Associations between the American College of Rheumatology pediatric response measures and the continuous measures of disease activity used in adult rheumatoid arthritis: a secondary analysis of clinical trial data from children with polyarticular-course juvenile idiopathic arthritis

Bone erosions associated with systemic bone loss on HR-pQCT in women with longstanding polyarticular juvenile idiopathic arthritis

OBJECTIVES

To analyze longstanding polyarticular juvenile idiopathic arthritis (pJIA) for possible associations between localized bone damage (erosions), and systemic bone loss. Besides, to compare the systemic bone mass of pJIA with healthy controls.

METHODS

Thirty-four pJIA women and 99 healthy controls (HC) were included. Radius and tibia of all subjects were scanned by HR-pQCT. Volumetric bone mineral density (vBMD), bone microarchitecture, and -finite element parameters were analyzed. Patients underwent HR-pQCT of 2nd and 3rd metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of the dominant hand, for bone erosions quantification.

RESULTS

The mean age of patients was 31.5 ± 7.4yrs with a mean disease duration of 21.7 ± 9.2yrs. Bone erosions were detectable in 79% of patients. The number of bone erosions was positively correlated with cortical porosity (Ct.Po) at tibia (r = 0.575, p = 0.001), and radius (r = 0.423, p = 0.018); and negatively correlated with cortical vBMD at tibia (r=-0.420, p = 0.015). In a logistic regression analysis, adjusted for anti-CCP, the presence of bone erosions was independently associated with Ct.Po at radius (p = 0.018) and cortical vBMD at tibia (p = 0.020). Moreover, cortical and trabecular vBMD, trabecular number, and μ-finite element parameters were decreased in patients compared to HC (p < 0.05).

CONCLUSION

Bone erosions in longstanding pJIA women were associated with decreased cortical bone parameters, and these patients showed systemic bone impairment at peripheral sites compared with healthy controls.

Early prediction for over two years efficacy of the first biologic agent for polyarticular juvenile idiopathic arthritis: A multi-institutional study in Japan

OBJECTIVE

To estimate target of treatment for long-term efficacy of the first biologic agent used to treat polyarticular juvenile idiopathic arthritis (pJIA).

METHODS

A retrospective cohort of patients with pJIA treated at six medical institutions in Japan between 1 March 2005 and 31 October 2014 was identified. The patients were divided by 2-year treatment periods with the first biologic agent into continuous treatment group and switching group. Three markers were examined: matrix metalloproteinase-3 (MMP-3), erythrocyte sedimentation rate (ESR), and disease activity score (DAS) 28-ESR.

RESULTS

Thirty-two pJIA patients (8 boys, 24 girls) from 43 recruited patients were included in this study. The treatment periods with the first biologic agent in continuous treatment group (24 patients, 75%) was 40 months (median, range 24-119) and switching group (8 patients; 25%) was 9.5 months (median, 6-18). Markers [odds ratio (95% confidence interval)] at 3 months were MMP-3 [1.02 (0.99-1.05), p = .219], ESR [1.00 (0.78-1.30), p = .998], and DAS28-ESR [13.9 (2.08-409.82), p = .035]. The cut-off point for DAS28-ESR at 3 months to distinguish the two groups was 2.49 (sensitivity, 87.5%; specificity, 87.5%).

CONCLUSION

DAS28-ESR of 2.49 at 3 months after initiating the first biologic agent can be a target of sustained treatment in pJIA patients.

Improvement in latent variable indirect response joint modeling of a continuous and a categorical clinical endpoint in rheumatoid arthritis

Improving the quality of exposure-response modeling is important in clinical drug development. The general joint modeling of multiple endpoints is made possible in part by recent progress on the latent variable indirect response (IDR) modeling for ordered categorical endpoints. This manuscript aims to investigate, when modeling a continuous and a categorical clinical endpoint, the level of improvement achievable by joint modeling in the latent variable IDR modeling framework through the sharing of model parameters for the individual endpoints, guided by the appropriate representation of drug and placebo mechanism. This was illustrated with data from two phase III clinical trials of intravenously administered mAb X for the treatment of rheumatoid arthritis, with the 28-joint disease activity score (DAS28) and 20, 50, and 70% improvement in the American College of Rheumatology (ACR20, ACR50, and ACR70) disease severity criteria were used as efficacy endpoints. The joint modeling framework led to a parsimonious final model with reasonable performance, evaluated by visual predictive check. The results showed that, compared with the more common approach of separately modeling the endpoints, it is possible for the joint model to be more parsimonious and yet better describe the individual endpoints. In particular, the joint model may better describe one endpoint through subject-specific random effects that would not have been estimable from data of this endpoint alone.

Vitamin D concentrations and disease activity in Moroccan children with juvenile idiopathic arthritis

Background

In addition to its important metabolic activities, vitamin D also contributes to the regulation of the immune system. The aim of this study was to assess the relationship between hypovitaminosis D and disease activity in Moroccan children with juvenile idiopathic arthritis (JIA).

Methods

In this cross-sectional study, forty children with JIA were included, all having been diagnosed according to the classification criteria of International League of Associations for Rheumatology (ILAR). The children underwent anthropometric assessment and clinical evaluation. Disease activity was measured using the Disease Activity Score in 28 joints (DAS28) for polyarticular and oligoarticular JIA and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) for enthesitis-related arthritis. Serum 25-hydroxyvitamin [25(OH)D] D₂ and D₃ were measured using radioimmunoassay (RIA). Hypovitaminosis D was defined as serum 25(OH)D <30 ng/ml.

