Tumor necrosis factor-blocking agents for children with enthesitis-related arthritis--data from the dutch arthritis and biologicals in children register, 1999-2010

Ten-year safety and clinical benefit from open-label etanercept treatment in children and young adults with juvenile idiopathic arthritis

OBJECTIVES

CLIPPER2 was an 8-year, open-label extension of the phase 3b, 2-year CLIPPER study on the safety and efficacy of etanercept in patients with JIA, categorized as extended oligoarticular arthritis (eoJIA), enthesitis-related arthritis (ERA) or PsA.

METHODS

Participants with eoJIA (2-17 years old), ERA or PsA (each 12-17 years old) who received ≥1 etanercept dose (0.8 mg/kg weekly; maximum 50 mg) in CLIPPER could enter CLIPPER2. Primary end point was occurrence of malignancy. Efficacy assessments included proportions achieving JIA ACR 30/50/70/90/100 criteria and ACR inactive disease criteria, and clinical remission (ACR criteria) or Juvenile Arthritis DAS (JADAS) ≤1.

RESULTS

Overall, 109/127 (86%) CLIPPER participants entered CLIPPER2 [n = 55 eoJIA, n = 31 ERA, n = 23 PsA; 99 (78%) on active treatment]; 84 (66%) completed 120 months' follow-up [32 (25%) on active treatment]. One malignancy (Hodgkin's disease in 18-year-old patient with eoJIA treated with methotrexate for 8 years) was reported; there were no cases of active tuberculosis or deaths. Numbers and incidence rates (events per 100 patient-years) of TEAEs (excluding infections/ISRs) decreased from 193 (173.81) in Year 1 to 9 (27.15) in Year 10; TE infections and serious infections also decreased. Over 45% of participants (n = 127) achieved JIA ACR50 responses from Month 2 onwards; 42 (33%) and 34 (27%) participants achieved JADAS and ACR clinical remission, respectively.

CONCLUSIONS

Etanercept treatment up to 10 years was well tolerated, consistent with the known safety profile, with durable response in the participants still on active treatment. The benefit-risk assessment of etanercept in these JIA categories remains favourable.

TRIAL REGISTRATION

ClinicalTrials.gov IDs: CLIPPER (NCT00962741); CLIPPER2 (NCT01421069).

The Juvenile Spondyloarthritis Disease Activity Index Is a Useful Tool in Enthesitis-Related Arthritis: Real-Life Data

OBJECTIVE

To compare enthesitis-related arthritis (ERA) patients with active and inactive disease at 6 months and define baseline predictors for disease inactivity. In addition, to evaluate the demographic, clinical, and laboratory characteristics of ERA patients and to identify the real-life impact of the Juvenile Spondyloarthritis Disease Activity Index (JSpADA) in predicting active disease in ERA.

METHODS

This medical record review study was conducted with 56 patients who were diagnosed with ERA at our clinic between June 2009 and June 2022. Demographic and clinical characteristics, laboratory parameters, treatment, and JSpADA were recorded.

RESULTS

The patients were divided into 2 groups as active (n = 34) and inactive (n = 22) according to their disease activity at month six. Sex, age at diagnosis, number and type of affected joints, and presence of sacroiliitis were similar in both groups. There was no difference in baseline erythrocyte sedimentation rate, but there was a significant difference in erythrocyte sedimentation rate at the third month ( p = 0.52 and p = 0.018, respectively). The median JSpADA values at disease onset were 3.5 (interquartile range [IQR], 3.0-4.5) and 3.3 (IQR, 2.5-4.0) in the active and inactive groups, respectively ( p = 0.27). At the third month, the median JSpADA values were 1.5 (IQR, 0.5-2.1) in the active group and 0.5 (IQR, 0.5-1.5) in the inactive group ( p = 0.037). The cutoff value for JSpADA at the third month for active disease persisting at the month six was determined as 1 point (area under the curve, 0.662 ± 0.06; p = 0.042; 95% confidence interval, 0.51-0.80) by receiver operating characteristic curve analysis.

CONCLUSION

In ERA patients, a persistently high JSpADA value at follow-up is a predictive factor for active disease at the sixth month.

Comparison of the outcomes between early and late anti-tumor necrosis factor therapy in patients with enthesitis-related subcategory of juvenile idiopathic arthritis: a multi-center study in Southeast Asia

BACKGROUND

Little is known about the impact of delayed initiation of anti-tumor necrosis factor (TNF) therapy in patients with enthesitis-related arthritis (ERA). Here, we compared the impact of delayed treatment on disease outcomes of ERA patients in Southeast Asia.

RESEARCH DESIGN AND METHODS

This retrospective study enrolled 149 ERA patients from Thailand and Singapore. Early (e-aTNF) and late (l-aTNF) treatment groups received anti-TNF therapy starting at ≤6 months and >6 months, respectively, after diagnosis. Outcomes included mean differences in disease activity parameters, Juvenile Spondyloarthritis Disease Activity (JSpADA) score, Juvenile Arthritis Diseases Activity (JADAS)-10 score, and American College of Rheumatology Pediatric (ACR Pedi) criteria, and the frequency of clinically inactive disease and first flare event.

RESULTS

The mean changes in JSpADA (p = 0.002) and JADAS-10 (p < 0.001) scores over time were significantly higher in the e-aTNF group than in the l-aTNF group. A significantly higher proportion of patients in the e-aTNF group than l-aTNF group satisfied ACR Pedi 100 criteria at 2 years (p = 0.042). All other long-term outcomes were not significantly different between the groups.

CONCLUSIONS

Although early anti-TNF treatment improved disease activity parameters somewhat better than delayed anti-TNF therapy, there was no significant difference in long-term outcomes.

Determinants of Tumor Necrosis Factor Inhibitor Use in Juvenile Spondyloarthropathy and Impact on Clinical Disease Outcomes

Objective

The objectives of this study were to characterize the reasons for tumor necrosis factor inhibitor (TNFi) initiation in patients with juvenile spondyloarthropathy (JSpA) and identify clinical correlates and to assess the effect of TNFi therapy on JSpA disease activity.

Methods

We conducted a retrospective cohort study of 86 patients with JSpA with first‐time use of a TNFi over a 7‐year period at Stanford Children's Health. We assessed the physician's reason for TNFi initiation, disease activity at 6 months, and clinical disease status at 12 months following TNFi start. Changes in active joint count, enthesitis count, and pain were measured. Demographics, physician reasons for TNFi initiation, and clinical characteristics were summarized.

