Juvenile Spondyloarthropathies

Single cell RNA-sequencing identified CCR7+/RELB+/IRF1+ T cell responding for juvenile idiopathic arthritis pathogenesis

Background

To further explore the disease heterogeneity of different subtypes of Juvenile idiopathic arthritis (JIA) and analyze their pathogenesis mechanisms.

Method

The single-cell RNA sequencing (scRNA-seq) analysis of peripheral blood mononuclear cells (PBMCs) was carried out to investigate the disease heterogeneity and molecular mechanisms of immune responses in immune cells in JIA.

Result

In our study, we provided a immunological landscape of HLA-B27-positive JIA and HLA-B27-negative JIA immune cells at single cell RNA-Seq resolution. We found a higher proportion of CCR7+/RELB+/IRF1+ triple positive T cells in the peripheral blood of patients with JIA, and such T cells were predominantly present in HLA-B27+ JIA patients. Furthermore, we hypothesized that CCR7+/RELB+/IRF1+ triple positive T cells were highly activated T cells capable of promoting the differentiation of osteoclasts by producing IL-17, thus causing damage to cartilage in HLA-B27+ JIA patients. Unlike JIA patients, CCR7+/RELB+/IRF1+ triple positive T cells were not found in the peripheral blood of pSS patients and SLE patients, moreover, T cells from pSS patients and SLE patients were less able to produce IL-17 than those from JIA patients.

Conclusion

Our study provided evidence of cellular and molecular levels of involvement in JIA pathogenesis and identified the critical roles for T cells in JIA pathogenesis. Furthermore, our results suggested that there were significant differences in T cell composition and gene expression between HLA-B27+ JIA patients and HLA-B27- JIA patients. Our findings indicated that CCR7+/RELB+/IRF1+ positive T cells could damage the cartilage of HLA-B27+ JIA by producing cytokines such as IL-17.

Application of the new classification proposal for juvenile idiopathic arthritis of the pediatric rheumatology international trials organization in a group of Mexican patients

Objective

Apply the PRINTO classification proposal for diagnosing Juvenile Idiopathic Arthritis (JIA) to Mexican patients, analyzing demographic, clinical, and laboratory characteristics.

Material and methods

Cross-sectional study analyzing patients diagnosed with JIA using International League of Associations for Rheumatology (ILAR 2001) criteria over two years at a national rheumatic disease center. Reclassification was done using the Pediatric Rheumatology International Trials Organization (PRINTO) proposal. Comparisons were made between antinuclear antibodies (ANAs) positive vs. negative and rheumatoid factor (RF) positive vs. negative patients.

Results

Seventy-six patients were analyzed, mostly female. Median age was lower in systemic JIA (sJIA) and early onset JIA with positive ANAs (eoANA JIA). ANAs was present in 78.6% of patients. Reclassification according to PRINTO disorders showed RF positive polyarticular JIA, sJIA, and enthesitis-related JIA (ER JIA) reclassified to RF JIA, sJIA, and enthesitis/spondylitis-related JIA (ESR JIA) by 100%, 94.7%, and 80%, respectively. The ILAR category with the most variation was RF negative polyarticular JIA. Early disease onset was associated with a lower probability of positive RF after adjusting for sex, age, and ANAs. No association was found between ANAs positive vs. negative in adjusted multivariate analysis.

Conclusions

We found compatibility of sJIA, RF positive polyarticular JIA, and RE JIA categories with sJIA, RF JIA, and ESR JIA disorders, respectively. Differences were noted in variables such as sex and the number of affected joints. There was high ANAs positivity; however, few patients were classified into eoANA JIA disorder, with only one presenting uveitis. Most patients were classified as other JIA.

Profile of HLA-B27-positive enthesitis/spondylitis-related arthritis in Senegal, West Africa

BACKGROUND

Enthesitis/spondylitis-related arthritis (ERA) is a type of juvenile idiopathic arthritis (JIA) frequently associated with HLA-B27. In sub-Saharan Africa, HLA-B27-positive ERA hasn't been the subject of a specific study.

OBJECTIVES

We aimed to describe the clinical features, disease activity, functional disability and treatment of HLA-B27-positive ERA at diagnosis in Senegal and compare the findings to other populations.

