Background Oligoarticular JIA (OA) is the most common subtype of JIA in Caucasian patients and may lead to a wide spectrum of outcomes. Clinical outcome predictors are required for a risk-adapted treatment of patients.
Objectives To assess the 4-year outcome of patients with OA, and to identify clinical predictors for an unfavorable outcome (i.e., uveitis, active disease, and functional impairment at follow-up).
Methods Patients with recent onset of OA (disease duration <12 months) who were for the first time recorded in the German pediatric rheumatologic database (PRD) in the years 2000 to 2005 and then followed-up prospectively for four years, were considered for this analysis. Clinical parameters, including the juvenile arthritis disease activity score (JADAS) and the childhood health assessment score (CHAQ), were recorded at baseline and follow-up. Linear or logistic regression analyses were applied to determine predictors of outcome.
Results 544 patients with recent onset of OA and a 4-year-follow-up were identified in the PRD. At first documentation (5 months after disease onset), patients had a median age of 5 years and a median JADAS of 7.8 (IQR 4.3 to 11.0). Methotrexate (MTX) was given to 27% of the patients within the first year of disease. At the 4-year-follow-up 15% of the patients had developed extended OA and 16% uveitis. A JADAS of 0 (corresponding to inactive disease ) was recorded in 28% of cases, an acceptable symptom state (JADAS=1) in 11%, and a JADAS of ≥2 in 61%. The median CHAQ score was 0 (mean 0.13), with three quarters of the patients having a CHAQ score of 0.
Neither age at onset, sex, presence of antinuclear antibodies (ANA), HLA-B27-positivity, nor JADAS at baseline had an influence on JADAS and CHAQ at follow-up. However, early treatment with MTX was significantly associated with a better outcome, i.e. with a lower disease activity (p=0.039) and a better functional status (p=0.015). ANA-positivity (p=0.036), young age (p=0.001) and the JADAS (p=0.012) at onset predicted uveitis at follow-up. With every point increase of the baseline JADAS the probability of uveitis at follow-up increased by 1.09. Patients with a JADAS >10 had a 2fold higher odds to have experienced uveitis at follow-up than those with a lower JADAS at baseline (OR=1.9; uveitis rate of 11.5% in patients with JADAS ≤10 vs. uveitis rate of 20% in patients with JADAS >10). Early MTX use, however, was a negative predictor for uveitis (p=0.019).
Conclusions Disease activity at onset as measured by the JADAS seems to be a useful clinical outcome predictor, at least for uveitis. The JADAS may help to allocate patients to specific treatments, for example to an early MTX treatment. Early MTX therapy on the other hand improves the outcome of patients with OA which includes the prevention of uveitis.
Supported by a grant from the child arthritis foundation.
Consolaro A, Bracciolini G, Ruperto N, Pistorio A, Magni-Manzoni S, Malattia C, Pederzoli S, Davì S, Martini A, Ravelli A. Remission, minimal disease activity and acceptable symptom state in juvenile idiopathic arthritis. Arthritis Rheum 2012 Jan 9 [Epub ahead of print]
Disclosure of Interest None Declared