Results

The mean age at JSpA diagnosis was 12.4 years (SD 4.0 years), and the mean time from diagnosis to TNFi initiation was 1.6 years (SD 2.3 years). The most common reason for initiating a TNFi was active disease on physical examination (61%). At 6 months post TNFi initiation, patients on average had three fewer active joints and one fewer active enthesitis point. Patient‐reported pain improved from moderate/severe to mild. After 12 months, 54% of patients had active disease.

Conclusion

The physician's decision to initiate a TNFi relied mostly on physical examination findings. Despite improvement in arthritis, enthesitis, and patient‐reported pain at 6 months post TNFi initiation, the majority of the patients still had active disease after 1 year of therapy.

Similarities and Differences Between Juvenile and Adult Spondyloarthropathies

Spondyloarthritis (SpA) encompasses a broad spectrum of conditions occurring from childhood to middle age. Key features of SpA include axial and peripheral arthritis, enthesitis, extra-articular manifestations, and a strong association with HLA-B27. These features are common across the ages but there are important differences between juvenile and adult onset disease. Juvenile SpA predominantly affects the peripheral joints and the incidence of axial arthritis increases with age. Enthesitis is important in early disease. This review article highlights the similarities and differences between juvenile and adult SpA including classification, pathogenesis, clinical features, imaging, therapeutic strategies, and disease outcomes. In addition, the impact of the biological transition from childhood to adulthood is explored including the importance of musculoskeletal and immunological maturation. We discuss how the changes associated with adolescence may be important in explaining age-related differences in the clinical phenotype between juvenile and adult SpA and their implications for the treatment of juvenile SpA.

Juvenile Spondyloarthritis: What More Do We Know About HLA-B27, Enthesitis, and New Bone Formation?

Juvenile spondyloarthritis (JSpA) refers to a diverse spectrum of immune-mediated inflammatory arthritides whose onset occurs in late childhood and adolescence. Like its adult counterpart, JSpA is typified by a strong association with human leukocyte antigen-B27 (HLA-B27) and potential axial involvement, while lacking rheumatoid factor (RF) and distinguishing autoantibodies. A characteristic manifestation of JSpA is enthesitis (inflammation of insertion sites of tendons, ligaments, joint capsules or fascia to bone), which is commonly accompanied by bone resorption and new bone formation at affected sites. In this Review, advances in the role of HLA-B27, enthesitis and its associated osteoproliferation in JSpA pathophysiology and treatment options will be discussed. A deeper appreciation of how these elements contribute to the JSpA disease mechanism will better inform diagnosis, prognosis and therapy, which in turn translates to an improved quality of life for patients.

Tapering of Biological Agents in Juvenile ERA Patients in Daily Clinical Practice

Objectives: We aim to evaluate the proportion and characteristics of enthesitis-related arthritis (ERA) patients in whom medications can be withdrawn in daily practice and to analyze the factors associated with flare-ups during medication tapering of these patients.

Methods: We retrospectively reviewed records of patients under 16 years old diagnosed with ERA from April 2001 to March 2020 in one tertiary medical center in Taiwan. Patients were categorized by different medication uses: conventional disease modifying anti-rheumatic drugs (cDMARDs) only and cDMARDs plus biologics. Demographics, laboratory data, presence of uveitis, and medication withdrawal rate were analyzed. Subgroup analysis was performed in the patients with cDMARDs plus biologics to identify factors associated with flare-ups during medication tapering of these patients. Statistical analysis was performed using R (v3.6.0).

Results: There were 75 juvenile ERA patients with a median onset age of 10.28 years old. Nineteen (25.3%) patients used cDMARDs for disease control; 56 (74.7%) patients depended on cDMARDs plus biologics. Poly-articular involvement was noted in 29 (38.7%) patients, and it occurred more frequently in the cDMARDs plus biologics subgroup (cDMARDs only, 5.3%; cDMARDs plus biologics, 53.6%; P = 0.0001). ANA positivity was observed in 18 (24.0%) patients, and it occurred more frequently in the cDMARDs plus biologics subgroup (cDMARDs, 0%; cDMARDs plus biologics, 32.1%; P = 0.0038). The overall medication withdrawal rate was 34.7%, and it occurred more frequently in patients with cDMARDs only (cDMARDs only, 84.2%; cDMARDs plus biologics, 17.9%; P < 0.001). In the subgroup analysis of patients with cDMARDs plus biologics, patients on biologics tapering with flare-up had a significantly longer time interval between disease onset and initiation of cDMARDs (biologics tapering without flare-up: 0.27 (0.11–0.73) years; biologics tapering with flare-up: 1.14 (0.39–2.02) years; ever withdrawing biologics: 0.26 (0.18–0.42) years, P = 0.0104).

Conclusion: Juvenile ERA patients with polyarticular involvement had a higher risk of developing cDMARDs refractory and progressing to biologics use. Patients with a long time interval between disease onset and initiation of cDMARDs were prone to experience flare-up during tapering of biologics.

Pharmacotherapy for juvenile spondyloarthritis: an overview of the available therapies

INTRODUCTION

Spondyloarthropathies (SpA) represent a heterogeneous group of inflammatory arthritides with autoimmune pathogenesis that can affect both adults and children with peculiar features such as enthesitis, sacroiliac joint, and axial involvement. Since juvenile onset of SpA (JSpA) is not well codified by the current juvenile idiopathic arthritis classification, studies in this field are restricted to single categories and therefore cannot be exhaustive. This review aims to report recent advances in the treatment of JSpA.

AREAS COVERED

In order to assess the available therapies for JSpA, the authors have analyzed data obtained from retrospective and prospective studies, case reports, and case series, as well as from controlled trials.

EXPERT OPINION

Given the challenging classification of JSpA, research in this field has been restricted to single subcategories. Little is known of which patients are more likely to develop axial involvement leading to severe spinal damage. Whether TNF inhibitors are capable to prevent or stop disease progression, once started, is yet to be ascertained with structural damage still a matter for research. Therefore, trials on the efficacy of TNF inhibitors in JSpA are strongly advocated since they may help to elucidate their place as a treatment option.

Enthesitis-related arthritis is the most common category of juvenile idiopathic arthritis in Taiwan and presents persistent active disease

BACKGROUND

Juvenile idiopathic arthritis (JIA) has been categorized into seven different categories according to the International League of Associations for Rheumatology (ILAR) criteria. Enthesitis-related arthritis (ERA) was found to represent the largest category in a Taiwanese cohort study. The aim in this study was to compare the clinical characteristics, treatments, and outcomes of ERA in a single tertiary center in Taiwan, as compared to those of other categories of JIA. Furthermore, we determined patients' characteristics and risk factors that can help assess the outcomes in ERA.

