Comparison of clinical and radiographic severity of juvenile-onset versus adult-onset ankylosing spondylitis

The childhood arthritis radiographic score of the hip: the proposal cut-off value using cluster analysis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a chronic rheumatic disease that affects children. It is crucial to detect and treat hip involvement in JIA early to prevent functional impairment and reduced quality of life. The Childhood Arthritis Radiographic Score of the Hip (CARSH) is a validated radiographic scoring system used to assess hip involvement in JIA. In this study, we aimed to determine cut-off values for CARSH scores using cluster analysis.

METHODS

The study was conducted as a cross-sectional analysis and included JIA patients with hip involvement who underwent a pelvic radiograph. The same pelvic radiograph was interpreted by two experienced pediatric rheumatologists at baseline and after 3 weeks by both readers for reliability. The CARSH scores were calculated for each hip four times (twice by each reader). For the 50 hips, a total of 200 interpretations of the CARSH score were obtained. Model-based clustering was employed to identify distinct groups of CARSH score interpretations and characterize the phenotype of each cluster.

RESULTS

Twenty-five children with hip involvement were included. The mean age was 13.9 ± 4.6 years. JIA subtypes were as follows: ERA in 64%, oligoarthritis in 16%, psoriatic arthritis in 12%, polyarthritis RF + in 4%, and RF - in 4% of patients. For the 200 hip interpretations, three clusters based on the level of the CARSH were identified by model-based clustering. Cluster 1 consisted of 17 CARSH score interpretations with a median score of 7 ± 3 (ranging from 1 to 15). This group primarily comprised patients with enthesitis-related arthritis (ERA) and psoriatic arthritis. Patients in cluster 1 were generally older, experienced longer diagnostic delays, and had a longer disease duration compared to the other clusters. Cluster 2 exhibited a moderate CARSH score, with an average score of 4 ± 3 (1 to 15). Patients in this group had significantly higher body weight compared to the other clusters. Cluster 3 represented the group with the least severe hip involvement, characterized by CARSH scores of 2 ± 1 (ranging from 0 to 9). This cluster had a higher proportion of male patients and higher C-reactive protein (CRP) levels than the other clusters. Regarding the individual items of the CARSH score, cluster 1 showed higher percentages of hip radiograph abnormalities such as joint space narrowing, erosions, growth abnormalities, and subchondral cysts. Cluster 2 was characterized by a high rate of acetabular sclerosis, with little to no abnormalities in other CARSH score items. Cluster 3 was the only group that exhibited hip subluxation, with minimal abnormalities in the other score items. In conclusion, this study identified three distinct groups of CARSH scores, representing varying levels of severity in hip involvement in JIA. These findings provide valuable insights for clinicians in assessing and managing JIA patients with hip involvement, enabling tailored treatment strategies based on the severity of the condition. Key Points • While a Childhood Arthritis Radiographic Score of the Hip (CARSH) is a valid and reliable tool in hip-related juvenile idiopathic arthritis, its use is limited in daily practice due to the lack of available cut-off values. • The cluster analysis defined three clusters based on the CARSH levels. • Cluster 1 exhibited the highest score with more damage and disability. Cluster 2 involved a moderate score and more overweight patients. Cluster 3 included the least level of the score but with an active disease parameter.

Current Role of Conventional Radiography of Sacroiliac Joints in Adults and Juveniles with Suspected Axial Spondyloarthritis: Opinion from the ESSR Arthritis and Pediatric Subcommittees

This opinion article by the European Society of Musculoskeletal Radiology Arthritis and Pediatric Subcommittees discusses the current use of conventional radiography (CR) of the sacroiliac joints in adults and juveniles with suspected axial spondyloarthritis (axSpA). The strengths and limitations of CR compared with magnetic resonance imaging (MRI) and computed tomography (CT) are presented.Based on the current literature and expert opinions, the subcommittees recognize the superior sensitivity of MRI to detect early sacroiliitis. In adults, supplementary pelvic radiography, low-dose CT, or synthetic CT may be needed to evaluate differential diagnoses. CR remains the method of choice to detect structural changes in patients with suspected late-stage axSpA or established disease and in patients with suspected concomitant hip or pubic symphysis involvement. In children, MRI is the imaging modality of choice because it can detect active as well as structural changes and is radiation free.

Comparison of clinical characteristics between adult-onset and juvenile-onset non-radiographic axial spondyloarthritis in Chinese patients: results from the COCAS cohort

BACKGROUND

Axial spondyloarthritis (axSpA) is a chronic inflammatory rheumatic disease predominantly affecting the axial skeleton. We aimed to describe the clinical characteristics of patients with non-radiographic axSpA (nr-axSpA) in China and compare the differences between adult- and juvenile-onset cases.

METHODS

A cross-sectional study was conducted using data from 776 patients with nr-axSpA in the Clinical Characteristic and Outcome in Chinese Axial Spondyloarthritis (COCAS) study cohort. Patients were divided into two groups including the adult-onset group (n = 662) and the juvenile-onset group (n = 114) according to age at disease onset. Baseline demographics and clinical characteristics were compared between patients with adult-onset and juvenile-onset nr-axSpA.

RESULTS

Overall, the male-to-female ratio was 1.26:1, the prevalence of HLA-B27 positivity was 72.2%, and the median age at disease onset of nr-axSpA was 22 years. Nearly 75% of nr-axSpA patients had peripheral arthritis in the disease course, and the prevalence of extra-articular manifestations was 10.4%. The juvenile-onset group contained a higher proportion of men (66.7% vs. 53.9%, P = 0.011) and a longer baseline disease duration (4.0 [4.0] vs. 1.6 [3.5], P < 0.001) than the adult-onset group. A family history of spondyloarthritis was more frequent in the juvenile-onset group than in the adult-onset group (23.7% vs. 15.4%, P = 0.028), but no significant difference in the prevalence of HLA-B27 positivity was observed between the two groups (P = 0.537). Regarding initial symptoms, peripheral arthritis occurred more often in patients with juvenile-onset nr-axSpA, whereas patients with adult-onset nr-axSpA presented more frequently with axial involvement. The prevalence of inflammatory back pain (IBP) was higher in the adult-onset group than in the juvenile-onset group (85.0% vs. 75.4%, P = 0.010), whereas the juvenile-onset group showed a higher prevalence of peripheral arthritis and enthesitis than the adult-onset group (67.5% vs. 48.5%, P < 0.001; 35.1% vs. 23.3%, P = 0.007, respectively).

CONCLUSIONS

Compared with adult-onset nr-axSpA, juvenile-onset nr-axSpA was more common in men and those with a family history of spondyloarthritis. Juvenile-onset nr-axSpA presents with a "peripheral predominant" mode at disease onset and a higher frequency of peripheral arthritis and enthesitis during the disease course.

