Abstract:OBJECTIVE: To evaluate the efficacy of thalidomide in the treatment of juvenile idiopathic arthritis (JIA). METHODS: Twelve children with JIA who did not respond to conventional treatment were administered with thalidomide (2 mg/kg daily). The symptoms, signs, and laboratory test results were compared before and after treatment. The thalidomide-related side effects were observed. RESULTS: The average dosage of prednisone was reduced from 1.92±0.16 mg/kg?d to 0.49±0.42 mg/kg?d in the 12 patients 6 months after thalidomide treatment (P<0.01). Four patients did not need prednisone treatment any more. White blood cell count, erythrocyte sedimentation rate (ESR), C reactive protein (CRP) and serum ferritin (SF) significantly decreased after treatment in all of 12 patients (P<0.01). Hemoglobin level increased to normal in 8 patients after treatment (P<0.01). The number of affected joints decreased from 5 before treatment to zero to 2 after treatment in patients with polyarticular JIA (P<0.01). Signs of hip involvement and Schober′s sign turned negative in enthesitis-related cases. No thalidomide-related side effects were observed. CONCLUSIONS: Thalidomide is effective in the treatment of JIA in children who do not respond to conventional treatment.