Correlation of serum interleukin-6 levels with joint involvement and thrombocytosis in systemic juvenile rheumatoid arthritis

Effectiveness of first-line treatment with recombinant interleukin-1 receptor antagonist in steroid-naive patients with new-onset systemic juvenile idiopathic arthritis: results of a prospective cohort study

OBJECTIVE

To conduct a prospective cohort study using anakinra, a recombinant IL-1 receptor antagonist (IL-1Ra), as first-line therapy in patients with new-onset systemic juvenile idiopathic arthritis (JIA).

METHODS

Therapy with recombinant IL-1Ra (2 mg/kg) was initiated in 20 patients who fulfilled the International League of Associations for Rheumatology criteria for systemic JIA, before systemic steroid treatment was administered. Patients were monitored clinically and immunologically. The protocol contained a stop strategy for patients who met at least the adapted American College of Rheumatology 90% criteria for improvement in JIA (ACR Pediatric 90 [ACR Pedi 90]) after 3 months.

RESULTS

We included consecutive patients with new-onset systemic JIA. The mean followup period was 32 months (range 12-54 months). At the 3-month time point, 85% of the patients showed an adapted ACR Pedi 90 response or had inactive disease; 75% of the patients achieved this response while receiving recombinant IL-1Ra alone. After 1 year, 17 of the 20 patients met the criteria for clinically inactive disease, and 13 of these patients met these criteria while receiving monotherapy with recombinant IL-1Ra. However, because of persistent disease activity, 7 of the 20 patients required additional therapy besides recombinant IL-1Ra. According to our stop strategy, 73% of patients with at least an adapted ACR Pedi 90 response at 3 months could stop recombinant IL-1Ra treatment within 1 year. After 2 years, 12 (86%) of 14 patients met the criteria for disease remission, either while receiving (n = 4) or not receiving (n = 8) medication. After 3 years, 10 (91%) of 11 patients met the criteria for disease remission, either while receiving (n = 2) or not receiving (n = 8) medication.

CONCLUSION

This is the first prospective study in which recombinant IL-1Ra was used as first-line therapy in patients with systemic JIA. We observed excellent responses in nearly all patients within 3 months. In the majority of responding patients, treatment with recombinant IL-1Ra could be stopped within 1 year, with remission being preserved during followup. In approximately one-third of patients, concomitant therapy was required for maintenance of clinical response.

Treatment advances in systemic juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis (JIA) is an autoinflammatory condition that is distinct from other forms of childhood arthritis. Recently, biologic agents that specifically inhibit the cytokines interleukin (IL)-1 and IL-6 have demonstrated remarkable clinical effectiveness and confirmed the importance of these cytokines in the disease process. Future studies are likely to optimize the care of children with systemic arthritis and further elucidate the disease pathogenesis.

Macrophage activation syndrome and cytokine-directed therapies

Macrophage activation syndrome (MAS) is an episode of overwhelming inflammation that occurs most commonly in children with systemic juvenile idiopathic arthritis (SJIA). It is characterized by expansion and activation of T lymphocytes and hemophagocytic macrophages and bears great similarity to hemophagocytic lymphohistiocytosis (HLH). This disorder has substantial morbidity and mortality, and there is frequently a delay in recognition and initiation of treatment. Here, we will review what is known about the pathogenesis of MAS and, in particular, its similarities to HLH. The development of MAS is characterized by a cytokine storm, with the elaboration of numerous pro-inflammatory cytokines. We will examine the evidence for various cytokines in the initiation and pathogenesis of MAS and discuss how new biologic therapies may alter the risk of MAS. Finally, we will review current treatment options for MAS and examine how cytokine-directed therapy could serve as novel treatment modalities.

Clinical experience of IL-6 blockade in rheumatic diseases - implications on IL-6 biology and disease pathogenesis

Interleukin 6 (IL-6) plays a significant role in many rheumatological diseases and has been described as both a pro- and anti-inflammatory cytokine. IL-6 blockade has been investigated in various rheumatic diseases and a humanised anti-IL-6 receptor antibody has been licensed for use in rheumatoid arthritis, systemic and polyarticular juvenile idiopathic arthritis. The increasing clinical experience of IL-6 blockade in rheumatic diseases adds to the existing knowledge regarding the physiological and pathological roles of IL-6.

Advances in the pathogenesis and treatment of systemic juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis (s-JIA) is clinically distinct from other types of JIA. It is typified by extraarticular features such as quotidian fevers, rash, splenomegaly, lymphadenopathy, laboratory abnormalities (including leukocytosis, thrombocytosis, anemia, hyperferritinemia, and elevated inflammatory markers), and a close association with the macrophage activation syndrome. Recent investigations have highlighted dysregulation of the innate immune system as the critical pathogenic driver of s-JIA. Key innate immune mediators of s-JIA are the macrophage-derived cytokines interleukin-1 (IL-1) and IL-6. Increased understanding of the roles of IL-1 and IL-6 in the pathogenesis of s-JIA has led to major changes in therapeutic options. Until recently, the most commonly used medications included corticosteroids, methotrexate, and tumor necrosis factor (TNF) inhibitors, which are incompletely effective in most cases. Newer biologic agents targeting IL-1 and IL-6 have proven very effective in treating s-JIA and in minimizing corticosteroid exposure. Here we review recent advances in the understanding of the pathogenesis of s-JIA and the recent clinical trials that have revolutionized the care of children with s-JIA.