Enthesitis-related arthritis: monitoring and specific tools

OBJECTIVES

In this article, the authors aimed to review the different tools used in the monitoring of enthesitis-related arthritis.

SOURCES

The authors performed a literature review on PubMed, Google Scholar, and Scopus databases. The dataset included the original research and the reviews including patients with enthesitis-related arthritis or juvenile spondylarthritis up to October 2020.

SUMMARY OF FINDING

Enthesitis-related arthritis is a category of juvenile idiopathic arthritis. It is characterized by the presence of enthesitis, peripheral arthritis, as well as axial involvement. The only validated tool for disease activity measurement in juvenile idiopathic arthritis is the Disease Activity Score: It has proven its reliability and sensitivity. Nevertheless, due to an absence of validated evaluation tools, the extent of functional impairment, as well as the children and parents' perception of the disease, could not be objectively perceived. Despite the great progress in the field of imaging modalities, the role they play in the evaluation of disease activity is still controversial. This is partially due to the lack of validated scoring systems.

CONCLUSIONS

Further work is still required to standardize the monitoring strategy and validate the outcome measures in enthesitis-related arthritis.

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.

Risk factors for progression of juvenile-onset non-radiographic axial spondyloarthritis to juvenile-onset ankylosing spondylitis: a nested case-control study

Objective

To evaluate the clinical characteristics of juvenile-onset non-radiographic axial spondyloarthritis (nr-axSpA) and to investigate risk factors associated with progression to juvenile-onset ankylosing spondylitis (JoAS).

Methods

A nested case–control study was conducted using the retrospectively collected data of 106 patients with juvenile-onset nr-axSpA (age at disease onset, <16 years) in the Clinical characteristic and Outcome in Chinese Axial Spondyloarthritis study cohort. Baseline demographic and clinical characteristics and prognosis were reviewed. Logistic regression analyses were performed to investigate risk factors associated with progression to JoAS.

Results

Overall, 58.5% of patients with juvenile-onset nr-axSpA presented with peripheral symptoms at disease onset. In 82.1% of these patients, axial with peripheral involvement occurred during the disease course. The rate of disease onset at >12 years and disease duration of ≤10 years were significantly higher in those with progression to JoAS than in those without progression to JoAS (83.0% vs 52.8%, p=0.001; 92.5% vs 56.6%, p<0.001, respectively). Multivariable logistic regression analysis revealed that inflammatory back pain (IBP) (OR 13.359 (95% CI 2.549 to 70.013)), buttock pain (OR 10.171 (95% CI 2.197 to 47.085)), enthesitis (OR 7.113 (95% CI 1.670 to 30.305)), elevated baseline C reactive protein (CRP) levels (OR 7.295 (95% CI 1.984 to 26.820)) and sacroiliac joint-MRI (SIJ-MRI) positivity (OR 53.821 (95% CI 9.705 to 298.475)) were significantly associated with progression to JoAS.

Conclusion

Peripheral involvement was prevalent in juvenile-onset nr-axSpA. IBP, buttock pain, enthesitis, elevated baseline CRP levels and SIJ-MRI positivity in patients with the disease are associated with higher risk of progression to JoAS.

Changes over time in inflammatory and structural lesions at the sacroiliac joint in children with spondyloarthritis exposed and unexposed to tumor necrosis factor inhibitor

BACKGROUND

The objective of this work was to describe magnetic resonance imaging (MRI) changes over time in inflammatory and structural lesions at the sacroiliac joint (SIJ) in children with spondyloarthritis (SpA) exposed and unexposed to tumor necrosis factor inhibitor (TNFi).

METHODS

This was a retrospective, multicenter study of SpA patients with suspected or confirmed sacroiliitis who underwent at ≥2 pelvic MRI scans. Images were reviewed independently by 3 radiologists and scored for inflammatory and structural changes using the Spondyloarthritis Research Consortium of Canada (SPARCC) SIJ inflammation score (SIS) and structural score (SSS). Longitudinal, quantitative changes in patient MRI scans were measured using descriptive statistics and stratified by TNFi exposure. We used an average treatment effects (ATE) regression model to explore the average effect of TNFi exposure over time on inflammatory and structural lesions, adjusting for baseline lesion scores.

RESULTS

Forty-six subjects were evaluated using the SIS (n = 45) and SSS (n = 18). Median age at baseline imaging was 13.6 years, 63% were male and 71% were white. Twenty-three subjects (50%) were TNFi exposed between MRI studies. The median change in SIS in TNFi exposed and unexposed subjects with a baseline SIS ≥0 was - 20.7 and - 14.3, respectively (p = 0.09). Eleven (85%) TNFi exposed and 8 (89%) unexposed subjects with a baseline SIS ≥0 met the SIS minimal clinically important difference (MCID; ≥2.5). Using the ATE model adjusted for baseline SIS, the average effect of TNFi on SIS in patients with a baseline SIS ≥2 was - 14.5 (p < 0.01). Unadjusted erosion change score was significantly worse in TNFi unexposed versus exposed subjects (p = 0.03) but in the ATE model the effect of TNFi was not significant.

CONCLUSION

This study quantitatively describes how lesions in the SIJs on MRI change over time in patients exposed to TNFi versus unexposed. Follow-up imaging in TNFi exposed patients showed greater improvement than the unexposed group by most metrics, some of which reached statistical significance. Surprisingly, a majority of TNFi unexposed children with a baseline SIS≥2 met the SIS MCID. Additional studies assessing the short and long-term effects of TNFi on inflammatory and structural changes in juvenile SpA are needed.

Enthesitis-related arthritis and spondylarthritis: the same disease or disparate entities?

OBJECTIVES

The aim of this study is to compare the clinical features, disease activity and physical impairment, between enthesitis-related arthritis, adult and late-onset spondylarthritis in Tunisian patients.

METHODS

This study included 190 patients divided into three groups according to their age at the onset of symptoms: ERA (onset of symptoms ≤ 16 years of age), AOSpA (16 < onset of symptoms < 50 years of age) and LOSpA (onset of symptoms ≥ 50 years of age). AOSpA and LOSpA patients fulfilled the ASAS criteria for SpA. Whereas, ERA patients were classified according to the ILAR criteria.

RESULTS

Among 190 patients, 21% had ERA, 70.5% had AOSpA, and 8.5% had LOSpA. There were no differences in gender ratio between ERA and AOSpA groups. Regarding the clinical presentation, ERA and LOSpA groups had more peripheral symptoms than AOSpA in whom the axial manifestation pattern continued throughout the course of the disease. HLA-B27 was more associated with ERA (p = 0,007). Extra-articular manifestations were more observed in the ERA group (p = 0.004). Disease activity, functional status and anthropometric parameters were similar between groups. Nevertheless, health-related quality-of-life assessed by ASQoL and SF-36 scores were better in the AOSpA group but with no significant differences. Regarding the treatment option, methotrexate was widely used in the ERA group (p < 0.001).

