Cytokine Biomarkers of Disease Activity and Therapeutic Response after Initiating Methotrexate Therapy in Patients with Juvenile Idiopathic Arthritis

Inflammatory biomarkers predicting long-term remission and active disease in juvenile idiopathic arthritis: a population-based study of the Nordic JIA cohort

OBJECTIVES

To assess the ability of baseline serum biomarkers to predict disease activity and remission status in juvenile idiopathic arthritis (JIA) at 18-year follow-up (FU) in a population-based setting.

METHODS

Clinical data and serum levels of inflammatory biomarkers were assessed in the longitudinal population-based Nordic JIA cohort study at baseline and at 18-year FU. A panel of 16 inflammatory biomarkers was determined by multiplexed bead array assay. We estimated both univariate and multivariate logistic regression models on binary outcomes of disease activity and remission with baseline variables as explanatory variables.

RESULTS

Out of 349 patients eligible for the Nordic JIA cohort study, 236 (68%) had available serum samples at baseline. We measured significantly higher serum levels of interleukin 1β (IL-1β), IL-6, IL-12p70, IL-13, MMP-3, S100A9 and S100A12 at baseline in patients with active disease at 18-year FU than in patients with inactive disease. Computing receiver operating characteristics illustrating the area under the curve (AUC), we compared a conventional prediction model (gender, age, joint counts, erythrocyte sedimentation rate, C reactive protein) with an extended model that also incorporated the 16 baseline biomarkers. Biomarker addition significantly improved the ability of the model to predict activity/inactivity at the 18-year FU, as evidenced by an increase in the AUC from 0.59 to 0.80 (p=0.02). Multiple regression analysis revealed that S100A9 was the strongest predictor of inactive disease 18 years after disease onset.

CONCLUSION

Biomarkers indicating inflammation at baseline have the potential to improve evaluation of disease activity and prediction of long-term outcomes.

Serum and salivary inflammatory biomarkers in juvenile idiopathic arthritis-an explorative cross-sectional study

BACKGROUND

Biomarkers may be useful in monitoring disease activity in juvenile idiopathic arthritis (JIA). With new treatment options and treatment goals in JIA, there is an urgent need for more sensitive and responsive biomarkers.

OBJECTIVE

We aimed to investigate the patterns of 92 inflammation-related biomarkers in serum and saliva in a group of Norwegian children and adolescents with JIA and controls and in active and inactive JIA. In addition, we explored whether treatment with tumor necrosis factor inhibitors (TNFi) affected the biomarker levels.

METHODS

This explorative, cross-sectional study comprised a subset of children and adolescents with non-systemic JIA and matched controls from the Norwegian juvenile idiopathic arthritis study (NorJIA Study). The JIA group included individuals with clinically active or inactive JIA. Serum and unstimulated saliva were analyzed using a multiplex assay of 92 inflammation-related biomarkers. Welch's t-test and Mann-Whitney U-test were used to analyze the differences in biomarker levels between JIA and controls and between active and inactive disease.

RESULTS

We included 42 participants with JIA and 30 controls, predominantly females, with a median age of 14 years. Of the 92 biomarkers, 87 were detected in serum, 73 in saliva, and 71 in both biofluids. A pronounced difference between serum and salivary biomarker patterns was found. Most biomarkers had higher levels in serum and lower levels in saliva in JIA versus controls, and in active versus inactive disease. In serum, TNF and S100A12 levels were notably higher in JIA and active disease. The TNF increase was less pronounced when excluding TNFi-treated individuals. In saliva, several biomarkers from the chemokine family were distinctly lower in the JIA group, and levels were even lower in active disease.

CONCLUSION

In this explorative study, the serum and salivary biomarker patterns differed markedly, suggesting that saliva may not be a suitable substitute for serum when assessing systemic inflammation in JIA. Increased TNF levels in serum may not be a reliable biomarker for inflammatory activity in TNFi-treated children and adolescents with JIA. The lower levels of chemokines in saliva in JIA compared to controls and in active compared to inactive disease, warrant further investigation.

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.

B Cells on the Stage of Inflammation in Juvenile Idiopathic Arthritis: Leading or Supporting Actors in Disease Pathogenesis?

Juvenile idiopathic arthritis (JIA) is a term that collectively refers to a group of chronic childhood arthritides, which together constitute the most common rheumatic condition in children. The International League of Associations for Rheumatology (ILAR) criteria define seven categories of JIA: oligoarticular, polyarticular rheumatoid factor (RF) negative (RF-), polyarticular RF positive (RF+), systemic, enthesitis-related arthritis, psoriatic arthritis, and undifferentiated arthritis. The ILAR classification includes persistent and extended oligoarthritis as subcategories of oligoarticular JIA, but not as distinct categories. JIA is characterized by a chronic inflammatory process affecting the synovia that begins before the age of 16 and persists at least 6 weeks. If not treated, JIA can cause significant disability and loss of quality of life. Treatment of JIA is adjusted according to the severity of the disease as combinations of non-steroidal anti-inflammatory drugs (NSAIDs), synthetic and/ or biological disease modifying anti-rheumatic drugs (DMARDs). Although the disease etiology is unknown, disturbances in innate and adaptive immune responses have been implicated in JIA development. B cells may have important roles in JIA pathogenesis through autoantibody production, antigen presentation, cytokine release and/ or T cell activation. The study of B cells has not been extensively explored in JIA, but evidence from the literature suggests that B cells might have indeed a relevant role in JIA pathophysiology. The detection of autoantibodies such as antinuclear antibodies (ANA), RF and anti-citrullinated protein antibodies (ACPA) in JIA patients supports a breakdown in B cell tolerance. Furthermore, alterations in B cell subpopulations have been documented in peripheral blood and synovial fluid from JIA patients. In fact, altered B cell homeostasis, B cell differentiation and B cell hyperactivity have been described in JIA. Of note, B cell depletion therapy with rituximab has been shown to be an effective and well-tolerated treatment in children with JIA, which further supports B cell intervention in disease development.

Achieving sustained minimal disease activity with methotrexate in early interleukin 23-driven early psoriatic arthritis

Objectives

Methotrexate (MTX) is currently the recommended first-line therapy for treating psoriatic arthritis (PsA), despite lacking clear evidence. No estimates of efficacy of MTX in usual care and no clear MTX responsive clinical or laboratory variables are currently available. This study describes the response to MTX monotherapy in newly diagnosed patients with PsA in usual care. Second, we compared clinical variables and cytokine profiles in patients responding and not responding to MTX monotherapy.

Methods

We used data collected in the Dutch southwest Early Psoriatic Arthritis cohoRt study to select patients with PsA with oligoarthritis or polyarthritis, and at least 1 year follow-up. We analysed disease activity at 6 months of patients who started MTX monotherapy and still used MTX monotherapy 1 year after diagnosis. Cytokine profiles were determined at baseline and after 3 and 6 months with a bead-based multi-immunoassay.

Results

We identified 219 patients of which 183 (84%) patients started MTX monotherapy within 6 months after diagnosis. 90 patients used MTX monotherapy throughout the first year of which 44 patients (24%) reached minimal disease activity(MDA) at 6 months, decreasing to 33 patients (18%) after 1 year. Non-responders had significantly higher concentrations of interleukin (IL) 23 and IL-10 before and during MTX therapy.

Conclusions

Our results showed that only 18% of patients with PsA are in sustained MDA after 1 year of MTX monotherapy and non-responders more often had IL-23-driven disease. Our results indicate the need for more treat-to-target and personalised therapy strategies in PsA.

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.

Concerted Actions by PIICP, CTXII, and TNF-α in Patients with Juvenile Idiopathic Arthritis

Joint destruction in juvenile idiopathic arthritis (JIA), initiated in the early, preclinical stage of the disease, is diagnosed on the basis of clinical evaluation and radiographic imaging. The determination of circulating cartilage-matrix turnover markers can facilitate the diagnosis and application of better and earlier treatment strategies for JIA. We have shown that 96 JIA patients have elevated levels of procollagen II C-terminal propeptide (PIICP), reflecting the extent of joint cartilage biosynthesis, and C-telopeptide of type II collagen (CTXII), a biomarker of the resorption of this tissue. Patients who did not respond to treatment had particularly high levels of these markers. JIA treatment resulted in the normalization of these markers in remissive patients, but not in those with active JIA. We showed correlations between examined variables and inflammatory process indicators, i.e., C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and tumor necrosis factor-α (TNF-α). The TNF-α of patients responding to treatment correlated with PIICP, especially in the patients before treatment (r = 0.898, p < 0.001). Significant changes in serum PIICP during JIA therapy suggest its potential diagnostic utility in the monitoring of disease activity and the possibility of its use in assessing treatment towards remission. Understanding changes in type II collagen metabolism over the course of the discussed arthritis may allow the implementation of both new diagnostic tools and new therapeutic strategies in children with JIA.

Procalcitonin Differs in Children With Infection and Children With Disease Flares in Juvenile Idiopathic Arthritis

BACKGROUND/OBJECTIVE

Patients with juvenile idiopathic arthritis (JIA) often present with signs and symptoms suggestive of serious bacterial infection (SBI). Procalcitonin (PCT) is a biomarker that is elevated in SBI. We conducted a comparative cohort study to test the hypothesis that PCT levels will differ between active JIA, quiescent JIA, and bacteremic patients and healthy controls.

METHODS

From October 2016 to May2018, consecutive children 6 months to 18 years of age with (a) active untreated JIA, (b) quiescent JIA, and (c) healthy elective presurgical candidates were recruited from clinics at a musculoskeletal specialty hospital. Juvenile idiopathic arthritis was defined according to the International League of Associations for Rheumatology criteria. Clinical data and serum samples meeting the same criteria were included from a prior study. Consecutive bacteremic patients were identified over the same period. Procalcitonin and other common measures of inflammation were measured. Descriptive statistics and univariate logistic analyses were performed.

RESULTS

Ninety-two study subjects were recruited. Erythrocyte sedimentation rate, C-reactive protein (CRP), and PCT levels were all elevated in bacteremic patients in comparison to the other groups. Erythrocyte sedimentation rate and CRP both had wide ranges that overlapped between groups; however, the PCT concentration was 0.15 μg/mL or greater in 1 of 59 patients with JIA, whereas it was 0.15 μg/mL or less in only 1 bacteremic patient.

CONCLUSIONS

Our study indicates that serum erythrocyte sedimentation rate, CRP, and PCT levels are all biomarkers that can be used to distinguish SBI versus active JIA at presentation. However, PCT is the most accurate, with the least overlap between patients with infection and noninfectious inflammatory arthritis. This finding can help clinicians direct therapy.

Predicting disease severity and remission in juvenile idiopathic arthritis: are we getting closer?

PURPOSE OF REVIEW

To summarize current research on the prediction of severe disease or remission in children with juvenile arthritis, and define further steps needed towards developing prediction tools with sufficient accuracy for clinical use.

RECENT FINDINGS

High disease activity, poor patient-reported outcomes, ankle or wrist involvement, and a longer time from onset to the start of treatment herald a severe disease course and a low chance of remission. Other studies confirmed that age less than 7 years and positive ANA are the strongest predictors of uveitis development. Preliminary evidence suggests ultrasound findings may predict flare in patients with clinically inactive disease, and several new biomarkers show promise. A few prediction tools that combine predictors to estimate the chance of remission or a severe disease course in the medium-term to long-term have shown good accuracy when internally validated in the population in which they were developed.

SUMMARY

Promising candidate tools for predicting disease severity and long-term remission in juvenile arthritis are now available. These tools need external validation in other populations, and ideally formal trials to assess whether their use in practice improves patient outcomes. We are definitively getting closer, but we are not there yet.