Remission in juvenile idiopathic arthritis: current facts

MicroRNAs in Juvenile Idiopathic Arthritis: State of the Art and Future Perspectives

Juvenile Idiopathic Arthritis (JIA) represents the most common chronic pediatric arthritis in Western countries and a leading cause of disability in children. Despite recent clinical achievements, patient management is still hindered by a lack of diagnostic/prognostic biomarkers and targeted treatment protocols. MicroRNAs (miRNAs) are short non-coding RNAs playing a key role in gene regulation, and their involvement in many pathologies has been widely reported in the literature. In recent decades, miRNA's contribution to the regulation of the immune system and the pathogenesis of autoimmune diseases has been demonstrated. Furthermore, miRNAs isolated from patients' biological samples are currently under investigation for their potential as novel biomarkers. This review aims to provide an overview of the state of the art on miRNA investigation in JIA. The literature addressing the expression of miRNAs in different types of biological samples isolated from JIA patients was reviewed, focusing in particular on their potential application as diagnostic/prognostic biomarkers. The role of miRNAs in the regulation of immune responses in affected joints will also be discussed along with their potential utility as markers of patients' responses to therapeutic approaches. This information will be of value to investigators in the field of pediatric rheumatology, encouraging further research to increase our knowledge of miRNAs' potential for future clinical applications in JIA.

Clinical remission and subsequent relapse in patients with juvenile idiopathic arthritis: predictive factors according to therapeutic approach

BACKGROUND

Juvenile idiopathic arthritis constitutes a significant cause of disability and quality of life impairment in pediatric and adult patients. The aim of this study was to ascertain clinical remission (CR) and subsequent relapse in juvenile idiopathic arthritis (JIA) patients, according to therapeutic approach and JIA subtype. Evidence in literature regarding its predictors is scarce.

METHODS

We conducted an observational, ambispective study. Patients diagnosed of JIA, treated with synthetic and/or biologic disease modifying antirheumatic drugs (DMARD) were included and followed-up to December 31st, 2015. Primary outcome was clinical remission defined by Wallace criteria, both on and off medication. In order to ascertain CR according to therapeutic approach, DMARD treatments were divided in four groups: 1) synthetic DMARD (sDMARD) alone, 2) sDMARD combined with another sDMARD, 3) sDMARD combined with biologic DMARD (bDMARD), and 4) bDMARD alone.

RESULTS

A total of 206 patients who received DMARD treatment were included. At the time the follow-up was completed, 70% of the patients in the cohort had attained CR at least once (144 out of 206), and 29% were in clinical remission off medication (59 out of 206). According to treatment group, CR was more frequently observed in patients treated with synthetic DMARD alone (53%). Within this group, CR was associated with female sex, oligoarticular persistent subtypes, ANA positivity, Methotrexate treatment and absence of HLA B27, comorbidities and DMARD toxicity. 124 DMARD treatments (62%) were withdrawn, 64% of which relapsed. Lower relapse rates were observed in those patients with persistent oligoarticular JIA (93%) when DMARD dose was tapered before withdrawal (77%).

CONCLUSIONS

More than two thirds of JIA patients attained CR along the 9 years of follow-up, and nearly one third achieved CR off medication. Females with early JIA onset, lower active joint count and ANA positivity were the ones achieving and sustaining remission more frequently, especially when receiving synthetic DMARD alone and in the absence of HLA B27, comorbidities or previous DMARD toxicity.

Specific Sports Habits, Leisure-Time Physical Activity, and School-Educational Physical Activity in Children With Juvenile Idiopathic Arthritis: Patterns and Barriers

OBJECTIVE

Juvenile idiopathic arthritis (JIA) may cause functional impairment and reduced time engaged in physical activity. The aim of this study was to investigate the habits of patients with JIA regarding participation in club sports, leisure-time physical activity, and school-educational physical activity and relate this to objectively measured physical activity using accelerometry and to compare the findings with those in healthy controls.

METHODS

Consecutive patients from the Aarhus University Hospital outpatient clinic were included. Clinical characteristics, functional ability, and exploration of specific habits in club sports, leisure-time physical activity, and school-educational physical activity (based on a standardized questionnaire) in patients were recorded and compared with those in healthy controls. The intensity and frequency of physical activity were measured by accelerometer monitoring, using ActiGraph GT1M.

