Sequential Tocilizumab and Tofacitinib Treatment for Systemic Juvenile Idiopathic Arthritis: a Case Report.

Systemic juvenile idiopathic arthritis (sJIA) is a complex and difficult to cure condition with high disability and mortality rates. Herein, we report the case of a patient with sJIA who was treated with sequential tocilizumab (TCZ) and tofacitinib treatment. The patient was a 4-year-old girl hospitalised with fever accompanied by multiple joint swelling and pain in June 2020. Laboratory tests revealed a white blood cell count of 15.3 × 109/L, platelet count of 676.8 × 109/L, haemoglobin of 91.8 g/L, serum ferritin level of 1103.8 U/L, erythrocyte sedimentation rate of 85.0 mm/h, C-reactive protein level of 146.0 g/L and interleukin (IL)-6 level of 288.0 pg/ml. Rheumatoid factor and autoantibodies test results were negative, and she was diagnosed with sJIA. The patient was started on a combination of ibuprofen, methotrexate and TCZ, and her fever decreased to the normal range without any recurrence. Painful joint swelling had resolved significantly at 3-month follow-up. Janus kinase (JAK) inhibitors inhibit the effects of several cytokines, particularly IL-6, and are economical and convenient. Therefore, we selected tofacitinib to replace TCZ in this case, while the other drugs remained unchanged. Arthritis symptoms disappeared gradually after 9-month follow-up. In May 2021, the patient was hospitalised owing to a slight recurrence of the upper respiratory tract infection. She was administered one intravenous infusion of TCZ along with a switch to oral tofacitinib, which quickly relieved the symptoms. In March 2022, the patient's condition was stable. The curative effect of sequential TCZ and tofacitinib treatment was remarkable. IL-6 inhibitors sequential to JAK inhibitors could be a new option in the treatment of systemic juvenile idiopathic joints.