CONCLUSION

ERA is characterized mainly by marked peripheral arthritis, more extra-articular manifestations, and a higher frequency of hip involvement.

Update on Juvenile Spondyloarthritis

Spondyloarthritis (SpA) is a blanket term encompassing entities such as enthesitis-related arthritis, nonradiographic axial SpA, and ankylosing spondylitis. These diseases share many clinical features, including a predilection for inflammation of the entheses and the sacroiliac joints. The nomenclature is based on the evolution of the classification of the disease and the age of the patient. SpA has a prevalence of approximately 1% of the population of the United States, with 10% to 20% of patients experiencing the onset during childhood. Children with onset of arthritis before age 16 years are classified as having juvenile idiopathic arthritis. Children with enthesitis and/or sacroiliitis are further classified as belonging to the enthesitis-related arthritis subtype of juvenile idiopathic arthritis. The initial manifestations can be subtle and will usually include a peripheral pattern of arthritis and enthesitis. It may take several years for axial disease to develop in children. Except for an association with the human leukocyte antigen (HLA-B27) serotype, there are no laboratory markers for the disease, and the radiographic findings are often negative. A careful clinical evaluation for evidence of inflammation in the entheses and the joints and a search for comorbidities are required. Magnetic resonance imaging facilitates the early detection of sacroiliitis, an important feature that may be clinically silent. Because recent studies indicate that earlier introduction of therapy can help achieve better outcomes, rapid identification and treatment of children with SpA is essential.

Risk factors for radiological hip involvement in patients with ankylosing spondylitis

OBJECTIVE

Our study aimed to explore the potential risk factors for radiological hip joint involvement in patients with ankylosing spondylitis (AS).

METHODS

This cross-sectional convey collected the clinical data, laboratory indicators, and radiographic data of patients with AS. Radiographic hip joint involvement was defined as a Bath Ankylosing Spondylitis Radiology Hip Index (BASRI-hip) score ≥2. Multivariate logistic regression analyses were conducted to explore the potential risk factors for radiological hip involvement in patients with AS.

RESULTS

Based on BASRI-hip score, all enrolled 386 patients with AS were classified as patients involving with radiological hip joint involvement (BASRI-hip ≥2; n=203) and those without it (BASRI-hip ≤1; n=183). Mean age of enrolled patients with AS were 36.7±11.9 years, and 320 (82.9%) patients were male. Mean course of disease was 10.7±8.3 years, and 349 (90.4%) patients were with a positive HLAB27. Multivariate analyses indicated that Juvenile onset (onset age ≤16 years) (odds ratio [OR]=4.159, 95% confidence interval [CI], 1.779-9.721, p<0.001), body mass index (BMI) <18.5 kg/m2 (OR=1.986, 95%CI 1.187-3.323, p=0.009), continuous nonsteroidal anti-inflammatory drug (NSAID) use (OR=0.351, 95%CI 0.155-0.794, p=0.012), and bone mass below the expected range for age (Z score ≤-2) (OR=2.791, 95%CI 1.456-5.352, p=0.002) were independently associated with radiological hip joint involvement in patients with AS.

CONCLUSIONS

The potential risk factors for radiological hip joint involvement were juvenile onset, lower BMI, and bone mass below the expected range for age. Furthermore, continuous NSAID use was the protective factor for radiological hip joint involvement in these population.

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-Versus Adult-Onset Spondyloarthritis: Similar, but Different

This article provides an overview of juvenile spondyloarthritis and important differences in the classification criteria, clinical presentation, outcomes, and pathology in juvenile versus adult-onset disease. Key differences in classification criteria between children and adults with spondyloarthritis are important to understand, as they can make transition from pediatric to adult care challenging. MRI and ultrasonography are increasingly relied on for the assessment of adult-onset disease activity and change over time in the pediatric population. The unique features of the maturing axial and peripheral skeleton are described for each modality, as they are key to understand for accurate interpretation of pathology in the pediatric population.

Prospective validation of the Juvenile Spondyloarthritis Disease Activity Index in children with enthesitis-related arthritis

Objective

To measure disease activity in children with enthesitis-related arthritis the Juvenile Spondyloarthritis Disease Activity Index (JSpADA) was developed and retrospectively validated. We prospectively validated JSpADA and also assessed performance of adult SpA scores.

Methods

Children with enthesitis-related arthritis (ILAR criteria) less than 18 years of age were enrolled. Baseline characteristics and different disease activity measures (JSpADA, BASDAI, Ankylosing Spondylitis Disease Activity Score-ESR, juvenile arthritis DAS-10 joints), and Childhood HAQ, physician global assessment and patient global assessment were recorded at baseline. In some children follow-up was also done.

Results

The mean (s.d.) age of 127 children (116 boys) was 14.3 (2.4) years and disease duration was 36.9 (3) months. Ninety of 104 (86.5%) children were HLA-B27 positive. JSpADA showed high correlation with physician global assessment (r = 0.87; P < 0.0001), patient global assessment (r = 0.80, P < 0.0001), juvenile arthritis DAS-10 joints (r = 0.89; P < 0.0001) and Childhood HAQ (r = 0.83, P < 0.0001). The JSpADA scores showed good internal consistency, discriminative validity and sensitivity to change. In 15% of children back mobility could not be tested due to active arthritis in lower limbs. The 7-variable JSpADA excluding back mobility performed as well as the original JSpADA. Adult scores showed good construct validity, discriminative capacity and sensitivity to change, and had good correlation with JSpADA (BASDAI, r = 0.84; Ankylosing Spondylitis Disease Activity Score-ESR, r = 0.84).

Conclusion

JSpADA is a valid score for measuring disease activity in enthesitis-related arthritis. Adult scores also performed well. Excluding back mobility needs to be assessed in future to improve JSpADA performance.

Spondyloarthritis Research Consortium of Canada Scoring System for Sacroiliitis in Juvenile Spondyloarthritis/Enthesitis-related Arthritis: A Reliability, Validity, and Responsiveness Study

OBJECTIVE

Intra- and interreader reliability, construct validity, and responsiveness of the Spondyloarthritis Research Consortium of Canada (SPARCC) magnetic resonance imaging (MRI) scoring system were investigated for scoring sacroiliitis in patients with juvenile spondyloarthritis (JSpA)/enthesitis-related arthritis (ERA) who have received biologic and/or nonbiologic treatment.

METHODS

Ninety whole-body MRI examinations with dedicated oblique coronal planes of the sacroiliac joints in 46 patients were independently reviewed and scored by 2 pediatric musculoskeletal radiologists, blinded to clinical details, using the SPARCC system. Intra- and interreader reliability was assessed by intraclass correlation coefficients (ICC). Construct validity testing was done by (1) correlating the SPARCC MRI scores of sacroiliitis with clinical disease activity indicators (cross-sectional validity), and (2) correlating the change in the MRI score with the change in clinical indicators before and after treatment (longitudinal validity). Responsiveness of the MRI and clinical indicators was also evaluated, grouped by biologic and nonbiologic treatment.

