Use of infliximab in patients with systemic juvenile idiopathic arthritis refractory to etanercept

To analyse the effectiveness and safety of Infliximab in a group of patients with systemic juvenile idiopathic arthritis (SJIA) who had failed treatment with etanercept in a single paediatric rheumatology clinic.

Patients with SJIA with active polyarthritis refractory to methotrexate (MTX) [> or = 20 mg/m2/week] for at least 3 months and to etanercept (up to 1 mg/kg twice weekly) for at least 6 months were included. All children received infliximab 3-10 mg per kg of body weight intravenously concomitantly with MTX 7.5-10 mg/week for 19 (2-113) weeks. Evaluation included ACR paediatric 30 criteria and presence of signs of systemic activity (fever, rash).

Six patients were included. Three patients met ACR paediatric 30 criteria at 2 weeks (2 patients) and 10 weeks after initiation of infliximab. Improvement lasted for 4, 12, and 84 weeks respectively. The presence of fever/rash was not modified by the treatment. Infliximab was discontinued due to moderate side effects in 4 patients. No serious side effects were observed.

Most patients with SJIA who fail to respond to etanercept may not reach sustained improvement when switched to infliximab. The only patient in our group who improved sustainedly with infliximab did not show any systemic features at the beginning of therapy. Further controlled studies are needed in order to assess efficacy of infliximab in children with refractory SJIA.