Neprilysin levels in plasma and synovial fluid of juvenile idiopathic arthritis patients

Objective Neprilysin (neutral endopeptidase, 3:4:24:11, CD10) (NEP) is a Zn metallopeptidase linked to controlling inflammation through the degradation of neuropeptides involved in neurogenic inflammation of chronic rheumatic diseases. The aim of our study was to evaluate circulating activity and cellular expression of NEP in the plasma of 58 children with juvenile idiopathic arthritis (JIA) and 52 controls. In 20 subjects requiring local steroid injection, NEP was measured in synovial fluid.Methods Plasma and synovial NEP were evaluated using a fluorimetric technique. Neprilysin, expressed as the antigen CD10, was determined on circulating and synovial fluid cells as mean fluorescence intensity (MFI) and as percentage of positive cells by two-color immunofluorescence.Results Circulating NEP levels were lower in JIA patients than in controls (42.0±16.6 vs 76.5±24 pmol/ml per min, P<0.001), while synovial fluid NEP values were higher than circulating levels (241.4±86.2 vs 40±15.3 pmol/ml per min, P<0.001). In monocytes, the percentage of CD10-positive circulating cells and the MFI in JIA were lower than in controls (11.6±5.2% vs 41.4±13%, P<0.001 and 18.1±7.5 vs 31.2±5.4, P<0.05, respectively). On synovial monocytes, the percentage of CD10-positive cells and the MFI were higher than on circulating monocytes (35.2±14.6% vs 9.1±2.4%, P<0.001 and 66.4±5.4 vs 22.8±14.7, P<0.001, respectively).Conclusions The downregulation of CD10 expression in monocytes and the reduction in NEP activity may be linked to the enzymes role in the control of peptides involved in the inflammation. The increased levels of NEP, MFI, and CD10-positive monocytes in synovial fluid, even though in plasma, might reflect a reactive effort to control synovial proliferation.     

Nitric oxide levels and the severity of juvenile idiopathic arthritis

In this study, we evaluate the distribution of nitric oxide (NO) in the serum of juvenile idiopathic arthritis (JIA) patients, correlating it with parameters of the severity of the disease. Ninety-seven patients with mean age 11.7 years and disease duration 4.8 years, showing active disease or not, grouped as oligoarticular (n = 34), polyarticular (n = 29) and systemic (n = 34) group, presenting uveitis and positive RF with erosive arthritis or active disease and erosions had significantly high levels of NO than the inactive ones. NO correlated with TNF-α in the oligoarticular subtype (P < 0.03), with pain in the polyarticular subtype with active disease (P < 0.04) and with ESR in the systemic subtype with active disease (P < 0.03). TNF-α concentration was high in all patients with active disease, accompanying NO production. The data confirm the production of NO in JIA patients, indicating a possible positive correlation between the production of NO and severity of the disease.     

Chitotriosidase activity in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is an inflammatory joint disease of unknown etiology. The pathogenesis is driven by T and B cells. The role of macrophages remains unclear. Chitotriosidase belongs to the chitinase protein family and is secreted by activated macrophages. The chitinases are able to catalyze the hydrolysis of chitin or chitin-like substrates such as 4-methylumbelliferyl chitotrioside. Chitotriosidase activity was determined using the substrate 4-methylumbelliferyl beta-DNN'N'-triacetylchitotrioside (4-MU-TCT, SIGMA Chemical Co.). The substrate and serum were incubated with the serum in a citrate/phosphate buffer. The reaction was stopped by adding a buffer (Na(2)CO(3)). The fluorescence of 4-methylumbelliferone was evaluated by fluorimeter at excitation 360 nm and emission 450 nm. We report about chitotriosidase measurements in patients with JIA. The chitotriosidase level in synovial fluid was up to approximately 1,000 nmol/(h ml) at disease onset before therapy. The level in the sera was below 600 nmol/(h ml). Serum chitotriosidase levels could represent the activity of macrophages in the synovial fluid in JIA.     