METHODS

We conducted a retrospective study by reviewing the medical records of patients diagnosed with ERA with an age of symptom onset < 18 years according to the 2019 PRINTO provisional criteria for ERA from January 2012 to December 2022. We collected demographic, clinical, paraclinical and therapeutic data. Disease activity score was assessed by Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Functional disability was assessed using Bath Ankylosing Spondylitis Functional Index (BASFI).

RESULTS

A total of 31 patients with HLA-B27-positive ERA were included. Twenty of 31 (64.5%) were males. Twenty-seven (87%) were Fula (ethnicity). The median age at symptom onset and at diagnosis was 12 years and 19 years, respectively. Seven patients had a family history of Spondyloarthritis. Peripheral arthritis and enthesitis were the most common presenting features at disease onset. Peripheral arthritis was present in 29 (93.5%) and located in the lower limbs in 27/29 (93.1%) patients. Heel enthesitis was present in 26 (83.8%) patients. Axial involvement was present in 27 (87%) patients, dominated by low back pain and sacroiliac pain/ buttock pain in 24 (88.8%) and 22 (81.5%) patients, respectively. Seven (22.5%) patients had anterior uveitis. The ESR and CRP were elevated in 65.5% and 57.1% of cases, respectively. On imaging, sacroiliitis was found in 22 patients. The mean BASDAI was 5.5/10 (77.2% of patients had a high active disease; BASDAI ≥ 4/10). The mean ASDAS-ESR/CRP was 3.8. The mean BASFI was 5.4/10 (80% of patients had high functional disability; BASFI ≥ 4/10). Twenty-seven (87%) patients were treated with methotrexate and non-steroidal anti-inflammatory drugs. After 6 months of treatment, mean BASDAI was 3/10 and mean BASFI was 2.5/10.

CONCLUSION

In our study, HLA-B27-positive ERA was found in our Senegalese cohort mainly in adolescents of the Fula ethnic group. 22 (70.9%) patients developed ankylosing spondylitis at adulthood. The disease was very active at the time of diagnosis with significant functional disability. Treatment was mainly based on methotrexate and NAISDs.

Clinical examination and imaging resources in children and adolescent back pain

Back pain is a relatively common complaint in children and adolescents. The pediatric patient presenting with back pain can often be challenging, and there are many well-known organic diagnoses that should not be missed. In younger children, an organic cause of back pain can often be found. However, back pain in older children and adolescents is often "non-specific." The differential diagnosis of back pain in children includes neoplasms, developmental, and inflammatory conditions. Basic steps should include an in-depth anamnesis, a systematic physical examination, and standard spine radiographs (anteroposterior and lateral). Nevertheless, advanced diagnostic imaging and laboratory studies should be included when indicated to avoid missing or delaying a serious diagnosis. If other types of imaging tests are necessary (magnetic resonance imaging, computed tomography, bone scan, or single photon emission computed tomography), they should be guided by diagnostic suspicion.

Joint involvement, disease activity and quality of life in pediatric Crohn's disease - a cross-sectional study

BACKGROUND

Few published data describe how joint involvement, the most prevalent extraintestinal manifestation, affects quality of life (QoL) of children with Crohn's disease (CD). Arthritis and arthralgia rates in pediatric CD patients are reportedly 3-24% and 17-22%, respectively, but studies on pre-emptive and systematic screening of joint involvement with detailed musculoskeletal rheumatological exam are lacking. More detailed data collection on joint involvement improves our understanding of how arthropathy relates to disease activity and QoL measured by the Pediatric CD Activity Index (PCDAI) and IMPACT-III questionnaire. Our study aims were to assess joint involvement in pediatric CD and correlate it with the PCDAI and IMPACT-III.

METHODS

In this cross-sectional, observational study, a pediatric gastroenterologist assessed consecutively-seen pediatric CD patients at a tertiary care center. Patients were screened for prevalence of current and previous arthropathy, including arthritis, enthesitis and arthralgia. A single experienced pediatric rheumatologist evaluated detailed musculoskeletal history, joint status, and modified Juvenile Arthritis Multidimensional Assessment Reports (JAMAR). PCDAI, IMPACT-III, sacroiliac MRI, and HLA-B27 genetic testing were also completed.