RESULTS

Sixty-eight patients with JIA and 118 healthy control subjects were included. Despite having low disease activity, children with JIA had significantly lower accelerometry-monitored physical activity levels compared with healthy controls. The distribution of specific club sport activities was the same among patients and controls. However, the proportion of patients spending >3 hours/week participating in club sports was significantly lower than the proportion of controls, whereas no difference in time spent engaging in physical activity during leisure-time was observed. Participation in compulsory school-educational physical activity was equally high in patients and controls, although participation by patients was significantly less consistent than that by controls. Patient reports of time spent with club sport and leisure-time physical activity was significantly related to accelerometry measures, whereas this was not observed for school-educational physical activity.

CONCLUSION

The results of this study indicate the need for structured guidance for all patients with JIA (including those with minimal disease activity) in both understanding and coping with the consequences of a low level of physical activity.

How common is remission in juvenile idiopathic arthritis: A systematic review

Objectives

The ideal goal of treatment for juvenile idiopathic arthritis (JIA) is disease remission. However, many sets of remission criteria have been developed and no systematic review of remission in JIA exists.

The current systematic review investigated (1) how remission has been defined across JIA clinical cohorts and (2) the frequency of remission overall and within disease categories.

Methods

Studies using prospective inception cohorts published after 1972 were selected if they estimated remission in cohorts of ≥50 patients. Articles focusing on specific medical interventions, not defining remission clearly or not reporting disease duration at remission assessment were excluded. Studies were selected from Medline, Embase, PubMed and bibliographies of selected articles. Risks of selection, missing outcome data and outcome reporting biases were assessed.

Results

Within 17 studies reviewed, 88% had majority female participants and patient disease duration ranged from 0.5 to 17 years. Thirteen sets of criteria for clinically inactive disease and remission were identified. Uptake of Wallace’s preliminary criteria was good in studies recruiting or following patients after their publication (78%).

Remission frequencies increased with longer disease duration from 7% within 1.5 years to 47% by 10 years following diagnosis. Patients with persistent oligoarticular and rheumatoid-factor positive polyarticular JIA were most and least likely to achieve remission, respectively.

Conclusions

Achievement of remission increased with longer disease duration, but many patients remain in active disease, even in contemporary cohorts. Multiple sets of outcome criteria limited comparability between studies.

Dynamic tracking of functional gene modules in treated juvenile idiopathic arthritis

BACKGROUND

We have previously shown that childhood-onset rheumatic diseases show aberrant patterns of gene expression that reflect pathology-associated co-expression networks. In this study, we used novel computational approaches to examine how disease-associated networks are altered in one of the most common rheumatic diseases of childhood, juvenile idiopathic arthritis (JIA).

METHODS

Using whole blood gene expression profiles derived from children in a pediatric rheumatology clinical trial, we used a network approach to understanding the impact of therapy and the underlying biology of response/non-response to therapy.

RESULTS

We demonstrate that therapy for JIA is associated with extensive re-ordering of gene expression networks, even in children who respond inadequately to therapy. Furthermore, we observe distinct differences in the evolution of specific network properties when we compare children who have been treated successfully with those who have inadequate treatment response.

CONCLUSIONS

Despite the inherent noisiness of whole blood gene expression data, our findings demonstrate how therapeutic response might be mapped and understood in pathologically informative cells in a broad range of human inflammatory diseases.

Effect of methotrexate upon antigen-induced arthritis of the rabbit temporomandibular joint

BACKGROUND

Juvenile idiopathic arthritis (JIA) of the temporomandibular joint (TMJ) can cause severe growth disturbances of the craniomandibular system. Antigen-induced arthritis (AIA) of the rabbit TMJ is simulating the inflammatory process of the TMJ in JIA. The aim of this study was to investigate the effect of a systemic administration of methotrexate (MTX) on AIA in rabbits by means of three different histological staining methods.

