Successful use of extracorporeal membrane oxygenation for life‐threatening macrophage activation syndrome after treatment with tocilizumab in an systemic juvenile idiopathic arthritis patient

Abstract Macrophage activation syndrome (MAS) is a rare, potentially life‐threatening condition in rheumatic diseases. The primary treatments consist of high‐dose corticosteroids and immunosuppressive drugs, although more recently, cytokine inhibitors like anakinra or tocilizumab (TCZ) have been reported. We present a case of a child with systemic juvenile idiopathic arthritis (sJIA). After receiving a single infusion of TCZ, the child developed progressive hypoxia and was subsequently transferred to the pediatric intensive care unit (PICU) after 4 days. An immediate postintubation chest X‐ray revealed a diffuse exudative lesion. Despite continuous efforts to provide mechanical ventilation and respiratory support, the patient's oxygen saturation continued to decline. Moreover, the patient developed hemodynamic compromise, necessitating the administration of norepinephrine. Eventually, vasopressin and dopamine were added to maintain stable hemodynamics. After an intensive but ineffective treatment, extracorporeal membrane oxygenation (ECMO) was initiated in the PICU after 16 h. The patient successfully recovered and was weaned off ECMO support after 60 h. Following discharge from the PICU, given the severe refractory clinical features, we made an attempt to readminister TCZ treatment. However, within half an hour of TCZ infusion, the patient experienced anaphylaxis characterized by palpitations and chest tightness, leading to the discontinuation of TCZ. TCZ, as a biological agent, is commonly used in the treatment of sJIA. Nonetheless, the occurrence of MAS and anaphylaxis following TCZ administration for sJIA may be more prevalent than previously recognized. Pediatric rheumatologists should exercise caution when initiating TCZ for active sJIA. Furthermore, we want to underscore the importance of life‐saving techniques such as ECMO for sJIA patients in emergency situations.