Adapted versions of the Sharp/van der Heijde score are reliable and valid for assessment of radiographic progression in juvenile idiopathic arthritis

Juvenile idiopathic arthritis

Juvenile idiopathic arthritis is a heterogeneous group of diseases characterised by arthritis of unknown origin with onset before age of 16 years. Pivotal studies in the past 5 years have led to substantial progress in various areas, ranging from disease classification to new treatments. Gene expression profiling studies have identified different immune mechanisms in distinct subtypes of the disease, and can help to redefine disease classification criteria. Moreover, immunological studies have shown that systemic juvenile idiopathic arthritis is an acquired autoinflammatory disease, and have led to successful studies of both interleukin-1 and interleukin-6 blockade. In other forms of the disease, synovial inflammation is the consequence of a disturbed balance between proinflammatory effector cells (such as T-helper-17 cells), and anti-inflammatory regulatory cells (such as FOXP3-positive regulatory T cells). Moreover, specific soluble biomarkers (S100 proteins) can guide individual treatment. Altogether these new developments in genetics, immunology, and imaging are instrumental to better define, classify, and treat patients with juvenile idiopathic arthritis.

Comparison of clinical and ultrasonographic evaluations for peripheral synovitis in juvenile idiopathic arthritis

OBJECTIVES

The characteristics of synovitis in juvenile idiopathic arthritis (JIA) are important to evaluate, as they define several clinical categories. The metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints are frequently involved. Few studies have investigated peripheral joint evaluation using ultrasonography, a sensitive tool for detecting subclinical synovitis. Our objectives here were to compare clinical and ultrasound evaluations of MCP and MTP joint synovitis and to determine the prevalence of predefined ultrasound abnormalities in JIA patients and healthy controls.

METHODS

Standardized physical and ultrasound assessments of the same joints were done in 31 consecutive patients with JIA and 41 healthy volunteers. Joint pain, motion limitation, and swelling were recorded. Ultrasonography was performed on the same joints by 2 trained sonographers who recorded synovial fluid, synovial hypertrophy, erosion, and power Doppler signal. Intraobserver reproducibility of ultrasonography was assessed.

RESULTS

Of 558 peripheral joints examined in JIA patients, 69 (12.5%) had ultrasonographic synovitis and 83 (15%) had abnormal physical findings. All the physical abnormalities were significantly associated with ultrasonographic synovitis (P < 0.0001) but agreement was low between ultrasonographic and physical findings. Ultrasonographic synovitis was most common at the feet (59.4%), where it was detected clinically in only 25% of cases. Ultrasonographic synovitis was associated with the presence of synovial fluid. Cartilage vascularization was found in 2 (4.2%) healthy controls.

CONCLUSION

Ultrasonography is useful for monitoring synovitis in JIA. Subclinical involvement of the MTP joints is common. Clinicians should be aware of the specific ultrasonographic findings in children.

Abatacept in the treatment of polyarticular JIA: development, clinical utility, and place in therapy

Juvenile idiopathic arthritis (JIA) is a group of chronic arthritides affecting children. The polyarthritis category, affecting five or more joints in the first six months, tends to be more aggressive, leading to a destructive joint disease with significant morbidity, disability, and costs to society. The current treatment regimen, which primarily combines methotrexate and tumor necrosis factor alpha (TNF-α) blockade, still leaves a significant group of patients with an inadequate response. Therefore, the development of new medications that act via other mechanisms of pathogenesis is necessary. T cell lymphocytes are key components in the immune reaction in JIA. Cytotoxic lymphocyte-associated antigen-4 (CTLA-4) is a potent inhibitor of the costimulation pathway necessary to activate T cells. Abatacept is a recombinant fusion protein comprising the extracellular part of human CTLA-4 connected to a modified Fc part of IgG-1. In a randomized, multinational, blinded withdrawal study in children with polyarticular JIA, abatacept was found to be effective in about 70% of the patients, including 39% of TNF-α blockade failures, with significantly fewer flares occurring during the withdrawal phase than in patients receiving placebo. Abatacept continued to show good efficacy in a three-year open-label extension study, with a beneficial effect on health-related quality of life. The safety profile of abatacept is generally good. In 2008, the US Food and Drug Administration approved abatacept for use in children over six years of age with JIA and a polyarticular course. In 2010, the European Medicines Agency gave approval for abatacept to be used in combination with methotrexate for those who fail at least one disease-modifying medication and TNF-α blockade.

Synovial and inflammatory diseases in childhood: role of new imaging modalities in the assessment of patients with juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) represents a group of heterogeneous diseases characterized by a chronic inflammatory process primarily targeting the synovial membrane. A persistent synovitis is associated with an increased risk of osteocartilaginous damage.With the advent of effective structure-modifying treatment for JIA, it may be possible to significantly reduce or even completely prevent structural damage and associated functional disability. The trend towards early suppression of inflammation, in order to prevent erosive disease, shifts the emphasis away from conventional radiographic detectable structural damage to the slightest traces of early joint damage, and drives the need for alternative imaging techniques more sensitive in detecting early signs of disease activity and damage. In this regard MRI and US are playing an increasing role in the evaluation of arthritic joints.This article will review the key aspects of the current status and recent important advances of imaging techniques available to investigate the child with rheumatic disease, briefly discussing conventional radiography, and particularly focusing on MRI and US. In this era of advancing imaging technology, knowledge of the relative values of available imaging techniques is necessary to optimize the management of children with JIA.