RESULTS

When applied in children with JSpA/ERA, the SPARCC showed almost perfect intra- and interreader reliability (ICC 0.79-1.00). There was poor cross-sectional and longitudinal correlation between clinical assessment indicators and MRI scoring. SPARCC scores showed higher responsiveness to treatment-related change than most clinical outcome measures. Three clinical outcome measures correlated longitudinally with SPARCC score in nonbiologic treatment: active joint count (r = 0.72, p < 0.001), FABER (Flexion, Abduction, External Rotation) test (r = 0.58, p = 0.012), and physician's global assessment (r = 0.61, p = 0.034).

CONCLUSION

The SPARCC MRI scoring system is a reliable tool with relatively higher responsiveness than clinical indicators and is suitable for objective quantification of sacroiliitis when applied to pediatric patients with JSpA/ERA.

Radiographic progression in non-radiographic axial spondyloarthritis

INTRODUCTION

Non-radiographic axial spondyloarthritis (nr-axSpA) represents a subtype of axial spondyloarthritis (axSpA) with no significant structural damage in sacroiliac joints and spine. In addition, patients with nr-axSpA demonstrate a substantial burden of illness, and a considerable share of them might progress to radiographic axSpA (r-axSpA) over time. The amount and quality of published data allows crude estimation of progression rate and factors related to a higher risk of progression. Areas covered: This review discusses the available data reporting the rates and predictors of radiographic progression in the sacroiliac joints and in the spine in patients with nr-axSpA as well as predisposing factors for such a progression. Expert commentary: Most of the studies report about 10-40% of patients with nr-axSpA to progress to r-axSpA over a period of 2-10 years. Multiple risk factors for the radiographic sacroiliitis progression are outlined and explored. There are not enough data to presume that any treatment modality may influence progression from nr-axSpA to r-axSpA, with TNFi showing some promising results. Radiographic progression in the spine is in general low in nr-axSpA; thus, long-term studies are required to investigate the natural course of the progression and possible treatment effects.

Feasibility and reliability of the Spondyloarthritis Research Consortium of Canada sacroiliac joint inflammation score in children

BACKGROUND

Published methods for quantification of magnetic resonance imaging (MRI) evidence of inflammation in the sacroiliac joint lack validation in pediatric populations. We evaluated the reliability and construct validity of the Spondyloarthritis Research Consortium of Canada (SPARCC) sacroiliac joint inflammation score (SIS) in children with suspected or confirmed juvenile spondyloarthritis (JSpA).

METHODS

The SPARCC SIS measures the presence, depth, and intensity of bone marrow inflammation on MRI through the cartilaginous part of the joint. Six readers blinded to clinical details except age, participated in two reading exercises, each preceded by a calibration exercise. Inter-observer reliability was assessed using intraclass correlation coefficients (ICCs) and for pre-specified acceptable reliability the inraclass correlation coefficient (ICC) was > 0.8.

RESULTS

The SPARCC SIS had face validity and was feasible to score in pediatric cases in both reading exercises. Cases were mostly male (64%) and the median age at the time of imaging was 14.9 years. After calibration, the median ICC across all readers for the SIS total score was 0.81 (IQR 0.71-0.89). SPARCC SIS had weak correlation with disease activity (DA) as measured by the JSpADA (r = - 0.12) but discriminated significantly between those with and without elevated C-reactive protein (p = 0.03).

CONCLUSION

The SPARCC SIS was feasible to score and had acceptable reliability in children. The ICC improved with additional calibration and reading exercises, for both experienced and inexperienced readers.

Review: Genetics and the Classification of Arthritis in Adults and Children

Current classification of primary inflammatory arthritis begins from the assumption that adults and children are different. No form of juvenile idiopathic arthritis bears the same name as an adult arthritis, a nomenclature gap with implications for both clinical care and research. Recent genetic data have raised questions regarding this adult/pediatric divide, revealing instead broad patterns that span the age spectrum. Combining these genetic patterns with demographic and clinical data, we propose that inflammatory arthritis can be segregated into 4 main clusters, largely irrespective of pediatric or adult onset: seropositive, seronegative (likely including a distinct group that usually begins in early childhood), spondyloarthritis, and systemic. Each of these broad clusters is internally heterogeneous, highlighting the need for further study to resolve etiologically discrete entities. Eliminating divisions based on arbitrary age cutoffs will enhance opportunities for collaboration between adult and pediatric rheumatologists, thereby helping to promote the understanding and treatment of arthritis.

Low frequency of HLA-B27 in ankylosing spondylitis and its relationship with clinical findings in patients from Turkey

Objective

Human leukocyte antigen B27 (HLA-B27) is strongly associated with ankylosing spondylitis (AS). However, the association between clinical findings and HLA-B27 vary in terms of geographic area. This study aimed to determine the frequency of HLA-B27 positivity and its relationship with clinical findings.

Material and Methods

All subjects fulfilling the modified New York diagnosis criteria for AS enrolled in study. The demographic data and histories of the patients were collected retrospectively from patient files. Polymerase chain reaction-based HLA-B27 analysis of all cases was performed.

Results

The male to female ratio was 2.5, and mean age of disease onset was 28.3 years. HLA-B27 positivity was detected in 115 patients (70%). Although there was no significant connection between the clinical findings and HLA-B27 positivity, there was a positive relationship between the presence of syndesmophytes and HLA-B27 positivity (p=0.044). The number of patients treated with anti-tumor necrosis factor was higher in the HLA-B27-positive group; however, the difference was not significant (39.1% and 28.9%, respectively). More patients were treated with anti-tumor necrosis factor in the HLA-B27-positive group than in the HLA-B27-negative group; however, the difference was not significant (39.1% and 28.9%, respectively).

Conclusion

Compared with northern Europe, HLA-B27-positive rate of patients with AS has been shown to be lower in Turkey. Except for the presence of syndesmophytes, there was not a statistically significant relationship between HLA-B27 positivity and clinical and radiologic findings.

Course of patients with juvenile spondyloarthritis during 4 years of observation, juvenile part of GESPIC

OBJECTIVE

To describe the course and the 4-year outcome of juvenile spondyloarthritis (jSpA).

METHODS

Patients with a diagnosis of jSpA and an age at onset ≤16 years were included in the German Spondyloarthritis Inception cohort (GESPIC) and followed up prospectively for 4 years.

