Juvenile Spondyloarthritis: A Distinct Form of Juvenile Arthritis

Whole-Body MRI at Initial Presentation of Chronic Recurrent Multifocal Osteomyelitis, Juvenile Idiopathic Arthritis, Their Overlapping Syndrome, and Non-Specific Arthropathy

(1) Background: Whole-body magnetic resonance imaging (WB-MRI) is central to defining total inflammatory burden in juveniles with arthritis. Our aim was to determine and compare the initial distribution of lesions in the WB-MRI in patients with chronic recurrent multifocal osteomyelitis (CRMO), juvenile idiopathic arthritis (JIA), their overlapping syndrome (OS), and with Non-specific Arthropathy (NA). (2) Methods: This retrospective single center study was performed on an Avanto 1.5-T MRI scanner with a dedicated multichannel surface coil system. A total of 173 pediatric patients were included with the following final diagnoses: CRMO (15.0%), JIA (29.5%), OS (4.6%), and NA (50.9%). (3) Results: Bone marrow edema (BME) was the most common abnormality, being seen in 100% patients with CRMO, 88% with OS, 55% with JIA, and 11% with NA. The bones of the lower extremities were the most affected in all compared entities. Effusion was seen in 62.5% children with OS, and in 52.9% with JIA, and in CRMO and NA, the exudate was sporadic. Enthesitis was found in 7.8% of patients with JIA and 3.8% with CRMO, and myositis was seen in 12.5% of patients with OS and in 3.9% with JIA. (4) Conclusions: The most frequent indication for WB-MRI in our center was JIA. The most common pathology in all rheumatic entities was BME, followed by effusion mainly seen in in OS and JIA. Enthesitis and myositis were less common; no case was observed in NA.

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.

MRI for axial SpA: Diagnosis, disease activity assessment, and recent advances

Magnetic resonance imaging (MRI) is a sensitive imaging modality to detect early inflammatory changes in axial spondyloarthritis (SpA). Over a decade has passed since the inclusion of MRI assessment in the 2009 Assessment of SpondyloArthritis International Society (ASAS) classification criteria for axial SpA. Evidence and clinical experience of MRI in axial SpA have accumulated rapidly since. This has led to a better understanding of the clinical utility of MRI in early diagnosis, disease activity assessment, and monitoring of treatment response in axial SpA. Furthermore, technological advancements have paved the way for the development of novel MRI sequences for the quantification of inflammation and image optimization. The field of artificial intelligence has also been explored to aid medical imaging interpretation, including MRI in axial SpA. This review serves to provide an update on the latest understanding of the evolving roles of MRI in axial SpA.

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.

Advances in the Diagnosis and Treatment of Enthesitis-Related Arthritis

Enthesitis-related arthritis (ERA) represents 5-30% of all cases of juvenile idiopathic arthritis (JIA) and belongs to the spectrum of the disorders included in the group of juvenile spondyloarthritis. In the last decade, there have been considerable advances in the classification, diagnosis, monitoring, and treatment of ERA. New provisional criteria for ERA have been recently proposed by the Paediatric Rheumatology INternational Trials Organisation, as part of a wider revision of the International League of Associations for Rheumatology criteria for JIA. The increased use of magnetic resonance imaging has shown that a high proportion of patients with ERA present a subclinical axial disease. Diverse instruments can be used to assess the disease activity of ERA. The therapeutic recommendations for ERA are comparable to those applied to other non-systemic JIA categories, unless axial disease and/or enthesitis are present. In such cases, the early use of a TNF-alpha inhibitor is recommended. Novel treatment agents are promising, including IL-17/IL-23 or JAK/STAT pathways blockers.

Juvenile idiopathic arthritis and its associated uveitis

INTRODUCTION

Juvenile idiopathic arthritis is the most common chronic rheumatologic disease in children. Uveitis is the most common extra-articular manifestation of JIA, and it can be a sight-threatening condition.

AREAS COVERED

In this review article, we discussed epidemiology, risk factors, clinical presentation, supportive laboratory tests, treatment options, and complications of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis associated uveitis. We covered conventional immunomodulatory therapy and biologic response modifiers agents for different types of Juvenile idiopathic arthritis and their associated uveitis. Finally, we discussed the course of disease, functional outcome, and the quality of life of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis-associated uveitis.