Analysis of childhood reactive arthritis and comparison with juvenile idiopathic arthritis

There is currently no agreement on how to classify and diagnose reactive arthritis (ReA) and what kind of clinical and laboratory findings are specific for the diagnosis. This study retrospectively analyzed the initial clinical manifestations and laboratory findings in children diagnosed with ReA and juvenile idiopathic arthritis (JIA). A comparison was also made between these two groups to see if there were differences. A retrospective chart review was performed and 44 patients diagnosed with ReA and 80 patients with JIA were enrolled in this study. Their initial clinical manifestations and laboratory findings were also analyzed and compared. The initial clinical manifestations in ReA were analyzed including the demographic data, the preceding infection history, the duration of the infectious episode to the onset of arthritis, the duration of arthritic symptoms, and the involved joint pattern. Comparison of the initial laboratory findings between patients with ReA and JIA showed significant differences between erythrocyte sedimentation rates (ESR) in the first hour, platelet counts (p<0.05), and ESR in the second hour (p=0.052). Further, comparing ReA with the subtypes of JIA, significant differences were noted between ReA and the systemic type in terms of hemoglobin level, platelet counts, C-reactive protein, and first and second hour ESR (p<0.05). However, if compared with the polyarticular or pauciarticular type, only the platelet counts showed any significant statistical difference (p<0.05). This study summarizes clinical experiences in ReA. The differences in laboratory findings of ReA and JIA may provide a clue in making a differential diagnosis.     

Hip involvement in juvenile idiopathic arthritis

We analyzed the clinical, biological, and radiological aspects of hip involvement in juvenile idiopathic arthritis (JIA) in a developing country. The recruited patients fulfilled the International League Against Rheumatism criteria for the diagnosis of the JIA. Clinical, biological, and radiological parameters relating to the JIA were collected. Hip involvement was assessed according to clinical and radiological data related to hip disease. One hundred twenty-one patients were included (68 girls and 53 boys). The mean age of the disease onset was 9 ± 4.2 years (1–16 years).The mean age of the patients at the time of the study was 15 ± 10 years (2–46 years). The duration of the disease was 5 ± 8.5 years (0.5–39 years). Forty cases (33%) of the hip involvement were noted. The mean age was 24 ± 10.03 years (3–46 years); the sex ratio was 1:3. The mean duration of the hip disease was 0.6 ± 3.6 years (3–14 years). Hip arthritis seemed to be more frequent in polyarticular and enthesitis-related arthritis. The severity of the hip involvement was significantly correlated with early disease onset, disease duration, subtypes, and high disability (for all these data p < 0.05). This study suggested that in JIA hip involvement was more frequent in enthesitis-related arthritis and polyarticular subtypes. It was correlated with the severity and the early disease onset of the JIA, which was similar to reported data.     

Differential plasma microRNAs expression in juvenile idiopathic arthritis

Objectives. To identify potential novel biomarkers for juvenile idiopathic arthritis (JIA), we evaluated the correlation between plasma expression levels of specific miRNAs and disease characteristics of JIA.

Methods. Differentially expressed miRNAs in JIA plasma were identified by microarray analysis. Five candidate plasma miRNAs with differential expression were further evaluated by qRT-PCR. The correlation between the expression of candidate plasma miRNAs and clinical parameters of JIA patients was assessed.

Results. The expression of miR-16, miR-146a, and miR-223 was higher, and miR-132 was lower, in the plasma of JIA patients as compared with healthy subjects and juvenile ankylosing spondylitis patients (p < 0.05). Plasma miR-16 concentrations were considerably higher for polyarticular JIA patients than oligoarticular JIA patients and correlated with the juvenile arthritis magnetic resonance imaging scores for the hip and plasma interleukin-6 or IL-6 levels. Additionally, miR-146a levels correlated directly with the Juvenile Arthritis Disease Activity Scores in 27 joints, the swollen joint count, the limited joint count, and the juvenile arthritis magnetic resonance imaging scores for the hip, but correlated inversely with plasma tumor necrosis factor-α or TNF-α levels.

Conclusions. This study demonstrates that the expression of plasma miRNAs correlates with JIA disease and suggests that plasma miR-16 and miR-146a have potential novel value for JIA diagnosis.     

Anticyclic citrullinated peptide antibodies in juvenile idiopathic arthritis

Anticyclic citrullinated peptide (anti-CCP) antibodies have been detected in patients with juvenile idiopathic arthritis (JRA), particularly in those with polyarticular JIA. We analyzed the presence of anti-CCP antibodies of the IgG class in sera of patients with defined juvenile idiopathic arthritis (JIA) of various subgroups. One hundred and fifty-nine serum samples were investigated. Forty-five patients were diagnosed with JIA (15 male and 30 female) aged 1.9–17.3 years (median 12.9, mean 11.0). Thirty-eight samples were taken from patients suffering from other autoimmunopathies and 34 patients with other underlying diseases were taken at different time points in their disease course. Under 42 samples were taken from patients with noninflammatory diseases. Enzyme-linked immunosorbent assay (ELISA) was used for the detection of anti-CCP antibodies. Anti-CCP antibodies were found in 6.9% of all samples and in 4.4% patients with JIA. Disease duration and medication did not differ significantly between anti-CCP positive and negative patients. A review of the literature and our own results shows that anti-CCP antibodies can be detected in the sera of only some patients with JIA. Routine determination of anti-CCP cannot be recommended.     

