Objectives: To identify contributing factors associated with inactive disease (ID) and clinical remission for patients with juvenile idiopathic arthritis (JIA) treated with etanercept.
Methods: Data of an ongoing, long-term, multicentre, prospective, open-label observational study were analysed. Results. A total of 4898 follow-up forms from 787 JIA patients treated with etanercept were evaluated. Sixty-four per cent of the patients were female, 75% concomitantly received MTX and 45.9% received corticosteroids. Until the last observation, 47.6% of patients reached the criteria for ID and 26.6% achieved the remission on medication criteria. For both, ID and remission on medication, a significant influence of shorter disease duration (P<0.01 and P<0.001), a weekly dosage of at least 0.8 mg/kg (P=0.02), lower active joint counts (P=0.001) and lower childhood HAQ score (P<0.001 and P=0.004) at baseline was found. The odds ratio (OR) for a girl's chance to reach ID was 0.73 (P=0.049) and for remission on medication was 0.68 (P=0.04) compared with boys. The concomitant administration of MTX raised the relative chance, especially in patients with seronegative polyarthritis (OR 2.0; P=0.03).
Conclusion: Upon treatment with etanercept, many JIA patients reached ID and remission on medication, although they had suffered from long-standing, refractory disease. Earlier initiation of treatment, less severe disease, use of at least the recommended weekly dosage of etanercept, and concomitant treatment with MTX seemed to independently increase the chance for reaching remission. These data should be confirmed by controlled prospective studies.