RESULTS

118 patients (73% men, 66% HLA-B27 positive, mean age 13.5 years, mean symptom duration 2.2 years) were enrolled in 2 study centres: 52% of patients with jSpA were captured by the enthesitis-related arthritis subgroup of the International League of Associations for Rheumatology classification criteria. At inclusion, the majority of patients had active peripheral arthritis (75.4%), followed by inflammatory back pain (IBP) (19.5%) and enthesitis (16.1%). There was a significant improvement in clinical manifestations and in patient-reported outcomes over time. During the 4-year follow-up, 85% of the patients had at least 1 period of remission on drug ≥6 months, and 46% of the patients achieved remission ≥12 months without medication, of whom 68% kept this status and 32% worsened. At the end of 4 years of observation, 23% of the patients were in remission without medication, but 57% still suffered from active disease. Patients with peripheral arthritis had a likelihood of 29% for having peripheral arthritis after 4 years, whereas the likelihood of IBP persistence was 53% for those with IBP at enrolment.

CONCLUSIONS

Although 1 quarter of patients with jSpA achieved remission off medication after 4 years, the likelihood of having recurrent or persistent disease into adulthood is substantial, particularly for jSpA with IBP.

TRIAL REGISTRATION NUMBER

NCT 01277419.

Clinical Features in Juvenile-Onset Ankylosing Spondylitis Patients Carrying Different B27 Subtypes

Background. Ankylosing spondylitis (AS) is a common rheumatic disease and is characterized by inflammation of the axial skeleton. HLA-B27 is strongly associated with AS. Juvenile-onset AS (JAS) with disease onset before 16 years of age differs from adult-onset AS (AAS) in many respects. Objective. To compare the clinical features in JAS with different B27 subtypes and analyze the differences between JAS and AAS. Methods. 145 JAS and 360 AAS patients were included. The demographic data, clinical manifestations, laboratory markers, Bath AS indices, and B27 subtypes were recorded. Results. Peripheral arthritis, enthesitis, BASDAI, ESR, and CRP were significantly higher in JAS patients with HLA-B^*2704 than those with B27-negative. Enthesitis and ESR were significantly higher in patients with HLA-B^*2705 than those with B27-negative. The onset age of HLA-B^*2715 group was much earlier than the other groups. The peripheral arthritis, enthesitis, and hip joint involvement in JAS with HLA-B^*2704 were significantly higher than those in AAS with HLA-B^*2704. Conclusion. JAS with different B27 subtypes had similar features in most of manifestations; JAS and AAS patients with the same subtype could have distinctive courses. Early diagnosis, hip detection, and control of systemic active inflammation in JAS patients will be helpful for improving the prognosis.

Clinical outcomes and progression to orthopedic surgery in juvenile- versus adult-onset ankylosing spondylitis

OBJECTIVE

Juvenile- and adult-onset ankylosing spondylitis (AS) are subtypes of AS that may have different clinical outcomes. We compared cohorts of juvenile-onset AS and adult-onset AS in terms of clinical characteristics, clinical outcomes, proceeding to AS-related orthopedic surgery, and type of orthopedic surgery.

METHODS

A retrospective cohort study was conducted of all AS patients attending a teaching hospital. Demographics, clinical parameters, and history of AS-related orthopedic surgery to the spine, root, or peripheral joints were recorded. Differences between surgery for juvenile- and adult-onset AS patients, and effects of covariates were assessed using logistic regression and survival analyses.

RESULTS

A total of 553 AS patients were studied: 162 juvenile-onset AS and 391 adult-onset AS cases. After adjusting for significant covariates, adult-onset AS cases were less likely to proceed to surgery (odds ratio [OR] 0.31, P < 0.001), have a hip procedure (resurfacing or arthroplasty; OR 0.374, P = 0.001), and have hip arthroplasty (OR 0.43, P = 0.01). Significant differences were also observed when comparing Kaplan-Meier survival curves (P = 0.001) and using Cox proportional hazards regression (P = 0.002). A history of smoking was not associated with surgery. AS cases with older age at symptom onset were far less likely to have surgery than those with younger onset, in a nonlinear manner.

CONCLUSION

Juvenile-onset AS cases are more likely than adult-onset AS cases to proceed to hip arthroplasty, but equally likely to have hip resurfacing and hip arthroplasty revision/re-revisions. Smoking was not associated with the risk of orthopedic surgery. Orthopedic surgery was unlikely after 40 years of disease in both subsets.

Enthesitis-related arthritis: time to re-define?

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. Enthesitis-related arthritis (ERA) is one of the seven JIA subtypes classified by the International League of Associations for Rheumatology (ILAR). Due to inclusion and exclusion criteria, a pitfall of the ERA category is that it does not include all subsets of juvenile spondyloarthropathy, with many children ending up in the undifferentiated category. The ERA nomenclature also does not have a method for distinguishing between axial and peripheral disease, two phenotypes which vary in presentation and treatment requirements. This distinction is very important given the overall poor prognosis seen in ERA patients, specifically in those with axial involvement. Since axial involvement is more common and presents earlier than previously thought in ERA, the pediatric rheumatology community should develop more accurate and sensitive classification criteria based on disease course to assist in improving timely diagnosis and appropriate management.

Fluoroscopy-guided Intra-articular Sacroiliac Joint Steroid Injection for Sacroiliitis in Ankylosing Spondylitis: A Case Report

Sacroiliitis, a condition commonly seen in Ankylosing Spondylitis, is well known to be one of the main pain generators of low back pain, which may result in difficulty with walking. A 20-year old male with history of ankylosing spondylitis presented to the University Hospital of the West Indies, Physical Medicine and Rehabilitation clinic, with a two-year history of right buttock, low back and groin pain. Radiographic evaluation revealed increased sclerosis and erosive changes in bilateral sacroiliac joints, right greater than left. Right intra-articular sacroiliac joint steroid injection was administered under fluoroscopy guidance. Post-injection visual analogue pain scale (VAS) score with activity improved from 8 to 1 and Oswestry Disability Index improved from 40% moderate disability to 16% minimal disability. The patient's overall assessment was 95% perceived improvement in pain. This case report illustrates the effectiveness of intra-articular sacroiliac joint steroid injection in treating sacroiliitis in ankylosing spondylitis.

[Epidemiologic profile of juvenile-onset compared to adult-onset spondyloarthritis in a large Brazilian cohort]

OBJECTIVE

To analyze the clinical and epidemiologic characteristics of juvenile-onset spondyloarthritis (SpA) (< 16 years) and compare them with a group of adult-onset (≥ 16 years) SpA patients.

PATIENTS AND METHODS

Prospective, observational and multicentric cohort with 1,424 patients with the diagnosis of SpA according to the European Spondyloarthropathy Study Group (ESSG) submitted to a common protocol of investigation and recruited in 29 reference centers participants of the Brazilian Registry of Spondyloarthritis (RBE - Registro Brasileiro de Espondiloartrites). Patients were divided in two groups: age at onset<16 years (JOSpA group) and age at onset ≥ 16 years (AOSpA group).

