Correlation of a multi-cytokine panel with clinical disease activity in patients with rheumatoid arthritis.
OBJECTIVE
Explore the potential use of a cytokine panel as biochemical markers of disease activity in rheumatoid arthritis (RA) patients.


METHODS
57 adult RA patients were assessed using five validated clinical disease activity tools: Health Assessment Questionnaire (HAQ), standard 28-joint Disease Activity Score (DAS28), DAS28 using C-reactive protein (DAS28-CRP), Clinical Disease Activity Index (CDAI), and Simple Disease Activity Index (SDAI). Plasma cytokine levels (IL-2, IL-4, IL-6, IL-8, IL-10, VEGF, IFN-γ, TNF-α, IL1α, IL1β, MCP1, and EGF) were measured in 47 of the 57 patients and correlated with clinical indicators.


RESULTS
We found significant correlations between plasma levels of IL-6 and all clinical measures of disease activity; Spearman coefficients (p values) were: HAQ: 0.347(0.017); DAS28: 0.409(0.005); DAS-CRP: 0.378(0.011); CDAI: 0.312(0.033); SDAI: 0.310(0.039); ESR: 0.448(0.002); and CRP: 0.513(0.001). IFN-γ also correlated with DAS-CRP: 0.309(0.039) and SDAI: 0.301(0.044). Furthermore, the levels of IL-6 and IFN-γ increased significantly with worsening disease, as defined by the European League Against Rheumatism (EULAR) classification of disease activity.


CONCLUSIONS
A significant correlation between plasma levels of IL-6 and clinical disease activity in patients with RA suggests a future role of IL6 as a disease activity marker.
Milman
Nataliya
N
Faculty of Medicine, University of Ottawa, 451 Smyth Rd., Ottawa ON, Canada K1H 8M5.
Karsh
Jacob
J
Booth
Ronald A
RA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000188:drug therapy / Q000276:immunology / Q000473:pathology*; D001685:Biological Factors / Q000627:therapeutic use; D016207:Cytokines / Q000097:blood*; D003710:Demography; D006801:Humans; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D055815:Young Adult
D001685:Biological Factors; D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha