

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.

Risk of flare in juvenile idiopathic arthritis: Is it related to the methotrexate treatment strategy or patient characteristics?

Objectives

The study aimed to determine the factors that increase the risk of disease flare in patients with juvenile idiopathic arthritis who stopped methotrexate (MTX) monotherapy following inactive disease (ID).

Patients and methods

In the retrospective study, files of all juvenile idiopathic arthritis cases between April 1992 and June 2022 were examined. Patients who stopped MTX monotherapy following ID were evaluated. Patients with disease flare and persistent ID were compared. Juvenile idiopathic arthritis subgroup, age of symptom onset, autoantibodies, acute phase reactants, MTX method of use, and withdrawal strategy were recorded. Systemic juvenile idiopathic arthritis patients were excluded from the study due to different clinical symptoms, diagnosis, and treatment methods.

Results

Files of 1,036 patients were evaluated, and 107 patients (88 females, 19 males; mean age: 5.9±4.2 years; range, 0.8-16.5 years) were included in the study. The median age at symptom onset was 4.8 (interquartile range [IQR]: 2-7.6) years. In terms of juvenile idiopathic arthritis subgroups, 52 (48.6%) had oligoarticular juvenile idiopathic arthritis, 43 (40.2%) had polyarticular juvenile idiopathic arthritis, and 12 (11.2%) had juvenile psoriatic arthritis. The patients reached ID in nine (IQR: 4.8-17.7) months after starting MTX, and MTX treatment was discontinued after one (IQR: 0.7-1.3) year following ID. The disease flare developed in 59 (55%) of the cases. The ID continued in 48 (45%) patients. In multivariate analysis, the risk of flare was associated with younger symptom onset (odds ratio [OR]=2.2, p=0.006), antinuclear antibody positivity (OR=1.6, p=0.03), higher erythrocyte sedimentation rate (OR=1.01, p=0.04), and C-reactive protein (OR=1, p=0.02) at the MTX onset. No difference was observed between the two groups regarding MTX dose, route of administration, prior and concomitant treatments, time to reach ID, and time and method of MTX discontinuation.

Conclusion

In this study, the risk of flare was associated with patient's characteristics, rather than the administration and discontinuation method of MTX.

Treatment of systemic juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis (sJIA) is an inflammatory disease with hallmarks of severe systemic inflammation, which can be accompanied by arthritis. Contemporary scientific insights set this paediatric disorder on a continuum with its counterpart, adult-onset Still disease (AOSD). Patients with sJIA are prone to complications, including life-threatening hyperinflammation (macrophage activation syndrome (sJIA-MAS)) and sJIA-associated lung disease (sJIA-LD). Meanwhile, the treatment arsenal in sJIA has expanded markedly. State-of-the-art therapeutic approaches include biologic agents that target the IL-1 and IL-6 pathways. Beyond these, a range of novel agents are on the horizon, some of them already being used on a compassionate use basis, including JAK inhibitors and biologic agents that target IL-18, IFNγ, or IL-1β and IL-18 simultaneously. However, sJIA, sJIA-MAS and sJIA-LD still pose challenging conundrums to rheumatologists treating paediatric and adult patients worldwide. Although national and international consensus treatment plans exist for the treatment of 'classic' sJIA, the treatment approaches for early sJIA without arthritis, and for refractory or complicated sJIA, are not well defined. Therefore, in this Review we outline current approaches for the treatment of sJIA and provide an outlook on knowledge gaps.

A novel serum calprotectin (MRP8/14) particle-enhanced immuno-turbidimetric assay (sCAL turbo) helps to differentiate systemic juvenile idiopathic arthritis from other diseases in routine clinical laboratory settings

BACKGROUND

Differential diagnosis in children with signs of unprovoked inflammation can be challenging. In particular, differentiating systemic juvenile idiopathic arthritis (SJIA) from other diagnoses is difficult. We have recently validated the complex of myeloid-related proteins 8/14 (MRP8/14, also known as S100A8/A9 complex or serum calprotectin) as a helpful biomarker supporting the diagnosis of SJIA. The results were subsequently confirmed with a commercial ELISA. However, further optimization of the analytical technology is important to ensure its feasibility for large-scale use in routine laboratory settings.

METHODS

To evaluate the accuracy in identifying children with SJIA, the performance of a particle-enhanced immuno-turbidimetric assay for serum calprotectin (sCAL turbo) on an automated laboratory instrument was analyzed. Samples from 615 children were available with the diagnoses SJIA (n = 99), non-systemic JIA (n = 169), infections (n = 51), other inflammatory diseases (n = 126), and acute lymphoblastic leukemia (ALL, n = 147). In addition, samples from 23 healthy controls were included.

RESULTS

The sCAL turbo assay correlated well with the MRP8/14 ELISA used in previous validation studies (r = 0.99, p < 0.001). It could reliably differentiate SJIA from all other diagnoses with significant accuracy (cutoff at 10,500 ng/ml, sensitivity 84%, specificity 94%, ROC area under curve 0.960, p < 0.001).

CONCLUSIONS

Serum calprotectin analyses are a helpful tool supporting the diagnosis of SJIA in children with prolonged fever or inflammatory disease. Here, we show that an immuno-turbidimetric assay for detection of serum calprotectin on an automated laboratory instrument can be implemented in clinical laboratory settings to facilitate its use as a diagnostic routine test in clinical practice.

The clinical and experimental treatment of Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children and comprises of multiple subtypes. The most relevant disease subtypes, grouped upon current insight in disease mechanisms, are nonsystemic (oligo- and polyarticular) JIA and systemic JIA (sJIA). In this review, we summarize some of the main proposed mechanisms of disease in both nonsystemic and sJIA and discuss how current therapeutic modalities target some of the pathogenic immune pathways. Chronic inflammation in nonsystemic JIA is the result of a complex interplay between effector and regulatory immune cell subsets, with adaptive immune cells, specifically T-cell subsets and antigen-presenting cells, in a central role. There is, however, also innate immune cell contribution. SJIA is nowadays recognized as an acquired chronic inflammatory disorder with striking autoinflammatory features in the first phase of the disease. Some sJIA patients develop a refractory disease course, with indications for involvement of adaptive immune pathways as well. Currently, therapeutic strategies are directed at suppressing effector mechanisms in both non-systemic and sJIA. These strategies are often not yet optimally tuned nor timed to the known active mechanisms of disease in individual patients in both non-systemic and sJIA. We discuss current treatment strategies in JIA, specifically the 'Step-up' and 'Treat to Target approach' and explore how increased insight into the biology of disease may translate into future more targeted strategies for this chronic inflammatory disease at relevant time points: preclinical disease, active disease, and clinically inactive disease.

What to Expect When Systemic Treatment in Juvenile Idiopathic Arthritis Is Withdrawn?

OBJECTIVE

The goal of juvenile idiopathic arthritis (JIA) treatment is to maintain clinical remission. It is also important to reduce drug exposure, whenever possible, in order to avoid or decrease potential side effects. We aimed to analyze remission survival after systemic treatment withdrawal and to determine which factors can influence it.

METHODS

We conducted a multicenter, observational, longitudinal study. All patients included had a diagnosis of JIA. We analyzed remission survival using Kaplan-Meier curves according to the systemic treatment received (methotrexate [MTX] alone or in combination with biologic disease-modifying antirheumatic drugs [bDMARDs]) and JIA subgroups (oligoarticular and polyarticular course, juvenile spondyloarthritis, and systemic JIA). In addition, risk factors were examined using multivariate analysis.

