Figure 2

Percentages of circulating CD4⁺CD25^low/-GITR⁺and CD4⁺CD25^highGITR^-cells in HC are different from those in SLE patients . Percentage of CD4⁺CD25^low/-GITR⁺(A), CD4⁺CD25^highGITR^-(B) and CD4⁺CD25^highGITR⁺(C) in CD4⁺ T lymphocytes evaluated with flow-cytometry analysis of anti-GITR- and anti-CD25-stained CD4⁺ T lymphocytes, isolated from PB of 25 HC and 32 SLE patients, is shown. Horizontal lines indicate mean percentage. P values are according to Mann-Whitney U test comparing differences in HC and SLE. The percentage of patients with more than 1.4% CD4⁺CD25^low/-GITR⁺ cells (90th percentile of HC) is also indicated (A). Percentage of CD4⁺CD25^low/-GITR⁺(D) and CD4⁺CD25^highGITR^-(E) in CD4⁺ T cells purified from freshly isolated PB of HC, patients with inactive disease identified by an SLEDAI =0 (n =13), and patients with active disease identified by an SLEDAI >0 (n =19) was evaluated. Bars indicate mean ± SEM. n.s., P >0.05, *P <0.05 and ***P <0.001, according to Kruskal-Wallis test comparing active SLE, inactive SLE, and HC. (F) Correlation between levels of CD4⁺CD25^low/-GITR⁺ and CD4⁺CD25^highGITR^- in CD4⁺ cells purified from freshly isolated SLE patients (Spearman ρ = -0.5; P <0.01). (G) Distribution of CD4⁺CD25^highGITR^- cells according to the expansion of CD4⁺CD25^low/-GITR⁺ cells. SLE patients with a percentage of these cells higher than 1.4% (90th percentile of the distribution in HC) were defined as having expansion of the CD4⁺CD25^low/-GITR⁺ cells (16 of 32 patients). P <0.001 according to χ² test on raw data.