METHODS

After sensitization, a bilateral arthritis of the TMJ was induced by an intra-articular administration of ovalbumin in 12 New Zealand white rabbits aged 10 weeks. From the 13th week of age, six of the 12 rabbits received weekly intramuscular injections of MTX, and the other six animals remained without therapy. Another six animals served as controls, receiving no treatment or intra-articular injections at all. After euthanasia at the age of 22 weeks, all TMJs were retrieved en bloc. Sagittal sections were cut and stained with haematoxylin-eosin (H-E), Safranin-O for the evaluation of the Mankin score and tartrate-resistant acid phosphatase (TRAP).

RESULTS

In the arthritis group, a chronic inflammation with degeneration of the articular cartilage was visible. In the MTX group, the signs of cartilage degeneration were significantly reduced compared with the arthritis group. In contrast, the joints in the control group were inconspicuous. A correlation between the Mankin score and TRAP-positive cells could be found.

CONCLUSIONS

Systemic administration of MTX seems to have a positive effect upon the inflammatory process in the rabbit TMJ but fails to eliminate the sign of arthritis completely.

Histomorphometry in antigen-induced arthritis of the rabbit temporomandibular joint

BACKGROUND

Juvenile idiopathic arthritis (JIA) of the temporomandibular joint (TMJ) can cause severe growth disturbances of the craniomandibular system. Antigen-induced arthritis (AIA) of the rabbit TMJ is simulating the inflammatory process of the TMJ in JIA. The aim of this study was to investigate the effect of a systemic administration of the tumor necrosis factor-alpha (TNF-α) antagonist etanercept on AIA in rabbits by means of three different histological staining methods.

METHODS

After sensitization, a bilateral arthritis of the TMJ was induced and maintained by repeated intra-articular administrations of ovalbumin in 12 New Zealand white rabbits aged 10 weeks. From the 13th week of age, 6 of the 12 rabbits received weekly subcutaneous injections of etanercept, and the other 6 animals remained without therapy. Another 6 animals served as controls, receiving no treatment or intra-articular injections at all. After euthanasia at the age of 22 weeks, all TMJs were retrieved en bloc. Sagittal sections were cut and stained with hematoxylin-eosin (H-E), Safranin-O for the evaluation of the Mankin score, and tartrate-resistant acid phosphatase (TRAP).

RESULTS

In the arthritis group, a chronic inflammation with degeneration of the articular cartilage was visible. In the etanercept group, the signs of cartilage degeneration were significantly reduced but present. In contrast, the joints in the control group were inconspicuous. A strong correlation between the Mankin score and TRAP-positive cells could be found.

CONCLUSIONS

Antigen-induced arthritis causes severe damage in the TMJ of young rabbits. An improvement seems to be achievable by a systemic administration of etanercept.

Clinically Inactive Disease in a Cohort of Children with New-onset Polyarticular Juvenile Idiopathic Arthritis Treated with Early Aggressive Therapy: Time to Achievement, Total Duration, and Predictors

Objective.

To determine the elapsed time while receiving aggressive therapy to the first observation of clinically inactive disease (CID), total duration of CID and potential predictors of this response in a cohort of children with recent onset of polyarticular juvenile idiopathic arthritis (poly-JIA).

Methods.

Eighty-five children were randomized blindly to methotrexate (MTX), etanercept, and rapidly tapered prednisolone (MEP) or MTX monotherapy and assessed for CID over 1 year of treatment. Patients who failed to achieve intermediary endpoints were switched to open-label MEP treatment.

Results.

Fifty-eight (68.2%) of the 85 patients achieved CID at 1 or more visits including 18 who received blinded MEP, 11 while receiving MTX monotherapy, and 29 while receiving open-label MEP. Patients starting on MEP achieved CID earlier and had more study days in CID compared to those starting MTX, but the differences were not significantly different. Patients given MEP (more aggressive therapy) earlier in the disease course were statistically more likely to have a higher proportion of followup visits in CID than those with longer disease course at baseline. Those who achieved American College of Rheumatology Pediatric 70 response at 4 months had a significantly greater proportion of followup visits in CID, compared to those who failed to achieve this improvement (p < 0.0001). Of the 32 patients who met criteria for CID and then lost CID status, only 3 fulfilled the definition of disease flare.

Conclusion.

Shorter disease duration prior to treatment, a robust response at 4 months, and more aggressive therapy result in a higher likelihood and longer duration of CID in patients with poly-JIA. The original trial from which data for this analysis were obtained is registered on www.clinicaltrials.gov NCT 00443430.