RESULTS

We included 404 patients with JIA; 370 of them (92%) had received systemic treatment at some point and half of them (185 patients) had withdrawn on at least 1 occasion. There were 110 patients who flared (59%) with a median time of 2.3 years. There were no differences in remission survival between JIA subcategories. Twenty-nine percent of patients with JIA who received MTX and bDMARDs, in which MTX alone was withdrawn, flared; median time to flare of 6.3 years. However, if only the bDMARD was withdrawn, flares occurred 57% of the time; median time to flare of 1.1 years.

CONCLUSION

Flares are frequent when systemic treatment is withdrawn, and uveitis or joint injections could be related risk factors. In MTX and biologic-naïve patients, the frequency of flares occurred in more than half of patients, although they were less frequent when clinical remission lasted for > 1 year.

Juvenile idiopathic arthritis and its associated uveitis

INTRODUCTION

Juvenile idiopathic arthritis is the most common chronic rheumatologic disease in children. Uveitis is the most common extra-articular manifestation of JIA, and it can be a sight-threatening condition.

AREAS COVERED

In this review article, we discussed epidemiology, risk factors, clinical presentation, supportive laboratory tests, treatment options, and complications of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis associated uveitis. We covered conventional immunomodulatory therapy and biologic response modifiers agents for different types of Juvenile idiopathic arthritis and their associated uveitis. Finally, we discussed the course of disease, functional outcome, and the quality of life of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis-associated uveitis.

EXPERT OPINION

Although clinical outcomes of Juvenile idiopathic arthritis and its associated uveitis have been improved over the past three decades by biologic response modifier agents, a significant proportion of patients require active treatment into adult life therefore screening and monitoring of these patients is required during the patient's entire life. The limited number of food and drug administration approved biologic response modifier agents for the treatment of Juvenile idiopathic arthritis associated uveitis justify more randomized clinical trials with new medications in this field.

Inflammatory Biomarkers Can Differentiate Acute Lymphoblastic Leukemia with Arthropathy from Juvenile Idiopathic Arthritis Better Than Standard Blood Tests

OBJECTIVE

To evaluate the predictive value of biomarkers of inflammation like phagocyte-related S100 proteins and a panel of inflammatory cytokines in order to differentiate the child with acute lymphoblastic leukemia (ALL) from juvenile idiopathic arthritis (JIA).

STUDY DESIGN

In this cross-sectional study, we measured S100A9, S100A12, and 14 cytokines in serum from children with ALL (n = 150, including 27 with arthropathy) and JIA (n = 236). We constructed predictive models computing areas under the curve (AUC) as well as predicted probabilities in order to differentiate ALL from JIA. Logistic regression was used for predictions of ALL risk, considering the markers as the respective exposures. We performed internal validation using repeated 10-fold cross-validation and recalibration, adjusted for age.

RESULTS

In ALL, the levels of S100A9, S100A12, interleukin (IL)-1 beta, IL-4, IL-13, IL-17, matrix metalloproteinase-3, and myeloperoxidase were low compared with JIA (P < .001). IL-13 had an AUC of 100% (95% CI 100%-100%) due to no overlap between the serum levels in the 2 groups. Further, IL-4 and S100A9 had high predictive performance with AUCs of 99% (95% CI 97%-100%) and 98% (95% CI 94%-99%), respectively, exceeding both hemoglobin, platelets, C-reactive protein, and erythrocyte sedimentation rate.

CONCLUSIONS

The biomarkers S100A9, IL-4, and IL-13 might be valuable markers to differentiate ALL from JIA.

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.

Individual and environmental determinants associated with longer times to access pediatric rheumatology centers for patients with juvenile idiopathic arthritis, a JIR cohort study

BACKGROUND

Despite guidelines, poor access to appropriate care for juvenile idiopathic arthritis (JIA) patients remains a global issue. Prompt referral to a pediatric rheumatology (PR) center and effective care is known to be critical for changing the natural history of the disease and improving long-term prognosis. This project assesses socio-economic factors of delayed referral to a pediatric rheumatologist (PRst) for JIA patients in France and Switzerland within the Juvenile Inflammatory Rheumatism (JIR) Cohort.

METHODS

All patients diagnosed with JIA, presenting at one center of the JIRcohort in France or Switzerland with additional data on referral pathway were included. Patient characteristics at first visit to the PR center, dates of visits to healthcare providers during referral, and parent characteristics were extracted from the JIRcohort database.

RESULTS

Two hundred fifty children were included. The overall median time to first PR assessment was 2.4 months [1.3; 6.9] and ranged widely across the JIA subtypes, from 1.4 months [0.6; 3.8] for children with systemic juvenile idiopathic arthritis (sJIA) to 5.3 months [2.0; 19.1] for children with enthesitis-related arthritis (ERA). A diagnosis of ERA and an appointment with an orthopedist during the referral pathway were significantly associated with a longer time before the first PR visit (hazard ratio HR 0.50 [95% CI: 0.29; 0.84]) and HR 0.68 [95% CI: 0.49; 0.93], respectively) in multivariable analysis. Having a mother with a post-graduate educational attainment level was tendentially associated with a shorter time before the first PR visit, (HR 1.32 [95% CI: 0.99; 1.78]).

CONCLUSIONS

Time to first PRst visit was most often short compared to other studies and close to the British recommendations. However, this time remained too long for many patients. We observed no social inequities in access to a PRst, but we show the need to improve effective pathway and access to a PR center for JIA patients.

Withdrawal of biologic therapy in juvenile idiopathic arthritis due to remission: predictors of flare and outcomes

OBJECTIVES

To investigate patients who flared after discontinuation of biological disease-modifying anti-rheumatic agents (bDMARDs) and identify risk factors associated with flare.

METHODS

A multicenter study evaluating systemic and non-systemic juvenile idiopathic arthritis (sJIA and non-sJIA) patients whose bDMARDs were ceased after remission.

RESULTS

A total of 101 patients whose bDMARDs were ceased after remission was evaluated. Children with sJIA had the lowest risk of flare and 11.1% of 36 sJIA patients experienced flare after a median of 9 (4-24) months of bDMARDs cessation with three of them flaring in the first year. High leukocyte counts in sJIA patients were associated with inactive disease at 1-year after the start of treatment (p = 0.004). In the non-sJIA group, 46.1% patients experienced flare after a median of 7 (1-32) months of biologic cessation, and of these, 25 flared in the first year. Antinuclear antibody positivity (p = 0.02), earlier disease onset (p = 0.03), long disease duration (p = 0.01), and follow-up (p = 0.02) and extended time from diagnosis to first biological onset (p = 0.03) were more common among patients with flare.

CONCLUSIONS

When considering discontinuation of bDMARDs, it should be kept in mind that the risk of exacerbation requiring re-initiation therapy is quite significant within the first year after discontinuation of therapy.

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.

What drives the decision to optimise biological treatment in children and youngsters with juvenile idiopathic arthritis? A discrete-choice experiment

OBJECTIVE

To analyse factors involved in the decision to optimise biologics in juvenile idiopathic arthritis.

METHODS

A "discrete-choice" methodology was used. In a nominal group meeting, factors which may influence physicians' decisions to optimise biological dose were identified, together with decision nodes. 1000Minds® was used to create multiple fictitious clinical scenarios based on the factors identified, and to deploy surveys that were sent to a panel of experts. These experts decided for each item which of two clinical scenarios prompted them to optimise the dose of biologic. A conjoint analysis was carried out, and the partial-value functions and the weights of relative importance calculated.