Tocilizumab in pediatric rheumatology: the clinical experience

During the last two decades, clinical use of novel biological therapy has led to increased mechanistic understanding of complex rheumatological diseases. Conversely, basic and translational studies have led to development of new and varied therapeutic agents. These new medications which "target" specific steps in one or more immune pathways have the potential to control disease symptoms, improve quality of life and long-term prognosis, and perhaps in some, restore immunological tolerance. Use of these agents in clinical trials, combined with post-marketing surveillance, has revealed both the benefits and the undesirable side-effects of biological disease-modifying anti-rheumatic drugs (DMARDs). In this review we focus on the use of tocilizumab, a monoclonal antibody directed against the IL6 receptor (IL6R), which potently inhibits IL-6/IL6R signaling.

Pulmonary hypertension and other potentially fatal pulmonary complications in systemic juvenile idiopathic arthritis

OBJECTIVE

Systemic juvenile idiopathic arthritis (JIA) is characterized by fevers, rash, and arthritis, for which interleukin-1 (IL-1) and IL-6 inhibitors appear to be effective treatments. Pulmonary arterial hypertension (PAH), interstitial lung disease (ILD), and alveolar proteinosis (AP) have recently been reported with increased frequency in systemic JIA patients. Our aim was to characterize and compare systemic JIA patients with these complications to a larger cohort of systemic JIA patients.

METHODS

Systemic JIA patients who developed PAH, ILD, and/or AP were identified through an electronic Listserv and their demographic, systemic JIA, and pulmonary disease characteristics as well as their medication exposure information were collected. Patients with these features were compared to a cohort of systemic JIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry.

RESULTS

The patients (n = 25) were significantly (P < 0.05) more likely than the CARRA registry cohort (n = 389) to be female; have more systemic features; and have been exposed to an IL-1 inhibitor, tocilizumab, corticosteroids, intravenous immunoglobulin, cyclosporine, and cyclophosphamide. Twenty patients (80%) were diagnosed with pulmonary disease after 2004. Twenty patients (80%) had macrophage activation syndrome (MAS) during their disease course and 15 patients (60%) had MAS at pulmonary diagnosis. Sixteen patients had PAH, 5 had AP, and 7 had ILD. Seventeen patients (68%) were taking or recently discontinued (<1 month) a biologic agent at pulmonary symptom onset; 12 patients (48%) were taking anti-IL-1 therapy (primarily anakinra). Seventeen patients (68%) died at a mean of 10.2 months from the diagnosis of pulmonary complications.

CONCLUSION

PAH, AP, and ILD are underrecognized complications of systemic JIA that are frequently fatal. These complications may be the result of severe uncontrolled systemic disease activity and may be influenced by medication exposure.

Reaching the Threshold: A Multilayer Pathogenesis of Macrophage Activation Syndrome

Macrophage activation syndrome (MAS) is a potentially fatal complication of rheumatic diseases. The condition is considered part of secondary hemophagocytic lymphohistiocytoses (HLH). There are similarities in genetic background, pathogenesis, and clinical and laboratory features with primary HLH (p-HLH). We describe findings in mouse models of secondary HLH, comparing them with models of p-HLH and the cellular and molecular mechanisms involved, and relate them to recent findings in patients with secondary HLH. A multilayer model is presented in which background inflammation, infections, and genetics all contribute in different proportions and in several ways. Once the “threshold” has been reached, inflammatory cytokines are the final effectors, independent of the interplay between different upstream pathogenic factors.

[Febrile responses in patients with pediatric rheumatic diseases]

Fever is one of the critical symptoms of patients in pediatrics field. It indicates inflammatory focus somewhere in the body, and the major causes of fever are infectious diseases. Recent progresses of our knowledge about autoinflammatory syndrome promoted the investigation of the mechanism of fever, and suggested that the pro-inflammatory cytokines are the direct causative agents of fever. The basic science revealed that cooperation of IL-6 and IL-1β induces febrile response. Fever of unknown origin (FUO) remains a challenging problem. Rheumatic diseases, rare infectious diseases, and benign tumors and malignancies are diagnoses to be differentiated. FDG-PET is recently proved a valuable tool for the identification of the etiology in patients with FUO. Since the introduction of biological response modifiers into the treatment of patients with pediatric rheumatic diseases has shifted the therapeutic paradigm, a new concept that the blockade of a unique pro-inflammatory cytokine brings cessation of whole inflammatory responses affected tremendously the clinical medicine. A more investigation of inflammation and its pathophisiology will be needed in pediatric rheumatology.

Distinct subsets of patients with systemic juvenile idiopathic arthritis based on their cytokine profiles

To assess the serum interleukin (IL)-6 and IL-18 levels in patients with systemic juvenile idiopathic arthritis (s-JIA) and to identify the clinical features of patient subsets with different cytokine profiles, we analyzed the serum levels of IL-6 and IL-18 in patients with s-JIA and compared them with the clinical features of s-JIA. Eighteen patients were analyzed. IL-6 and IL-18 levels were quantified in serum by enzyme-linked immunosorbent assays. Interestingly, two distinct s-JIA patient subsets based on their serum IL-6 and IL-18 levels were identified: an IL-6 dominant and an IL-18 dominant. The serum IL-6 and IL-18 levels were consistent both at relapse and at the onset of s-JIA in each subset. The IL-6-dominant subset had a significantly greater number of joints with active disease and higher serum levels of matrix metalloproteinase-3, whereas the IL-18-dominant subset was more likely to develop macrophage activation syndrome (MAS). These findings indicate that two subsets of patients with s-JIA, one which is prone for arthritis and another with prone for MAS, can be identified on the basis of their serum IL-6 and IL-18 levels. These two subsets appear to be characterized by certain distinct clinical features.