METHODS

A retrospective chart review of all patients with JIA referred to a pediatric rheumatology clinic in the National Taiwan University Hospital between 1993 and 2018 were identified according to ILAR criteria. Outcomes were assessed based on the Wallace criteria to categorize patients into active and non-active, including inactive, remission on medication, and remission off medication, groups. A subset of samples was further tested by DNA sequencing to identify HLA-B27 subtypes.

RESULTS

One-hundred and eighty-three patients were included in the study, with a mean of 8 years' follow-up. ERA was the single largest category of JIA (39.9%); psoriasis and undifferentiated JIA were both the least common type (0.5%). ERA was male predominant (86%), had a late age of onset (11.0 ± 3.2 years), and the majority of ERA patients was HLA-B27-positive (97%). Of 25 HLA-B27-positive ERA patients checked by HLA-B27 sequencing, 23 were B*27:04 and 2 were B*27:05. ERA patients were significantly less likely to achieve non-active status compared to patients with persistent oligoarthritis (P = 0.036). In terms of treatment response to TNF-α inhibitors in methotrexate-refractory ERA, 26 patients remained active and only 11 patients (30%) achieved a non-active status. Sacroiliitis was a risk factor contributing to poorer treatment response in ERA (P = 0.006).

CONCLUSION

ERA represented the most common category of JIA in Taiwan. Those ERA patients with sacroiliitis were likely to have persistent active disease and may require a more aggressive treatment strategy to improve their outcomes.

Etanercept treatment for extended oligoarticular juvenile idiopathic arthritis, enthesitis-related arthritis, or psoriatic arthritis: 6-year efficacy and safety data from an open-label trial

BACKGROUND

To describe the 6-year safety and efficacy of etanercept (ETN) in children with extended oligoarticular juvenile idiopathic arthritis (eoJIA), enthesitis-related arthritis (ERA), and psoriatic arthritis (PsA) METHODS: Patients who completed the 2-year, open-label, phase III CLinical Study In Pediatric Patients of Etanercept for Treatment of ERA, PsA, and Extended Oligoarthritis (CLIPPER) were allowed to enroll in its 8-year long-term extension (CLIPPER2). Children received ETN at a once-weekly dose of 0.8 mg/kg, up to a maximum dose of 50 mg/week. Efficacy assessments included the JIA core set of outcomes, the JIA American College of Rheumatology response criteria (JIA-ACR), and the Juvenile Arthritis Disease Activity Score (JADAS). Efficacy data are reported as responder analyses using a hybrid method for missing data imputation and as observed cases. Safety assessments included treatment-emergent adverse events (TEAEs).

RESULTS

Out of 127 patients originally enrolled in CLIPPER, 109 (86%) entered CLIPPER2. After 6 years of trial participation (2 years in CLIPPER and 4 years in CLIPPER2), 41 (32%) patients were still taking ETN, 13 (11%) entered the treatment withdrawal phase after achieving low/inactive disease (of whom 7 had to restart ETN), 36 (28%) discontinued treatment for other reasons but are still being observed, and 37 (29%) discontinued treatment permanently. According to the hybrid imputation analysis, proportions of patients achieving JIA ACR90, JIA ACR100, and JADAS inactive disease after the initial 2 years of treatment were 58%, 48%, and 32%, respectively. After the additional 4 years, those proportions in patients who remained in the trial were 46%, 35%, and 24%. Most frequently reported TEAEs [n (%), events per 100 patient-years] were headache [28 (22%), 5.3], arthralgia [24 (19%), 4.6], and pyrexia [20 (16%), 3.8]. Number and frequency of TEAEs, excluding infections and injection site reactions, decreased over the 6-year period from 193 and 173.8, respectively, during year 1 to 37 and 61.3 during year 6. A single case of malignancy (Hodgkin's lymphoma) and no cases of active tuberculosis, demyelinating disorders, or deaths were reported.

CONCLUSIONS

Open-label etanercept treatment for up to 6 years was safe, well tolerated, and effective in patients with eoJIA, ERA, and PsA.

TRIAL REGISTRATION

ClinicalTrials.gov: CLIPPER, NCT00962741 , registered 20 August, 2009, CLIPPER2, NCT01421069 , registered 22 August, 2011.

Evaluation of factors affecting the duration of disease-modifying anti-rheumatic drugs application in patients with enthesitis-related arthritis

OBJECTIVE

Treatments for enthesitis-related arthritis (ERA) consist of a mono- or combination therapy with non-steroidal anti-inflammatory drugs, disease-modifying anti-rheumatic drugs (DMARDs), and biological agents, and they are primarily based on adult studies and studies on other forms of juvenile idiopathic arthritis, depending on whether there is axial or peripheral involvement. We use DMARDs frequently in our daily practice, even in patients with axial involvement. The main reason for this is that the health insurance system in Turkey does not allow the use of Tumor Negrosis Factor (TNF) blockers as the first line of treatment. The aim of this study is to evaluate the factors affecting the duration of DMARDs application in patients with ERA.

METHODS

Fifty-two patients with ERA were accepted in this retrospective cohort study. These patients did not have an inflammatory bowel disease, reactive arthritis or undifferentiated arthritis, psoriasis, and familial Mediterranean fever. Demographic characteristics, medical history, the initial and follow-up physical examination, initial Juvenile Spondyloarthritis Disease Activity Index (JSpADA), initial laboratory tests, radiographic tests, Juvenile Arthritis Damage Index-articulary (JADI-A) and extra-articulary (JADI-E) on the last admission, and data on medical treatments were recorded from the registered data. The univariate Cox proportional hazards regression analyses was used to determine factors affecting the non-response time of ERA patients to DMARDs before the biological treatment was started.

RESULTS

Twenty-seven patients (52%) achieved remission with DMARDs, while 25 (48%) patients did not. The age at diagnosis (HR=1.12; p=0.247); gender (HR=2.53; p=0.210); family history of ankylosing spondylitis (HR=1.17; p=0.730); inflammatory back pain (HR=0.57; p=0.175); the shoulder (HR=0.75 p=0.706), hip (HR=0.45; p=0.129), and small-joint involvement (HR=1.53; p=0.439); sacroiliitis with physical examination (HR=0.90; p=0.814) and magnetic resonance imaging (MRI) (HR=2.84; p=0.110); enthesitis (HR=0.83; p=0.670); presence of uveitis (HR=2.04; p=0.342); presence of HLA-B27 (HR=1.39; p=0.524); initial high acute phase reactants levels(HR=1.89; p=0.183); initial JSpADA score (HR=0.98; p=0.944); and last JADI-A (HR=1.41; p=0.060) score did not affect the duration of DMARDs treatment before switching to biological treatments.

