Tc17 in ITP Figure 1. The percentages of circulating Tc17 and Th17 cells in ITP patients and controls. Heparinized peripheral whole blood from all subjects was stimulated with phorbol myristate acetate, ionomycin, and monensin for 4 h, then stained with labeled antibodies as described in the Design and Methods section. (a) Lymphocytes were gated by flow cytometry in Gate 1. (b,d,f) CD3+ T subsets were gated by flow cytometry; the plots in intern box Gate 2 represent CD3+ T cells. (c, e, g) The percentages of circulating Tc17 and Th17 cells from ITP patients and controls; the percentage of positive cells is shown in each panel. doi:10.1371/journal.pone.0026522.g001 in the healthy controls (median, 3.3852; range, 1.0000–5.8571; P,0.0001) and 0.70-fold lower than in the patients with CR (median, 3.6771; range, 2.3896–5.5000; P,0.0001). There were no significant differences in the Th17:Tc17 ratio in patients with CR compared to healthy controls (P = 0.2483). Tc17 are positively correlated with Th17 cells in healthy controls, but not in ITP patients The relationships between Tc17 and Th17 cells in ITP patients and the healthy control group were investigated. As shown in Fig. 3, the frequencies of Tc17 and Th17 cells were positively correlated in healthy controls (r = 0.7239, P,0.0001), but not in newly-diagnosed patients (r = 20.3150, P = 0.1762) or patients with CR (r = 0.0773, P = 0.7017). Tc17 are positively correlated with the CD8:CD4 ratio and the percentage of CD8+ cells in ITP patients Because the CD4:CD8 ratio is an important index by which to evaluate immune status, as shown in Figs. 4a and b, we determined the difference in CD4:CD8 ratios between ITP PLoS ONE | www.plosone.org 3 October 2011 | Volume 6 | Issue 10 | e26522