Randomized trial of tocilizumab in systemic juvenile idiopathic arthritis

BACKGROUND

Systemic juvenile idiopathic arthritis (JIA) is the most severe subtype of JIA; treatment options are limited. Interleukin-6 plays a pathogenic role in systemic JIA.

METHODS

We randomly assigned 112 children, 2 to 17 years of age, with active systemic JIA (duration of ≥6 months and inadequate responses to nonsteroidal antiinflammatory drugs and glucocorticoids) to the anti-interleukin-6 receptor antibody tocilizumab (at a dose of 8 mg per kilogram of body weight if the weight was ≥30 kg or 12 mg per kilogram if the weight was <30 kg) or placebo given intravenously every 2 weeks during the 12-week, double-blind phase. Patients meeting the predefined criteria for nonresponse were offered open-label tocilizumab. All patients could enter an open-label extension.

RESULTS

At week 12, the primary end point (an absence of fever and an improvement of 30% or more on at least three of the six variables in the American College of Rheumatology [ACR] core set for JIA, with no more than one variable worsening by more than 30%) was met in significantly more patients in the tocilizumab group than in the placebo group (64 of 75 [85%] vs. 9 of 37 [24%], P<0.001). At week 52, 80% of the patients who received tocilizumab had at least 70% improvement with no fever, including 59% who had 90% improvement; in addition, 48% of the patients had no joints with active arthritis, and 52% had discontinued oral glucocorticoids. In the double-blind phase, 159 adverse events, including 60 infections (2 serious), occurred in the tocilizumab group, as compared with 38, including 15 infections, in the placebo group. In the double-blind and extension periods combined, 39 serious adverse events (0.25 per patient-year), including 18 serious infections (0.11 per patient-year), occurred in patients who received tocilizumab. Neutropenia developed in 19 patients (17 patients with grade 3 and 2 patients with grade 4), and 21 had aminotransferase levels that were more than 2.5 times the upper limit of the normal range.

CONCLUSIONS

Tocilizumab was efficacious in severe, persistent systemic JIA. Adverse events were common and included infection, neutropenia, and increased aminotransferase levels. (Funded by Hoffmann-La Roche; ClinicalTrials.gov number, NCT00642460.).

Efficacy, safety and tolerability of tocilizumab in patients with systemic juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis (SJIA), a subtype of juvenile idiopathic arthritis, is characterized by systemic features, such as spiking fever, salmon-colored macular rash, serositis, lymphadenopathy, hepatosplenomegaly, and joint inflammation. It is also often complicated with growth retardation, osteoporosis, and sometimes macrophage activation syndrome (MAS) develops, a potentially fatal disease. Pathogenesis of SJIA and MAS is not yet fully understood, but activation of the innate immune system, which causes phagocytosis by dendritic cells, monocytes, and macrophages to produce proinflammatory cytokines such as interleukin-6 (IL-6), IL-1β and IL-18, is thought to be a primary abnormality associated with SJIA. Dysregulated production of IL-6 plays a major role in the development of systemic clinical features. The blockade of IL-6 might thus represent a novel strategy for the treatment of SJIA. Several phase II and III clinical trials of a humanized anti-IL-6 receptor antibody, tocilizumab, proved its outstanding efficacy and tolerable safety profile for SJIA refractory to conventional treatment regimens. This resulted in the approval of tocilizumab for the treatment of SJIA in Japan, India, the EU and the USA.

Systemic juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis (sJIA) sets well apart from all the other forms of JIA. Several observations show that sJIA is etiopathogenically different from all the other forms of JIA and has a prominent autoinflammatory component. A major role in the pathogenesis is played by two proinflammatory cytokines, interleukin-6 and interleukin-1. The specific inhibition of these two cytokines is going to change not only the therapeutic approach to the disease but also, presumably, its long term prognosis.

Radiologic analysis of the effect of tocilizumab on hands and large joints in children with systemic juvenile idiopathic arthritis

OBJECTIVES

To assess the efficacy of tocilizumab for preventing damage to the joints of systemic juvenile idiopathic arthritis (sJIA) patients, we examined serial radiographs of the hands and large weight-bearing joints of these patients before and after treatment with this agent.

METHODS

Nine patients with sJIA receiving 8 mg/kg of tocilizumab intravenously every 2 weeks were studied. The mean follow-up period was 82 months. The number of active joints and laboratory markers of inflammation were assessed before and after tocilizumab treatment, together with radiologic evaluation of the hips, knees, ankles, shoulders, and elbows. The latter examination included soft tissue swelling, juxta-articular osteoporosis, epiphyseal irregularity, joint-space narrowing, cyst formation, erosion, and localized growth abnormalities. Modified Larsen scores for the large joints and the Poznanski score were also recorded.

RESULTS

After tocilizumab treatment, the number of active joints and serum inflammatory markers decreased (p < 0.01). There was a decrease in radiologic abnormalities at the final follow-up (p < 0.01) with the exception of localized growth abnormalities. Radiologic improvement was observed in 47 joints (52%), but ten (11%) worsened. Total Larsen score was decreased from 15.8 to 10.9 at the final follow-up. Although the Poznanski score did not change after tocilizumab treatment, it was closely correlated with the total Larsen score (r = 0.53, p < 0.05).