EXPERT OPINION

Although clinical outcomes of Juvenile idiopathic arthritis and its associated uveitis have been improved over the past three decades by biologic response modifier agents, a significant proportion of patients require active treatment into adult life therefore screening and monitoring of these patients is required during the patient's entire life. The limited number of food and drug administration approved biologic response modifier agents for the treatment of Juvenile idiopathic arthritis associated uveitis justify more randomized clinical trials with new medications in this field.

MRI in pediatric sacroiliitis, what radiologists should know

MRI is used for early detection of inflammation of sacroiliac joints as it shows active lesions of sacroiliitis long before radiographs show damage to the sacroiliac joints. Early diagnosis of arthritis allows early treatment of inflammation and can help delay disease progression and prevent irreversible damage. Also, early identification of axial involvement in juvenile spondyloarthropathy is crucial, as treatment options are different than for peripheral juvenile spondyloarthropathy. In general, standard sequences used in adults are also applied to children. However, interpreting MR images of pediatric sacroiliac joints is more challenging than in adults, because of normal physiological changes during skeletal maturation, which can simulate disease on MR images. Furthermore, classical definitions of sacroiliitis used in adults, for both active inflammatory and structural lesions, can be difficult to extrapolate to children. The development of reliable pediatric-specific definitions for sacroiliitis is still in active study. Understanding both normal and pathological signal changes in children is important to distinguish physiologic findings from disease and to make a correct diagnosis. In this review, the main imaging characteristics of sacroiliitis on MRI in children and its frequent pitfalls will be illustrated, while also citing some discussion points regarding the scan protocol.

Evaluation and Treatment of the Child with Acute Back Pain

Back pain is common, in up to 30% of children, increasing with age. Eighty percent is benign, mechanical type, improving within 2 weeks of conservative care. Required for those not improving is in-depth evaluation, including MRI, laboratory, and peer consultations. Spondylolysis and spondylolisthesis comprise almost 10% of pediatric back pain, often caused by lumbar hyperextension activities and treated conservatively in most cases. Osteoid osteomas and osteoblastomas constitute the most common benign spinal tumors in childhood. Aggressive and malignant tumors of the spine are rare but when present require tertiary care referral and a comprehensive oncology team for optimal life-sustaining outcomes.

High prevalence of sacroiliitis and early structural changes in the sacroiliac joint in children with enthesitis-related arthritis: findings from a tertiary centre in Hong Kong

BACKGROUND

Epidemiological studies have demonstrated a wide, unexplained disparity in the prevalence of juvenile idiopathic arthritis (JIA) subtypes depending on geographical location, ethnicity and other factors. Enthesitis-related arthritis (ERA) is more prevalent in Southeast Asia. Axial involvement in ERA patients is increasingly recognised to occur early in the disease course. Inflammation in the sacroiliac joint (SIJ) observed on MRI seems highly predictive of subsequent structural radiographic progression. The resulting structural damage can have significant impacts on both functional status and spinal mobility. This study aimed to evaluate the clinical characteristics of ERA in a tertiary centre in Hong Kong. The primary objective of the study was to provide a comprehensive description of the clinical course and radiological findings of the SIJ among ERA patients.

METHOD

Paediatric patients diagnosed with JIA attending the paediatric rheumatology clinic from January 1990 to December 2020 were recruited from our registry based at the Prince of Wales Hospital.

RESULTS

In our cohort, 101 children were included. The median age of diagnosis was 11 years, interquartile range (IQR) 8-15 years. The median follow-up duration was 7 years (IQR 2-11.5 years). ERA was the most prevalent subtype (40%), followed by oligoarticular JIA (17%). Axial involvement was frequently reported in our cohort of ERA patients. 78% demonstrated radiological evidence of sacroiliitis. Among those, 81% had bilateral involvement. The median duration from disease onset to confirmation of radiological sacroiliitis was 17 months (IQR 4-62 months). Among the ERA patients, 73% had structural changes of the SIJ. Alarmingly, 70% of these patients had already developed radiological structural changes when sacroiliitis was first detected on imaging (IQR 0-12 months). Erosion was the most common finding (73%), followed by sclerosis (63%), joint space narrowing (23%), ankylosis (7%) and fatty change (3%). The duration from symptom onset to diagnosis was significantly longer in ERA patients with SIJ structural changes (9 vs 2 months, p = 0.009), comparing with those without.

