Fig. 2

Flow cytometric analysis of Treg cell frequencies and immune checkpoints. CTLA-4, GITR, and PD-1 were evaluated on Treg cells in acute brucellosis (n = 34), chronic brucellosis (n = 15), and HC (n = 29). Results are expressed as percentages of Treg cells (A) and percentages of cells expressing (B) CTLA-4, (C) GITR, and (D) PD-1. Percentages (%) are indicated on the Y-axis and lines represent median values. Kruskal–Wallis tests were used for comparisons between groups, and Bonferroni correction was applied to compensate for multiple comparisons. Treg CD4⁺CD25⁺FoxP3⁺ T cells, HC healthy control, Acute acute brucellosis, Chronic chronic brucellosis