CONCLUSIONS

We describe radiologic improvement of the majority of damaged large joints in sJIA following tocilizumab therapy, but some deteriorated further despite stabilization of systemic inflammatory responses. Further studies with a larger number of patients are needed.

Th1 and Th17 cell subpopulations are enriched in the peripheral blood of patients with systemic juvenile idiopathic arthritis

Objective. The role of the adaptive immune system has not been explored in detail compared with the innate immune system in systemic JIA (sJIA) pathogenesis. The aim of this study was to examine the phenotype of circulating peripheral blood CD4⁺ T-cell subpopulations in a cross-sectional study of sJIA patients during disease remission on medication and during acute flare of the disease.

Methods. Flow cytometry was used to examine the phenotype and cytokine production of IFNγ-, IL-4- and IL-17-producing CD4⁺ T cells in the peripheral blood of 10 sJIA patients with active disease, 9 sJIA with inactive disease, 14 JIA patients with oligoarticular onset, 10 adult control subjects and 10 age-matched control subjects. In parallel, we examined the proportion of FoxP3⁺ Tregs.

Results. IFNγ- and IL-17-producing CD4⁺ T cells and IL-17-producing CD3⁺CD4⁻ T cells were present at higher proportions in the peripheral blood of sJIA patients, irrespective of their disease status. Our data also confirm the known increase of the proportions of IFNγ-producing Th1 cells with increasing age and suggest an increase with age in the IL-17-producing CD4⁺ T-cell population.

Conclusion. This study is the first to describe significantly higher proportions of Th1 and Th17 T helper cell subsets in the peripheral blood of sJIA patients. These proinflammatory cells may play a pathogenic role in sJIA. Our data also emphasize the importance of using paediatric age-matched control subjects when evaluating the T-cell cytokine profile in JIA.

Tocilizumab in the treatment of systemic juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis is one of the common rheumatic diseases in childhood and characterized by spiking fever, evanescent skin rash, lymphadenopathy, hepatosplenomegaly, and serositis, in addition to arthritis. Children with systemic juvenile idiopathic arthritis often show growth retardation and developmental abnormality, as well as macrophage activation syndrome, a life-threatening complication. Overproduction of interleukin-6 is pathologically responsible for the systemic inflammatory manifestations and abnormal laboratory results with systemic juvenile idiopathic arthritis. Thus, tocilizumab, a humanized antihuman interleukin-6 receptor antibody, has been developed as a therapeutic agent for the disease. A series of clinical studies have demonstrated the excellent efficacy and safety of tocilizumab for patients with active disease. Tocilizumab was approved for systemic juvenile idiopathic arthritis in Japan in 2008 and in the European Union and the United States in 2011.

The Toll-like receptor 4 agonist MRP8/14 protein complex is a sensitive indicator for disease activity and predicts relapses in systemic-onset juvenile idiopathic arthritis

BACKGROUND

Analysis of myeloid-related protein 8 and 14 complex (MRP8/14) serum concentrations is a potential new tool to support the diagnosis of systemic-onset juvenile idiopathic arthritis (SJIA) in the presence of fever of unknown origin.

OBJECTIVE

To test the ability of MRP8/14 serum concentrations to monitor disease activity in patients with SJIA and stratify patients at risk of relapse.

METHODS

Serum concentrations of MRP8/14 in 52 patients with SJIA were determined by a sandwich ELISA. The monitoring of therapeutic regimens targeting interleukin 1 and tumour necrosis factor α, and methotrexate treatment was analysed and diagnostic power to predict flares was tested.

RESULTS

MRP8/14 levels were clearly raised in active disease and decreased significantly in response to successful treatments. Serum concentrations of MRP8/14 increased significantly (p<0.001) (mean±95% CI 12.030±3.090 ng/ml) during disease flares compared with patients with inactive disease (864±86 ng/ml). During clinical remission MRP8/14 serum levels of >740 ng/ml predicted disease flares accurately (sensitivity 92%, specificity 88%). MRP8/14 levels correlated well with clinical disease activity, as assessed by physician's global assessment of disease activity (r=0.62), Childhood Health Assessment Questionnaire (r=0.56), active joint count (r=0.46) and with C-reactive protein (r=0.71) and erythrocyte sedimentation rate (r=0.72) (for all p<0.001).

CONCLUSION

MRP8/14 serum concentrations correlate closely with response to drug treatment and disease activity and therefore might be an additional measurement for monitoring anti-inflammatory treatment of individual patients with SJIA. MRP8/14 serum concentrations are the first predictive biomarker indicating subclinical disease activity and stratifying patients at risk of relapse during times of clinically inactive disease.

Is Still's Disease an Autoinflammatory Syndrome?

Systemic juvenile idiopathic arthritis (sJIA), formerly called Still's disease, is officially classified as a subset of juvenile idiopathic arthritis (JIA). Beside arthritis, it is characterized by prominent systemic features and a marked inflammatory response. Even if it is still included in the group of juvenile arthritides, sJIA is set apart from all the other forms of JIA. This disorder has markedly distinct clinical and laboratory features suggesting a different pathogenesis. sJIA does not show any association with HLA genes or with autoantibodies and is characterised by an uncontrolled activation of phagocytes with hypersecretion of IL-1 and IL-6. Based on clinical and laboratory features, as well as on new acquisitions on the pathogenesis, it seems evident that sJIA is an autoinflammatory disease related to abnormality in innate immune system. The new insights on the pathogenesis of sJIA have therefore dramatically changed the approach to treatment, with the development of targeted treatments (anti-IL-1 and anti-IL-6 agents) more effective and safer than earlier medications.

