Article in Japanese

One infant case strongly suspected of systemic juvenile idiopathic arthritis due to treatment complication of Kawasaki disease with macrophage activation syndrome

Maki SAITO¹⁾, Daishi HIRANO¹⁾

The clinical manifestations of systemic juvenile idiopathic arthritis (sJIA) and Kawasaki disease are similar, with many cases difficult to diagnose, especially in infants, because the joint symptoms are developed poorly at the early stage of the disease. This paper reports infantile onset of suspected sJIA by cytokine profiling.
A 6-month-old boy was diagnosed as Kawasaki disease at another hospital, where immunoglobulin high-dose therapy (IVIG) and prednisolone were administered. However, his fever had persisted, and he was referred to this hospital. At the time of admission, his condition was evaluated as the Kawasaki disease was refractory to IVIG and infliximab administration. Finally, his fever was resolved as a result of plasma exchange therapy. However, a decrease in two blood cell lines, marked increase in ferritin value, and blood cell phagocytosis image in his bone marrow led to the diagnosis of macrophage activation syndrome (MAS). In addition, the result of cytokine measurement showed that the IL-18 level was markedly elevated, which is characteristic of sJIA. Based on these clinical findings and cytokine results, this case was suspected of having MAS as a complication of sJIA. Ciclosporin administration was effective in controlling the disease, and no recurrence of the symptoms has appeared over the last year.
In cases of Kawasaki disease being refractory to treatment, the possibility of other etiologies should be kept in mind, such as collagen disease. Cytokine profiling was a useful aid in differentiating an unexplained high cytokine hematology.

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1) Department of Pediatrics, The Jikei University School of Medicine

Key words	Kawasaki Disease, Systemic juvenile idiopathic arthritis, macrophage activation syndrome, cytokine profile, IL-18
Received	July 9, 2018
Accepted	February 14, 2019

31 (2)：143─150,2019