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A prediction rule for polyarticular extension in oligoarticular-onset juvenile idiopathic arthritis
Benedetta Schiappapietra1, Cecilia Bava2, Silvia Rosina1
1UOC Clinica Pediatrica e Reumatologia, IRCCS Istituto Giannina Gaslini, Genova, Italy.
Insights
In children with oligoarticular-onset juvenile idiopathic arthritis (JIA), having two or more joints affected and elevated CRP levels within six months predict polyarticular extension. This finding aids in developing a prediction model for disease course.
Area of Science:
- Pediatric Rheumatology
- Immunology
- Clinical Prediction Modeling
Background:
- Oligoarticular-onset juvenile idiopathic arthritis (JIA) can progress to polyarticular involvement.
- Identifying early predictors is crucial for managing disease progression and outcomes.
Purpose of the Study:
- To identify predictors of polyarticular extension in children with oligoarticular-onset JIA.
- To develop a prediction model for an extended disease course.
Main Methods:
- Retrospective review of clinical charts for patients with oligoarticular-onset JIA and at least two years of disease duration.
- Analysis of demographic data, joint involvement, iridocyclitis, laboratory tests (including CRP and ANA), and early therapeutic interventions.
- Development of a logistic regression model to predict polyarticular extension based on early disease indicators.
Main Results:
- A total of 480 patients were analyzed, with 38.8% experiencing polyarticular extension.
- Independent predictors for extended course included the involvement of ≥2 joints and a C-reactive protein (CRP) level >0.8 mg/dl within the first six months.
- A prediction score was developed, with a cut-off >1 showing sensitivity of 59.6% and specificity of 79.8% for predicting polyarticular extension.
Conclusions:
- The number of affected joints and CRP levels in the initial six months are significant predictors of polyarticular extension in oligoarticular-onset JIA.
- These factors can be utilized to develop a clinical prediction score for disease course.
- Early identification of at-risk patients can inform timely and targeted treatment strategies.
Objectives:
To search for predictors of polyarticular extension in children with oligoarticular-onset juvenile idiopathic arthritis (JIA) and to develop a prediction model for an extended course.
Methods:
The clinical charts of consecutive patients with oligoarticular-onset JIA and ≥2 years of disease duration were reviewed. Predictor variables included demographic data, number and type of affected joints, presence of iridocyclitis, laboratory tests including antinuclear antibodies, and therapeutic interventions in the first 6 months. Joint examinations were evaluated to establish whether after the first 6 months of disease patients had persistent or extended course (i.e. involvement of 4 or less, or 5 or more joints). Statistics included univariable and multivariable analyses. Regression coefficients (β) of variables that entered the best-fitting logistic regression model were converted and summed to obtain a "prediction score" for an extended course.
Results:
A total of 480 patients with a median disease duration of 7.4 years were included. 61.2% had persistent oligoarthritis, whereas 38.8% experienced polyarticular extension. On multivariable analysis, independent correlations with extended course were identified for the presence of ≥2 involved joints and a CRP >0.8 mg/dl in the first 6 months. The prediction score ranged from 0 to 6 and its cut-off that discriminated best between patients who had or did not have polyarticular extension was >1. Sensitivity and specificity were 59.6 and 79.8, respectively.
Conclusions:
The number of affected joints and the CRP level in the first 6 months were the strongest predictors of polyarticular extension in our children with oligoarticular-onset JIA.
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