RESULTS

In the nominal group, three decision nodes were identified: (1) time to decide; (2) to maintain/reduce or prolong interval; (3) what drug to reduce. The factors elicited were different for each node and included patient and drug attributes. The presence of macrophage activation syndrome (MAS), systemic involvement, or subclinical inflammation made the decision easier (highest weights). The presence of joints of difficult control and year of debut influenced the decision in some but not all, and in different directions. Immunogenicity, adherence, and concomitant treatments were also aspects taken into account.

CONCLUSIONS

The decision to optimise the dose of biological therapy in children and youngster can be divided into several nodes, and the factors, both patient and therapy-related, leading to the decision can be detailed. These decisions taken by experts may be transported to practice, study designs, and guidelines.

Contribution of Ultrasound in Current Practice for Managing Juvenile Idiopathic Arthritis

The interest and application of musculoskeletal ultrasound (MSUS) in juvenile idiopathic arthritis (JIA) are increasing. Numerous studies have shown that MSUS is more sensitive than clinical examination for detecting subclinical synovitis. MSUS is a well-accepted tool, easily accessible and non-irradiating. Therefore, it is a useful technique throughout JIA management. In the diagnostic work-up, MSUS allows for better characterizing the inflammatory involvement. It helps to define the disease extension, improving the classification of patients into JIA subtypes. Moreover, it is an essential tool for guiding intra-articular and peritendinous procedures. Finally, during the follow-up, in detecting subclinical disease activity, MSUS can be helpful in therapeutic decision-making. Because of several peculiarities related to the growing skeleton, the MSUS standards defined for adults do not apply to children. During the last decade, many teams have made large efforts to define normal and pathological US features in children in different age groups, which should be considered during the US examination. This review describes the specificities of MSUS in children, its applications in clinical practice, and its integration into the new JIA treat-to-target therapeutic approach.

Soluble interleukin-2 receptor serum levels facilitate prediction of relapses in subgroups of patients with juvenile idiopathic arthritis

OBJECTIVES

JIA is characterised by a chronic disease course. Once patients achieve a state of inactive disease, there are no established biomarkers to predict the further course of inflammation for these patients. Therefore, the purpose of this study was to quantify serum biomarkers during quiescent disease to evaluate their use in identifying JIA patients at risk for future disease flare.

METHODS

Patients with non-systemic JIA reaching inactive disease status were divided into two groups: 92 patients with future active disease after a median period of 6 months (range 3-9) and 80 patients with persistent inactive disease for the following period (median 11 months, range 7-16) according to the juvenile arthritis DAS (JADAS). Clinical parameters and serum levels of various biomarkers were measured in the state of inactive disease using immunoassays in both groups and were analysed for their potential to predict the further course of disease.

RESULTS

Soluble interleukin-2 receptor (sIL-2R) serum levels were significantly higher in patients with future active disease (P = 0.021), which especially applied to patients with RF-negative polyarticular and extended oligoarticular JIA (P < 0.001). Higher sIL-2R serum levels during inactive disease were associated with a greater number of active joints at future active disease.

CONCLUSION

Patients without clinical signs of disease activity already presented with increased sIL-2R serum levels several months before disease relapses, whereas conventional inflammation parameters were not elevated. Determination of sIL-2R serum levels during inactive disease may facilitate identifying patients with subclinical disease activity at risk for future active disease.

Myeloid-related protein 8/14 in plasma and serum in patients with new-onset juvenile idiopathic arthritis in real-world setting in a single center

OBJECTIVE

The aim of this study was to analyze the usefulness of myeloid-related protein 8/14 (MRP8/14) in the prediction of disease course in a real-world setting for patients with new-onset juvenile idiopathic arthritis (JIA), to identify the relationship between MRP8/14 and disease activity using the physician's global assessment of disease activity (PGA), and determine whether the MRP8/14 levels measured in serum and plasma are equally useful.

METHODS

In this prospective follow-up study, 87 new-onset non-systemic JIA patients were studied. Blood and synovial fluid samples were collected prior to any antirheumatic medication use. MRP8/14 was measured from serum (S-MRP8/14), plasma (P-MRP8/14), and synovial fluid samples using ELISA.

RESULTS

The baseline MRP8/14 blood levels were significantly higher in patients using synthetic antirheumatic drugs than in patients with no systemic medications at 1 year after diagnosis in serum (mean 298 vs. 198 ng/ml, P < 0.001) and in plasma (mean 291 vs. 137 ng/ml, P = 0.001). MRP8/14 levels at the time of JIA diagnosis were higher in patients who started methotrexate during 1.5-year follow-up compared to those who achieved long-lasting inactive disease status without systemic medications (serum: mean 298 vs. 219 ng/ml, P = 0.006 and plasma: 296 vs. 141 ng/ml, P = 0.001). P-MRP8/14 was the most effective predictive variable for disease activity (by PGA) in linear multivariate regression model (combined to ESR, CRP, leukocytes, and neutrophils), whereas S-MRP8/14 was not significant.

CONCLUSION

Blood MRP8/14 levels at baseline seem to predict disease course in new-onset JIA patients. P-MRP8/14 might be better than S-MRP8/14 when assessing disease activity at the time of JIA diagnosis.

Prevention of disease flares by risk-adapted stratification of therapy withdrawal in juvenile idiopathic arthritis: results from the PREVENT-JIA trial

Objectives

To investigate the ability of high-sensitivity C-reactive protein (hsCRP) and S100A12 to serve as predictive biomarkers of successful drug withdrawal in children with clinical remission of juvenile idiopathic arthritis (JIA).

Methods

This multicentre trial (PREVENT-JIA) enrolled 119 patients with JIA in clinical remission, and 100 patients reached the intervention phase in which the decision whether to continue or stop treatment was based on S100A12 and hsCRP levels. Patients were monitored for 12 months after stopping medication for flares of disease. Results were compared with withdrawal of therapy without biomarker-based stratification in patients from the German Biologika in der Kinderrheumatologie (BiKeR) pharmacovigilance registry.

Results

In the PREVENT-JIA group, 49 patients had a flare, and 45% of patients stopping medication showed flares within the following 12 months. All patients (n=8) continuing therapy due to permanently elevated S100A12/hsCRP at more than one visit flared during the observation phase. In the BiKeR control group, the total flare rate was 62%, with 60% flaring after stopping medication. The primary outcome, time from therapy withdrawal to first flare (cumulative flare rate after therapy withdrawal), showed a significant difference in favour of the PREVENT-JIA group (p=0.046; HR 0.62, 95% CI 0.38 to 0.99). As additional finding, patients in the PREVENT-JIA trial stopped therapy significantly earlier.

Conclusion

Biomarker-guided strategies of therapy withdrawal are feasible in clinical practice. This study demonstrates that using predictive markers of subclinical inflammation is a promising tool in the decision-making process of therapy withdrawal, which translates into direct benefit for patients.

Trial registration number

ISRCTN69963079.

Juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is an umbrella term for arthritis of unknown origin, lasting for >6 weeks with onset before 16 years of age. JIA is the most common chronic inflammatory rheumatic condition of childhood. According to the International League Against Rheumatism (ILAR) classification, seven mutually exclusive categories of JIA exist based on disease manifestations during the first 6 months of disease. Although the ILAR classification has been useful to foster research, it has been criticized mainly as it does not distinguish those forms of chronic arthritis observed in adults and in children from those that may be unique to childhood. Hence, efforts to provide a new evidence-based classification are ongoing. Similar to arthritis observed in adults, pathogenesis involves autoimmune and autoinflammatory mechanisms. The field has witnessed a remarkable improvement in therapeutic possibilities of JIA owing to the availability of new potent drugs and the possibility to perform controlled trials with support from legislative interventions and large networks availability. The goal of drug therapy in JIA is to rapidly reduce disease activity to inactive disease or clinical remission, minimize drug side effects and achieve a quality of life comparable to that of healthy peers. As JIA can influence all aspects of a child's and their family's life, researchers increasingly recognize improvement of health-related quality of life as a key treatment goal.

Use of MRP8/14 in clinical practice as a predictor of outcome after methotrexate withdrawal in patients with juvenile idiopathic arthritis

The objective of this study was to determine the effectiveness of MRP8/14 as a predictor of disease flare in patients with juvenile idiopathic arthritis (JIA) following the withdrawal of methotrexate (MTX) in a routine clinical setting. All MRP8/14 tests performed at a single centre in a 27-month period were considered for analysis. Patients were assessed against criteria for inactive disease and subsequent disease flare. Decisions on whether or not to stop treatment were recorded. MRP8/14 results were assessed in conjunction with clinical information. Clinicians were also surveyed to investigate if MRP8/14 influenced their decision to discontinue MTX where this was available at that time point. One hundred four cases met the inclusion criteria during the study period. Although there was no significant difference in flares between patients with an elevated or low MRP8/14 value, in those who stopped MTX (n = 22), no patients with a low MRP8/14 (≤ 4000 ng/ml) result flared (follow-up time 12 months). Clinicians reported that for patients with clinically inactive disease and an elevated MRP8/14 result (> 4000 ng/ml), none would advise withdrawal of MTX. Low MRP8/14 was interpreted favourably when considering stopping MTX treatment in patients with JIA. Implementation of MRP8/14 testing has changed clinical practice at this centre. However, the observation that some patients in our cohort who had an elevated MRP8/14 value did not flare after stopping MTX for non-disease-related reasons highlights the need for further biomarkers to predict the risk of flare off medication in JIA and aid clinicians in treatment decisions. Key Points • First study of serum MRP8/14 measurement in clinical practice to inform treatment decisions in patients with JIA. • No patients with a low MRP8/14 test result went on to suffer a disease flare in 12 months of follow follow-up. • Further biomarkers are needed to predict the risk of flare off medication in JIA and treatment decisions.

Uveitis in Children and Adolescents

Childhood noninfectious uveitis leads to sight-threatening complications. Idiopathic chronic anterior uveitis and juvenile idiopathic arthritis-associated uveitis are most common. Inflammation arises from an immune response against antigens within the eye. Ophthalmic work-up evaluates anatomic involvement, disease activity, ocular complications, and disease course. Local and/or systemic glucocorticoids are initial treatment, but not as long-term sole therapy to avoid glucocorticoids-induced toxicity or persistent ocular inflammation. Children with recurrent, refractory, or severe disease require systemic immunosuppression with methotrexate and/or anti-tumor necrosis factor monoclonal antibody medications (adalimumab, infliximab). Goals of early detection and treatment are to optimize vision in childhood uveitis.

Precision medicine in juvenile idiopathic arthritis-has the time arrived?

The introduction of disease-modifying anti-rheumatic drug therapies for treating children and adolescents with chronic arthritis (ie, juvenile idiopathic arthritis [JIA]) has revolutionised care and outcomes. The biologic revolution continues to expand, with ever-changing immunological targets coming to market after basic research and clinical trials. The first class of biologics that was beneficial for children with JIA was tumour necrosis factor (TNF) inhibitors. If used early and aggressively, TNF inhibitors are capable of inducing disease remission for most of the seven subtypes of JIA, with the exception of systemic JIA (which more frequently responds to interleukin [IL]-1 or IL-6 inhibition). Nevertheless, there are still subsets of patients with JIA with disease that is difficult to treat or who develop extra-articular features that require a different therapeutic approach. Although finding an effective biological therapy for individual children with JIA can be trial and error, ongoing research and clinical trials are providing insight into a more personalised approach to care. In addition, redefining the JIA classification, in part based on shared similarities with various adult arthritides, could allow for extrapolation of knowledge from studies in adults with chronic arthritis.

Serum Calprotectin a Potential Biomarker in Juvenile Idiopathic Arthritis: A Meta-Analysis

Juvenile idiopathic arthritis (JIA) is the most common inflammatory chronic disease affecting children and adolescents. Today, there are no specific biomarkers of inflammation. Therefore, it is important to identify new markers as predictors of disease activity. Recently, some researchers have directed their interest toward a protein, calprotectin (CLP), as a potential biomarker. The primary objective of our systematic review and meta-analysis was to analyze the possible role of CLP in JIA. Method: A literature search was conducted using PubMed, EMBASE, Scopus, Science Direct on 10 August 2021. The selection of studies was made using the PRISMA 2020 guidelines. Cohen’s d with 95% CI and p-value were used as a measure of effect size. The random effects model was used to account for different sources of variation among studies. Heterogeneity was assessed using Q statistics and I². The publication bias was analyzed and represented by a funnel plot, and funnel plot symmetry was assessed with Egger’s test. Results: Our results at follow-up showed a statistically significant difference between patients with active disease compared to patients with inactive disease: 0.39 (0.16; 0.62), p = 0.001; without statistical heterogeneity. Another important aspect that emerged were the differences between the systemic disease form and any form of inactive disease showing a different concentration of calprotectin: 0.74 (0.40; 1.08), p < 0.001; without statistical heterogeneity. On the other hand, meta-regression analyses performed on gender, age, duration of disease, percentage of patients with ANA+ or RF+, medium value of ESR or CRP were not statistically significant. A statistically significant difference in serum calprotectin concentration between patients with JIA and healthy controls were observed. In fact, it presented lower values in the control group. Conclusions: The use of serum CLP could represent, in the future, a useful tool in JIA in order to stratify disease activity more accurately and may aid a more tailored approach to drug of choice in children with JIA. Further studies are needed to evaluate CLP as a predictor of flare in combination with other potential biomarkers of subclinical disease activity.

Serum calprotectin (S100A8/A9): a promising biomarker in diagnosis and follow-up in different subgroups of juvenile idiopathic arthritis

Introduction

In the management of juvenile idiopathic arthritis (JIA), there is a lack of diagnostic and prognostic biomarkers. This study assesses the use of serum calprotectin (sCal) as a marker to monitor disease activity, and as a classification and prognosis tool of response to treatment or risk of flares in patients with JIA.

Methods

Eighty-one patients with JIA from the CAP48 multicentric cohort were included in this study, as well as 11 non-paediatric healthy controls. An ELISA method was used to quantify sCal with a commercial kit.