Anticyclic citrullinated peptide antibodies in juvenile idiopathic arthritis

Abstract

Anticyclic citrullinated peptide (anti-CCP) antibodies have been detected in patients with juvenile idiopathic arthritis (JRA), particularly in those with polyarticular JIA. We analyzed the presence of anti-CCP antibodies of the IgG class in sera of patients with defined juvenile idiopathic arthritis (JIA) of various subgroups. One hundred and fifty-nine serum samples were investigated. Forty-five patients were diagnosed with JIA (15 male and 30 female) aged 1.9–17.3 years (median 12.9, mean 11.0). Thirty-eight samples were taken from patients suffering from other autoimmunopathies and 34 patients with other underlying diseases were taken at different time points in their disease course. Under 42 samples were taken from patients with noninflammatory diseases. Enzyme-linked immunosorbent assay (ELISA) was used for the detection of anti-CCP antibodies. Anti-CCP antibodies were found in 6.9% of all samples and in 4.4% patients with JIA. Disease duration and medication did not differ significantly between anti-CCP positive and negative patients. A review of the literature and our own results shows that anti-CCP antibodies can be detected in the sera of only some patients with JIA. Routine determination of anti-CCP cannot be recommended.     

Inflammatory cytokines in juvenile idiopathic arthritis: Effects on physical growth and the insulin-like-growth factor axis

OBJECTIVE: To investigate the relationship between markers of inflammation with physical growth and systemic markers of GH secretion in JIA. DESIGN: This is a cross sectional prospective study of patients with JIA recruited during therapeutic arthrocentesis of 17 children with JIA (F,10): 8 oligoarticular (OJIA) and 9 polyarticular (PJIA). RESULTS: Median adjusted height (AHt) SDS was -0.3 (-2.2 to 1.6). Serum ALS SDS (median -1.3, range -2.7 to -0.6) was reduced compared with serum IGFBP-3 SDS (median -0.5, range -7.7 to 2.3) and IGF-1 SDS (median -0.2, range -0.5 to 0.5). Log serum IL5 (95% CI -3.25, -0.81) and log serum IL15 (95% CI -9.58, -4.10) were independent factors associated with AHt SDS. Inflammatory cytokines individually showed no association with IGF-1, IGFBP-1, -2, -3 and ALS. CONCLUSION: Children with JIA and mild degree of growth retardation show decreased ALS and IGFBP-3. Cytokines did not show an association to systemic markers of GH secretion. However, this study reports the novel, preliminary association between serum levels of IL5 and IL15 and the extent of short stature.     

Therapeutic advancements in juvenile idiopathic arthritis

The treatment of juvenile idiopathic arthritis (JIA) has substantially evolved over the past two decades. Research has been conducted and is ongoing on how therapies can best be utilized either as monotherapy or in combination for enhanced efficacy. The introduction of biologic therapies that selectively target specific cytokines has changed the acceptable clinical course of childhood arthritis. In addition to the development and utilization of new therapeutic agents, the pediatric rheumatology community has made vital progress toward defining disease activity, developing validated outcome measures, and establishing collaborative networks to assess both clinical outcomes and the long-term side effects related to therapeutics for juvenile arthritis. In this chapter, we will discuss the therapeutic evolution in JIA over the past two decades. Although the largest strides have been made with biologic agents, and these newer drugs have more rigorous data to support their use, select commonly used non-biologic therapies are included, with the discussion focused on more recent updated literature.     

