TXA changes levels of T cell subsets and functional marker expression on lymphoid cell populations in healthy volunteers. Expression of functional markers on lymphoid subsets was evaluated in healthy volunteers at various time points after administration of TXA. (A) A marked increase was observed in the levels of CD4⁺ T cells, including Tregs and CD8⁺ T cells (n = 7). (B) CCR4, which mediates migration to sites of inflammation, was upregulated after 24 hours in NKT cells, CD4⁺ T cells, CD8⁺ T cells, and the CD8⁺ Teff and Tmem subsets (n = 7). (C) TNFR2 expression was significantly reduced on CD8⁺ Teffs after 4 hours, yet it returned to normal levels after 24 hours (n = 7). (D) Expression of PD-1, the receptor of PD-L1, which mediates programmed cell death upon activation, was enhanced on Tregs and CD8⁺ Tmems (n = 7). (E) CD95, another death receptor, was rapidly upregulated by TXA on NKT cells and CD4⁺ T cells after 4 hours but had returned to normal levels at the 24-hour time point (n = 7). (F) Augmented CTLA4 expression was evident on CD4⁺ T cells at 4 hours and on NK cells at 24 hours post-TXA intake (n = 7). (G) The TGF-β releasing LAP was expressed significantly more weakly on NK and NKT cells, as well as CD4⁺ and CD8⁺ T cells, including CD8⁺ Teffs, 24 hours after TXA intake (n = 7). Data are expressed as mean ± standard error of the mean. *P < .05, **P < .01, repeated-measures 1-way ANOVA with Dunnett’s correction test for multiple comparisons.