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2 cases of HLA-B27-positive seronegative spondylarthritides in pediatric age treated with adalimumab.

Seronegative spondyloarthritis is strongly correlated to HLA-B27, and in the long term, it causes limitations to the movements of vertebral joints. In recent years, the numbers of patients diagnosed with axial spondyloarthritis have increased due to the widespread use of magnetic resonance imaging (MRI) for diagnostic imaging. We report the cases of 2 pediatric patients diagnosed with axial spondyloarthritis, and whose disease activity was successfully controlled using adalimumab. In case 1, the patient was a 15-year-old boy. The onset of the disease was marked by neck pain ; HLA-B27 was positive, and the MRI revealed sacroiliac arthritis. After being diagnosed with axial spondyloarthritis, he began receiving oral steroid therapy. Gradual recurrence was observed, and adalimumab treatment was initiated. In case 2, the patient was a 9-year-old boy. Bilateral pain was present in the shoulder joints, ankles, and knee joints. The patient was diagnosed with polyarticular juvenile idiopathic arthritis, and treatment using oral steroids, immunosuppressants and tocilizumab. The arthralgia disappeared, but at the age of 12 years, pain recurred in the sacroiliac joint and the Achilles tendon, the HLA-B27 was positive, and the MRI revealed sacroiliac arthritis. The condition was diagnosed as axial spondyloarthritis; adalimumab treatment was initiated. Adalimumab was effective in the treatment of axial spondylitis occurring in childhood.