Articular damage in adults with juvenile idiopathic arthritis

The goal of this study was to assess the long-term articular damage in adults with juvenile idiopathic arthritis (JIA) using the Rheumatoid Arthritis Articular Damage (RAAD) score and to determine any associations between the disease-related parameters and RAAD score. Thirty-eight adults identified with JIA at 18 years of age or older with disease duration of at least 5 years were assessed by means of the RAAD score. Patients were divided into three groups according to disease duration as 5-10 years (group 1), 11-15 years (group 2) and more than 16 years (group 3), and into three groups according to JIA subtypes as seropositive polyarticular (group A), seronegative polyarticular (group B), and oligoarticular (group C). Functional disability, functional status, disease activity and depression were measured by Health Assessment Questionnaire (HAQ), Steinbrocker classification, Disease Activity Score 28 (DAS 28), and Beck Depression Inventory, respectively. We investigated any possible associations between the RAAD score and groups, sex, age at onset of the disease, HAQ, Steinbrocker classification, DAS 28, and Beck Depression Inventory. We observed significant differences in RAAD scores according to groups A, B, C (p < 0.01), but not according to groups 1, 2, 3 or sex (p > 0.05). While the RAAD score correlated well with HAQ (p < 0.001), Steinbrocker classification (p < 0.001) and DAS 28 (p < 0.01), it did not correlate with age at onset of the disease (p > 0.05) or Beck Depression Inventory (p > 0.05). Seropositive polyarticular patients demonstrate the worst articular damage scores. Even though articular damage does not progress over time and JIA frequently has a benign course, care should be given to establishing regular follow-up periods and well-arranged treatments, especially for seropositive polyarticular groups, to maintain satisfactory long-term disease outcome throughout the lives of JIA patients.     

Disease and family contributors to adaptation in juvenile rheumatoid arthritis and juvenile diabetes

Objective. Research in the areas of pediatric rheumatology and pediatric chronic illness has emphasized comprehensive models of adaptation involving risk and resistance factors. This study examined adaptation, within this framework, among a large sample of children with chronic illness and children without chronic illness. Methods. A comprehensive battery of adaptation measures was administered to a sample of 107 children with juvenile rheumatoid arthritis, 114 children with insulin-dependent diabetes mellitus, and 88 healthy controls. Results. Medical diagnosis was associated with mothers' depression and a composite measure of parental (mother and father) distress and passive coping. Children's emotional and behavioral functioning was not related to medical diagnosis, but mothers' depression and parental distress were associated with child behavior problems. Conclusion. Because parental distress was associated with child functioning, interventions to ameliorate parental distress may have beneficial effects on the children's behavior and on parents' reactions to their children.     

Antinuclear antibody-positive cohort constitutes homogeneous entity in juvenile idiopathic arthritis

Objective. To identify a homogeneous entity for antinuclear antibody (ANA)-positive patients suffering from juvenile idiopathic arthritis (JIA).

Methods. All of the clinical features were recorded retrospectively. ANA positivity was defined as more than twice positive results at a titer of > 1:100. The correlation between ANA positivity and clinical parameters was assessed by multiple logistic regression analysis.

Result. Of 120 patients, 49 patients were ANA positive (31 oligoarthritis, 18 rheumatoid factor [RF]-negative polyarthritis) and 71 patients were ANA negative (48 oligoarthritis, 23 RF-negative polyarthritis), and were recruited retrospectively to this study according to the International League of Associations for Rheumatology (ILAR) criteria. In ANA-positive cohort, the characteristics of early-onset age, female predominance, and asymmetric arthritis were observed compared with ANA-negative cohort including oligoarthritis and RF-negative polyarthritis. Correspondingly, we found that ANA-positive cohort had higher cumulative number of joints affected at 9 and 12 months after disease presentation than ANA-negative cohort, had lower frequency of occurrence of image change, and had a different pattern of affected arthritis than ANA-negative cohort, which was more likely to have knee involvement and less likely to have hip and shoulder involvement. ANA positivity correlated strongly with asymmetric arthritis, female predominance and wrist involvement.

Conclusion. This study demonstrates that ANA-positive cohort divided into different subgroups by present ILAR criteria share the similar features and suggests that ANA positivity might serve as a novel potential value for JIA classification.     

幼年特发性关节炎诊疗规范

幼年特发性关节炎(JIA)临床上常见亚型包括全身型JIA、少关节型/多关节型JIA和幼年脊柱关节炎。本病无特异性诊断指标, 需与感染性疾病和恶性病相鉴别。全身型JIA起病多急骤, 病情进展快, 易合并巨噬细胞活化综合征而危及生命。儿童风湿科医生对JIA的诊断及治疗经验仍不足, 规范化诊疗水平有待进一步提高。中华医学会风湿病学分会组织有关专家, 在借鉴国内外诊疗规范和分类标准的基础上, 制定本规范, 旨在规范JIA各亚型及全身型JIA合并巨噬细胞活化综合征的诊断和治疗方案, 以降低致死率和严重并发症的发生率, 从而改善患儿预后。     

Health‐related quality of life in adolescents with juvenile idiopathic arthritis

Objective

To describe the health‐related quality of life (HRQOL) of adolescents with juvenile idiopathic arthritis (JIA), and to examine the usefulness of the Juvenile Arthritis Quality of Life Questionnaire (JAQQ) in a UK context. It was hypothesized that HRQOL would decrease with worsening disease and disability.