CONCLUSION

We found that a high proportion of ERA patients had sacroiliitis and a significant number of them had radiological structural changes during early disease. Our findings illustrate the importance of prompt diagnosis and early treatment in these children.

Modified Juvenile Spondyloarthritis Disease Activity Index in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry

OBJECTIVE

To validate the Juvenile Spondyloarthritis Disease Activity Index (JSpADA), and modified versions thereof, in a North American cohort of patients with enthesitis-related arthritis (ERA).

METHODS

We utilized the Childhood Arthritis and Rheumatology Research Alliance Registry database ERA cohort to validate the JSpADA and its modifications (JSpADA6-no Schober, no C-reactive protein [CRP]/erythrocyte sedimentation rate [ESR]; JSpADA7-no Schober; and JSpADA7-no CRP/ESR) using the Outcome Measures in Rheumatology principles of face validity, discriminative validity, and responsiveness to change.

RESULTS

There were 51 subjects (64 visits) with complete JSpADA data with a mean age of 13.7 years and disease duration of 30.9 months. Subjects were predominantly White (84.3%), and 56.9% were male and 50% were HLA-B27 positive. The JSpADA showed high correlation with the clinical 10-joint Juvenile Arthritis Disease Activity Score (cJADAS10; r = 0.81), moderate-to-high correlation with physician global assessment (PGA; r = 0.69), and low-to-fair correlation with Childhood Health Assessment Questionnaire (CHAQ; r = 0.22). The modifications of the JSpADA (JSpADA7-no Schober; JSpADA7-no CRP/ESR; and JSpADA6-no Schober, no CRP/ESR) performed similarly with high correlation with cJADAS10 (r = 0.81, 0.79, and 0.80, respectively), moderate-to-high correlation with PGA (r = 0.65, 0.67, 0.64, respectively), and low-to-fair correlation with CHAQ (r = 0.35, 0.34, 0.39, respectively). All modified versions of JSpADA had good responsiveness to change. All versions of JSpADA had excellent discriminative validity.

CONCLUSION

We propose the term modified JSpADA for the modification of JSpADA with 6 elements (JSpADA6-no Schober, no CRP/ESR). This shorter disease activity index may improve implementation of JSpADA in both clinical practice and research trials.

Seronegative spondyloarthropathy-associated inflammatory bowel disease

Seronegative spondyloarthropathy (SpA) usually starts in the third decade of life with negative rheumatoid factor, human leukocyte antigen-B27 genetic marker and clinical features of spinal and peripheral arthritis, dactylitis, enthesitis and extra-articular manifestations (EAMs). Cases can be classified as ankylosing spondylitis, psoriatic arthritis, reactive arthritis, enteropathic arthritis, or juvenile-onset spondyloarthritis. Joint and gut inflammation is intricately linked in SpA and inflammatory bowel disease (IBD), with shared genetic and immunopathogenic mechanisms. IBD is a common EAM in SpA patients, while extraintestinal manifestations in IBD patients mostly affect the joints. Although individual protocols are available for the management of each disease, the standard therapeutic guidelines of SpA-associated IBD patients remain to be established. Nonsteroidal anti-inflammatory drugs are recommended as initial therapy of peripheral and axial SpA, whereas their use is controversial in IBD due to associated disease flares. Conventional disease-modifying anti-rheumatic drugs are beneficial for peripheral arthritis but ineffective for axial SpA or IBD therapy. Anti-tumor necrosis factor monoclonal antibodies are effective medications with indicated use in SpA and IBD, and a drug of choice for treating SpA-associated IBD. Janus kinase inhibitors, approved for treating SpA and ulcerative colitis, are promising therapeutics in SpA coexistent with ulcerative colitis. A tight collaboration between gastroenterologists and rheumatologists with mutual referral from early accurate diagnosis to appropriately prompt therapy is required in this complex clinical scenario.

Juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is an umbrella term for arthritis of unknown origin, lasting for >6 weeks with onset before 16 years of age. JIA is the most common chronic inflammatory rheumatic condition of childhood. According to the International League Against Rheumatism (ILAR) classification, seven mutually exclusive categories of JIA exist based on disease manifestations during the first 6 months of disease. Although the ILAR classification has been useful to foster research, it has been criticized mainly as it does not distinguish those forms of chronic arthritis observed in adults and in children from those that may be unique to childhood. Hence, efforts to provide a new evidence-based classification are ongoing. Similar to arthritis observed in adults, pathogenesis involves autoimmune and autoinflammatory mechanisms. The field has witnessed a remarkable improvement in therapeutic possibilities of JIA owing to the availability of new potent drugs and the possibility to perform controlled trials with support from legislative interventions and large networks availability. The goal of drug therapy in JIA is to rapidly reduce disease activity to inactive disease or clinical remission, minimize drug side effects and achieve a quality of life comparable to that of healthy peers. As JIA can influence all aspects of a child's and their family's life, researchers increasingly recognize improvement of health-related quality of life as a key treatment goal.

2022 French Society for Rheumatology (SFR) recommendations on the everyday management of patients with spondyloarthritis, including psoriatic arthritis

OBJECTIVE

Update the French Society for Rheumatology (SFR) recommendations on the everyday management of patients with spondyloarthritis, including psoriatic arthritis.

METHODS

Following standardized procedures, a systematic literature review was done by four supervised rheumatology residents based on questions defined by a task force of 16 attending rheumatologists. The findings were reviewed during three working meetings that culminated in each recommendation receiving a grade and the level of agreement among experts being determined.

RESULTS

Five general principles and 15 recommendations were developed. They take into account pharmacological and non-pharmacological measures along with treatment methods based on the dominant phenotype present (axial, articular, enthesitis/dactylitis) and the extra-articular manifestations (psoriasis, inflammatory bowel disease, uveitis). NSAIDs are the first-line pharmacological treatment in the various presentations. Conventional synthetic disease modifying antirheumatic drugs (csDMARDs) are not indicated in the axial and isolated entheseal forms. If the response to conventional treatment is not adequate, targeted therapies (biologics, synthetics) should be considered; the indications depend on the clinical phenotype and presence of extra-articular manifestations.

CONCLUSION

This update incorporates recent data (published since the prior update in 2018) and the predominant clinical phenotype concept. It aims to help physicians with the everyday management of patients affected by spondyloarthritis, including psoriatic arthritis.

Feasibility of T2 Mapping of the Sacroiliac Joints in Healthy Control Subjects and Children and Young Adults with Sacroiliitis

OBJECTIVE

To assess the feasibility of T2 mapping for evaluating pediatric SIJ cartilage at 3 Tesla (T) magnetic resonance imaging (MRI).

METHODS

Healthy control subjects and adolescents with sacroiliitis underwent a 3T MRI dedicated pelvic protocol that included a T2 mapping sequence consisting of multislice, multiecho acquisition. Healthy control subjects were prospectively recruited from our primary care practices as part of a larger imaging study, whereas adolescents with sacroiliitis were recruited specifically for this study. Regions of interest (ROIs) were hand-drawn by a senior pediatric radiologist twice and a radiology fellow twice to calibrate and test reliability using the intraclass correlation coefficient (ICC). T2 relaxation time between control subjects and cases was compared using univariate linear regression. We tested the association of T2 relaxation time in adolescents with sacroiliitis with patient-reported outcomes and the Spondyloarthritis Research Consortium of Canada sacroiliac joint (SIJ) inflammation and structural scores using Pearson correlation coefficients.

RESULTS

Fourteen subjects were evaluable (six control subjects: median age 13.7 years [interquartile range (IQR): 12.2-15.5], 67% male patients; eight cases: median age 17.4 years [IQR: 12.5-20], 88% male patients]. Acquisition time for T2 mapping sequences was approximately 6 minutes, and segmenting the ROI for each SIJ took approximately 3 minutes. The intrarater and inter-rater ICCs were 0.67 and 0.46, respectively, indicating good to fair reliability. There was a trend, albeit statistically insignificant, in longer median T2 relaxation time in cases (43.04 ms; IQR: 41.25-49.76 ms) versus healthy control subjects (40.0 ms; IQR: 38.9-48.6 ms). Although not statistically significant, cases with longer T2 relaxation time tended to occur with poorer patient-reported outcomes. Correlations with the SIJ inflammation and structural lesion scores were weak.