CONCLUSION

In our study, the absence of factors affecting the duration of DMARDs application in patients with ERA showed that DMARDs may still be applied as the first line of treatment.

Enthesitis-related arthritis: current perspectives

In this narrative review, we overview the recent literature on enthesitis-related arthritis (ERA). For the purpose of our review, we searched Scopus for recent articles on this subject from 2013 onward, including some classic older articles for perspective. ERA is a juvenile idiopathic arthritis (JIA) subtype more common in males, associated in a majority with human leucocyte antigen B27. Such children generally present with asymmetric oligoarthritis or polyarthritis, predominantly of lower limb joints, associated with enthesitis or sacroiliitis. While diagnosis remains clinical, ultrasound is being increasingly used to detect subclinical enthesitis and for guiding entheseal site injections. Spine MRI can help detect sacroiliitis, inflammatory spinal changes, and pelvic sites of enthesitis in such patients. The recent juvenile spondyloarthropathy disease activity index recognizes the key clinical features of ERA, viz enthesitis and inflammatory back pain, which other disease activity indices used in JIA did not include. Management includes NSAIDs with physical therapy. Conventional disease-modifying agents like sulfasalazine and methotrexate may be used to minimize duration of NSAID use and in those with high inflammatory burden. In patients refractory to these drugs, biologics such as antitumor necrosis factor alpha agents have proven useful, based on evidences from randomized controlled trials and retrospective registry analyses. Factors predicting a poorer outcome in such children include hip or ankle involvement or restricted spinal mobility. Considering that children with ERA have overall poorer long-term outcomes than other subtypes of JIA, there is a need to further optimize therapeutic strategies for such patients.

Methotrexate in juvenile idiopathic arthritis: advice and recommendations from the MARAJIA expert consensus meeting

BACKGROUND

Conventional pharmacological therapies for the treatment of juvenile idiopathic arthritis (JIA) consist of non-biological, disease-modifying antirheumatic drugs, among which methotrexate (MTX) is the most commonly prescribed. However, there is a lack of consensus-based clinical and therapeutic recommendations for the use of MTX in the management of patients with JIA. Therefore, the Methotrexate Advice and RecommendAtions on Juvenile Idiopathic Arthritis (MARAJIA) Expert Meeting was convened to develop evidence-based recommendations for the use of MTX in the treatment of JIA.

METHODS

The preliminary executive committee identified a total of 9 key clinical issues according to the population, intervention, comparator, outcome (PICO) approach, and performed an evidence-based, systematic, literature review. During the subsequent Expert Meeting, the relevant evidence was assessed and graded, and 10 recommendations were made.

RESULTS

Recommendations relating to the efficacy, optimal dosing and route of administration and duration of treatment with MTX in JIA, and to the issue of folic acid supplementation to prevent MTX side effects, use of MTX in the treatment of chronic JIA-associated uveitis, combination treatment with biologic agents, and the use of vaccinations in patients with JIA were developed. The selected topics were considered to represent clinically important issues facing clinicians caring for patients with JIA. Evidence was insufficient to formulate recommendations for the use of biomarkers predictive of treatment response.

CONCLUSIONS

These consensus recommendations provide balanced and evidence-based recommendations designed to have broad value for physicians and healthcare clinicians involved in the clinical management of patients with JIA.

Magnetic resonance imaging of sacroiliitis in children: frequency of findings and interobserver reliability

BACKGROUND

Clinicians increasingly rely on imaging in juvenile idiopathic arthritis (JIA) to identify sacroiliitis and guide treatment. However, there is limited evidence about magnetic resonance imaging (MRI) for sacroiliitis in children, and interobserver reliability is variable.

OBJECTIVE

Identify the frequency of MRI findings in children with suspected sacroiliitis, calculate inter-reporter reliability and assess the value of diffusion-weighted imaging and contrast-enhanced sequences.

MATERIALS AND METHODS

We retrospectively reviewed 3 years of sacroiliac joint MRI records for suspected sacroiliitis in patients <21 years at a United Kingdom tertiary referral paediatric hospital. Five radiologists (panel of three radiologists and two independent radiologists) reviewed all MRI examinations using a pictorial checklist to identify oedema, effusions, diffusion-weighted signal abnormality, enhancement, erosions and sclerosis. The frequency of panel findings was reported. Interobserver agreement was calculated using the Cohen kappa coefficient.

RESULTS

An MRI diagnosis of sacroiliitis was made in 12 of 99 examinations (12%). The findings in all scans included oedema (9%), erosions (8%), diffusion-weighted signal abnormality (6%), abnormal enhancement (6%) and effusion (4%). All scans with abnormal contrast enhancement had other MRI features of sacroiliitis. Interobserver agreement was slight to moderate.

CONCLUSION

Oedema and erosions were the most common findings. Inter-reporter reliability was variable with at best moderate agreement for the presence of sacroiliitis and erosions. The use of contrast enhancement for diagnosing sacroiliitis in children with JIA may be questionable.

Comparative Effectiveness of Tumor Necrosis Factor Agents and Disease-modifying Antirheumatic Therapy in Children with Enthesitis-related Arthritis: The First Year after Diagnosis

OBJECTIVE

To characterize the effect of anti-tumor necrosis factor (TNF) therapy compared to conventional synthetic disease-modifying antirheumatic drugs (csDMARD) in children with enthesitis-related arthritis (ERA) over the first year after diagnosis.

METHODS

We conducted a multicenter retrospective comparative effectiveness study of children diagnosed with ERA. We estimated the effect of anti-TNF therapy on clinical variables (active joint count, tender entheses count) and patient-reported pain and global assessment of disease activity over the first year after diagnosis using state-of-the-art comparative effectiveness analytic methods.

RESULTS

During the study period, 217 patients newly diagnosed with ERA had a total of 965 clinic visits the first year after disease diagnosis. Children [median age 11.6 yrs, interquartile range 10-14] were treated with anti-TNF monotherapy (n = 33, 15.2%), csDMARD monotherapy (n = 73, 33.6%), or both (n = 52, 23.9%) in the first year after disease diagnosis. There was a statistically significant improvement in the primary outcome, active joint count, over time in children who received an anti-TNF drug versus those who did not (p = 0.03). Additionally, use of anti-TNF therapy versus no anti-TNF therapy was associated with less patient-reported pain (p < 0.01) and improved disease activity over time as assessed by the clinical Juvenile Arthritis Disease Activity Score (p < 0.01). The magnitude of estimated effect on clinical outcomes was uniformly greater, with the exception of tender entheses count, in children treated with an anti-TNF drug versus a csDMARD.