Methods

Patients with JIA ages 11, 14, and 17 years were recruited from 10 major rheumatology centers. HRQOL was measured using the JAQQ. Other data were core outcome variables including the Childhood Health Assessment Questionnaire, demographic characteristics, arthritis‐related knowledge, and satisfaction with health care.

Results

Questionnaires were completed by 308 adolescents. One‐fifth had persistent oligoarthritis. Median disease duration was 5.7 years (range <1–16 years). The JAQQ was shown to have good psychometric properties when used in the UK, but was not without limitations. HRQOL of adolescents with JIA was less than optimal, particularly in the domains of gross motor and systemic functioning. Items most frequently rated as adolescents' biggest psychological problems were “felt frustrated” and “felt depressed,” rated by 30.2% and 23.4%, respectively. These were particularly problematic for the 17‐year‐olds, with 39% reporting frustration as one of their biggest problems and 63.6% reporting depression. Variation in the adolescent JAQQ scores was explained by functional disability, pain, and disease activity.

Conclusion

JIA can have a significant adverse effect on the HRQOL of adolescents. The JAQQ is a useful tool to assess the HRQOL of UK adolescents with JIA, but there is need for improved measures that incorporate developmentally appropriate issues.

     

Interleukin-18 as a mediator of systemic juvenile idiopathic arthritis

The objective of this report is to explore the balance between serum and synovial fluid levels of interleukin (IL)-18 in children with juvenile idiopathic arthritis (JIA). Blood samples were obtained from 81 children with JIA and 18 control children. Synovial fluid samples were collected from 16 children with oligoarticular JIA. Concentrations of IL-18 were determined using commercial kit. Patients with systemic JIA had higher serum levels of IL-18 than patients with other forms of JIA or control children, both during the active (median, range: 6,240, 1,600–78,750 pg/ml) and inactive (1,615, 513–3,270 pg/ml) phase of disease [analysis of variance (ANOVA), P < 0.05). Levels of IL-18 in sera of children with oligoarticular JIA (255, 89–4,342 pg/ml) were similar to the respective synovial fluid levels (217, 89–1,245 pg/ml). Serum levels of IL-18 were proportional to the erythrocyte sedimentation rate and levels of C-reactive protein, but inversely proportional to the haemoglobin levels. IL-18 appears to be an important mediator of systemic JIA, while it seems of a lesser relevance in pathogenesis of other JIA forms. Therefore, inhibition of IL-18 might be a base for a successful biological therapy for systemic JIA.     

Health related quality of life survey about children and adolescents with juvenile idiopathic arthritis

This study aimed to investigate the proxy-reported Health related quality of life (HRQOL) and its determinants in patients with juvenile idiopathic arthritis (JIA). It was hypothesized that HRQOL would decrease with worsening disease and disability. Data were available in cross-sectional study on children and adolescents with JIA according to the ILAR criteria. Patient demographics, type of JIA, clinical determinants and laboratory parameters relating to JIA were obtained for each patient. Functional disability was assessed using the parent’s or children’s version of the child health assessment questionnaire (CHAQ). The HRQOL was evaluated using the juvenile arthritis quality of life questionnaire (JAQQ). These questionnaires were previously translated and validated in Moroccan children. A total of 80 participants were enrolled with mean age of 11 [6–17 years], and female predominance (59%). Many patients (42.5%) had oligoarticular subtype; 31.3% polyarticular subtypes and 26.2% systemic form. The mean global score of JAQQ was 2.6 ± 1.3 (1–6). Patients with persistant oligoarticular had better gross motor function (P < 0.0001), better fine motor function (P < 0.0001), less psychosocial impact (P = 0.001), and less symptoms (P = 0.001) in comparison with polyarticular and systemic subtypes. The HRQOL assessed by the JAQQ was worse in adolescent patients in comparison with children except for symptoms (P = 0.15). The gender (P = 0.95), age at onset of JIA (P = 0.81), and evolution duration (P = 0.34) were not correlated with global score of JAQQ. The diagnosis delay was significantly associated with decrease of HRQOL (P = 0.001). The decrease of HRQOL was correlated with disease activity [pain (VAS), painful and swollen joints, erythrocyte sedimentation rate (for P < 0.0001)], with disability index (CHAQ) (P = 0.001) and presence of hip involvement (P = 0.01). This study suggests that JIA can have a significant adverse effect on the HRQOL of moroccan patients, particularly adolescents with polyarticular and systemic subtypes. Disease duration, disability score (CHAQ) and pain were the strongest determinants of poorer HRQOL.     