Results

Patients with an active disease compared with healthy controls and with patients with inactive disease showed an eightfold and a twofold increased level of sCal, respectively. sCal was found to be correlated with the C-reactive protein (CRP) and even more strongly with the erythrocyte sedimentation rate. Evolution of DAS28 scores correlated well with evolution of sCal, as opposed to evolution of CRP. With regard to CRP, sCal could differentiate forms with active oligoarthritis from polyarthritis and systemic forms. However, sCal brought an added value compared with the CRP as a prognosis marker. Indeed, patients with active disease and reaching minimal disease activity (according to Juvenile Arthritis Disease Activity Score) at 6 months following the test had higher sCal levels, while patients with inactive disease had higher sCal levels if a flare was observed up to 3–9 months following the test.

Conclusions

This study confirms the potential uses of sCal as a biomarker in the diagnosis and follow-up of JIA.

Responses of patients with juvenile idiopathic arthritis to methotrexate: a genomic outlook

INTRODUCTION

Juvenile idiopathic arthritis (JIA) is a chronic disease characterized by persistent joint inflammation. JIA is the most common pediatric chronic rheumatic disease and no curative therapy is currently available. Methotrexate (MTX) is an important treatment for JIA even though a high inter-individual variability in response is observed in patients. Among the factors of this variability, genetics and epigenetics might play an important role.

AREAS COVERED

This review summarizes the results of pharmacogenetic and pharmacoepigenetic studies regarding MTX response in JIA. Studies considering epigenetic factors in JIA patients are still very limited, therefore this review includes also studies performed in adult patients with rheumatoid arthritis. Moreover, the relevance of biomarkers measured in blood or urine of JIA patients in relation to MTX treatment is discussed.

EXPERT OPINION

Nowadays, even though many pharmacogenomics studies have been published, a specific genetic marker predictor of MTX efficacy or adverse events has not yet been identified. Encouraging results are available and great expectations rely on the study of epigenetics. Future studies are needed in order to identify genetic and epigenetic biomarkers that can be implemented in the clinical practice.

The new role of musculoskeletal ultrasound in the treat-to-target management of juvenile idiopathic arthritis

This article reviews the role of musculoskeletal ultrasound (MSUS) for the diagnosis, monitoring and treat-to-target management of JIA. Technological advancements in MSUS allow more precise evaluation of arthritis, tenosynovitis and enthesitis versus clinical examination alone, which may assist treatment decisions. In adult studies, serum and synovial biomarkers have correlated with MSUS findings. Within paediatric rheumatology, significant developments in the definition of normal and pathology, a necessity for the future integration of MSUS into treat-to-target management, have already been reached or are underway, which in turn could allow tighter control of disease activity and earlier identification of treatment response and failure, bringing the goal of 'precision medicine' closer. Additionally, the utility of MSUS for the evaluation of subclinical disease remains an unexamined area of interest. 'Ultrasound remission' combined with clinical assessment and immunological markers could therefore potentially improve the treat-to-target management of JIA.

Toward pharmacogenetic SLCO1B1-guided dosing of methotrexate in arthritis using a murine Slco1b2 knockout model

Low‐dose methotrexate (MTX) is a first‐line therapy for the treatment of arthritis. However, there is considerable interindividual variability in MTX exposure following standard dosing. Polymorphisms in SLCO1B1 significantly effect MTX clearance, altering therapeutic response. One decreased function variant, rs4149056 (c.521T>C, Val174Ala), slows MTX clearance and in vitro uptake of MTX. This phenotype was recapitulated in a mouse model using a knockout (KO) of the murine orthologue, Slco1b2. Our objective was to investigate the impact of this phenotype on the pharmacokinetics and therapeutic outcomes of low‐dose MTX in a murine model of collagen‐induced arthritis (CIA). We evaluated response to MTX in mice with CIA using wildtype (WT), heterozygous, and KO Slco1b2 mice on a DBA1/J background. Arthritis was macroscopically evaluated daily to quantify disease progression. Mice received 2 mg/kg or a pharmacogenetically guided MTX dose subcutaneously 3 times a week for 2 weeks. MTX concentrations were collected at the end of the study and exposure (day*µM) was estimated using a two‐compartment model. Mice displayed a seven‐fold range in MTX exposure and revealed a significant exposure‐response relationship (p = 0.0027). KO mice receiving the 2 mg/kg dosing regimen had 2.3‐fold greater exposure to MTX (p < 0.0001) and a 66% reduction in overall disease progression (p = 0.011) compared to WT mice. However, exposure and response were equivalent when pharmacogenetically guided dosing was used. These studies demonstrate that an exposure‐response relationship exists for MTX and that Slco1b2 genotype affects MTX exposure and therapeutic response. Such evidence supports the use of SLCO1B1‐pharmacogenetic dosing of low‐dose MTX for patients with arthritis.

Trajectories of disease courses in the inception cohort of newly diagnosed patients with JIA (ICON-JIA): the potential of serum biomarkers at baseline

OBJECTIVE

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of inflammatory joint disorders with a chronic-remitting disease course. Treat-to-target approaches have been proposed but monitoring disease activity and predicting the response to treatment remains challenging.

METHODS

We analyzed biomarkers and their relationship to outcome within the first year after JIA diagnosis in the German Inception Cohort of Newly diagnosed patients with JIA (ICON-JIA). CRP, CXCL9, CXCL10, CXCL11, erythrocyte sedimentation rate, G-CSF, IL-6, IL-17A, IL-18, MCP-1, MIP-1α, MMP-3, S100A8/A9, S100A12, TNFα, and TWEAK were measured at baseline and 3 months later.

RESULTS

Two-hundred-sixty-six JIA patients with active disease at baseline were included, with oligoarthritis and rheumatoid factor-negative polyarthritis representing the most frequent categories (72.9%). Most biomarkers were elevated in JIA compared to healthy pediatric controls. Patients with systemic JIA had higher CRP, S100A8/A9 and S100A12 levels compared to other JIA categories. Baseline levels of TWEAK, G-CSF and IL-18 were lower in oligoarthritis patients with disease extension within 1 year. Increased baseline levels of CRP, S100A8/A9, S100A12 and ESR were associated with the subsequent addition of biologic disease-modifying antirheumatic drugs (DMARDs). Higher baseline ESR, G-CSF, IL-6, IL-17A and TNF levels indicated an increased risk for ongoing disease activity after 12 months.

CONCLUSION

Our data demonstrate that elevated baseline levels of CRP, S100A8/A9 and S100A12 as well as increased ESR are associated with the necessity to escalate therapy during the first 12 month of follow-up. Furthermore, biomarkers related to Th17 activation may inform on future disease course in previously treatment-naïve JIA patients.

Re-treatment with etanercept is as effective as the initial firstline treatment in patients with juvenile idiopathic arthritis

Objectives

To determine (i) correlates for etanercept (ETA) discontinuation after achieving an inactive disease and for the subsequent risk of flare and (ii) to analyze the effectiveness of ETA in the re-treatment after a disease flare.

Methods

Data from two ongoing prospective registries, BiKeR and JuMBO, were used for the analysis. Both registries provide individual trajectories of clinical data and outcomes from childhood to adulthood in juvenile idiopathic arthritis (JIA) patients treated with biologic disease-modifying anti-rheumatic drugs (bDMARDs) and conventional synthetic DMARDs (csDMARDs).