Tocilizumab masks the clinical symptoms of systemic juvenile idiopathic arthritis-associated macrophage activation syndrome: the diagnostic significance of interleukin-18 and interleukin-6

Macrophage-activation syndrome (MAS) is a potentially life-threatening complication of systemic juvenile idiopathic arthritis (s-JIA). Tocilizumab (TCZ), a humanized anti-IL-6 receptor monoclonal antibody, is an effective cytokine inhibitor for the treatment of s-JIA. We described the clinical courses of five cases of MAS during TCZ therapy and demonstrated the need for monitoring serum interleukin (IL)-18 and IL-6 concentrations. Clinical symptoms of patients with s-JIA receiving TCZ were apparently mild compared to those not receiving TCZ. Furthermore, serum CRP concentrations never increased during TCZ therapy, even in MAS. Serum IL-6 concentrations increased during s-JIA flare-up and with the complication of infection. Serum IL-18 concentrations increased persistently before the other measures of disease activity. The clinical symptoms of MAS and s-JIA could be masked during TCZ therapy; hence, monitoring serum concentrations of IL-18 and IL-6 is recommended for the evaluation of disease activity in s-JIA and to detect the complication of infection.

Treatment of Systemic Juvenile Idiopathic Arthritis with Tocilizumab - the Role of Anti-Interleukin-6 Therapy After a Decade of Treatment

With the recent approval of tocilizumab as the first biologic for the treatment of systemic juvenile idiopathic arthritis (sJIA), an important unmet medical need for this historically challenging disease has now been met. The purpose of this review article is to revisit the established therapeutic options for sJIA, to summarize the history of the clinical trials with tocilizumab, and to discuss its role in the treatment of sJIA.

Update on the pathogenesis and treatment of systemic idiopathic arthritis

PURPOSE OF REVIEW

Systemic juvenile idiopathic arthritis (SJIA) is an inflammatory condition characterized by fever, lymphadenopathy, rash, arthritis, and serositis. Although the ultimate cause of this disorder remains elusive, recent work defining cytokine effector mechanisms has led to a new treatment paradigm for this condition. In this review, we describe the recent immunological reclassification of SJIA as an autoinflammatory disorder as well as detailing the dramatic changes in its treatment.

RECENT FINDINGS

SJIA is an autoinflammatory disorder in which defects of innate immune system pathways lead to significant inflammation. Recent studies of the pathophysiology, as well as successful treatment trials, have established interleukin-1β (IL-1β) and IL-6 as key cytokines in the pathogenesis of this condition. As a result, their inhibition has become the centerpiece of the current SJIA treatment paradigm.

SUMMARY

There has been a major shift away from the traditional treatments of SJIA towards therapeutics that inhibit IL-1β and IL-6. In fact, the IL-1 blocker anakinra is now regarded as standard of care for SJIA patients with systemic symptoms, while the IL-6 inhibitor tocilizumab shows great potential. Future research holds promise for the development of more efficient cytokine inhibition as well a more comprehensive knowledge of the innate cytokine networks in this disease.

Safety and efficacy of tocilizumab, an anti-IL-6-receptor monoclonal antibody, in patients with polyarticular-course juvenile idiopathic arthritis

We evaluated the safety and efficacy of tocilizumab in polyarticular-course juvenile idiopathic arthritis (pJIA) with polyarticular or oligoarticular onset. Patients received 8 mg/kg tocilizumab every 4 weeks in the open-label studies: initial study (to week 12) and then an extension study (at least 48 weeks). Nineteen patients intractable to conventional methotrexate therapy were enrolled. Seventeen patients had polyarticular-onset pJIA; two had oligoarticular-onset pJIA. Mean age was 11.6 years; mean disease duration 5.3 years. American College of Rheumatology Pediatric (ACR Pedi) 30, 50, 70, and 90 response rates, respectively, were 94.7%, 94.7%, 57.9%, and 10.5% at week 12, and 100%, 94.1%, 88.2%, and 64.7% at week 48. Mean disease activity score (DAS28) remained below the remission level (2.6) from week 24. Administration was discontinued in two patients during the extension study because the ACR Pedi 50 response was judged insufficient (one patient) and antitocilizumab antibodies developed (one patient). Adverse events were generally mild, and the four serious adverse events resolved spontaneously or with treatment. In conclusion, tocilizumab showed early and sustained efficacy and tolerability for treating intractable pJIA, which suggests that it is a promising new treatment for this disease.

