Fig. 1

Subtraction of baseline improves biomarker ability of sVCAM-1 for tracking longitudinal changes in SLE disease activity. a sVCAM-1 assayed by ELISA and compared with SLE disease activity measured by ECLAM score. Correlation with ECLAM score is shown for conventional markers of disease activity: anti-dsDNA antibody titre by Farr radioimmunoassay, complement C3 level and ESR. Dotted lines represent laboratory lower limit for C3 to show individuals with hypocomplementaemia. Statistical analysis by Spearman correlation. b Correlation plots showing change in biomarker level against change in ECLAM score for sVCAM-1 compared with conventional serum biomarkers of SLE disease activity. Delta values for each parameter were calculated by subtracting the parameter value at the first visit for each individual. c Comparison of biomarker levels in SLE responders (∆ECLAM ≤ −3) versus nonresponders (∆ECLAM > −3) for ∆sVCAM-1, ∆anti-dsDNA titre, ∆C3 level and ∆ESR. Bars represent mean ± standard deviation. Statistical analysis by unpaired t test. d ROC curves for changing levels of serum biomarkers for detection of clinical response in SLE (∆ECLAM ≤ −3). e Graph showing interval time course of ∆sVCAM-1 levels compared with ∆ECLAM score. dsDNA double-stranded DNA, ECLAM European Consensus Lupus Activity Measure, ESR erythrocyte sedimentation rate, sE-selectin soluble E-selectin, sICAM-1 soluble intercellular adhesion molecule-1, sP-selectin soluble P-selectin, sVCAM-1 soluble vascular cell adhesion molecule-1