CONCLUSION

T2 mapping of the SIJ cartilage in children was feasible and reliable. Larger controlled and longitudinal assessments are needed to assess the validity and utility of these measurements for routine clinical practice and trials.

Torticollis as a Sole Presentation of Spondyloarthritis in a 4-Year-Old Child

Spondyloarthritis presents in various and occasionally unusual ways that imitates other diseases. Without forthcoming risk factors, such atypical presentation may elude diagnosis for months. The case presented here of a child, aged 4 years, who is negative for human leukocyte antigen B27 (HLA-B27) and with no family history of HLA-B27 related disease, who developed torticollis with neck pain and lymphadenopathy, highlights the necessity of continually evaluating a diagnosis, especially when treatment fails to produce expected results. Painful torticollis in a child with adenopathy often is infectious in nature or potentially due to Griesel syndrome when persistent. Chronic arthritis of the cervical spine may enter the differential diagnosis when torticollis is persistent, and early recognition and aggressive treatment is necessary to prevent permanent functional impairment.

Langfristentwicklungen in der Kinder- und Jugendrheumatologie

Im Gebiet der Kinderrheumatologie gab es in den letzten Jahrzehnten immense Fortschritte, die sowohl die Diagnostik, als auch die Therapie nachhaltig verbessert haben. Obwohl erst seit 2003 in Deutschland offiziell als Zusatzbezeichnung anerkannt, stehen heutzutage über 200 Kinder- und Jugendrheumatologen (d. h. 1,4 Kinderrheumatologen pro 100 000 Kinder) für die Erkennung und Behandlung von rheumatischen Erkrankungen bei Kindern und Jugendlichen bundesweit zur Verfügung. Neue Erkenntnisse in der Pathogenese rheumatischer Erkrankungen und die sich stetig weiterentwickelnde genetische Diagnostik haben das rheumatische Krankheitsspektrum und die Behandlungsmöglichkeiten dramatisch erweitert Internationale Forschungsnetzwerke und eine spezielle Gesetzgebung für die Entwicklung von pädiatrischen Medikamenten führten zur Zulassung von zahlreichen neuen Rheumamedikamenten, deren Sicherheit im klinischen Alltag seit der Jahrtausendwende systematisch in Deutschland untersucht wird. Maßnahmen zur Sicherung der Versorgungsqualität wurden implementiert, Standardinstrumente zur Bewertung der Krankheitsaktivität und Krankheitslast aus Patientensicht eingeführt sowie Initiativen zur Verbesserung der Versorgung Betroffener (z. B. die ProKind-Initiative) auf den Weg gebracht. Diese Veränderungen haben die Prognose und Lebensperspektive rheumakranker Kinder und Jugendlicher verbessert, wenngleich noch weiterer Optimierungsbedarf besteht.

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.

[Polyarticular juvenile idiopathic arthritis and rheumatoid arthritis : Common features and differences]

The spectrum of polyarthritic diseases in childhood as well as in adulthood is wide. In the differential diagnostics different age-related diseases must be taken into consideration. Although, a clear similarity is obvious in all age groups for the classical diseases of polyarticular juvenile idiopathic arthritis and rheumatoid arthritis with respect to the pathogenesis, clinical manifestation and treatment options, this review points to specific differences. The prognosis of polyarthritis in children mainly depends on the joint manifestation, whereas extra-articular comorbidities play a predominant role in the older adult population.

Immunopathophysiology of Juvenile Spondyloarthritis (jSpA): The "Out of the Box" View on Epigenetics, Neuroendocrine Pathways and Role of the Macrophage Migration Inhibitory Factor (MIF)