RESULTS

A total of 82 (male:female, 1.2:1; age, 13.7 ± 3.2 years) patients were involved in this study. Mean disease duration at time of study was 21.6 ± 21 months; eight of the patients were newly-diagnosed. Of the 82 patients, 29 (35%) had evidence of arthritis; for 24 of those, this was revealed by physical exam during cross-sectional screening, and by prior documentation for the remaining five patients. Joint examination confirmed active arthritis in 8/24 (33%), active enthesitis in 1/24 (4%), and evidence of previous arthritis in 15/24 (62.5%) patients. Hip (41%) and knee (38%) joints were most commonly affected. Cumulative incidence of arthralgia was 48% (39/82), and 46% (18/39) of those patients had only arthralgia without arthritis, usually affecting the knee. Axial involvement was present in 10/82 (12%) patients. Joint involvement correlated with more severe CD disease activity, specifically higher PCDAI and lower IMPACT-III scores, and increased requirement for infliximab treatment. Sacroiliitis and HLA-B27 positivity were insignificant factors in this cohort.

CONCLUSIONS

When a rheumatologist performed the assessment, joint involvement in pediatric CD was more prevalent than previously reported, in this cross-sectional study. Arthritis was associated with more severe CD disease activity and lower QoL.

Systolic and Diastolic Cardiac Functions in Juvenile Spondyloarthropathies

BACKGROUND/OBJECTIVE

Juvenile spondyloarthropathies (JSpAs) are a group of inflammatory diseases characterized by asymmetric peripheral arthritis (especially in lower extremities), axial skeleton involvement, and enthesitis. Although cardiovascular findings of inflammatory diseases such as juvenile systemic lupus erythematosus (SLE) and juvenile scleroderma (SD) are well documented, there are only a few studies assessing the cardiovascular consequences of JSpA in the literature.

METHODS

Forty patients with JSpA and 20 healthy controls were included into this cross-sectional study. Cardiac functions of the participants were evaluated by conventional echocardiography and pulse-wave (PW) tissue Doppler.

RESULTS

The patients with JSpA had higher mitral lateral S (p = 0.005) and E' wave (p < 0.001), tricuspid A' wave (p = 0.03), ejection fraction (p = 0.03) and shortening fraction (p = 0.01) than the control patients. In contrast, the patients with JSpA had lower left ventricle MPI (p = 0.01) and the ratio of tricuspid E'/A' waves (p = 0.05). Patients with enthesitis detected on magnetic resonance imaging had lower ejection fraction (p = 0.05), the ratio of E/A waves (p = 0.03) and had higher Mitral lateral A' wave (p = 0.01) than those without. There was a significant inverse correlation between the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and PW transmitral A velocity (r = -0.256, p = 0.03), the BASDAI score and tricuspid annular plane systolic excursion (r = -0.301, p = 0.04), the BASDAI score and the ratio of E/E' waves (r = -0.276, p = 0.02), and the Juvenile Spondyloarthritis Disease Activity Index and PW transmitral A velocity (r = -0.246, p = 0.04).

CONCLUSIONS

In this study, we report the possible early signs of RV diastolic dysfunction and possible association between magnetic resonance imaging-confirmed enthesitis and lower LV systolic functions. Early identification of cardiac dysfunctions can help with prevention of long-term cardiovascular complications.

The Development of Extra-Articular Manifestations in Children With Enthesitis-Related Arthritis: Natural Course or Different Disease Entity?

Introduction: Enthesitis-related Arthritis (ERA) is a specific category of juvenile idiopathic arthritis (JIA) characterized by axial and/or peripheral arthritis, and enthesitis, although other different extra-articular manifestations may encompass its clinical spectrum.

Materials and Methods: In order to examine if ERA-JIA with extra-articular involvement may represent a different entity from ERA without extra-articular involvement, we performed a retrospective, observational, monocentric study, in a cohort of ERA patients followed between 2001 and September 2020 at the Pediatric Rheumatology Unit of Meyer Children Hospital of Florence. We analyzed the demographic, clinical, laboratory and imaging data at the disease onset, as well as after 3, 6, and 12 months follow up.