Antibodies to mutated citrullinated vimentin and antibodies to cyclic citrullinated peptides in juvenile idiopathic arthritis

BACKGROUND

The goal of the study was to assess the presence of antibodies to mutated citrullinated vimentin (anti-MCV) and cyclic citrullinated peptides (anti-CCP) in patients with juvenile idiopathic arthritis (JIA) compared with patients with other juvenile onset rheumatic diseases.

METHODS

The study included 56 patients who fulfilled the International League of Associations for Rheumatology (ILAR) classification criteria for JIA, and 17 control patients with other juvenile onset rheumatic diseases. Data on six core outcome variables and the Sharp score were collected for patients with JIA. Sera and synovial fluid, if available, were tested for anti-CCP and anti-MCV antibodies using a commercial enzyme-linked immunosorbent assay (ELISA).

RESULTS

Anti-MCV antibodies were positive in 3/56 (5.4%) and anti-CCP in 1/56 (1.8%) of patients with JIA. Two out of three anti-MCV positive patients (one of them also anti-CCP positive) were found to be rheumatoid factor (RF)-positive with polyarticular disease. Within the control group, anti-MCV was positive in 4/17 (23.5%) patients, while anti-CCP positivity was not observed. No correlation between anti-MCV with anti-CCP antibody levels was found for any of the six core outcome variables or for the adapted Sharp score.

CONCLUSIONS

Our results show that antibodies targeting citrullinated proteins are not a useful diagnostic marker for JIA, but can indicate severe patterns of disease in JIA.

Development and Initial Validation of a Radiographic Scoring System for the Hip in Juvenile Idiopathic Arthritis

Objective.

To develop and validate a radiographic scoring system for the assessment of radiographic damage in the hip joint in patients with juvenile idiopathic arthritis (JIA).

Methods.

The Childhood Arthritis Radiographic Score of the Hip (CARSH) assesses and scores these radiographic abnormalities: joint space narrowing (JSN), erosion, growth abnormalities, subchondral cysts, malalignment, sclerosis of the acetabulum, and avascular necrosis of the femoral head. Score validation was accomplished by evaluating reliability and correlational, construct, and predictive validity in 148 JIA patients with hip disease who had a total of 381 hip radiographs available for study.

Results.

JSN was the most frequently observed radiographic abnormality, followed by erosion and sclerosis of the acetabulum. The least common abnormalities were avascular necrosis, growth abnormalities, and malalignment. Interobserver and intraobserver reliability on baseline and longitudinal score values and on score changes was good, with intraclass correlation coefficients ranging from 0.76 to 0.98. Early score changes, but not absolute baseline score values, were moderately correlated (rs > 0.4) with clinical indicators of disease damage at last followup observation, thereby demonstrating that the CARSH has good construct and predictive validity. The amount of structural damage in the hip radiograph at last followup observation was predicted better by baseline to 1-year score change (rs = 0.66; p < 0.0001) than by absolute baseline score values (rs = 0.40; p = 0.002).

Conclusion.

Our results show that the CARSH is reliable and valid for the assessment of radiographic hip damage and its progression in patients with JIA.

Development and validation of a composite disease activity score for juvenile idiopathic arthritis

OBJECTIVE

To develop and validate a composite disease activity score for juvenile idiopathic arthritis (JIA), the Juvenile Arthritis Disease Activity Score (JADAS).

METHODS

The JADAS includes 4 measures: physician global assessment of disease activity, parent/patient global assessment of well-being, active joint count, and erythrocyte sedimentation rate. These variables are part of the American College of Rheumatology (ACR) Pediatric 30 (Pedi 30), Pedi 50, and Pedi 70 criteria for improvement. Validation analyses were conducted on >4,500 patients and included assessment of construct validity, discriminant validity, and responsiveness to change. Three versions of the JADAS were tested based on 71-joint (range 0-101), 27-joint (range 0-57), or 10-joint (range 0-40) counts. Statistical performances of the JADAS were compared with those of 2 rheumatoid arthritis composite scores, the Disease Activity Score in 28 joints (DAS28) and the Clinical Disease Activity Index (CDAI).

RESULTS

The JADAS demonstrated good construct validity, yielding strong correlations with JIA activity measures not included in the score and moderate correlations with the Childhood Health Assessment Questionnaire. Correlations obtained for the 3 JADAS versions were comparable, but superior to those yielded by the DAS28 and CDAI. The area under the curve of the JADAS predicted long-term disease outcome, measured as radiographic progression over 3 years. In 2 clinical trials, the JADAS discriminated well between ACR Pedi 30, Pedi 50, and Pedi 70 response and revealed strong responsiveness to clinical change.

CONCLUSION

The JADAS was found to be a valid instrument for assessment of disease activity in JIA and is potentially applicable in standard clinical care, observational studies, and clinical trials.