Juvenile spondyloarthritis (jSpA) is a an umbrella term for heterogeneous group of related seronegative inflammatory disorders sharing common symptoms. Although it mainly affects children and adolescents, it often remains active during adulthood. Genetic and environmental factors are involved in its occurrence, although the exact underlying immunopathophysiology remains incompletely elucidated. Accumulated evidence suggests that, in affected patients, subclinical gut inflammation caused by intestinal dysbiosis, is pivotal to the future development of synovial-entheseal complex inflammation. While the predominant role of IL17/23 axis, TNF-α, and IL-7 in the pathophysiology of SpA, including jSpA, is firmly established, the role of the cytokine macrophage migration inhibitory factor (MIF) is generally overlooked. The purpose of this review is to discuss and emphasize the role of epigenetics, neuroendocrine pathways and the hypothalamic-pituitary (HPA) axis, and to propose a novel hypothesis of the role of decreased NLRP3 gene expression and possibly MIF in the early phases of jSpA development. The decreased NLRP3 gene expression in the latter, due to hypomethylation of promotor site, is (one of) the cause for inflammasome malfunction leading to gut dysbiosis observed in patients with early jSpA. In addition, we highlight the role of MIF in the complex innate, adaptive cellular and main effector cytokine network, Finally, since treatment of advanced bone pathology in SpA remains an unmet clinical need, I suggest possible new drug targets with the aim to ultimately improve treatment efficacy and long-term outcome of jSpA patients.

Juvenile Idiopathic Arthritis Treatment Updates

Juvenile idiopathic arthritis is a group of heterogeneous chronic inflammatory arthropathies occurring in childhood without a known cause. This article discusses the key clinical features of juvenile idiopathic arthritis and treatment updates for oligoarthritis, polyarthritis, enthesitis-related arthritis, psoriatic arthritis, and systemic arthritis. Paradigm changes in management include the earlier use of biologic agents and the introduction of biosimilars and targeted synthetic disease modifying agents like tofacitinib. This review summarizes recent developments while considering potential areas for improvement and study.

Outcomes in Juvenile-Onset Spondyloarthritis

Some studies have suggested children with juvenile onset spondyloarthritis (JoSpA) have a relatively poor outcome compared to other juvenile idiopathic arthritis (JIA) categories, in regards to functional status and failure to attain remission. Thus, in the interest of earlier recognition and risk stratification, awareness of the unique characteristics of this group is critical. Herein, we review the clinical burden of disease, prognostic indicators and outcomes in JoSpA. Of note, although children exhibit less axial disease at onset compared to adults with spondyloarthritis (SpA), 34–62% have magnetic resonance imaging (MRI) evidence for active inflammation in the absence of reported back pain. Furthermore, some studies have reported that more than half of children with “enthesitis related arthritis” (ERA) develop axial disease within 5 years of diagnosis. Axial disease, and more specifically sacroiliitis, portends continued active disease. The advent of TNF inhibitors has promised to be a “game changer,” given their relatively high efficacy for enthesitis and axial disease. However, the real world experience in various cohorts since the introduction of more widespread TNF inhibitor usage, in which greater than a third still have persistently active disease, suggests there is still work to be done in developing new therapies and improving the outlook for JoSpA.

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

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

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

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

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

Spondyloarthritis evolution: what is in your history?

PURPOSE OF REVIEW

This review encompasses a detailed history of spondyloarthritis (SpA) evolution as early as the 17th century, continues on to the current concept of SpA, and ends with current gaps in our understandings of SpA.

RECENT FINDINGS

Until the early 1960s, ankylosing spondylitis and other SpA family members were considered to be variants of rheumatoid arthritis (RA). The formal medical community separated them from RA at that time, and shortly thereafter they were recognized to be inter-connected based on shared clinical, laboratory, and imaging features. The last two decades have witnessed the formal distinction between axial and peripheral SpA and the connections that exist between nonradiographic and radiographic axial SpA. Recent studies have revealed different microbial compositions among patients with SpA and healthy controls and also between HLA-B27 positive and negative healthy individuals.

SUMMARY

Further investigation of the roles of intestinal microbiome and physical force transduction toward SpA pathogenesis, strategies to improve delay in SpA diagnosis, biomarkers to better predict radiographic progression, and modification of current classification criteria to better address the axial and peripheral groups are gaps in our understandings that pose top priorities for SpA research.

A 2-year longitudinal study of bone health in adolescent patients with axial spondyloarthritis

PURPOSE

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that primarily affects the axial skeleton and typically has an early onset. Although earlier onset is associated with worse prognosis, there have been few studies of bone mineral density (BMD) in adolescent patients with axSpA.

METHODS

We analysed the clinical characteristics of 43 adolescent patients with axSpA at a baseline assessment and at a follow-up 2 years later. The baseline assessment included age, disease duration, treatment agents, and clinical, radiologic, and laboratory data. BMD of the lumbar spine, femoral neck, and total hip were measured by dual-energy X-ray absorptiometry during both the baseline assessment and the 2-year follow-up. We performed multivariate linear regression analyses to identify factors independently associated with BMD. We analysed the associations between changes in BMD and reductions in inflammatory markers.

