Figure 3.

sCD163 is elevated in the urine of those with active renal vasculitis, but not active extrarenal vasculitis. sCD163 levels were measured by ELISA in an inception cohort (n=177) (A) and two validation cohorts (n=155+133) (B, C). Graphs show comparison of levels found in active renal vasculitis, active extrarenal vasculitis, remission (Rem) renal vasculitis, and remission extrarenal vasculitis. Data are presented as median sCD163 ng/mmol creatinine with interquartile range. The boxes in panels (B) and (C) indicate the fraction of positive samples in each group using the optimum cutoff of 0.3 ng/mmol. Nonparametric one-way ANOVA (Kruskal-Wallis test) and Dunn’s multiple comparison test were used to test for significance of each group compared with the active renal vasculitis group (**P<0.01, ***P<0.001). (D) ROC curves calculated from normalized (solid line) and non-normalized (dashed line) data derived from the inception cohort depicting the ability of sCD163 to detect active renal vasculitis. The respective areas under the curves were 0.94 and 0.96, respectively. (E) sCD163 was measured by ELISA in serial samples during periods of active disease, low disease activity (LDA), and remission (Rem). Graphs show sCD163 levels over time in renal and extrarenal vasculitis patients. Lines depict samples from the same subject at different time points.