Results: We have enrolled 53 patients, 33 males. At the time of diagnosis, average age was 10.9 years, 53 patients had active arthritis and 25 active enthesitis. The middle foot involvement was present in 20 patients. Twenty-five children achieved clinical remission on medication. Extra-articular manifestations were observed in 14 patients, of whom 3 had inflammatory bowel disease, 5 uveitis, one uveitis associated with Crohn disease, 4 SAPHO syndrome, one celiac disease. The cohort was stratified according to the presence/absence of extra-articular manifestations. It was observed that middle foot involvement was more frequent in patients with no extra-articular manifestations (18/39 vs. 2/14; χ² = 4.45, p = 0.05). Additionally, patients presenting extra-articular manifestation needed more frequently (12/14 vs. 21/39, χ²= 4.45, p = 0.05), and preciously (months: 3.7 ± 5.4 vs. 16.7 ± 26.5, p = 0.02), treatment with biologic agents. Finally, these patients achieved belatedly (months: 31.6 ± 32.3 vs. 22.9 ± 18.3, p = 0.01) and less frequently (3/14 vs. 22/39; χ²= 5.50, p = 0.03) the clinical remission on medication. Eventually, extra-articular involvement inversely correlated with the middle-foot arthritis (ρ_s −0.29, p = 0.03), the chance to achieve remission on medication (ρ_s −0.31 e p = 0.02), as well as the chance to keep overall remission, with and without medication (ρ_s −0.28, p = 0.04).

Conclusion: In our cohort, children diagnosed with ERA-JIA at the onset of disease and then developed extra-articular manifestations show the absence of middle foot involvement and worse prognosis with an early need for the use of biologic agents, and overall low chance to achieve remission.

Spondyloarthritis and the Human Leukocyte Antigen (HLA)-B*27 Connection

Heritability of Spondyloarthritis (SpA) is highlighted by several familial studies and a high association with the presence of human leukocyte antigen (HLA)-B^*27. Though it has been over four decades since the association of HLA-B^*27 with SpA was first determined, the pathophysiological roles played by specific HLA-B^*27 allotypes are not fully understood. Popular hypotheses include the presentation of arthritogenic peptides, triggering of endoplasmic reticulum (ER) stress by misfolded HLA-B^*27, and the interaction between free heavy chains or heavy chain homodimers of HLA-B^*27 and immune receptors to drive IL-17 responses. Several non-HLA susceptibility loci have also been identified for SpA, including endoplasmic reticulum aminopeptidases (ERAP) and those related to the IL-23/IL-17 axes. In this review, we summarize clinical aspects of SpA including known characteristics of gut inflammation, enthesitis and new bone formation and the existing models for understanding the association of HLA-B^*27 with disease pathogenesis. We also examine newer insights into the biology of HLA class I (HLA-I) proteins and their implications for expanding our understanding of HLA-B^*27 contributions to SpA pathogenesis.

Unexpected increase of aortic stiffness in juvenile Spondyloarthropathies

Juvenile spondyloarthropathy is an umbrella term for a group of childhood rheumatic diseases that can cause chronic arthritis extending to the axial skeleton before the age of 16. Although ankylosing spondylitis has aortic involvement as one of its most important effects, this relationship has not been extensively studied in children with juvenile spondyloarthropathy. Here, a cross-sectional study of the elastic properties of the aorta of 43 patients with juvenile spondyloarthropathy and 19 healthy controls is reported. Aortic stiffness assessed by echocardiography was used to predict the presence of aortitis, supplemented by pulsed-wave tissue Doppler indices. The right ventricular fractional area change was found to be significantly lower in the patients with juvenile spondyloarthropathy than in the healthy controls; aortic strain and distensibility were also significantly lower, and aortic stiffness index β was significantly higher; and the aortic root diameter change was significantly lower. According to HLA-B27 positivity, there was no difference in the stiffness parameters between the two groups. There was a significant correlation between juvenile Ankylosing Spondylitis Disease Activity Index and aortic diameter change, between juvenile Ankylosing Spondylitis Disease Activity Index and aortic stiffness. Thus, juvenile spondyloarthropathy is linked to high aortic stiffness parameters.

The conundrum of juvenile spondyloarthritis classification: Many names for a single disease? Lesson learned from an instructive clinical case

Pediatric rheumatic diseases are often characterized by an evolving phenotype, resulting in diagnostic dilemma for physicians involved in their management. Although several classification criteria are used in childhood to uniform patients' diagnoses, several conditions share similar clinical features and therefore their classifications may overlap or be ambiguous. This is particularly paradigmatic for the classification of juvenile spondyloarthritis (JSpA), as the currently available criteria do not encompass their complexity. The differential diagnosis of sacroiliitis is often challenging for clinicians and requires considering several conditions, which include infective, neoplastic and rheumatic diseases. We report the case of a 13-year-old boy with an evolving clinical phenotype; its progression shows the wide differential diagnosis required in pediatric rheumatic diseases and emphasizes the issues of the actual classification system.

