Anakinra: a safe and effective first-line treatment in systemic onset juvenile idiopathic arthritis (SoJIA).

Systemic onset juvenile idiopathic arthritis (SoJIA) is a rare inflammatory disorder. It can result in disease and treatment-related disability. SoJIA is characterized by remitting fevers, evanescent rash, generalized lymphadenopathy, hepatomegaly/splenomegaly, and/or serositis. Non-responsiveness to standard therapy with corticosteroids and disease modifying antirheumatic drugs is not uncommon. IL-1β has been shown to be a main contributor to the pathogenesis of SoJIA. Anakinra, a recombinant IL-1β receptor antagonist, was shown to be effective in small cohorts of therapy-resistant adult and pediatric Still's patients. In order to assess the efficacy and safety of first-line anakinra treatment in SoJIA, we reviewed the charts of all SoJIA patients in our institution from 2005 to 2010, searching for first-line anakinra-treated patients. We report the clinical and laboratory course of four SoJIA patients. The mean follow-up was 13.5 (range: 2-50) months. Anakinra was started at doses from 1.5 to 4 mg/kg for a median duration of 3 (range: 3-18) months. Two patients responded to anakinra mono-therapy; two cases required corticosteroids. Normalized body temperatures and the absence of evanescent rashes were achieved after a median of 4 (range: 2-10) days. We did not see treatment-related adverse reactions other than local injection site inflammation. This is the first single-center series, reporting anakinra as first-line treatment in SoJIA. We show rapid efficacy of anakinra in early SoJIA with reduced treatment-related side effects. A subset of patients remains corticosteroid dependent. Further studies are warranted to follow larger cohorts and to assess long-term safety.