Results

A total of 1724 patients were treated first with ETA treatment course (338 with second, 54 with third ETA course). Similar rates of discontinuation due to ineffectiveness and adverse events could be observed for the first (19.4%/6.2%), second (18.6%/5.9%), and third (14.8%/5.6%) ETA course. A total of 332 patients (+/−methotrexate, 19.3%) discontinued ETA after achieving remission with the first ETA course. Younger age (hazard ratio (HR) 1.08, p < 0.001), persistent oligoarthritis (HR 1.89, p = 0.004), and shorter duration between JIA onset and ETA start (HR 1.10, p < 0.001), as well as good response to therapy within the first 6 months of treatment (HR 1.11, p < 0.001) significantly correlated to discontinuation with inactive disease. Reoccurrence of active disease was reported for 77% of patients with mean time to flare of 12.1 months. We could not identify any factor correlating to flare risk. The majority of patients were re-treated with ETA (n = 117 of 161; 72.7%) after the flare. One in five patients (n = 23, 19.7%) discontinued ETA again after achieving an inactive disease and about 70% of the patients achieved an inactive disease 12 months after restarting ETA.

Conclusion

The study confirms the effectiveness of ETA even for re-treatment of patients with JIA. Our data highlight the association of an early bDMARD treatment with a higher rate of inactive disease indicating a window of opportunity.

Advancing the treatment of juvenile idiopathic arthritis

Treatment for juvenile idiopathic arthritis has undergone substantial changes in recent decades. These changes are partly due to the availability of new treatments, mainly biological agents, as well as developments in treatment strategies, including a focus on concepts such as treat-to-target. In addition, the creation of large paediatric research networks has improved patient access to, and design of, clinical trials for rare paediatric diseases. Although these advances have resulted in improvements in care for most patients with juvenile idiopathic arthritis, certain subgroups of patients continue to have a poor prognosis. Further research aims to identify patients in these subgroups early, to personalise their care, improve functional outcomes, and minimise long-term damage and harm. Optimising the duration of therapy for those individuals who require systemic immunosuppression is also of importance. Incorporation of novel biomarkers in combination with validated clinical measures in an effort to predict outcomes and target therapy accordingly is an exciting development.

Simultaneous determination of erythrocyte methotrexate polyglutamates by a novel and simple HPLC-MS/MS method with stable isotope-labeled internal standards

Low-dose methotrexate is the first-line therapy for juvenile idiopathic arthritis. In vivo, methotrexate is converted into a series of methotrexate polyglutamates whose intracellular levels contribute significantly to its efficacy and toxicity. In this study, a novel high-performance liquid chromatography-tandem mass spectrometry method was developed and validated to simultaneously determine erythrocyte methotrexate polyglutamates using stable isotope-labeled internal standards. Erythrocyte samples were precipitated by perchloric acid and then determined on an XBridge BEH C18 column with an XP vanguard precolumn in 12 min. The mobile phase consisted of 10 nM ammonium acetate (pH 10) and methanol under gradient elution. The detection was carried out in multiple reaction monitoring mode via an electrospray ionization source in positive ionization mode. The calibration curve for each metabolite was linear from 2.0 to 500.0 nmol/L (r²  > 0.99). The intraday and interday accuracies were between 93.0 and 107.0%, and the corresponding precisions were between 0.8 and 5.2%. The relative recovery ranged from 82.7 to 105.1%, and the relative matrix effect varied from 96.5 to 104.4%. The erythrocyte metabolites were stable for 30 days at -80°C. This simple and accurate method is applicable to routine monitoring of the concentration of erythrocyte methotrexate polyglutamates in patients to achieve individualized treatment.

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.

Access to paediatric rheumatology care in juvenile idiopathic arthritis: what do we know? A systematic review

OBJECTIVE

This review examines time to access appropriate care for JIA patients and analyses the referral pathway before the first paediatric rheumatology (PR) visit. We also describe factors associated with a longer referral.

METHODS

We performed a systematic literature review, screening electronic databases (PubMed, Web of Science, EMBASE, Cochrane library and Open Grey database) up to February 2020. Articles written before 1994 (i.e. before the introduction of the unifying term JIA) were excluded.

RESULTS

From 595 nonduplicate citations found, 15 articles were finally included in the review. Most of the studies took place in Europe. The median time to first PR visit ranged from 3 to 10 months, with some disparities between referral pathway and patient characteristics. Patients with systemic-onset JIA had the shortest time to referral. Some clinical and biological factors such as swelling, fever, and elevated CRP and/or ESR were associated with a shorter time to first PR visit. Conversely, enthesitis, older age at symptom onset or pain were associated with a longer time. Whatever the country or world region, and despite disparities in healthcare system organization and healthcare practitioner availabilities, times to access PR were not wide-ranging.

CONCLUSION

This is the first systematic review to summarize research on access to PR for JIA patients. The pathway of care for JIA patients remains complex, and reasons for delayed referral depend on several factors. Standardized clinical guidelines and fast-track pathways to facilitate prompt referral to specialized teams have to allow for worldwide disparities in healthcare provision.

Open-Label Phase 3 Study of Intravenous Golimumab in Patients With Polyarticular Juvenile Idiopathic Arthritis

Objectives

To assess efficacy, pharmacokinetics (PK) and safety of intravenous (i.v.) golimumab in patients with polyarticular-course JIA (pc-JIA).

Methods

Children aged 2 to <18 years with active pc-JIA despite MTX therapy for ≥2 months received 80 mg/m² golimumab at weeks 0, 4, then every 8 weeks through week 52 plus MTX weekly through week 28. The primary and major secondary endpoints were PK exposure and model-predicted steady-state area under the curve (AUC_ss) over an 8-week dosing interval at weeks 28 and 52, respectively. JIA ACR response and safety were also assessed.

Results

In total, 127 children were treated with i.v. golimumab. JIA ACR 30, 50, 70, and 90 response rates were 84%, 80%, 70% and 47%, respectively, at week 28 and were maintained through week 52. Golimumab serum concentrations and AUC_ss were 0.40 µg/ml and 399 µg ⋅ day/ml at week 28. PK exposure was maintained at week 52. Steady-state trough golimumab concentrations and AUC_ss were consistent across age categories and comparable to i.v. golimumab dosed 2 mg/kg in adults with rheumatoid arthritis. Golimumab antibodies and neutralizing antibodies were detected via a highly sensitive drug-tolerant assay in 31% (39/125) and 19% (24/125) of patients, respectively. Median trough golimumab concentration was lower in antibody-positive vs antibody-negative patients. Serious infections were reported in 6% of patients, including one death due to septic shock.

Conclusion

Body surface area-based dosing of i.v. golimumab was well tolerated and provided adequate PK exposure for clinical efficacy in paediatric patients with active pc-JIA.

ClinicalTrials.gov number NCT02277444

MRP8/14 and neutrophil elastase for predicting treatment response and occurrence of flare in patients with juvenile idiopathic arthritis

Objective

To study two neutrophil activation markers, myeloid-related protein (MRP) 8/14 and neutrophil elastase (NE), for their ability to predict treatment response and flare in patients with JIA.

Methods

Using samples from two cohorts (I and II), we determined MRP8/14 and NE levels of 32 (I) and 81 (II) patients with new-onset, DMARD-naïve arthritis and compared patients who responded to treatment (defined as fulfilling ≥ adjusted ACRpedi50 response and/or inactive disease) with non-responders (defined as fulfilling < adjusted ACRpedi50 response and/or active disease) at 6 and 12 months. Secondly, we compared biomarker levels of 54 (I) and 34 (II) patients with clinically inactive disease who did or did not suffer from a flare of arthritis after 6 or 12 months. Receiver operating characteristic analyses were carried out to study the predictive value of MRP8/14 and NE for treatment response and flare.