Juvenile idiopathic arthritis and the gut microbiome: Where are we now?

In recent decades, because of advances in technology there has been an explosion of knowledge on how microbiome affects human health. In most chronic immune-inflammatory diseases, alterations in gut microbiome has been shown. The successful use of faecal microbial transplants for the treatment of clostridium difficile associated diarrhoea has also paved the way for novel therapies. Gut microbiome is affected by early life events like the mode of delivery, breast feeding, the use of antibiotics, etc. and that may have an indirect effect on the developing immune system as well as on the predisposition to juvenile idiopathic arthritis (JIA). Multiple studies have found altered gut microbiome in JIA though no single organism or microbial community has been found to be associated with JIA. In JIA, attempts to modify gut microbiome by using probiotics, exclusive enteral nutrition and other modalities have had variable success. The current review discusses the current data available on gut microbiome in different categories of JIA and how this knowledge can translate into new therapies.

The LMP2 CfoI polymorphism is associated with ankylosing spondylitis (AS) risk but not with acute anterior uveitis (AAU): A meta-analysis

BACKGROUND

Ankylosing spondylitis (AS) is one of the most common chronic inflammatory disorders affecting the sacroiliac joints, spine, and peripheral joints. Apart from HLA-B27, the LMP2 gene has been shown to play a role in the pathogenesis of AS as well as AAU in AS. However, genetic associations between LMP2 CfoI polymorphism and AS and AAU were inconclusive. We aimed to investigate the correlation of LMP2 CfoI polymorphism and AS and AAU using meta-analysis.

METHODS

An exhaustive search was conducted using the PubMed, Embase, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI) electronic databases. The strength association was assessed by crude ORs with 95% CI.

RESULTS

Eight eligible records with 449 AS patients and 317 healthy controls were included in the present study. The allelic model of the LMP2 CfoI polymorphism is associated with AS risk (OR = 0.60, 95%CI = [0.32, 1.11], P = .003). A stratified analysis based on ethnicity has shown that the allelic model of LMP2 CfoI was associated with AS in the Caucasian population (OR = 0.72, 95%CI = [0.55, 0.93], P = .01) but not in the Asian population (P > .05). Furthermore, no association was detected between LMP2 CfoI polymorphism and AS complication (AAU).

CONCLUSION

Our combined results revealed that the allelic model of LMP2 CfoI might be a protective factor for AS in the Caucasian population. Nevertheless, future studies on different ethnicities with larger sample sizes are needed to obtain a more convincing result.

Update on the management of uveitis in children: an overview for the clinician

INTRODUCTION

Pediatric uveitis comprises a range of ocular inflammatory diseases that may lead to vision impairment, often due to ocular complications from the disease itself or side effects of therapies. The impact on vision, visual functioning, and vision-related quality-of-life over the lifetime horizon can be substantial, underscoring the importance of appropriate ophthalmic evaluation, diagnostic testing and treatment. This review focuses on the anatomic classification, laboratory diagnosis, associated systemic diseases, and management of pediatric uveitis.

AREAS COVERED

A review of the literature was performed to synthesize our current understanding of the anatomic classification of pediatric uveitis, disease epidemiology, associated systemic diseases, and management principles. We also review important corticosteroid-sparing strategies including non-biologic and biologic agents such as the anti-tumor necrosis factor (TNF)-alpha family of medications, given their key role in the treatment of pediatric uveitis, particularly juvenile idiopathic arthritis (JIA). Recent advances in the assessment of vision-related quality-of-life using the Effects of Youngsters' Eyesight on Quality of Life (EYE-Q) instrument are discussed.

EXPERT OPINION

Pediatric uveitis can lead to long-term vision impairment if not appropriately screened and treated. JIA is the most common systemic disease associated with uveitis, is typically asymptomatic, and thus requires rigorous screening to detect uveitis and avoid secondary ocular complications. While topical and systemic corticosteroids are useful for the acute treatment of uveitis, the disease chronicity of many pediatric uveitis syndromes including JIA, often warrants early escalation of therapy to immunosuppressive medications including methotrexate (MTX) and anti-TNF-alpha inhibitors. Future directions include an improved understanding of risk factors for uveitis and better metrics to evaluate the impact of disease on vision-related quality-of-life of pediatric uveitis patients.