RESULTS

Among the 1,424 patients, 235 presented disease onset before 16 years (16.5%). The clinical and epidemiologic variables associated with JOSpA were male gender (p<0.001), lower limb arthritis (p=0.001), enthesitis (p=0.008), anterior uveitis (p=0.041) and positive HLA-B27 (p=0.017), associated with lower scores of disease activity (Bath Ankylosing Spondylitis Disease Activity Index - BASDAI; p=0.007) and functionality (Bath Ankylosing Spondylitis Functional Index - BASFI; p=0.036). Cutaneous psoriasis (p<0.001), inflammatory bowel disease (p=0.023), dactylitis (p=0.024) and nail involvement (p=0.004) were more frequent in patients with adult-onset SpA.

CONCLUSIONS

Patients with JOSpA in this large Brazilian cohort were characterized predominantly by male gender, peripheral involvement (arthritis and enthesitis), positive HLA-B27 and lower disease scores.

Delayed diagnosis is linked to worse outcomes and unfavourable treatment responses in patients with axial spondyloarthritis

The diagnosis of spondyloarthritis (SpA) has a lengthy delay; we investigated the outcomes and factors associated with the delayed diagnosis of SpA. This was a cross-sectional study on patients with SpA who visited a rheumatology clinic at a single tertiary centre. The data were collected from face-to-face interviews, physician assessments of disease status and reviews of medical records. In total, 105 patients with SpA were consecutively enrolled. Of the included patients, 94 had axial SpA and 11 had peripheral SpA. The median diagnostic delay was 8 years (interquartile range, 3-14) for axial SpA. Comparisons between the early and late diagnosis groups were performed to identify the factors related to delayed diagnosis in axial SpA. A definite diagnosis of SpA led to proper management and clinical improvements. The patients with delayed diagnosis showed worse outcomes in disease activity, function, spinal mobility and/or radiographic damage. These patients also demonstrated a less favourable treatment response according to the Bath Ankylosing Spondylitis Disease Activity Index and the rate of radiographic progression. Multivariate analysis indicated that a prior diagnosis of mechanical back pain was an independent factor associated with diagnostic delay. The diagnosis of SpA is often delayed. Delayed diagnosis is associated with worse outcomes and poor treatment responses in SpA patients. Physician and patient awareness of inflammatory back pain are essential for the early diagnosis of SpA, and a referral guideline for patients with suspected SpA is needed.

Diagnostic Utility of Magnetic Resonance Imaging and Radiography in Juvenile Spondyloarthritis: Evaluation of the Sacroiliac Joints in Controls and Affected Subjects

Objective.

To compare the utility of radiography and magnetic resonance imaging (MRI) for the diagnosis of juvenile-onset spondyloarthritis in pediatric patients presenting with low back and/or sacroiliac (SI) pain of potentially inflammatory etiology.

Methods.

Radiographs and MRI studies of the SI joints in 26 patients with juvenile spondyloarthritis (JSpA) and 35 controls were assessed independently by 2 radiologists, with discrepancies arbitrated by a third. Radiographs and MRI were blinded and read in separate batches in random order.

Results.

Erosion was common and was the most useful diagnostic feature on radiography [positive likelihood ratio (LR) = 3.5] and was especially diagnostic of SpA on MRI (LR = 6.7). Subchondral sclerosis was common but was the least specific feature for both modalities. Joint space narrowing had some utility on radiography (LR = 2.0) and MRI (LR = 2.7) but was uncommon and had poor reader reliability. Bone marrow edema (LR = 3.1) and subarticular fat infiltration (LR = 4.5), detectable only on MRI, were both useful features. Global diagnostic impression of MRI (LR = 9.4) had very high utility for the diagnosis of JSpA, exceeding radiography (LR = 4.4) because of superior specificity. In addition, global diagnosis of SpA is much more reliably made on MRI (κ = 0.80) compared to radiography (κ = 0.30).

Conclusion.

Specificity and reliability of MRI of the SI joints are superior to radiography for the diagnosis of juvenile-onset SpA and, where available, MRI should replace radiography as the first line of investigation.

Juvenile Versus Adult-onset Ankylosing Spondylitis — Clinical, Radiographic, and Social Outcomes. A Systematic Review

Ankylosing spondylitis (AS) has 2 main modes of onset: juvenile-onset AS (JoAS) and adult-onset AS (AoAS). It is not known whether JoAS is a subtype of AS, or AS modulated by early age of onset and longer disease duration. We performed a systematic review of the literature, identifying 12 articles and 1 abstract directly comparing JoAS and AoAS cohorts, with observational study design. Patients with JoAS appear to have more peripheral joint involvement both clinically and radiographically (especially knees and ankles) and more root joint involvement (hips and shoulders); they are more likely to proceed to hip arthroplasty and often initially present with peripheral rather than axial symptoms. Patients with AoAS appear to have more axial symptoms and radiographic disease, particularly in the lumbar spine, and worse axial metrology. In terms of other characteristics, more evidence is needed to confidently state whether JoAS and AoAS are different.

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.

Double-blind, placebo-controlled randomized trial with adalimumab for treatment of juvenile onset ankylosing spondylitis (JoAS): significant short term improvement

INTRODUCTION

While adalimumab is licensed for ankylosing spondylitis (AS), open uncontrolled studies suggest therapeutic efficacy of TNF-inhibitors in juvenile onset AS (JoAS).

METHODS

A total of 32 patients aged 12 to 17 years with severe, active and refractory JoAS were enrolled in a multicenter, randomized, double-blind, placebo-controlled parallel study of 12 weeks, followed by open-label adalimumab until week 24 for all patients. ASAS40 was used as the primary, and ASAS20, PedACR and single items were used as the secondary outcome measures for the intention to treat population.

RESULTS

A total of 17 patients were randomized to receive adalimumab 40 mg/2 weeks and 15 patients received placebo. Two patients (one of each group) discontinued prematurely due to insufficient efficacy and were labeled as non-responders. In the double-blind part, more patients on adalimumab achieved an ASAS40 at week 4 (41%), week 8 (53%) and week 12 (53%) than on placebo (20%, 33%, 33%), while differences at week 8 only reached borderline significance (P = 0.05). Also, at 4, 8 and 12 weeks ASAS20/PedACR30/70 response rates were higher in the adalimumab group (53%/53%/29%; 59%/76%/41%; 53%/65%/53%) compared to placebo (27%/27%/7%; 27%/33%/13%; 33%/40%/27%). In the adalimumab group a significant decrease of all disease activity parameters was noted at week 12 and was even more pronounced at week 24. At week 12 the Bath Ankylosing Spondylitis Disease activity spinal inflammation score decreased by 65% (P <0.001), the back pain score decreased by 50% (P <0.005), the Bath AS Functional Index (BASFI) score decreased by 47% (P <0.02), while the Childhood Health Assessment Questionnaire-Disability Index (CHAQ-DI) score improved by 65% (P <0.005). ANCOVA analysis demonstrated superiority of adalimumab over placebo for the physician global assessment of disease activity, parents' global assessment of subject's overall well-being, active joint count (all P <0.05) and erythrocyte sedimentation rate (ESR) (P <0.01).