Results

The average age of participants was 11 years ± 4.23. Hypovitaminosis D was observed in 75% of patients. In univariate analyses, 25(OH)D levels were negatively associated with DAS28 for polyarticular and oligoarticular JIA. No significant relationship was found between 25(OH)D levels and BASDAI for juvenile spondylarthropathy. In multivariate linear regression analysis, no association persisted between 25(OH)D levels and DAS28.

Conclusions

Our study suggested that serum levels of vitamin D were low in Moroccan children with JIA disease. Future studies with a larger population are needed to confirm our results.

Effect of body composition on bone mineral density in Moroccan patients with juvenile idiopathic arthritis

Introduction

The link between bone mass and body composition is widely recognized, but only few works were selectively performed on subjects with juvenile idiopathic arthritis. The aim of our study was to investigate the effect of body composition on bone mineral density (BMD) in Moroccan patients with juvenile idiopathic arthritis.

Methods

Thirty three children with juvenile idiopathic arthritis (JIA) were included in a cross-sectional study. The diagnosis of JIA was made according to the criteria of the International League of Association of Rheumatology (ILAR). Body mass index (BMI) was calculated from the ratio of weight/height²(kg/m²). Pubertal status was determined according to the Tanner criteria. Bone status, body composition and bone mineral content (BMC) were analyzed by using dual-energy X-ray absorptiometry (DXA). BMD was assessed at the lumbar spine (L1-L4) and at total body in (g/cm²). Total body fat tissue mass (FTM) and lean tissue mass (LTM) were also analyzed by DXA and expressed in kilograms. In children, low BMD was defined as a Z-score less than -2 and osteoporosis was defined as a Z-score less than -2 with a fracture history.

Results

A cross-sectional study was conducted in 33 Moroccan patients with JIA aged between 4 and 16 years, Fat mass was not related to bone density; in contrast, BMD was positively associated to LTM in total body(r = =0.41, p= 0.04) but not in lumbar spine (r = 0.29, p= 0.17). There exist significant correlation between BMC and BMD in total body (r = 0.51, p = 0.01).

Conclusion

This study suggests that the LTM is a determining factor of the BMD during adolescence. Other studies with a broader sample would be useful to confirm this relation.

Do patients with juvenile idiopathic arthritis in clinical remission have evidence of persistent inflammation on 3T magnetic resonance imaging?

OBJECTIVE

Up to 90% of adults with rheumatoid arthritis (RA) in clinical remission have persistent synovitis and/or bone marrow lesions (BMLs) on magnetic resonance imaging (MRI). MRI findings in patients with juvenile idiopathic arthritis (JIA) in clinical remission have not been described. We utilized 3T MRI with contrast enhancement to examine JIA patients with hand and/or wrist involvement who were in clinical remission and compared them with a cohort of adult RA patients.

METHODS

In total, 11 JIA patients and 10 RA patients with arthritis involving the hands and/or wrists were identified by their primary rheumatologist as being in physician-defined clinical remission, having no signs or symptoms of active arthritis and no medication changes for at least 6 months. A study rheumatologist performed a joint evaluation for tenderness, swelling, and limitation of motion, and study participants self-reported tender joint counts. The participants underwent MRI with intravenous contrast enhancement of 1 hand and wrist with a history of prior symptoms. A pediatric musculoskeletal radiologist blinded to the clinical data scored the MRIs for synovitis, tenosynovitis, and/or BMLs.

RESULTS

Sixty-three percent of the JIA cohort and 70% of the RA cohort had MRI findings of synovitis, BMLs, and/or tenosynovitis. All pediatric patients with MRI abnormalities had normal physician tender and swollen joint counts. The patients' self-report of painful joint counts did not predict MRI abnormalities.

CONCLUSION

Over one-half of the patients in clinical remission had MRI evidence of persistent inflammation, defined as the presence of synovitis, tenosynovitis, or BMLs. A substantial portion of patients with JIA may have subclinical disease despite clinical remission.

Impact of juvenile idiopathic arthritis on schooling

Background

Juvenile idiopathic arthritis (JIA) is the most common arthropathy of childhood. Different diseases affect school attendance to varying degrees. The aim of this study was to assess the impact of juvenile idiopathic arthritis (JIA) on Moroccan children’s schooling.

Methods

Thirty-three children with JIA were included in this study, having been previously diagnosed according to the classification criteria of the International League of Associations for Rheumatology (ILAR). Seventy-four healthy children were recruited to serve as controls. Data was obtained for all children on their school level, educational performance, and attendance. The rate of absenteeism due to health complications was noted.

Results

All healthy children were able to attend school (p<0.0001), while 33% of children with JIA were unable to attend school due to their condition. The students with JIA who were able to attend school were absent much more often than controls (63% compared to 20%), with a highly significant p value (p<0.0001). Slightly less than half of the JIA patients (48.5%) failed in their schooling. In univariate analysis, there was an association between absenteeism and tender joints (p=0.02), disease activity score (DAS28) (p=0.007), Childhood Health Assessment Questionnaire (CHAQ) (p=0.01), and erythrocyte sedimentation rate (ESR) (p=0.03). In multivariate analysis, the only association persisted between DAS28 and absenteeism.

Conclusions

Our study suggested that the schooling of children with JIA was negatively impacted due to the disorder. More studies, with a larger sample of children, are needed to confirm our findings.