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.

Pediatric rheumatology in Turkey

Pediatric Rheumatology is an emerging specialty in Turkey with increasing number of available centers and specialists all over the country. In this paper, we sought to provide an overview on pediatric rheumatology service in our country, as well as to assess the principle published literature from Turkey in this field. A systematic literature search has been performed to achieve the significance and the impact of this manuscript. The most relevant used databases (PubMed/MEDLINE, Web of Science, SCOPUS) for peer-reviewed studies and reviews in English language published during the last 5 years were screened. In the first part of the manuscript, we tried to give more details on the history of pediatric rheumatology in Turkey. In further text, we put an accent over the most common rheumatologic conditions among children in Turkey, including Familial Mediterranean fever, juvenile idiopathic arthritis, juvenile spondyloarthropathies, and childhood vasculitides. Despite the considerable literature from Turkey on pediatric rheumatic diseases, a need for unique strategies that would guide the management of rheumatic diseases in childhood remains open. The cultural and historical inheritance together with geographical position make the Turkey a suitable ground for investigations in filed of auto-inflammation and all other inflammatory conditions. Prospective, multicentric studies especially among rheumatologic conditions common in this part of the world would give us more relevant data and open new horizons in diseases' management. International collaborations and databases should be highly encouraged and supported, to make the care of pediatric rheumatic disease uniform.

Classifications and imaging of juvenile spondyloarthritis

Juvenile spondyloarthritis may be present in at least 3 subtypes of juvenile idiopathic arthritis according to the classification of the International League of Associations for Rheumatology. By contrast with spondyloarthritis in adults, juvenile spondyloarthritis starts with inflammation of peripheral joints and entheses in the majority of children, whereas sacroiliitis and spondylitis may develop many years after the disease onset. Peripheral joint involvement makes it difficult to differentiate juvenile spondyloarthritis from other juvenile idiopathic arthritis subtypes. Sacroiliitis, and especially spondylitis, although infrequent in childhood, may manifest as low back pain. In clinical practice, radiographs of the sacroiliac joints or pelvis are performed in most of the cases even though magnetic resonance imaging offers more accurate diagnosis of sacroiliitis. Neither disease classification criteria nor imaging recommendations have taken this advantage into account in patients with juvenile spondyloarthritis. The use of magnetic resonance imaging in evaluation of children and adolescents with a clinical suspicion of sacroiliitis would improve early diagnosis, identification of inflammatory changes and treatment. In this paper, we present the imaging features of juvenile spondyloarthritis in juvenile ankylosing spondylitis, juvenile psoriatic arthritis, reactive arthritis with spondyloarthritis, and juvenile arthropathies associated with inflammatory bowel disease.

The performance of classification criteria for juvenile spondyloarthropathies

Juvenile spondyloarthropathies (JSpA) are a group of rheumatologic diseases with a disease onset before 16; characterized with enthesitis, lower extremity oligoarthritis, involvement of the axial skeleton and HLA B27 positivity. The diversity of classification criteria along with the phenotype heterogeneity makes the classification of JSpA challenging. The aim of our study was to evaluate the performance of the pre-determined and recently proposed classification criteria for JSpA. The study group consisted of 113 patients with JSpA and 150 patients with juvenile idiopathic arthritis (JIA). Eligible criteria for JSpA were applied to all of the enrolled patients. The analysis of sensitivity, specificity and the kappa index were used to verify the performance of the JSpA criteria. The Amor criteria showed the highest sensitivity (98.2%) while the ASAS criteria for the axial SpA had highest specificity (100%). The sensitivity and specificity of the remaining criteria were: 93.8 and 63.8% for ESSG, 95.6 and 62.7% for Garmisch-Partenkirchen, 91.2 and 75.3% for ASAS criteria for peripheral SpA, respectively. Criteria proposed by our group showed the high sensitivity, specificity and kappa value: 90.3, 90.7, 0.843%, respectively. We suggest that criteria proposed by us could be used in the classification of JSpA. However, neither the pre-determined nor the new criteria are totally adequate and efficacious for the classification and diagnosis of this disease. The evaluation of the validity and reliability of proposed criteria in multicentric studies are mandatory, to increase its utility in routine clinical practice.

