IL17A and granulomatosis with polyangiitis: Accordingly, circulating IL-17A+ T cells were elevated in GPA patients in remission compared to HC (% of CD4+ T cells = 1.9 ± 1.5% vs. 0.7 ± 0.3%, P < 0.0001) (Figure 1A, B) whereas IFNγ (22.1 ± 10.8% vs. 17.7 ± 7.9%, P = 0.20), and IL-4 producing-T-helper-cells (6.1 ± 2.5% vs. 4.9 ± 2.1%, P = 0.11) did not differ between patients with GPA and the HC.