Pathogenesis of systemic juvenile idiopathic arthritis: some answers, more questions

Systemic juvenile idiopathic arthritis (sJIA) has long been recognized as unique among childhood arthritides, because of its distinctive clinical and epidemiological features, including an association with macrophage activation syndrome. Here, we summarize research into sJIA pathogenesis. The triggers of disease are unknown, although infections are suspects. Once initiated, sJIA seems to be driven by innate proinflammatory cytokines. Endogenous Toll-like receptor ligands, including S100 proteins, probably synergize with cytokines to perpetuate inflammation. These and other findings support the hypothesis that sJIA is an autoinflammatory condition. Indeed, IL-1 is implicated as a pivotal cytokine, but the source of excess IL-1 activity remains obscure and the role of IL-1 in chronic arthritis is less clear. Another hypothesis is that a form of hemophagocytic lymphohistiocytosis underlies sJIA, with varying degrees of its expression across the spectrum of disease. Alternatively, sJIA with MAS might be a genetically distinct subtype. Yet another hypothesis proposes that inadequate downregulation of immune activation is central to sJIA, supporting evidence for which includes 'alternative activation' of monocyte and macrophages and possible deficiencies in IL-10 and T regulatory cells. Some altered immune phenotypes persist during clinically inactive disease, which suggests that this stage might represent compensated inflammation. Despite much progress being made, many questions remain, providing fertile ground for future research.

The pathogenesis of oligoarticular/polyarticular vs systemic juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) has had a long and difficult problem with classification. It is clearly a heterogeneous and multi-factorial autoimmune disease but all too often the distinctions among subtypes were unclear. In fact, there is now increasing evidence of a distinct pathogenesis of oligo/polyarticular JIA compared to systemic JIA. Oligo/polyarticular JIA is an antigen-driven lymphocyte-mediated autoimmune disease with abnormality in the adaptive immune system. Cartilage-derived auto-antigens activate autoreactive T cells including Th1 and Th17 cells with production of pro-inflammatory cytokines IFN-γ and IL-17. On the other hand, the inhibition of regulatory T (Treg) cells including natural Foxp3(+) Treg and self-heat shock protein-induced Treg cells with decreased anti-inflammatory cytokine IL-10 results in the loss of immune tolerance. Imbalance between autoreactive Th1/Th17 and Treg cells leads to the failure of T cell tolerance to self-antigens, which contributes to the synovial inflammation of oligo/polyarticular JIA. By contrast, systemic JIA is an autoinflammatory disease with abnormality in the innate immune system. A loss of control of the alternative secretory pathway leading to aberrant activation of phagocytes including monocytes, macrophages and neutrophils seems to be involved in the release of pro-inflammatory cytokines IL-1, IL-6, IL-18 and pro-inflammatory S100-proteins, which contribute to the multisystem inflammation of systemic JIA. Markedly distinct pathogenesis of oligo/polyarticular JIA and systemic JIA implies that they might need different treatment strategies.

Tumor necrosis factor inhibitors in the management of juvenile idiopathic arthritis: an evidence-based review

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disorder of unknown origin that is often treated with a variety of disease-modifying agents. Tumor necrosis factor (TNF) inhibitors are a group of genetically engineered biologic agents that target the proinflammatory cytokine TNF. This review focuses on the use of TNF inhibitors in JIA. Etanercept was the first TNF inhibitor approved for use in children with moderate to severe polyarticular-course JIA following encouraging results from a randomized, double-blind, placebo-controlled, multicenter trial in children. Open-label extension studies of the original trial involving 8 years of follow-up demonstrated the long-term safety and efficacy of etanercept in children. Other studies from established registries also corroborate the safety of etanercept in JIA. The second TNF inhibitor to be approved for use in JIA is adalimumab following recent favorable results from another randomized, placebo-controlled, multicenter study in polyarticular-course JIA. While infliximab is not approved by the US FDA for use in JIA, it is frequently used in clinical practice for this indication. However, because the chimeric structure of infliximab incorporates murine components, it has the potential for allergic and infusion reactions. Patient responses to individual TNF inhibitors may vary depending on concomitant medications such as methotrexate, and also on the category of JIA.

Pathogenesis and clinical manifestations of juvenile rheumatoid arthritis

Juvenile rheumatoid arthritis (JRA) is the most common rheumatic childhood disease; its onset is before 16 years of age and it persists for at least 6 weeks. JRA encompasses a heterogeneous group of diseases that is classified according to 3 major presentations: oligoarthritis, polyarthritis, and systemic onset diseases. These presentations may originate from the same or different causes that involve interaction with specific immunogenetic predispositions, and result in heterogeneous clinical manifestations. An arthritic joint exhibits cardinal signs of joint inflammation, such as swelling, pain, heat, and loss of function; any joint can be arthritic, but large joints are more frequently affected. Extra-articular manifestations include high fever, skin rash, serositis, and uveitis. The first 2 types of JRA are regarded as T helper 1 (Th1) cell-mediated inflammatory disorders, mainly based on the abundance of activated Th1 cells in the inflamed synovium and the pathogenetic role of proinflammatory cytokines that are mainly produced by Th1 cell-stimulated monocytes. In contrast, the pathogenesis of systemic onset disease differs from that of other types of JRA in several respects, including the lack of association with human leukocyte antigen type and the absence of autoantibodies or autoreactive T cells. Although the precise mechanism that leads to JRA remains unclear, proinflammatory cytokines are thought to be responsible for at least part of the clinical symptoms in all JRA types. The effectiveness of biologic therapy in blocking the action of these cytokines in JRA patients provides strong evidence that they play a fundamental role in JRA inflammation.

Transcriptional modulation of heat-shock protein gene expression

Heat-shock proteins (Hsps) are molecular chaperones that are ubiquitously expressed but are also induced in cells exposed to stressful stimuli. Hsps have been implicated in the induction and propagation of several diseases. This paper focuses on regulatory factors that control the transcription of the genes encoding Hsps. We also highlight how distinct transcription factors are able to interact and modulate Hsps in different pathological states. Thus, a better understanding of the complex signaling pathways regulating Hsp expression may lead to novel therapeutic targets.