Results

For both cohorts, baseline MRP8/14 and NE levels for patients who did or did not respond to treatment were not different. Also, MRP8/14 and NE levels were not different in patients who did or did not flare. Receiver operating characteristic analysis of MRP8/14 and NE demonstrated areas under the curve <0.7 in both cohorts.

Conclusion

In our cohorts, MRP8/14 and NE could not predict treatment response. Also, when patients had inactive disease, neither marker could predict flares.

Tapering Canakinumab Monotherapy in Patients With Systemic Juvenile Idiopathic Arthritis in Clinical Remission: Results From a Phase IIIb/IV Open-Label, Randomized Study

OBJECTIVE

To evaluate the efficacy and safety of 2 canakinumab monotherapy tapering regimens in order to maintain complete clinical remission in children with systemic juvenile idiopathic arthritis (JIA).

METHODS

The study was designed as a 2-part phase IIIb/IV open-label, randomized trial. In the first part, patients received 4 mg/kg of canakinumab subcutaneously every 4 weeks and discontinued glucocorticoids and/or methotrexate as appropriate. Patients in whom clinical remission was achieved (inactive disease for at least 24 weeks) with canakinumab monotherapy were entered into the second part of the trial, in which they were randomized 1:1 into 1 of 2 treatment arms. In arm 1, the dose of canakinumab was reduced from 4 mg/kg to 2 mg/kg and then to 1 mg/kg, followed by discontinuation. In arm 2, the 4 mg/kg dose interval was prolonged from every 4 weeks, to every 8 weeks, and then to every 12 weeks, followed by discontinuation. In both arms, canakinumab exposure could be reduced provided systemic JIA remained in clinical remission for 24 weeks with each step. The primary objective was to assess whether >40% of randomized patients in either arm maintained clinical remission of systemic JIA for 24 weeks in the first part of the study.

RESULTS

In part 1 of the study, 182 patients were enrolled, with 75 of those patients randomized before entering part 2 of the trial. Among the 75 randomized patients, clinical remission was maintained for 24 weeks in 27 (71%) of 38 patients in arm 1 (2 mg/kg every 4 weeks) and 31 (84%) of 37 patients in arm 2 (4 mg/kg every 8 weeks) (P ≤ 0.0001 for arm 1 versus arm 2 among those meeting the 40% threshold). Overall, 25 (33%) of 75 patients discontinued canakinumab, and clinical remission was maintained for at least 24 weeks in all 25 of these patients. No new safety signals were identified.

CONCLUSION

Reduction of canakinumab exposure may be feasible in patients who have achieved clinical remission of systemic JIA, but consistent interleukin-1 inhibition appears necessary to maintain this response.

Inflammasomes and Childhood Autoimmune Diseases: A Review of Current Knowledge

Inflammasomes are multiprotein complexes capable of sensing pathogen-associated molecular patterns (PAMPs), danger-associated molecular patterns (DAMPs), and cellular perturbations. Upon stimulation, the inflammasomes activate the production of the pro-inflammatory cytokines IL-1β and IL-18 and induce gasdermin D-mediated pyroptosis. Dysregulated inflammasome signaling could lead to hyperinflammation in response to environmental triggers, thus contributing to the pathogenesis of childhood autoimmune/autoinflammatory diseases. In this review, we group childhood rheumatic diseases into the autoinflammation to autoimmunity spectrum and discuss about the involvement of inflammasomes in disease mechanisms. Genetic mutations in inflammasome components cause monogenic autoinflammatory diseases, while inflammasome-related genetic variants have been implicated in polygenic childhood rheumatic diseases. We highlight the reported associations of inflammasome signaling-related genetic polymorphisms/protein levels with pediatric autoimmune disease susceptibility and disease course. Furthermore, we discuss about the use of IL-1 receptor antagonist as an adjunctive therapy in several childhood autoimmune diseases, including macrophage activation syndrome (MAS) and multisystem inflammatory syndrome in children (MIS-C) related to COVID-19. A comprehensive multi-cohort comparison on inflammasome gene expression profile in different pediatric rheumatic diseases is needed to identify patient subsets that might benefit from the adjunctive therapy of IL-1β inhibitors.

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.

Multi-Omics Identifies Circulating miRNA and Protein Biomarkers for Facioscapulohumeral Dystrophy

The development of therapeutics for muscle diseases such as facioscapulohumeral dystrophy (FSHD) is impeded by a lack of objective, minimally invasive biomarkers. Here we identify circulating miRNAs and proteins that are dysregulated in early-onset FSHD patients to develop blood-based molecular biomarkers. Plasma samples from clinically characterized individuals with early-onset FSHD provide a discovery group and are compared to healthy control volunteers. Low-density quantitative polymerase chain reaction (PCR)-based arrays identify 19 candidate miRNAs, while mass spectrometry proteomic analysis identifies 13 candidate proteins. Bioinformatic analysis of chromatin immunoprecipitation (ChIP)-seq data shows that the FSHD-dysregulated DUX4 transcription factor binds to regulatory regions of several candidate miRNAs. This panel of miRNAs also shows ChIP signatures consistent with regulation by additional transcription factors which are up-regulated in FSHD (FOS, EGR1, MYC, and YY1). Validation studies in a separate group of patients with FSHD show consistent up-regulation of miR-100, miR-103, miR-146b, miR-29b, miR-34a, miR-454, miR-505, and miR-576. An increase in the expression of S100A8 protein, an inflammatory regulatory factor and subunit of calprotectin, is validated by Enzyme-Linked Immunosorbent Assay (ELISA). Bioinformatic analyses of proteomics and miRNA data further support a model of calprotectin and toll-like receptor 4 (TLR4) pathway dysregulation in FSHD. Moving forward, this panel of miRNAs, along with S100A8 and calprotectin, merit further investigation as monitoring and pharmacodynamic biomarkers for FSHD.

Six-month flare risk after discontinuing long-term methotrexate treatment in patients having rheumatoid arthritis with low disease activity

OBJECTIVES

We investigated the disease flare rate in patients with rheumatoid arthritis (RA) who achieved low disease activity following long-term methotrexate (MTX) treatment and the factors related to flare.

METHODS

This retrospective longitudinal cohort study included patients with RA and low disease activity who were exposed to MTX for >10 years. Disease flare was defined as an increase in Disease Activity Score of 28 joints (DAS28) of >1.2 within 6 months of discontinuation of MTX. Logistic regression analysis was performed to identify the factors associated with flare.

RESULTS

In total, 97 patients with RA were included in the study. The mean baseline DAS28 was 1.96 ± 0.56. The median cumulative MTX dose was 11.7 g; the median duration of exposure to MTX was 19 years. Following MTX discontinuation, flare occurred in 43 (44.3%) patients; the median time to flare was 99 (28-168) days. According to univariate logistic regression analysis, C-reactive protein, erythrocyte sedimentation rate (ESR) at discontinuation, the average ESR in the 6 months before discontinuation of MTX, a weekly dose of MTX before discontinuation, and use of other conventional synthetic disease-modifying antirheumatic drugs were associated with a higher risk of disease flare. In multivariable analysis, a weekly dose of MTX before discontinuation (odds ratio 1.014; 95% CI 1.014-1.342; P = .031) was significantly associated with flare risk.

CONCLUSION

Among patients with RA who achieved low disease activity with long-term treatment with MTX, more than half remained flare free after MTX discontinuation. A higher MTX dose before discontinuation was associated with a high flare risk.