CONCLUSIONS

Adalimumab was well tolerated and highly effective in a double-blind randomized trial in patients with JoAS. Treatment effects rapidly occurred and persisted for at least 24 weeks of treatment.

TRIAL REGISTRATION

EudraCT 2007-003358-27.

The assessment of the spondyloarthritis international society concept and criteria for the classification of axial spondyloarthritis and peripheral spondyloarthritis: A critical appraisal for the pediatric rheumatologist

This review refers to the origin and current state of the assessment of the SpondyloArthritis International Society (ASAS) criteria for the classification of axial and peripheral spondyloarthritis (SpA) and the possible implications in the pediatric population. The ASAS criteria evolved from the idea that the earlier the recognition of patients with ankylosing spondylitis, the better the efficacy of tumor necrosis factor blockers. Strategies included the development of new concepts, definitions, and techniques for the study of clinical signs and symptoms. Of relevance, the new definition of inflammatory back pain (IBP) and the introduction of sacroiliitis by magnetic resonance imaging represented the most important advance in the early identification of AS in the "pre-radiographic stage" of the disease. AS is considered in this paper as a disease continuum with symptoms depending on age at onset. The application of those specific strategies in children and adolescents with SpA seems limited because the most important manifestation in the early stage of disease is not IBP, but peripheral arthritis and enthesitis. In this instance, the logical approach to juvenile onset SpA according to ASAS criteria should not be through the axial criteria but rather the peripheral set of criteria.

Clinical, functional, and radiographic differences among juvenile-onset, adult-onset, and late-onset ankylosing spondylitis

OBJECTIVE

The aim of our study was to compare the clinical, functional, and radiographic outcomes at different ages of onset in patients with ankylosing spondylitis (AS).

METHODS

A total of 546 patients were enrolled consecutively and classified into 3 groups based on their age at symptom onset: (1) juvenile-onset AS (age ≤ 16 years; JoAS); (2) adult-onset AS (> 16 but < 40 years; AoAS); and (3) late-onset AS (≥ 40 years; LoAS). We compared the differences among the 3 groups. OR for disease outcomes were calculated and adjusted for sex, HLA-B27, and disease duration.

RESULTS

There were 67 patients (12.3%) with JoAS, 460 (84.2%) with AoAS, and 19 (3.5%) with LoAS. Male sex and HLA-B27 were associated with a younger age at onset (p < 0.001). Compared to patients with AoAS, patients with JoAS were more likely to present with peripheral arthritis, while patients with JoAS and LoAS were less likely to have back pain at the onset of AS (p < 0.05). After controlling for multiple covariates, JoAS was found to be associated with a worse functional outcome and global assessment, and a high serum immunoglobulin A level (p < 0.05). Patients with JoAS had less lumbar spinal radiographic severity (p < 0.05). There were no statistical differences in clinical or functional outcome between the LoAS and AoAS groups. None of the LoAS patients had radiographic hip involvement.

CONCLUSION

Sex and HLA-B27 are significantly associated with age at onset of AS. Both JoAS and LoAS have their distinctive symptoms/signs at onset and different disease outcomes.

A modified juvenile arthritis damage index to improve articular damage assessment in juvenile idiopathic arthritis--enthesitis-related arthritis (JIA-ERA)

Juvenile arthritis damage index (JADI) consists of two parts which measure articular (JADI-A) and extra-articular (JADI-E) damage in patients with juvenile idiopathic arthritis (JIA). It does not include assessment of cardiac dysfunction and joint areas commonly affected in enthesitis-related arthritis (ERA) category of JIA. We have tried to study if modification of JADI will improve its performance in JIA-ERA. We studied 101 consecutive patients of JIA-ERA. JADI-A was modified (JADI-AM) to include damage assessment of tarsal joints and lumbar spine. JADI-E was modified (JADI-EM) to include assessment of symptomatic cardiac dysfunction. The performances of the modified and standard JADI were compared. Ninety-seven patients were male. The median age was 18 years (9-36). At a median disease duration of 6 years (1-24), joint damage was observed in 47 as assessed by JADI-A. JADI-AM could identify 11 more patients (N = 58) with articular damage. JADI-AM had good correlation with number of joints with limitation of movement (Spearman's [rS] = 0.9) and low to moderate correlation (rS < 0.7) with measures of disease activity and functional status. JADI-AM discriminated well among patients with different disability levels. Extra-articular damage was observed in 35, and modification of JADI-E with inclusion of cardiac dysfunction did not identify any additional patient. Thus, we propose a modification of the JADI-A (JADI-AM). In JIA-ERA, modification of JADI-A improves its ability to identify articular damage. Modification of the JADI-E may not be needed as symptomatic cardiac involvement is rare.

Enthesitis in an inception cohort of enthesitis-related arthritis

OBJECTIVE

To describe an enthesitis-related arthritis (ERA) inception cohort and determine which entheses and joints are most commonly affected.

METHODS

We reviewed a retrospective inception cohort study of children with ERA who were diagnosed and treated at The Children's Hospital of Philadelphia between November 2007 and December 2009.

RESULTS

During the study period, there were 32 newly diagnosed ERA patients. Fifty-nine percent were male, and the median age at the date of initial evaluation was 12.5 years (interquartile range [IQR] 10.2-14.3 years). The median number of tender entheses at presentation was 2 (IQR 0-5), and 21 subjects (66%) had at least 1 tender enthesis. The most prevalent tender entheses were the patellar ligament insertion at the inferior pole of the patella, the plantar fascial insertion at the calcaneus, the Achilles tendon insertion at the calcaneus, and the plantar fascial insertion at the metatarsal heads. Enthesitis was most often symmetric. The median number of active joints was 2 (IQR 0-4). The most commonly affected joints were the sacroiliacs, knees, and ankles. Sacroiliitis, which was defined clinically, was most often symmetric, while peripheral arthritis was most frequently asymmetric. The odds of having active enthesitis at 6 months increased significantly with each additional tender enthesis at the initial evaluation.

CONCLUSION

Among pediatric patients with ERA, lower extremity enthesitis is prevalent at the time of diagnosis and is likely to persist 6 months later. Future studies should address standardization of the enthesitis examination, the pattern of enthesitis over time, enthesitis response to therapy, and the impact of enthesitis on quality of life.

Early Predictors of Juvenile Sacroiliitis in Enthesitis-related Arthritis

Objective.

