IL18 and macrophage activation syndrome: Serum IL-18 and TNF-α levels were dominantly elevated in patients with sJIA-MAS (average of 5 cases) and JSLE-MAS (one case), respectively (sJIA-MAS IL-18: >100,000, TNF-α: 0–10, IL-6: 10–50 pg/mL, JSLE-MAS, IL-18: 1,000–3,000, TNF-α: > 1,000, IL-6: 100–500 pg/mL) [5, 12].