RESULTS

The average age of participants was 17.9 years and the mean disease duration was 2.2 years. Of the 43 patients, 10 (23%) had low BMD at any site (lumbar spine, femoral neck, and/or total hip). At baseline, multivariate analysis showed that body mass index (BMI), erythrocyte sedimentation rate (ESR), and spinal structural damage were associated with lumbar spine Z-scores. Increases in BMD in the lumbar spine were correlated with reductions in ESR (r = 0.40, P = 0.02) and C-reactive protein (CRP) (r = 0.40, P = 0.02). Increases in BMD in the total hip were correlated with reductions in CRP (r = 0.38, P = 0.03).

CONCLUSION

In adolescent axSpA patients, bone health was associated with systemic inflammation and the severity of structural damage. Reduced systemic inflammation was associated with improvements in bone health.

Juvenile Spondyloarthritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: High Biologic Use, Low Prevalence of HLA-B27, and Equal Sex Representation in Sacroiliitis

OBJECTIVE

To describe characteristics of children with enthesitis-related arthritis (ERA) and juvenile psoriatic arthritis (PsA) who were enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry.

METHODS

All children with ERA and those with juvenile PsA were identified. Demographic characteristics, clinical characteristics, and treatments were described. The children with sacroiliitis and those without sacroiliitis were compared. In the children with sacroiliitis, the first visit with clinically active sacroiliitis (which came first in 72% of cases) was compared to the first visit without clinically active sacroiliitis.

RESULTS

A total of 902 children with ERA or juvenile PsA were identified. Children with ERA were older at diagnosis (ages 10.8 years versus 8.2 years; P < 0.01) and were more likely to be male (56% versus 38%; P < 0.01). Polyarticular involvement was reported in 57% of children with ERA and in 72% of those with juvenile PsA. Of the children tested, HLA-B27 was positive in 38% of those in the ERA group and in 12% of those in the juvenile PsA group. At least 1 biologic was taken by 72% of those with ERA and 64% of those with juvenile PsA. Sacroiliitis (diagnosed clinically and/or by imaging) was reported in 28% of the children (40% of those with ERA and 12% of those with juvenile PsA). Of these, 54% of the children were female, 36% were HLA-B27 positive, and 81% took at least 1 biologic. In children with sacroiliitis, scores according to the physician global assessment of disease activity, parent/patient global assessment of well-being, and clinical Juvenile Arthritis Disease Activity Score 10 were all significantly worse at the first visit with clinically active sacroiliitis versus the first visit without active sacroiliitis.

CONCLUSION

In this registry, there are more than 900 children with ERA or juvenile PsA. There was high biologic use in this population, especially in those with sacroiliitis. Further, there was equal sex representation in those children with sacroiliitis.

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.

Juvenile Spondyloarthritis: focus on uveitis

BACKGROUND

Juvenile spondyloarthritis (JSpA) represents a group of inflammatory arthritides with several distinctive features (enthesitis, involvement of spine and sacroiliac joint, HLA-B27 association and development of uveitis). There are limited data on the course of uveitis in children with JSpA. This study aims to estimate the prevalence of uveitis and to look at the presence of HLA-B27 in relation to uveitis occurrence and ocular symptoms in a cohort of JSpA patients.

FINDINGS

This is a cross sectional/retrospective study involving patients with JSpA followed in a tertiary referral hospital. Two hundred twenty-three patients were enrolled in the study. The prevalent diagnosis was enthesitis-related arthritis (ERA) (62%) followed by juvenile psoriatic arthritis (PsA), undifferentiated arthritis (UA), and the arthropathies associated with inflammatory bowel disease (IBD-A) (18, 14, 6%, respectively). Uveitis was reported in twenty-four patients (11%) of the JSpA cohort (JSpA-U). ERA patients had the highest uveitis prevalence (ERA-U) (13%) with similar prevalences in UA, PsA and in IBD-A (7% each). The prevalence of HLA-B27 positivity was similar amongst the entire JSpA-U cohort (N = 22, 45%) and those with ERA-U (N = 8, 44%). The overall prevalence of symptomatic uveitis was 79%. Neither the likelihood of uveitis, nor of symptomatic uveitis, varied by HLA-B27 status either in the entire cohort nor in those with ERA.