Complementary and alternative medicine use in adolescents with inflammatory bowel disease and juvenile idiopathic arthritis

Background

The use of complementary alternative medicine (CAM) is potentially prevalent among paediatric patients with chronic diseases but with variable rates among different age groups, diseases and countries. There are no recent reports on CAM use among paediatric patients with inflammatory bowel disease (IBD) and juvenile idiopathic arthritis (JIA) in Europe. We hypothesized that CAM use associates with a more severe disease in paediatric IBD and JIA.

Methods

A cross-sectional questionnaire study among adolescent outpatients with IBD and JIA addressing the frequency and type of CAM use during the past year. The patients were recruited at the Children’s Hospital, University of Helsinki, Finland.

Results

Of the 147 respondents, 97 had IBD (Crohn’s disease: n = 46; median age 15.5, disease duration 3.4 years) and 50 had JIA (median age 13.8, disease duration 6.9 years). During the past 12 months, 48% regularly used CAM while 81% reported occasional CAM use. Compared to patients with JIA, the use of CAM in IBD patients tended to be more frequent. The most commonly used CAM included probiotics, multivitamins, and mineral and trace element supplements. Self-imposed dietary restrictions were common, involving 27.6% of the non-CAM users but 64.8% of all CAM users. Disease activity was associated with CAM use in JIA but not in IBD.

Conclusions

CAM use is frequent among adolescents with IBD and JIA and associates with self-imposed dietary restrictions. Reassuringly, adherence to disease modifying drugs is good in young CAM users. In JIA, patients with active disease used more frequently CAM than patients with inactive disease. As CAM use is frequent, physicians should familiarise themselves with the basic concepts of CAM. The potential pharmacological interaction or the toxicity of certain CAM products warrants awareness and hence physicians should actively ask their patients about CAM use.

Genetic variation in VTCN1 (B7-H4) is associated with course of disease in juvenile idiopathic arthritis

OBJECTIVE

The course of disease in juvenile idiopathic arthritis (JIA) is unpredictable with episodes of activity and remission. In order to identify predictive factors, 93 SNPs, JIA subtype, age at onset and ANA status were studied in relation to disease course.

METHODS

Genetic and clinical parameters were analysed in a cohort of 272 Caucasian patients with persistent oligoarthritis (n=129), extended oligoarthritis (n=57) and rheumatoid factor negative polyarthritis (n=86). Categories of disease course (remitting (n=65), intermediate (n=96) and unremitting (n=111)) were designed based on the cumulative time spent in active disease in the first 2 years.

RESULTS

Univariate analysis revealed association of the course of disease with JIA subtype (p=5.7*10(-5)) and three SNPs; VTCN1 rs10 923 223 (p=4.4*10(-5)), VTCN1 rs12 046 117 (p=0.017) and CDK6 rs42 041 (p=0.038). In a subsequent multivariate ordinal logistic regression analysis, VTCN1 rs10 923 223 (OR 0.41, 95%-CI 0.26 to 0.63) and JIA subtype (OR 3.8, 95%-CI 2.0 to 7.2; OR 2.5, 95%-CI 1.4 to 4.2, for extended oligoarthritis and RF-negative polyarthritis vs persistent oligoarthritis, respectively) were the strongest independent factors for course of disease.

CONCLUSIONS

This study provides evidence that VTCN1, encoding B7-H4, is associated with course of disease in selected subtypes of JIA. VTCN1 might be useful in predicting the course of disease.

Genomic characterization of remission in juvenile idiopathic arthritis

Introduction

The attainment of remission has become an important end point for clinical trials in juvenile idiopathic arthritis (JIA), although we do not yet have a full understanding of what remission is at the cell and molecular level.

Methods

Two independent cohorts of patients with JIA and healthy child controls were studied. RNA was prepared separately from peripheral blood mononuclear cells (PBMC) and granulocytes to identify differentially expressed genes using whole genome microarrays. Expression profiling results for selected genes were confirmed by quantitative, real-time polymerase chain reaction (RT-PCR).

