IL6 and granulomatosis with polyangiitis: IL-6 was produced most in unstimulated monocytes from patients with GPA (unstimulated median IL-6: GPA 12 379 pg/mL (IQR 9999–14 992), HC 1419 pg/mL (IQR 1231–1806), MPA 2020 pg/mL (IQR 23–8637); GPA vs HC p<0.01, GPA vs MPA p<0.05, two-way ANOVA) (figure 3B).