CONCLUSIONS

About one-tenth of patients developed uveitis, the majority of which was symptomatic. Fewer than half of the patients with uveitis were HLA-B27 positive. HLA-B27 status was not statistically associated with either the development of uveitis or symptomaticity of uveitis.

Pharmacotherapy for juvenile spondyloarthritis: an overview of the available therapies

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Is axial magnetic resonance imaging useful in early juvenile spondyloarthritis-preliminary report

INTRODUCTION/OBJECTIVES

Magnetic resonance imaging (MRI) is recommended for evaluation of changes in juvenile spondyloarthropathies (JSpA). To our knowledge, there is no previous prospective study analysing early changes on axial MRI. The objective is to investigate incidence of reparable changes on axial MRI in patients with established JSpA, lasting for less than 6 months.

MATERIALS AND METHODS

The pilot study included 27 patients with confirmed diagnosis of JSpA examined within 2 years. Prior to imaging, basic demographic and laboratory data and HLA-B27 were collected. Patients filled out a visual analogue scale for pain and a childhood health assessment questionnaire. A paediatric rheumatologist and a paediatric physiatrist examined patients and measured indices of flexion, extension and sagittal flexibility. Contrast-enhanced axial MRI examination and cervical x-ray were performed. Three experienced paediatric radiologists independently reviewed x-ray and MRI images of all patients.

RESULTS

There was no significant correlation between early changes detected on MRI and other parameters. The study revealed early changes of the cervical spine to be the most common finding. More patients had positive cervical MRI than positive sacroiliac joint (SIJ) MRI. Cervical x-ray and MRI were equally useful for diagnosis regardless of other parameters.

CONCLUSION

Study showed new information on axial involvement, striking cervical spine as the most involved part. The biggest study limitation is the small number of patients. Establishing early JSpA diagnosis is of utmost importance, especially in the light of novel therapy introduced in every day practice. It seems that cervical spine involvement is more represented than previously described in literature, especially in comparison with SIJ. Key Points • Contrast-enhanced MRI is considered the gold standard for detection early changes in JSpA. • Standardization of diagnostic criteria and better classification of changes using the unique scoring system for children are necessary. • It seems that cervical spine involvement is more represented than previously described in the literature, especially in comparison with SIJ involvement.

HLA associations in inflammatory arthritis: emerging mechanisms and clinical implications

Our understanding of the mechanisms underlying HLA associations with inflammatory arthritis continues to evolve. Disease associations have been refined, and interactions of HLA genotype with other genes and environmental risk factors in determining disease risk have been identified. This Review provides basic information on the genetics and molecular function of HLA molecules, as well as general features of HLA associations with disease. Evidence is discussed regarding the various peptide-dependent and peptide-independent mechanisms by which HLA alleles might contribute to the pathogenesis of three types of inflammatory arthritis: rheumatoid arthritis, spondyloarthritis and systemic juvenile idiopathic arthritis. Also discussed are HLA allelic associations that shed light on the genetic heterogeneity of inflammatory arthritides and on the relationships between adult and paediatric forms of arthritis. Clinical implications range from improved diagnosis and outcome prediction to the possibility of using HLA associations in developing personalized strategies for the treatment and prevention of these diseases.

The Challenges and Opportunities of Classifying Childhood Arthritis

PURPOSE OF REVIEW

Childhood arthritis is in need of a new system of classification, owing to deficiencies in the International League of Associations for Rheumatology (ILAR) criteria. We briefly review the history of classification of childhood arthritis, discuss the major criticisms of the current system, and highlight current initiatives to address those concerns.

RECENT FINDINGS

Recent studies in both pediatric and adult rheumatology into the biologic basis of disease as well as the clinical patterns of presentation have informed the efforts toward developing a new classification system. Several efforts are currently underway to improve the classification of childhood arthritis, most notably the project of the Pediatric Rheumatology International Trials Organization (PRINTO). This international alliance of pediatric rheumatologists has begun a 4-step process to create new classification criteria for childhood arthritis. They are currently on step 3 of the process.