Multicenter inception cohort of enthesitis-related arthritis: variation in disease characteristics and treatment approaches

Background

Enthesitis-related arthritis (ERA) is a specific subtype of juvenile idiopathic arthritis (JIA) defined according to the International League of Associations for Rheumatology (ILAR) criteria. We aimed to characterize the clinical features and treatment regimens in an inception cohort of children with ERA.

Methods

We performed a retrospective, cross-sectional, multicenter cohort study including subjects diagnosed with ERA between 1989 and 2012. Patients all fulfilled the ILAR criteria for ERA within 3 months of initial presentation to the rheumatology clinic. Differences in the prevalence of clinical criteria across study sites and by human leukocyte antigen (HLA)-B27 status were assessed using the Wilcoxon rank-sum or chi-square test, as appropriate.

Results

Two hundred thirty-four children met the inclusion criteria. Their median age at diagnosis was 11.6 years, and 59% were HLA-B27-positive. Sixty-nine percent had enthesitis and arthritis at the time of diagnosis. Seventy-eight percent had a pauciarticular onset. The prevalence of all ILAR criteria at diagnosis, except arthritis and acute anterior uveitis, differed significantly across sites (all p < 0.01). Medication use varied significantly across sites for children with peripheral arthritis (p < 0.001), but not for sacroiliitis or enthesitis only. Nonsteroidal anti-inflammatory drugs and disease-modifying antirheumatic drugs were the most commonly prescribed treatments, with anti-TNF agents primarily being initiation for sacroiliitis. HLA-B27 positivity was associated with male sex, higher active joint count, sacroiliitis, and higher disease activity at disease onset.

Conclusions

The majority of children had a pauciarticular onset, and several statistically significant clinical differences based on HLA-B27 status were identified. The observed heterogeneity in clinical presentation across sites reflects either true differences in patient populations or differences in how the ILAR criteria are being applied.

Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis is the most common chronic rheumatic disease of unknown aetiology in childhood and predominantly presents with peripheral arthritis. The disease is divided into several subgroups, according to demographic characteristics, clinical features, treatment modalities and disease prognosis. Systemic juvenile idiopathic arthritis, which is one of the most frequent disease subtypes, is characterized by recurrent fever and rash. Oligoarticular juvenile idiopathic arthritis, common among young female patients, is usually accompanied by anti-nuclear antibodie positivity and anterior uveitis. Seropositive polyarticular juvenile idiopathic arthritis, an analogue of adult rheumatoid arthritis, is seen in less than 10% of paediatric patients. Seronegative polyarticular juvenile idiopathic arthritis, an entity more specific for childhood, appears with widespread large- and small-joint involvement. Enthesitis-related arthritis is a separate disease subtype, characterized by enthesitis and asymmetric lower-extremity arthritis. This disease subtype represents the childhood form of adult spondyloarthropathies, with human leukocyte antigen-B27 positivity and uveitis but commonly without axial skeleton involvement. Juvenile psoriatic arthritis is characterized by a psoriatic rash, accompanied by arthritis, nail pitting and dactylitis. Disease complications can vary from growth retardation and osteoporosis secondary to treatment and disease activity, to life-threatening macrophage activation syndrome with multi-organ insufficiency. With the advent of new therapeutics over the past 15 years, there has been a marked improvement in juvenile idiopathic arthritis treatment and long-term outcome, without any sequelae. The treatment of juvenile idiopathic arthritis patients involves teamwork, including an experienced paediatric rheumatologist, an ophthalmologist, an orthopaedist, a paediatric psychiatrist and a physiotherapist. The primary goals of treatment are to eliminate active disease, to normalize joint function, to preserve normal growth and to prevent long-term joint damage. Timely and aggressive treatment is important to provide early disease control. The first-line treatment includes disease-modifying anti-rheumatic drugs (methotrexate, sulphasalazine, leflunomide) in combination with corticosteroids, used in different dosages and routes (oral, intravenous, intra-articular). Intra-articular application of steroids seems to be an effective treatment modality, especially in monoarthritis. Biological agents should be added in the treatment of unresponsive patients. Anti-tumour necrosis factor agents (etanercept, infliximab, adalimumab), anti-interleukin-1 agents (anakinra, canakinumab), anti- interleukin-6 agents (tocilizumab) and T-cell regulatory agents (abatacept) have been shown to be safe and effective in childhood patients. Recent studies reported sustained reduction in joint damage with even complete clinical improvement in paediatric patients, compared to previous data.