CONCLUSION

During the first year after diagnosis, anti-TNF exposure was associated with benefits for several clinically meaningful outcomes in children with enthesitis-related arthritis.

Update on enthesitis-related arthritis

PURPOSE OF REVIEW

This review provides a detailed update regarding the genetics, pathogenesis, disease phenotype evaluation, therapies and expected outcomes for children with enthesitis-related arthritis (ERA).

RECENT FINDINGS

Recent studies evaluated human leukocyte antigen (HLA)-B27 subtypes and non-major histocompatibility complex genes including toll like receptor 4, NLRP3, CXCR4 and PTPN12 in children with ERA. The microbiome and γδ-T cells have also been an area of active investigation. Several studies focus on the imaging phenotype of children with ERA, including the use of ultrasonography and MRI. MRI techniques studied in this population include dedicated MRI, whole-body MRI and diffusion-weighted imaging. Conventional and biologic disease-modifying agents continue to be the mainstay of therapy, though the past 2 years have witnessed several greatly needed randomized controlled trials to study the efficacy of these medications in ERA. Finally, long-term effectiveness studies of biologics in children with ERA have helped inform provider and patient expectations of disease response and prognosis.

SUMMARY

Further evaluation of the role of the microbiome and the interleukin 17/interleukin 23 axis, techniques to optimize evaluation of disease features, and efficacy and effectiveness of newer medications are greatly needed in this understudied population of children.

Management of Juvenile Idiopathic Arthritis: A Clinical Guide

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease of childhood. The outcome in patients with JIA has markedly improved with the advent of biologic drugs. Although early aggressive therapy with biologics seems to be very effective, this approach leads to overtreatment in patients who would respond to classic disease-modifying anti-rheumatic drugs. Therefore, methotrexate remains first-line long-term therapy for most children with polyarticular JIA. Tumor necrosis factor-α inhibitors have shown tremendous benefit in children with refractory non-systemic JIA. Similar effects have been observed with interleukin-1 and interleukin-6 blockade in patients with systemic JIA. Correct choice and timely use of available medications to achieve early and sustained remission with as few side effects as possible remain challenges for the treating physician. In this review, a practical, clinically oriented guide to the management of JIA is provided, focusing on pharmacological treatment with non-steroidal anti-inflammatory drugs, intra-articular and systemic corticosteroids, disease-modifying anti-rheumatic drugs, and biologic agents. In addition, issues regarding treatment failure, early aggressive treatment, and drug tapering are discussed, with alternative treatment options being suggested.

Inactive Disease in Enthesitis-related Arthritis: Association of Increased Body Mass Index

OBJECTIVE

Patients with enthesitis-related arthritis (ERA) were less likely to achieve and sustain inactive disease than children with other subtypes of juvenile idiopathic arthritis. The aim of this study was to evaluate the effect of increased body mass index (BMI) on clinical features of the disease and to investigate whether being overweight or obese limits the possibility of achieving clinically inactive disease in patients with ERA.

METHODS

The hospital charts of 72 patients with ERA were reviewed. Demographic and clinical findings were recorded. Patients were divided into 2 groups according to whether they had "healthy weight" (BMI < 85th percentile) or "increased weight" (BMI ≥ 85th percentile) at baseline. The primary outcome of this study was to achieve inactive disease at 1 year after the initiation of therapy. The inactive disease criterion of Wallace, et al was used to define inactive disease status.

RESULTS

Twenty patients had increased BMI. The frequency of tarsitis and ankle involvement was higher in patients with increased weight. Thirty-seven patients were inactive at the end of 1 year. In univariate analyses, male sex, increased BMI, ankle involvement, and tarsitis were found to be associated with failure to achieve inactive disease. Multivariate backward stepwise regression analyses revealed that failure to achieve clinically inactive disease was associated with increased BMI and ankle involvement.

CONCLUSION

Being overweight or obese was associated with failure to achieve inactive disease in patients with ERA. Because body weight is a modifiable factor, individualized interventions may have clinical implications for better therapeutic outcome.

Biologic agents in juvenile spondyloarthropathies

The juvenile spondyloarthropathies (JSpA) are a group of related rheumatic diseases characterized by involvement of peripheral large joints, axial joints, and entheses (enthesitis) that begin in the early years of life (prior to 16(th) birthday).The nomenclature and concept of spondyloarthropathies has changed during the last few decades. Although there is not any specific classification of JSpA, diseases under the spondyloarthropathy nomenclature umbrella in the younger patients include: the seronegative enthesitis and arthropathy (SEA) syndrome, juvenile ankylosing spondylitis, reactive arthritis, and inflammatory bowel disease-associated arthritis. Moreover, the ILAR criteria for Juvenile Idiopathic Arthritis includes two categories closely related to spondyloarthritis: Enthesitis-related arthritis and psoriatic arthritis.We review the pathophysiology and the use of biological agents in JSpA. JSpA are idiopathic inflammatory diseases driven by an altered balance in the proinflammatory cytokines. There is ample evidence on the role of tumor necrosis factor (TNF) and interleukin-17 in the physiopathology of these entities. Several non-biologic and biologic agents have been used with conflicting results in the treatment of these complex diseases. The efficacy and safety of anti-TNF agents, such as etanercept, infliximab and adalimumab, have been analysed in controlled and uncontrolled trials, usually showing satisfactory outcomes. Other biologic agents, such as abatacept, tocilizumab and rituximab, have been insufficiently studied and their role in the therapy of SpA is uncertain. Interleukin-17-blocking agents are promising alternatives for the treatment of JSpA patients in the near future. Recommendations for the treatment of patients with JSpA have recently been proposed and are discussed in the present review.

Two-year Efficacy and Safety of Etanercept in Pediatric Patients with Extended Oligoarthritis, Enthesitis-related Arthritis, or Psoriatic Arthritis

Objective.

The main objective was to determine the 2-year clinical benefit and safety of etanercept (ETN) in children with the juvenile idiopathic arthritis (JIA) categories of extended oligoarthritis (eoJIA), enthesitis-related arthritis (ERA), or psoriatic arthritis (PsA).

Methods.

