Fig. 1

Differences in the levels of blood chemokines between untreated early rheumatoid arthritis patients and healthy controls. Multivariate factor analysis was performed to investigate differences in the blood chemokine levels between the patients with untreated early rheumatoid arthritis (ueRA; n = 43) and healthy controls (HC; n = 14). a Orthogonal projection to latent structures discriminant analysis (OPLS-DA) score scatter plot showing the separation of ueRA and HC based on differences in chemokine levels. b OPLS-DA column loading plot depicting the association between ueRA or HC (y variables) and the levels of chemokines (x variables). x variables represented by bars pointing in the same direction as ueRA are positively associated, whereas variables with bars pointing in the opposite direction are inversely related to ueRA. R2Y indicates how well the variation of y is explained, whereas Q2 indicates how well y can be predicted. c Univariate comparisons of the levels of CXCL9, CXCL10, CCL22, CXCL13, CCL4, and CCL3 are shown between ueRA and HC. Horizontal bars indicate median. *P ≤ 0.05, **P ≤ 0.01, ****P ≤ 0.0001, by two-tailed Mann–Whitney U test