Results

We found that remission in JIA induced by either methotrexate (MTX) or MTX plus a TNF inhibitor (etanercept, Et) (MTX + Et) is characterized by numerous differences in gene expression in peripheral blood mononuclear cells and in granulocytes compared with healthy control children; that is, remission is not a restoration of immunologic normalcy. Network analysis of the differentially expressed genes demonstrated that the steroid hormone receptor superfamily member hepatocyte nuclear factor 4 alpha (HNF4α) is a hub in several of the gene networks that distinguished children with arthritis from controls. Confocal microscopy revealed that HNF4a is present in both T lymphocytes and granulocytes, suggesting a previously unsuspected role for this transcription factor in regulating leukocyte function and therapeutic response in JIA.

Conclusions

These findings provide a framework from which to understand therapeutic response in JIA and, furthermore, may be used to develop strategies to increase the frequency with which remission is achieved in adult forms of rheumatoid arthritis.

Do patients with juvenile idiopathic arthritis in clinical remission have evidence of persistent inflammation on 3T magnetic resonance imaging?

OBJECTIVE

Up to 90% of adults with rheumatoid arthritis (RA) in clinical remission have persistent synovitis and/or bone marrow lesions (BMLs) on magnetic resonance imaging (MRI). MRI findings in patients with juvenile idiopathic arthritis (JIA) in clinical remission have not been described. We utilized 3T MRI with contrast enhancement to examine JIA patients with hand and/or wrist involvement who were in clinical remission and compared them with a cohort of adult RA patients.

METHODS

In total, 11 JIA patients and 10 RA patients with arthritis involving the hands and/or wrists were identified by their primary rheumatologist as being in physician-defined clinical remission, having no signs or symptoms of active arthritis and no medication changes for at least 6 months. A study rheumatologist performed a joint evaluation for tenderness, swelling, and limitation of motion, and study participants self-reported tender joint counts. The participants underwent MRI with intravenous contrast enhancement of 1 hand and wrist with a history of prior symptoms. A pediatric musculoskeletal radiologist blinded to the clinical data scored the MRIs for synovitis, tenosynovitis, and/or BMLs.

RESULTS

Sixty-three percent of the JIA cohort and 70% of the RA cohort had MRI findings of synovitis, BMLs, and/or tenosynovitis. All pediatric patients with MRI abnormalities had normal physician tender and swollen joint counts. The patients' self-report of painful joint counts did not predict MRI abnormalities.

CONCLUSION

Over one-half of the patients in clinical remission had MRI evidence of persistent inflammation, defined as the presence of synovitis, tenosynovitis, or BMLs. A substantial portion of patients with JIA may have subclinical disease despite clinical remission.

Trial of early aggressive therapy in polyarticular juvenile idiopathic arthritis

OBJECTIVE

To determine whether aggressive treatment initiated early in the course of rheumatoid factor (RF)-positive or RF-negative polyarticular juvenile idiopathic arthritis (JIA) can induce clinical inactive disease within 6 months.

METHODS

Between May 2007 and October 2010, a multicenter, prospective, randomized, double-blind, placebo-controlled trial of 2 aggressive treatments was conducted in 85 children ages 2-16 years with polyarticular JIA of <12 months' duration. Patients received either methotrexate (MTX) 0.5 mg/kg/week (maximum 40 mg) subcutaneously, etanercept 0.8 mg/kg/week (maximum 50 mg), and prednisolone 0.5 mg/kg/day (maximum 60 mg) tapered to 0 by 17 weeks (arm 1), or MTX (same dosage as arm 1), etanercept placebo, and prednisolone placebo (arm 2). The primary outcome measure was clinical inactive disease at 6 months. An exploratory phase determined the rate of clinical remission on medication (6 months of continuous clinical inactive disease) at 12 months.

RESULTS

By 6 months, clinical inactive disease had been achieved in 17 (40%) of 42 patients in arm 1 and 10 (23%) of 43 patients in arm 2 (χ(2) = 2.91, P = 0.088). After 12 months, clinical remission on medication was achieved in 9 patients in arm 1 and 3 patients in arm 2 (P = 0.053). There were no significant interarm differences in adverse events.

CONCLUSION

Although this study did not meet its primary end point, early aggressive therapy in this cohort of children with recent-onset polyarticular JIA resulted in clinical inactive disease by 6 months and clinical remission on medication within 12 months of treatment in substantial proportions of patients in both arms.