CLIPPER was a 96-week, phase IIIb, open-label, multicenter study. Patients with eoJIA, ERA, or PsA received ETN 0.8 mg/kg once weekly (50 mg max) for up to 96 weeks. The proportions of patients reaching the JIA American College of Rheumatology (ACR) 30/50/70/90/100 and inactive disease responses at Week 96 were calculated. Adverse events (AE) were collected throughout the study (intention-to-treat sample).

Results.

There were 127 patients (eoJIA n = 60, ERA n = 38, PsA n = 29) who received ≥ 1 dose of ETN. The mean disease duration was 31.6 (eoJIA), 23.0 (ERA), and 21.8 (PsA) months. At Week 96, JIA ACR 30/50/70/90/100/inactive disease responses (95% CI) were achieved by 84.3% (76.7, 90.1), 83.5% (75.8, 89.5), 78.7% (70.6, 85.5), 55.1% (46.0, 63.9), 45.7% (36.8, 54.7), and 27.6% (20.0, 36.2) of patients, respectively. The most common AE (no. events, events per 100 patient-yrs) overall were headache (23, 10.7), pyrexia (12, 5.6), and diarrhea (10, 4.6). The most common infections were upper respiratory tract infection (83, 38.6), pharyngitis (50, 23.2), gastroenteritis (22, 10.2), bronchitis (19, 8.8), and rhinitis (17, 7.9). No cases of malignancy, active tuberculosis, demyelinating disorders, or death were reported.

Conclusion.

Over 96 weeks of therapy, ETN demonstrated sustained efficacy at treating the clinical symptoms of all 3 JIA categories, with no major safety issues.

Juvenile spondyloarthritis

PURPOSE OF REVIEW

This article provides a comprehensive update of the pathogenesis, diagnostic imaging, treatments, and disease activity measurements of juvenile spondyloarthritis (JSpA).

RECENT FINDINGS

Genetic and microbiome studies have provided new information regarding possible pathogenesis of JSpA. Recent work suggests that children with JSpA have decreased thresholds for pain in comparison to healthy children. In addition, pain on physical examination and abnormalities on ultrasound of the entheses are not well correlated. Treatment guidelines for juvenile arthritis, including JSpA, were published by the American College of Rheumatology and are based on active joint count and presence of sacroiliitis. Recent studies have established the efficacy of tumor necrosis factor inhibitors in the symptomatic treatment of axial disease, although their efficacy for halting progression of structural damage is less clear. Newly developed disease activity measures for JSpA include the Juvenile Arthritis Disease Activity Score and the JSpA disease activity index. In comparison to other categories of juvenile arthritis, children with JSpA are less likely to attain and sustain inactive disease.

SUMMARY

Further microbiome and genetic research may help elucidate JSpA pathogenesis. More randomized therapeutic trials are needed and the advent of new composite disease activity measurement tools will hopefully allow the design of these greatly needed trials.

A Randomized, Double-Blind, Placebo-Controlled Multicenter Study of Adalimumab in Pediatric Patients With Enthesitis-Related Arthritis

Objective

Enthesitis‐related arthritis (ERA) is a juvenile idiopathic arthritis (JIA) category, primarily affecting entheses and peripheral joints. This study evaluated efficacy, safety, and pharmacokinetics of adalimumab versus placebo in patients with ERA.

Methods

This is a phase III, multicenter, randomized double‐blind study in patients ages ≥6 to <18 years with ERA treated with adalimumab (24 mg/m², maximum dose 40 mg every other week) or placebo for 12 weeks, followed by up to 192 weeks of open‐label adalimumab. The primary end point was percent change from baseline in number of active joints with arthritis (AJC) at week 12. Samples were collected to determine adalimumab serum concentrations. Adverse events (AEs) were assessed throughout the study.

Results

Forty‐six patients were randomized (31 adalimumab/15 placebo). At baseline, mean age was 12.9 years, mean duration of ERA symptoms was 2.6 years, mean AJC was 7.8, and mean enthesitis count was 8.1. Mean percent change from baseline in AJC at week 12 was greater in the adalimumab group versus placebo (−62.6% versus −11.6%; P = 0.039). Most secondary variables favored adalimumab versus placebo at week 12. Treatment response further increased with continued adalimumab therapy through week 52. Mean steady‐state adalimumab serum concentrations were 7.5–11.8 μg/ml, similar to patients age ≥2 years with polyarticular JIA. AE rates were similar between placebo and adalimumab: any AE (53.3% versus 67.7%), serious AEs (0% versus 3.2%), and infectious AEs (20.0% versus 29.0%).

Conclusion

Adalimumab reduced signs and symptoms of ERA at week 12, with improvement sustained through week 52. The safety profile was consistent with previous adalimumab studies.

Efficacy and safety of etanercept in patients with the enthesitis-related arthritis category of juvenile idiopathic arthritis: results from a phase III randomized, double-blind study

OBJECTIVE

To evaluate the efficacy and safety of etanercept in patients with enthesitis-related arthritis (ERA) in juvenile idiopathic arthritis (JIA).

METHODS

This was a 2-phase study in JIA patients with active, refractory ERA. Phase I was an open-label, uncontrolled 24-week study period in which all patients were administered etanercept. Patients considered to be treatment responders at week 24 according to the American College of Rheumatology (ACR) Pediatric 30 (Pedi 30) criteria for improvement in juvenile arthritis entered the second phase, a 24-week randomized, double-blind, placebo-controlled withdrawal study, for an additional 24 weeks, for evaluation of the primary end point, occurrence of a disease flare from week 24 to week 48, based on the ACR preliminary definition of disease flare in juvenile arthritis.

RESULTS

Forty-one patients were enrolled. At week 24, treatment with etanercept resulted in response rates of 93%, 93%, 80%, 56%, and 54% based on the ACR Pedi 30, Pedi 50, Pedi 70, Pedi 90, and Pedi 100 criteria, respectively. In addition, a marked decrease in all disease activity measures was observed. The mean number of tender joints, swollen joints, and joints with active arthritis decreased by 91%, 97%, and 94%, respectively. Physician's global assessment of disease activity, parent's assessment of patient's overall well-being, and the Childhood Health Assessment Questionnaire disability index improved by 91%, 80%, and 86%, respectively. The number of tender enthesis sites and total scores for back pain, nocturnal pain, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, and Juvenile Arthritis Disease Activity Score based on 10-joint counts (JADAS10) decreased by 75%, 72%, 81%, 72%, 85%, and 87%, respectively. In phase II, 38 patients were randomly assigned to receive placebo (n = 18) or to continue receiving etanercept (n = 20). Up to week 48, 12 disease flares occurred, in 9 patients receiving placebo and 3 patients receiving etanercept (odds ratio 6.0, P = 0.02). There were no serious infections, malignancies, or deaths.