Serological screening for coeliac disease in patients with juvenile idiopathic arthritis

Background and study aimsJuvenile idiopathic arthritis (JIA) is characterized by autoimmune aetiology. A gene locus 4q27 related to rheumatoid arthritis, psoriatic arthritis, and coeliac disease is associated with susceptibility to JIA. There are reports indicating several patients with JIA had been diagnosed with CD. We aimed to assess the frequency of coeliac disease (CD) in patients with juvenile idiopathic arthritis (JIA).Patients and methodsThis prospective study was carried out from October 2015 to August 2016 and included 96 patients with JIA. All patients were evaluated in terms of clinical and laboratory findings of CD. Levels of total IgA and tissue transglutaminase antibody (tTG) IgA were measured in all patients. Those with increased level of tTG IgA were further tested for anti-endomysium IgA antibodies (EMA). Gastroduodenoscopy were planned for a definite diagnosis of CD in patients with positive EMA.ResultsOf the 96 patients in our study, 34 (35.4%) had oligoarticular form of JIA, 29 (30.2%) had polyarticular form, 12 (12.5%) had ERA form, 11 (11.5%) had systemic form, and 10 (10.4%) had psoriatic form. Sixteen of our patients (16.6%) were not using any drugs during the study. Neither EMA IgA antibodies were analysed nor gastro-duodenoscopy was performed because no patients were positive for tTG IgA. There was no difference in terms of tTG levels between the patients using NSAIDs or other drugs.ConclusionWe did not find CD in children with JIA. Long term studies with more JIA patients are needed to provide more precise interpretation.     

Pulmonary function in children with juvenile idiopathic arthritis and effects of methotrexate therapy

Summary Objective To evaluate impairment of lung function as an adverse effect associated with methotrexate therapy in patients with juvenile idiopathic arthritis (JIA). Methods We performed pulmonary function testing including diffusion capacity for carbon monoxide as measured by the single breath method (DLCO-SB) in 89 children with juvenile idiopathic arthritis. Forty (45%) were treated with methotrexate for a median of 24 months (range 3 to 120 months). Except for the presence of asthma in two children, there was no clinical or radiological evidence of pulmonary disease. Results Pulmonary function testing demonstrated moderate airway obstruction in two children with known bronchial asthma. Neither obstructive nor restrictive alteration of ventilation was found in any other patient. Two juvenile idiopathic arthritis patients showed a reduced CO diffusion capacity of 64 and 67%. One of them was treated with methotrexate. Conclusions With regard to lung function impairment treatment with low dose methotrexate appears to be safe even when performed for several years reaching a total amount of up to 3.5 g. In contrast to studies performed in adult rheumatoid arthritis patients, in children with juvenile idiopathic arthritis impairment of lung function is a rare event. Received: 23 February 2001 Accepted: 16 May 2001     

Inflammatory cytokines and systemic-onset juvenile idiopathic arthritis

Systemic-onset juvenile idiopathic arthritis (JIA) is a severe and steroid-dependent disease, which sometimes progresses to the fatal disease macrophage activation syndrome. An investigation of inflammatory cytokine levels revealed increases in IL-6 in serum of systemic-onset disease patients. Continuously elevated levels of IL-6 in serum may play a important role in manifesting the clinical symptoms and signs of systemic-onset JIA, including spiking fever, rash, arthritis, and serositis. The characteristic fever spikes parallel IL-6 levels. Long-term exposure to high levels of IL-6 in children results in severe growth impairment, which was strongly suggested by the recent establishment of IL-6 transgenic mice. To avoid disease progression to macrophage activation syndrome and the adverse effects of high-dose corticosteroids, it might be reasonable to inhibit the formation of IL-6/IL-6R complex in order to block the binding to gp130 receptor, a biologically active receptor for IL-6. This review will provide evidence of the relationship between IL-6 homeostasis and systemic-onset JIA, and our recent trials of anti-IL-6R antibody (MRA) for children with acute systemic disease intractable to long-term and high-dose corticosteroid therapy. MRA could be a therapeutic modality for children with systemic-onset JIA intractable to high-dose corticosteroids.