Effect of etanercept on refractory systemic-onset juvenile idiopathic arthritis

Treatment of systemic-onset juvenile idiopathic arthritis (So-JIA) is challenging, and the efficacy of injectable recombinant human tumor necrosis factor type 1 receptor-antibody fusion protein (etanercept) on So-JIA has been controversial.

We retrospectively studied 12 patients with refractory systemic juvenile arthritis treated with etanercept at our hospital in the past 5 years. The 12 patients were divided into a corticosteroid-dependent group (n=7) and an ineffective group (n=5) on the basis of their responses to treatment before the administration of etanercept. Etanercept was added to the treatment without substantially changing the original regimens in general, and doses, and signs of efficacy including alleviation or resolution of symptoms such as high fever, inflammatory arthropathy, eruption rash, hydrohymenitis, as well as changes in the levels of laboratory inflammatory markers such as the white blood cell count, erythrocyte sedimentation rate, levels of C-reactive protein and serum ferritin were recorded.

Etanercept was withdrawn after the first dose from one patient in the corticosteroid-dependent group because of a systemic allergic rash, and was also withdrawn from one patient in the ineffective group after 2 months of treatment owing to inefficacy; the remaining 10 patients completed the entire treatment protocol, at which point etanercept was discontinued. At that time, clinical symptoms and laboratory inflammatory markers of the remaining patients were within the normal range and the mean dose of prednisone was 0.18 mg/kg per day, an 81% decrease from the mean dose at baseline. At present, the corticosteroid has been discontinued and only methotrexate maintenance treatment is used in 3 patients; the other 7 patients are treated with prednisone and methotrexate maintenance therapy. All of the 10 patients are in a medicated remission with no recurrence.

In the treatment of patients with refractory So-JIA, the principles of individual therapy and combinations of drugs should be followed. Etanercept is an important and valid candidate for use in such combined treatment strategies.