MTX intolerance in children and adolescents with juvenile idiopathic arthritis

MTX is the medication most commonly used for antirheumatic treatment in juvenile idiopathic arthritis. It has high efficacy, is usually well tolerated and has an excellent safety profile. However, frequently intolerance symptoms develop that manifest as nausea, feelings of disgust or abdominal complaints prior to or directly after administration of the medication. No obvious toxicity is causing these intolerance symptoms, but symptoms are strictly limited to MTX and not transferred to other medications. MTX intolerance causes a significant reduction of quality of life in affected patients, frequently puts the treating physician in difficult situations regarding treatment choice, and may lead to uncomfortable decisions whether or not to stop an otherwise effective drug. Conventional countermeasures such as antiemetics, change of route from subcutaneous to oral or vice versa, or taste masking usually have only a limited effect. In this review, we present the current knowledge on MTX intolerance, its clinical picture and commonly employed strategies. We also consider newer behavioural treatment strategies that may offer a more effective symptom control.

Predictive factors and biomarkers for the 2-year outcome of uveitis in juvenile idiopathic arthritis: data from the Inception Cohort of Newly diagnosed patients with Juvenile Idiopathic Arthritis (ICON-JIA) study

Objective

To define predictors for the 2-year outcome in terms of achieving inactivity, subsequent uveitis reactivation and occurrence of uveitis-related complications of JIA-associated uveitis.

Methods

Demographic and clinical parameters and serum samples of JIA-associated uveitis patients enrolled in ICON at ⩽1 year of JIA diagnosis were collected at study enrolment, every 3 months during the first year and subsequently every 6 months. Predictors for the 2-year outcome were evaluated by linear mixed models.

Results

Of 954 JIA patients included, uveitis occurred in 106 up to the first 2-year follow-up, with 98 of them having complete ophthalmological documentation. In 81.8% and 80.0% of patients, uveitis inactivity was achieved at the 1- and 2-year follow-up after uveitis onset, respectively. JIA onset after the age of 5 years, no use of topical corticosteroids, and adalimumab treatment were significantly associated with an inactive uveitis for at least 6 months (n = 57). Correlates for subsequent uveitis reactivation (n = 16, 30.2%) were age at uveitis onset ⩽5 years and active disease (clinical Juvenile Arthritis Disease Activity Score >4.5). Uveitis-related complications were present in 29.8% of patients at first uveitis documentation and in 30.7% and 32.8% at 1- and 2-year follow-up, respectively. Older age at JIA onset, short duration between JIA and uveitis onset, high anterior chamber (AC) cell grades, poor visual acuity, and topical steroid use at first uveitis documentation correlated with uveitis-related complications.

Conclusion

In addition to demographic risk factors, JIA disease and uveitis activity scores and adalimumab are significant predictors for the 2-year outcome of JIA-associated uveitis patients.

Pharmacological conditioning for juvenile idiopathic arthritis: a potential solution to reduce methotrexate intolerance

BACKGROUND

Methotrexate (MTX) therapy has proven to be a successful and safe treatment for Juvenile Idiopathic Arthritis (JIA). Despite the high efficacy rates of MTX, treatment outcomes are often complicated by burdensome gastro-intestinal side effects. Intolerance rates for MTX in children are high (approximately 50%) and thus far no conclusive effective treatment strategies to control for side effects have been found. To address this need, this article proposes an innovative research approach based on pharmacological conditioning, to reduce MTX intolerance.

PRESENTATION OF THE HYPOTHESIS

A collaboration between medical psychologists, pediatric rheumatologists, pharmacologists and patient groups was set up to develop an innovative research design that may be implemented to study potential improved control of side effects in JIA, by making use of the psychobiological principles of pharmacological conditioning. In pharmacological conditioning designs, learned positive associations from drug therapies (conditioning effects) are integrated in regular treatment regimens to maximize treatment outcomes. Medication regimens with immunosuppressant drugs that made use of pharmacological conditioning principles have been shown to lead to optimized therapeutic effects with reduced drug dosing, which might ultimately cause a reduction in side effects.

TESTING THE HYPOTHESIS

This research design is tailored to serve the needs of the JIA patient group. We developed a research design in collaboration with an interdisciplinary research group consisting of patient representatives, pediatric rheumatologists, pharmacologists, and medical psychologists.

IMPLICATIONS OF THE HYPOTHESIS

Based on previous experimental and clinical findings of pharmacological conditioning with immune responses, we propose that the JIA patient group is particularly suited to benefit from a pharmacological conditioning design. Moreover, findings from this study may potentially also be promising for other patient groups that endure long-lasting drug therapies.

S100 family proteins in inflammation and beyond

The S100 family proteins possess a variety of intracellular and extracellular functions. They interact with multiple receptors and signal transducers to regulate pathways that govern inflammation, cell differentiation, proliferation, energy metabolism, apoptosis, calcium homeostasis, cell cytoskeleton and microbial resistance. S100 proteins are also emerging as novel diagnostic markers for identifying and monitoring various diseases. Strategies aimed at targeting S100-mediated signaling pathways hold a great potential in developing novel therapeutics for multiple diseases. In this chapter, we aim to summarize the current knowledge about the role of S100 family proteins in health and disease with a major focus on their role in inflammatory conditions.

Circulating calprotectin (S100A8/A9) is higher in rheumatoid arthritis patients that relapse within 12 months of tapering anti-rheumatic drugs

Objective

To investigate whether calprotectin (S100A8/A9 or MRP8/14), an inflammatory complex released by monocytes, could indicate residual subclinical inflammation in rheumatoid arthritis (RA) patients who are in stable remission on disease-modifying anti-rheumatic drugs (DMARDs) and serve as a marker for disease flare after DMARD tapering.

Methods

We used data from two trials. Patients from the IMPROVED study had early (< 2 years) RA, and when they achieved disease activity score remission (DAS44 < 1.6), they stopped methotrexate to attempt drug-free remission. Patients from the RETRO study had established RA in stable remission (DAS28 < 2.6) and either tapered by 50% or stopped (biological or conventional) DMARDs. Circulating calprotectin at the tapering time point was determined by ELISA, and its predictive value for flare (loss of remission) within 12 months of DMARD tapering/stopping was determined.

Results

In both IMPROVED (n = 104) and RETRO (n = 57), patients that flared within 12 months had higher calprotectin at the moment of DMARD tapering/stopping. Twofold higher calprotectin at the moment of DMARD tapering/stopping was associated with an increased risk (odds ratio) of flare of 1.07 (95% CI 0.98–1.18, p = 0.14) in the IMPROVED and 3.62 (95% CI 1.76–7.46, p < 0.001) in the RETRO. Correcting for clinical predictors of flare (DAS at study inclusion, anti-CCP2 positivity, gender) did not change these estimates. The area under the receiver operating curve of calprotectin levels for predicting flare within 12 months was 0.63 (95% CIs 0.51–0.76) in the IMPROVED study and 0.80 (95% CIs 0.69 to 0.92) in the RETRO study.

Conclusion

Circulating calprotectin levels in RA patients in remission on DMARDs are higher in patients that will flare upon DMARD tapering/stopping. Since the differences between the cohorts precluded definitive conclusions, more research is needed to determine whether calprotectin has prognostic value in predicting flare after attempting drug tapering in RA.

Trial registration

IMPROVED, ISRCTN11916566. RETRO, 2009-015740-42.