To identify early predictors of sacroiliac (SI) involvement in a cohort of patients with enthesitis-related arthritis (ERA).

Methods.

During a 7-year followup period, all consecutive patients fulfilling the ILAR classification criteria for ERA were enrolled. Data collected included demographic, clinical and laboratory variables at disease onset, at the onset of inflammatory back pain, and at the last available followup visit. Pelvis radiographs and dynamic magnetic resonance imaging (MRI) scans for SI joints were obtained simultaneously in all patients who developed inflammatory back pain.

Results.

Fifty-nine children with ERA were studied; 40 male, 19 female; median age at disease onset 9 years 4 months (range 6 yrs 6 mo – 13 yrs 3 mo). At a median interval after disease onset of 1 year 3 months, 21 children reported symptoms of inflammatory back pain. In all cases, radiographs of SI joints were negative, while dynamic MRI revealed acute sacroiliitis in 17 cases. Multivariate analysis showed that the early predictors of SI were the number of active joints (p < 0.03) and the number of active entheses (p < 0.001) at onset.

Conclusion.

In our cohort, roughly 30% of children with ERA/juvenile idiopathic arthritis develop clinical and MRI evidence of sacroiliitis, detectable with dynamic MRI as early as 1 year after disease onset. Additional data from larger case series are needed to assess the specificity and sensitivity of this technique in the early phase of the disease and to confirm the rate of SI involvement reported in this cohort.

Classification of juvenile spondyloarthritis: Enthesitis-related arthritis and beyond

Spondyloarthritis (SpA) refers to a spectrum of immune-mediated inflammatory diseases with overlapping features, which differ from other types of inflammatory arthritis in genetic predisposition, pathogenesis and outcome. SpA frequently involves the axial skeleton, and can result in abnormal bone formation with eventual ankylosis of the spine, resulting in substantial disability. SpA often begins as an 'undifferentiated' disease, the presentation of which differs in children and adults; most notably, spinal involvement is uncommon, while hip arthritis and enthesitis are frequently seen in juvenile-onset disease. Currently, the classification of SpA in adults and children is approached differently. Using the International League of Associations for Rheumatology (ILAR) system for juvenile idiopathic arthritis, most childhood SpA is classified as enthesitis-related arthritis. However, in contrast to adult SpA classification, the presence of, or a family history of, psoriasis dictates a separate category of juvenile idiopathic arthritis. More importantly, the ILAR system does not specifically recognize the presence of axial disease in juvenile SpA. Resolution of these issues will improve communication and the transitioning of patients from pediatric to adult clinics, will facilitate research in genetics and pathogenesis, and will be particularly important in the evaluation of tumor necrosis factor inhibitors and other biologic agents for early, axial SpA.

An overview of genetics of paediatric rheumatic diseases

The evidence so far suggests that the paediatric inflammatory diseases encountered in rheumatology practice may be largely genetic in origin, where common single nucleotide polymorphisms (SNPs) in multiple genes contribute to risk, with real but variable environmental components. As far as genetic susceptibility to common paediatric rheumatic diseases is concerned, only juvenile idiopathic arthritis (JIA) has been investigated in any substantial way so far. This article discusses susceptibility for different types of JIA, the different methods used and their advantages and disadvantages. The genetic code is also modifiable by epigenetic mechanisms and examples of these in immunity and rheumatoid arthritis are given to indicate another area of research in the elucidation of the genetics of paediatric rheumatic diseases.

Pattern of disease onset, diagnostic delay, and clinical features in juvenile onset and adult onset ankylosing spondylitis

OBJECTIVE

To assess the frequency of juvenile onset ankylosing spondylitis (JOAS) in Turkish patients with AS and to compare with adult onset AS (AOAS) in a cross-sectional study design.

METHODS

A total of 322 patients were recruited from the joint database of 5 university hospitals in eastern Turkey.

RESULTS

Patients with JOAS (n = 43, 13.4%) had significantly longer diagnostic delay (9.21 vs 5.08 yrs), less severe axial involvement and more prevalent uveitis (OR 2.92, 95% CI 1.25-6.79), and peripheral involvement at onset (OR 3.25, 95% CI 1.51-6.98, adjusted for current age; and OR 2.26, 95% CI 1.07-4.76, adjusted for disease duration). Patients with AOAS had higher radiographic scores and more restricted clinimetrics but similar functional limitations and quality of life.

CONCLUSION

JOAS and AOAS had distinctive courses and Turkish patients with AS had similar features compared to other Caucasian patient populations.

Differences between juvenile-onset ankylosing spondylitis and adult-onset ankylosing spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory disease, which involves the spine, peripheral joints and entheses. Juvenile-onset ankylosing spondylitis (JAS) affects children under the age of 16 years. JAS has been noted to present as clinical courses different from those of adult-onset ankylosing spondylitis (AAS). Therefore, the purpose of the present study was to compare the possible risk factors, clinical manifestations, laboratory markers, radiological changes, and functional outcome between these 2 patient groups.

METHODS

AS patients were enrolled from the rheumatologic clinic of a tertiary medical center from January 1 to June 30 in 2006. The demographic data, clinical symptoms/signs, Bath AS indices, HLA-B27, inflammatory markers, radiological findings, and treatment history were acquired with questionnaires, clinical evaluation, and chart review. The differences between JAS and AAS patients were evaluated and analyzed.

RESULTS

A total of 169 patients (142 males, 27 females) were included, comprising 47 JAS and 122 AAS patients. The ages of onset were 12.8 +/- 2.7 years and 25.0 +/- 7.4 years for JAS and AAS, respectively. They had similar gender distribution, years of delay to diagnosis and disease duration. A substantial proportion of our patients (40.4% of JAS and 34.4% of AAS) had physical trauma in the 1 month before disease onset. Also, 22.7% of JAS patients had intense physical training, while 25.2% of AAS patients did heavy work during the period. The first manifestation of JAS was mainly peripheral enthesopathy or arthritis, but axial symptoms in most AAS. More JAS patients had peripheral enthesopathies and arthritis on any occasion. Although there was a trend of higher score in Bath AS Disease Activity Index (BASDAI), Bath AS Metrology Index (BASMI) and Physician's Global Assessment (PGA) score, JAS patients had a comparable Bath AS Functional Index (BASFI) and Bath AS Patient's Global Assessment (BAS-G) as AAS patients. As to the laboratory and radiological tests, JAS patients had higher levels of C-reactive protein and erythrocyte sedimentation rate, and more radiographic changes of hip joints.

CONCLUSION

JAS and AAS patients had distinct presentations. JAS presented more peripheral enthesopathies and arthritis at disease onset and at any time of the course. If treated effectively, JAS will not lead to a worse functional outcome than AAS. Therefore, it is mandatory to diagnose and treat JAS as early as possible.