Successful use of ECMO for life-threatening macrophage activation syndrome after treatment with tocilizumab in a sJIA patient

Abstract Macrophage activation syndrome (MAS) is a rare, potentially life-threatening condition in rheumatic diseases. The main treatment includes high-dose corticosteroids and immunosuppressive drugs, although cytokine inhibitors like anakinra or tocilizumab (TCZ) have been reported more recently. We report one case in a child with systemic juvenile idiopathic arthritis (sJIA). He became progressively hypoxic and was transferred to the paediatric intensive care unit (PICU) after treatment with TCZ for 4 days. An immediate postintubation chest X-ray showed a diffuse exudative lesion. Despite efforts to continue mechanical ventilation and respiratory support, the patient continued to desaturate. Moreover, he subsequently developed haemodynamic compromise and was started on norepinephrine, ultimately requiring the addition of vasopressin and dopamine to maintain stable haemodynamics. After an intense but ineffective treatment, extracorporeal membrane oxygenation (ECMO) was started after 16 h in the PICU. The patient was successfully weaned from ECMO support after 60 h. After discharge from the PICU, considering the severe refractory clinical features, we tried TCZ again. The patient developed anaphylaxis with palpitations and chest stuffiness after half an hour of TCZ infusion, and TCZ was stopped. As a type of biological agent, TCZ is commonly used in the treatment of sJIA. However, the development of MAS and anaphylaxis after the administration of TCZ for sJIA may be more common than previously thought. Paediatric rheumatologists need to be more careful when initiating TCZ for active sJIA. Moreover, we also want to emphasize the need for lifesaving techniques such as ECMO for sJIA patients in emergency situation.