title: Urinary interleukin-6 as a predictor of radiographic progression in rheumatoid arthritis: A 3-year evaluation.
abstract: Previously, we demonstrated that the urine proteome signature of patients with rheumatoid arthritis (RA) reflects inflammation-related cellular processes. Here, we measured interleukin (IL)-6, IL-8, and chemokine ligand 2 (CCL2) concentrations in the urine of RA patients and prospectively investigated their role in predicting RA activity and prognosis. One hundred seventy-three RA patients and 62 non-RA controls were recruited. Urinary IL-6, CCL2, and IL-8 levels were elevated in RA patients and correlated well with disease activity. Urinary IL-6 level at presentation was an independent risk factor of radiographic progression at 1 and 3 years. High urinary IL-6 level increased the risk ratio of radiographic progression by 2.9-fold, which was comparable to high serum CRP. Moreover, combination of urinary IL-6 and serum CRP measures synergistically increased the predictability of radiographic progression. In a subgroup with normal ESR, patients with the highest tertile of urinary IL-6 were at 6.4-fold greater risk of radiographic progression. Conclusively, high urinary IL-6 level at presentation is an independent risk factor for radiographic progression of RA, reflecting disease activity. Urinary IL-6 in combination with serum CRP may be a useful parameter for estimating RA prognosis.
authors.affiliation: Department of Internal Medicine, Division of Rheumatology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Korea.|Center for Integrative Rheumatoid Transcriptomics and Dynamics, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yune-Jung
authors.initials: YJ
authors.lastname: Park
authors.affiliation: Center for Integrative Rheumatoid Transcriptomics and Dynamics, The Catholic University of Korea, Seoul, Korea.
authors.forename: Seung-Ah
authors.initials: SA
authors.lastname: Yoo
authors.affiliation: Center for Integrative Rheumatoid Transcriptomics and Dynamics, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ga-Ram
authors.initials: GR
authors.lastname: Kim
authors.affiliation: Center for Integrative Rheumatoid Transcriptomics and Dynamics, The Catholic University of Korea, Seoul, Korea.|Department of Internal Medicine, Division of Rheumatology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Chul-Soo
authors.initials: CS
authors.lastname: Cho
authors.affiliation: Center for Integrative Rheumatoid Transcriptomics and Dynamics, The Catholic University of Korea, Seoul, Korea.|Department of Internal Medicine, Division of Rheumatology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Wan-Uk
authors.initials: WU
authors.lastname: Kim
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000473:pathology* / Q000652:urine; D018932:Chemokine CCL2 / Q000652:urine; D018450:Disease Progression; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000652:urine*; D016209:Interleukin-8 / Q000652:urine; D008297:Male; D008875:Middle Aged
chemical_list: D018932:Chemokine CCL2; D015850:Interleukin-6; D016209:Interleukin-8