Is interleukin-18 useful for monitoring rheumatoid arthritis?

• Published in: Scandinavian journal of rheumatology Vol. 34; no. 6; pp. 433 - 436
• Main Authors: Bokarewa, M., Hultgren, O.
• Format: Journal Article
• Language: English
• Published: Colchester Informa UK Ltd 01.11.2005; Taylor & Francis
• Subjects: Arthritis; Arthritis, Rheumatoid - blood; Biological and medical sciences; Biological Markers; Biomarkers - blood; blood; Diseases of the osteoarticular system; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunologic; Inflammatory joint diseases; Interleukin-18; Interleukin-18 - blood; Male; MEDICAL AND HEALTH SCIENCES; Medical sciences; MEDICIN OCH HÄLSOVETENSKAP; metabolism; methods; Middle Aged; Monitoring; Monitoring, Immunologic - methods; Rheumatoid; Synovial Fluid; Synovial Fluid - metabolism; Autoimmune disease; Chronic; Inflammatory joint disease; Rheumatoid arthritis; Diseases of the osteoarticular system; Interleukin 18
• ISSN: 0300-9742; 1502-7732
• DOI: 10.1080/03009740510026724

Objective: Interleukin-18 (IL-18) is a proinflammatory regulator of immune responses. Its similarities to IL-1 and ability to induce tumour necrosis factor- (TNF- ) make it potentially important in the pathogenesis of rheumatoid arthritis (RA). Methods: The level of IL-18 was assessed in matched pairs of blood and synovial fluid samples from 90 RA patients (47 erosive, 43 non-erosive) by an enzyme-linked immunosorbent assay (ELISA), and the results compared to 40 healthy controls. Results: In RA patients with erosive joint disease, the IL-18 level was higher than that in non-erosive RA [(median±QR) blood: 385±200 vs. 235±183 pg mL, p = 0.02; synovial fluid: 392±392 vs. 224±324 pg mL, p = 0.05]. IL-18 levels in blood of RA patients were similar and closely related to the local, intra-articular level (r = 0.96). The IL-18 level was not related to other markers of inflammation, to the duration of RA, or to the treatment modality. The IL-18 level in RA patients was similar to that of the controls (278±234 vs. 344±179 pg mL, not significant). Conclusions: An increased IL-18 level is associated with erosive joint disease, but the measurement of IL-18 does not help to distinguish between RA patients and healthy controls.