CONCLUSION

In this study of patients with the ERA category of JIA, etanercept proved effective, as indicated by high ACR Pedi response rates and JADAS10 response rates at week 24. Patients who continued treatment with etanercept had significantly fewer flares than those who received placebo, although 50% of patients in the placebo group did not experience a flare. Treatment suspension may be a consideration for patients with the ERA category of JIA who achieve remission.

Patient-reported Outcomes across Categories of Juvenile Idiopathic Arthritis

OBJECTIVE

Although there is increasing reliance on patient-reported outcomes (PRO) for disease management, there is little known about the differences in PRO across juvenile idiopathic arthritis (JIA) categories. The purpose of our study was to assess PRO across JIA categories, including pain, quality of life, and physical function, and to determine clinical factors associated with differences in these measures across categories.

METHODS

This was a longitudinal cohort study of patients with JIA at a tertiary care pediatric rheumatology clinic. Subjects, PRO, and clinical variables were identified by querying the electronic medical record. Mixed-effects regression assessed pain, quality of life, and function.

RESULTS

Subjects with enthesitis-related arthritis (ERA) and undifferentiated JIA had significantly more pain, poorer quality of life, and poorer physical function. The ERA and undifferentiated JIA categories, physician's global disease activity assessment, female sex, and nonsteroidal antiinflammatory drug use were significantly associated with more pain, poorer quality of life, and poorer function. In models limited to ERA, female sex and tender enthesis count were significant predictors of decreased function.

CONCLUSION

ERA and undifferentiated JIA categories had poorer PRO than other JIA categories. Further work is needed to address ways to improve PRO in children with JIA, with a special focus on children with ERA and undifferentiated JIA.

Enthesitis-related arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic arthritis of childhood. Currently, it is characterized by seven categories. The enthesitis-related arthritis (ERA) category usually affects boys older than 6 years and presents with lower limb asymmetrical arthritis associated with enthesitis. Later, these children can develop inflammatory lumbosacral pain (IBP). These children are at risk of developing acute anterior uveitis. A recently devised disease activity index, Juvenile Spondyloarthropathy Disease Activity Index (JSpADA), has been validated in retrospective cohorts. The corner stone of treatment is NSAIDs, local corticosteroid injections, and exercise. Methotrexate and sulfasalazine can be used for peripheral arthritis while anti-tumor necrosis factor (TNF) agents are sometimes used to treat refractory enthesitis and sacroiliitis. Almost two third of patients with ERA have persistent disease and often have impairments in their quality of life. The presence of hip or ankle arthritis and a family history of spondyloarthropathy or polyarticular joint involvement at onset are associated with poorer prognosis.

Judicious use of biologicals in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disorder that may cause joint destruction. Biological treatments targeting specific cytokines and cell interactions have transformed the outcomes of JIA. This review focuses on the selection of patients for and the timing and selection of biological treatment in JIA. Tumor necrosis factor (TNF) inhibitors remain the first choice for polyarticular JIA, followed by abatacept and tocilizumab. Monoclonal-antibody TNF inhibitors and abatacept are usually chosen for methotrexate-resistant uveitis. Recent clinical trials of canakinumab, rilonacept, and tocilizumab have obtained great improvement in both systemic and arthritic features in chronic systemic JIA patients. Current guidelines support the early use of a short-acting IL-1 antagonist for macrophage activation syndrome, a life-threatening complication. TREAT and ACUTE studies suggest that a therapeutic window of opportunity during early disease may exist in JIA. Early initiation of biological therapy may be associated with slower progression of joint damage and longer remission.

2014 Update of the Canadian Rheumatology Association/Spondyloarthritis Research Consortium of Canada Treatment Recommendations for the Management of Spondyloarthritis. Part II: Specific Management Recommendations

Objective.

The Canadian Rheumatology Association (CRA) and the Spondyloarthritis Research Consortium of Canada (SPARCC) have collaborated to update the recommendations for the management of spondyloarthritis (SpA).

Methods.

A working group was assembled and consisted of the SPARCC executive committee, rheumatologist leaders from SPARCC collaborating sites, Canadian rheumatologists from across the country with an interest in SpA (both academic and community), a rheumatology trainee with an interest in SpA, an epidemiologist/health services researcher, a member of the CRA executive, a member of the CRA therapeutics committee, and a patient representative from the Canadian Spondylitis Association. An extensive review was conducted of literature published from 2007 to 2014 involving the management of SpA. The working group created draft recommendations using multiple rounds of Web-based surveys and an in-person conference.

Results.

Recommendations for the management of SpA were created. Part II: Specific Management Recommendations addresses management with nonpharmacologic methods, nonsteroidal anti-inflammatories and analgesics, disease-modifying antirheumatic drugs, antibiotics, tumor necrosis factor inhibitors, other biologic agents, and surgery. Also included are 10 modifications for application to juvenile SpA.

Conclusion.

These recommendations were developed based on current literature and applied to a Canadian healthcare context. It is hoped that implementation of these recommendations will promote best practices in the treatment of SpA.

Development and retrospective validation of the juvenile spondyloarthritis disease activity index

OBJECTIVE

To develop and validate the Juvenile Spondyloarthritis Disease Activity Index (JSpADA) for use in clinical practice and research.

METHODS

Using modified Delphi consensus techniques, 10 items were selected by participants in the international pediatric rheumatology listserv, the Childhood Arthritis and Rheumatology Research Alliance, and the listserv for the pediatric section of the American College of Rheumatology. Validation was performed in a retrospective multicenter cohort of 244 children.

RESULTS

In total, 106 physicians representing 14 countries completed the initial questionnaire. Completion rates for the subsequent questionnaires were 84%, 75%, and 77% of the original respondents. Ten items exceeded 80% consensus: arthritis, enthesitis, patient pain assessment, inflammatory markers, morning stiffness, clinical sacroiliitis, uveitis, back mobility, and patient and physician assessments of disease activity. After item analysis, 2 items were eliminated (patient and physician assessments of disease activity). Factor analysis identified 3 primary domains that explained 58% of the variance: peripheral disease, axial disease, and uveitis. The Cronbach's α coefficient was 0.66. The JSpADA had high or moderate correlations with the Juvenile Arthritis Disease Activity Score (r = 0.81), patient and physician assessments of disease activity (r = 0.70 and r = 0.66, respectively), and the Childhood Health Assessment Questionnaire (r = 0.56). The JSpADA discriminated well between subjects with active versus inactive disease (P < 0.001) and was responsive to improvement or worsening in disease activity over time (P < 0.001).