[The importance of biologicals in the treatment of SoJIA]

Systemic onset juvenile idiopathic arthritis (SoJIA) remains difficult to treat. In addition to conventional antirheumatic therapy with non-steroidal antirheumatic drugs (NSARDs), steroids or disease-modifying antirheumatic drugs (DMARDs), biologicals offer a new therapeutic approach for this disease in that they are able to target pathogenically relevant cytokines and effector cells. Some biologicals are already approved for use in children with rheumatic disease.In order to assess the currently available data on the use of biologicals in SoJIA, we performed a Medline search for the period 2005 to March 2010, including the MeSH terms "SoJIA", "systemic juvenile idiopathic arthritis" and"biologicals", as well as an NIH study registry search. At Present there are scant and unconvincing data on the use of Etanercept or Adalimumab for the treatment of SoJIA. No results are published on the use of Infliximab or other new TNF-alpha inhibitors. The inhibition of IL-1 or IL-6 shows promising results. Data on the efficacy of Abatacept is limited due to very low numbers of SoJIA patients in the studies.Further studies on the use of biologicals in SoJIA while taking individual factors into consideration are required. The long-term safety of all biologicals should be investigated in prospective registers.

Immature cell populations and an erythropoiesis gene-expression signature in systemic juvenile idiopathic arthritis: implications for pathogenesis

Introduction

Previous observations suggest that active systemic juvenile idiopathic arthritis (sJIA) is associated with a prominent erythropoiesis gene-expression signature. The aim of this study was to determine the association of this signature with peripheral blood mononuclear cell (PBMC) subpopulations and its specificity for sJIA as compared with related conditions.

Methods

The 199 patients with JIA (23 sJIA and 176 non-sJIA) and 38 controls were studied. PBMCs were isolated and analyzed for multiple surface antigens with flow cytometry and for gene-expression profiles. The proportions of different PBMC subpopulations were compared among sJIA, non-sJIA patients, and controls and subsequently correlated with the strength of the erythropoiesis signature. Additional gene-expression data from patients with familial hemophagocytic lymphohistiocytosis (FHLH) and from a published sJIA cohort were analyzed to determine whether the erythropoiesis signature was present.

Results

Patients with sJIA had significantly increased proportions of immature cell populations, including CD34⁺ cells, correlating highly with the strength of the erythropoiesis signature. The erythropoiesis signature strongly overlapped with the gene-expression pattern in purified immature erythroid precursors. The expansion of immature cells was most prominently seen in patients with sJIA and anemia, even in the absence of reticulocytosis. Patients with non-sJIA and anemia did not exhibit the erythropoiesis signature. The erythropoiesis signature was found to be prominent in patients with FHLH and in a published cohort of patients with active sJIA, but not in patients with inactive sJIA.

Conclusions

An erythropoiesis signature in active sJIA is associated with the expansion of CD34⁺ cells, also is seen in some patients with FHLH and infection, and may be an indicator of ineffective erythropoiesis and hemophagocytosis due to hypercytokinemia.

Tocilizumab: therapy and safety management

OBJECTIVES

To develop fact sheets about tocilizumab, in order to assist physicians in the management of patients with inflammatory joint disease.

METHODS

1. selection by a committee of rheumatology experts of the main topics of interest for which fact sheets were desirable; 2. identification and review of publications relevant to each topic; 3. development of fact sheets based on three levels of evidence: evidence-based medicine, official recommendations, and expert opinion. The 20 experts were rheumatologists and invited specialists in other fields, and they had extensive experience with the management of RA. They were members of the CRI (Club Rhumatismes et Inflammation), a section of the Société Francaise de Rhumatologie. Each fact sheet was revised by several. experts and the overall process was coordinated by three experts.

RESULTS

Several topics of major interest were selected: contraindications of tocilizumab; the management of adverse effects and concomitant diseases that may develop during tocilizumab therapy; and the management of everyday situations such as pregnancy, surgery, and immunizations. After a review of the literature and discussions among experts, a consensus was developed about the content of the fact sheets presented here. These fact sheets focus on several points: Several topics of major interest were selected: contraindications of tocilizumab; the management of adverse effects and concomitant diseases that may develop during tocilizumab therapy; and the management of everyday situations such as pregnancy, surgery, and immunizations. After a review of the literature and discussions among experts, a consensus was developed about the content of the fact sheets presented here. These fact sheets focus on several points: 1. in RA, initiation and monitoring of tocilizumab therapy, management of patients with specific past histories, and specific clinical situations such as pregnancy; 2. diseases other than RA, such as juvenile idiopathic arthritis; 3. models of letters for informing the rheumatologist and general practitioner; 4. and patient information.

CONCLUSION

These tocilizumab fact sheets built on evidence-based medicine and expert opinion will serve as a practical tool for assisting physicians who manage patients on tocilizumab therapy. They will be available continuously at www.cri-net.com and updated at appropriate intervals.

Tocilizumab: The evidence for its place in the treatment of juvenile idiopathic arthritis

Introduction:

Juvenile idiopathic arthritis (JIA) is one of the most common chronic diseases with childhood onset. It comprises different subtypes of which the systemic onset subtype is often resistant to treatment. With the advent of biological treatment with tumor necrosis factor-α (TNFα)-inhibitors, the clinical outcome of JIA has improved considerably, but only for subtypes other than systemic JIA. Substantial evidence shows that the proinflammatory cytokine interleukin-6 (IL-6) plays a pivotal role in systemic JIA. The blockage of IL-6 action by tocilizumab, a humanized anti-IL-6-receptor monoclonal antibody, could therefore be an effective treatment of systemic JIA.

