The article presents a case of successful application of a monoclonal antibodies drug to interleukin 6 receptors (tocilizumab) at severe systemic juvenile idiopathic arthritis with the development of secondary hemophagocytic syndrome. Tocilizumab treatment secured a decrease in clinical and laboratory parameters of the disease activity. life quality improvement. systemic juvenile idio... https://www.socialstudiesscholar.com/