CONCLUSION

Using international input and consensus formation techniques, we developed and validated the first disease activity assessment for juvenile spondyloarthritis. Future studies should validate the JSpADA in a prospective multicenter cohort.

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.

What does an adult rheumatologist need to know about juvenile idiopathic arthritis?

JIA is the most common chronic inflammatory arthritis in children and young people and an estimated one-third of individuals will have persistent active disease into adulthood. There are a number of key differences in the clinical manifestations, assessment and management of JIA compared with adult-onset arthritis. Transition and transfer to adult services present significant challenges for many patients, their families and health care professionals. We describe key clinical issues relevant to adult rheumatology health care teams responsible for ongoing care of these young people.

Update on juvenile spondyloarthritis

Spondyloarthritis (SpA) encompasses a group of disorders linked by overlapping clinical manifestations and genetic predisposition. Newer classification systems developed for adults with SpA focus on identifying individuals with axial or predominantly peripheral involvement. All forms of SpA can begin during childhood, and can be considered on a continuum with adult disease. Nevertheless, there are important differences in presentation and outcome that depend on age at onset. This article highlights these differences, what has been learned about genetics and pathogenesis of SpA, and important unmet needs for future studies.

Efficacy and safety of open-label etanercept on extended oligoarticular juvenile idiopathic arthritis, enthesitis-related arthritis and psoriatic arthritis: part 1 (week 12) of the CLIPPER study

OBJECTIVE

To investigate the efficacy and safety of etanercept (ETN) in paediatric subjects with extended oligoarticular juvenile idiopathic arthritis (eoJIA), enthesitis-related arthritis (ERA), or psoriatic arthritis (PsA).

METHODS

CLIPPER is an ongoing, Phase 3b, open-label, multicentre study; the 12-week (Part 1) data are reported here. Subjects with eoJIA (2-17 years), ERA (12-17 years), or PsA (12-17 years) received ETN 0.8 mg/kg once weekly (maximum 50 mg). Primary endpoint was the percentage of subjects achieving JIA American College of Rheumatology (ACR) 30 criteria at week 12; secondary outcomes included JIA ACR 50/70/90 and inactive disease.

RESULTS

122/127 (96.1%) subjects completed the study (mean age 11.7 years). JIA ACR 30 (95% CI) was achieved by 88.6% (81.6% to 93.6%) of subjects overall; 89.7% (78.8% to 96.1%) with eoJIA, 83.3% (67.2% to 93.6%) with ERA and 93.1% (77.2% to 99.2%) with PsA. For eoJIA, ERA, or PsA categories, the ORs of ETN vs the historical placebo data were 26.2, 15.1 and 40.7, respectively. Overall JIA ACR 50, 70, 90 and inactive disease were achieved by 81.1, 61.5, 29.8 and 12.1%, respectively. Treatment-emergent adverse events (AEs), infections, and serious AEs, were reported in 45 (35.4%), 58 (45.7%), and 4 (3.1%), subjects, respectively. Serious AEs were one case each of abdominal pain, bronchopneumonia, gastroenteritis and pyelocystitis. One subject reported herpes zoster and another varicella. No differences in safety were observed across the JIA categories.

CONCLUSIONS

ETN treatment for 12 weeks was effective and well tolerated in paediatric subjects with eoJIA, ERA and PsA, with no unexpected safety findings.

HLA-B27 predicts a more chronic disease course in an 8-year followup cohort of patients with juvenile idiopathic arthritis

OBJECTIVE

We investigated associations of HLA-B27 with clinical manifestations and longterm outcome in a near population-based setting among patients with juvenile idiopathic arthritis (JIA).

METHODS

We studied clinical and serological data from 410 patients with HLA-B27 results among 440 prospectively collected patients with JIA with 8-year followup data in a Nordic database. The study was structured to be as close to a population-based study as possible.

RESULTS

HLA-B27 was analyzed in 93% of patients, and was positive in 21% of the cohort, in 18.4% of the girls and in 25.9% of the boys. Boys who were HLA-B27-positive had significantly higher age at onset compared to HLA-B27-negative boys and compared to both HLA-B27-negative and positive girls. This difference in onset age in relation to HLA-B27 was not found in girls. HLA-B27 was associated with clinical signs of sacroiliitis, enthesitis, and tenosynovitis in boys, but not in girls. After 8 years of disease, 46 children (11.2%) were classified as having enthesitis-related arthritis (ERA). Boys with ERA had clinical signs of sacroiliitis more often than girls with ERA. HLA-B27-positive children, as well as children with clinical signs of sacroiliitis, enthesitis, and hip arthritis, had higher odds of not being in remission off medication after 8 years of disease.

CONCLUSION

In this near population-based Nordic JIA cohort we found significant differences between HLA-B27-positive boys and girls in age at disease onset, clinical signs of sacroiliitis, and ERA classification. HLA-B27 was negatively associated with longterm remission status, possibly because of its association with clinical disease characteristics, such as sacroiliitis, rather than being a general marker of persistent disease.

Juvenile spondyloarthropathies

Spondyloarthropathy (or spondyloarthritis) can begin in childhood (defined as individuals less than 16 years of age). These diseases are distinct in childhood, when compared with adult-onset disease. Because of overlapping features, especially sacroiliac joint involvement, diagnostic difficulty may arise from Behcet's disease, as well as familial Mediterranean fever. Despite advances in diagnostic techniques such as magnetic resonance imaging, the diagnosis of juvenile spondyloarthropathy may still be delayed many years from the onset of symptoms. Treatment of juvenile spondyloarthropathy has advanced rapidly in the last several years, with increasing evidence that agents targeting tumor necrosis factor are effective. These agents also have serious complications, including induction of other autoimmune diseases.

Diagnosis and treatment of enthesitis-related arthritis

Juvenile idiopathic arthritis (JIA) is a chronic, inflammatory disease of unknown etiology. The enthesitis-related arthritis (ERA) JIA category describes a clinically heterogeneous group of children including some who have predominately enthesitis, enthesitis and arthritis, juvenile ankylosing spondylitis, or inflammatory bowel disease-associated arthropathy. ERA accounts for 10%–20% of JIA. Common clinical manifestations of ERA include arthritis, enthesitis, and acute anterior uveitis. Axial disease is also common in children with established ERA. Treatment regimens for ERA, many of them based on adults with rheumatoid arthritis and ankylosing spondylitis, include the use of nonsteroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs, and biologic agents either individually or in combination.