Figure 2.

Urinary T cells show an altered phenotype between blood and urine, reflect the Berden classification, and show robust biomarker characteristics. Patients with active renal ANCA-associated vasculitis (AAV) show significantly higher urinary regulatory T cell (T_reg) frequency (a) and decreased CD4⁺/CD8⁺ ratio in urine (b). Frequency of chemokine receptor 6 (CCR6) positive CD4⁺ and T_reg is significantly higher in urine than in blood (c and d) in patients with active renal AAV. (e) Urinary CD3+ cells trend higher in patients classified as crescentic according to Berden classification. (f) Urinary CD3⁺ cells are significantly elevated when comparing crescentic class to pooled other classes. (g−h) receiver operator characteristic (ROC) curves for the diagnosis of active renal AAV of urinary T cells, soluble markers and traditional markers. Statistics: (a−d): Paired Wilcoxon signed-rank test, (e): Kruskal-Wallis, F: Mann-Whitney-Wilcoxon test, P-value summary: ns: not significant, ∗: 0.05 – 0.01, ∗∗: P = 0.01 – 0.001, ∗∗∗: P = 0.001 – 0.0001, ∗∗∗∗: P < 0.0001. CCR6, chemokine receptor 6; Erys dipstick, erythrocytes on urinary dipstick analysis; HC, healthy control; nrAAV, nonrenal active AAV; Prot dipstick, protein on urinary dipstick analysis; rAAV, active renal AAV; Rem, remission; ROC, receiver operator characteristics; T_reg, regulatory T cell.