Clinical significance of interleukin-18 for the diagnosis and prediction of disease course in systemic juvenile idiopathic arthritis

• Published in: Rheumatology (Oxford, England) England), 2021-05, Vol.60 (5), p.2421-2426
• Main Authors: Mizuta, Mao, Shimizu, Masaki, Inoue, Natsumi, Ikawa, Yasuhiro, Nakagishi, Yasuo, Yasuoka, Ryuhei, Iwata, Naomi, Yachie, Akihiro
• Format: Article
• Language: English
• ISSN: 1462-0324; 1462-0332
• DOI: 10.1093/rheumatology/keaa634

Abstract Objective To investigate the clinical significance of serum IL-18 levels for the diagnosis of systemic JIA (s-JIA) and to predict the disease course of s-JIA. Methods Overall, 116 patients with s-JIA, 151 with other diseases and 20 healthy controls were analysed. Serum IL-18 levels were measured longitudinally in 41 patients with s-JIA from active phase through remission phase. Serum IL-18 levels were quantified via enzyme-linked immunosorbent assay and the results were compared with clinical features and the disease course of s-JIA. Results The serum IL-18 level cut-off value for differentiation of s-JIA from other diseases was 4800 pg/ml. In patients with a monocyclic course, serum IL-18 levels steadily decreased during the inactive phase and low levels were sustained during remission. In contrast, in patients with a chronic course, elevated serum IL-18 levels were sustained even during the inactive phase. In patients with a polycyclic course, serum IL-18 levels were elevated during disease flares and normalized during the inactive phase. The serum IL-18 level cut-off value for diagnosis of remission in s-JIA was 595 pg/ml, Conclusion Serum IL-18 levels of >4800 pg/ml may be useful for differentiating between s-JIA and other diseases. Monitoring of serum IL-18 levels might be useful for predicting the disease course and assessing remission in s-JIA.