Aims:

The purpose of this article was to review the clinical trials of tocilizumab and to discuss its place in the treatment of JIA with the focus on the systemic onset of disease.

Evidence review:

Two phase II studies and one phase III clinical trial of tocilizumab demonstrating the clinical efficacy and safety in systemic onset JIA have been published. Within those studies, sustained and high response rates of clinical improvement have been achieved with American College of Rheumatology Pediatric criteria (ACRPed) 30, 50, and 70 observed in 98%, 94%, and 90% of patients, respectively, after 48 weeks. One study regarding the clinical efficacy of tocilizumab for the treatment of oligo- and polyarticular JIA has been presented only as a conference abstract.

Place in therapy:

The very promising results seen so far in patients with severe systemic JIA and acceptable tolerability gives tocilizumab a central role in the future therapy in controlling this disease. No other biological therapy has achieved similar high response rates when treating with tocilizumab 8 mg/kg every two weeks to patients with systemic onset JIA, but direct comparison of the efficacy of different biological agents are not yet available.

Distribution of circulating cells in systemic juvenile idiopathic arthritis across disease activity states

Juvenile idiopathic arthritis (JIA) encompasses a group of chronic childhood arthritides of unknown etiology. One subtype, systemic JIA (SJIA), is characterized by a combination of arthritis and systemic inflammation. Its systemic nature suggests that clues to SJIA pathogenesis may be found in examination of peripheral blood cells. To determine the immunophenotypic profiles of circulating mononuclear cells in SJIA patients with different degrees of disease activity, we studied PBMC from 31 SJIA patients, 20 polyarticular JIA patients (similar to adult rheumatoid arthritis), and 31 age-matched controls. During SJIA disease flare, blood monocyte numbers were increased, whereas levels of myeloid dendritic cells (DC) and gammadelta T cells were reduced. At both flare and quiescence, increased levels of CD14 and CD16 were found on SJIA monocytes. Levels of CD16-DC were elevated at SJIA quiescence compared both to healthy controls and to SJIA subjects with active disease. Overall, our findings suggest dysregulation of innate immunity in SJIA and raise the possibility that quiescence represents a state of compensated inflammation.

Systemic JIA: new developments in the understanding of the pathophysiology and therapy

Systemic juvenile idiopathic arthritis (sJIA) is a rare, systemic inflammatory disease classified as a subtype of JIA. Besides arthritis, it is characterised by systemic features such as spiking fever, skin rash, hepatosplenomegaly or serositis. It is becoming clear now that abnormalities in the innate immunity (cytokines such as interleukin (IL)-1, IL-6 and IL-18, and neutrophils and monocytes/macrophages rather than lymphocytes) play a major role in the pathogenesis of sJIA, distinguishing it from other JIA subtypes. Another distinctive feature of sJIA is its strong association with macrophage activation syndrome (MAS). Based on this, consensus is emerging that sJIA should be viewed as an autoinflammatory syndrome rather than a classic auto-immune disease. As a consequence of the progression in understanding the underlying mechanisms of sJIA, major changes in the management are evolving. So far, treatment has been based on glucocorticosteroids in combination with disease-modifying drugs such as methotrexate. Recently, remarkable improvement has been observed with IL-1 and IL-6 targeted therapies. These therapies might also change the long-term outcome of this disease. However, controlled trials set up in international collaboration are needed to determine the optimal treatment strategies for all sJIA patients.

IL‐6 promoter polymorphism in patients with rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory disease in which cytokines play an important role. The aim of the present study was to examine the interleukin-6 (IL-6) -174 promoter polymorphism in patients with RA and its association with disease susceptibility and activity.

METHODS

The study included 98 patients with RA diagnosed according to the criteria of the American College of Rheumatology. Polymerase chain reaction (PCR) amplification was used for analysis of the polymorphism at position -174 in the promoter of the IL-6 gene.

RESULTS

The distribution of IL-6 genotypes in RA patients did not differ from that in control subjects. Nevertheless, in patients with a GG genotype the active form of RA was more frequently diagnosed compared with homozygous CC and GC patients. Moreover, in carriers of two G alleles the parameters of disease activity score (DAS28), erythrocyte sedimentation rate (ESR), number of swollen and tender joints] were significantly increased.

CONCLUSION

We suggest that the IL-6 promoter polymorphism may be a genetic risk factor for RA activity.

Susceptibility to JRA/JIA: complementing general autoimmune and arthritis traits

Juvenile rheumatoid arthritis (JRA), also known as juvenile idiopathic arthritis (JIA), includes the most common chronic autoimmune arthropathies of childhood. These two nomenclatures for classification include components representing the major subclasses of disease. The chromosomal regions and the genes involved in these complex genetic traits are being elucidated, with findings often specific for a particular disease subtype. With the advent of new SNP technologies, progress is being made at an ever-increasing pace. This review discusses the difficulties of deciphering the genetic components in complex disorders, while demonstrating the similarities that JRA shares with other autoimmune disorders. Particular emphasis has been placed on positive findings either for candidate genes that have been replicated independently in JRA/JIA, or findings in JRA for which consistent results have been reported in other forms of autoimmunity.