Figure 3.

Oral contraception alters HLADR/CD45RA suppressive marker expression in CD4⁺ Treg cells in peripheral blood. Peripheral blood drawn at early-, mid-, and late-cycle phases from naturally cycling women (N), women using oral contraception (OC), and men was analyzed by flow cytometry to assess HLADR and CD45RA expression in CD3⁺CD4⁺CD25⁺FOXP3⁺CD127^−/lo Treg cells. Panels show the relative proportion of HLADR^hiCD45RA⁻, HLADR^loCD45RA⁻, HLADR⁻CD45RA⁻, and HLADR⁻CD45RA⁺ cells among Treg cells (A), the number of HLADR^hiCD45RA⁻ cells (B), the number of HLADR^loCD45RA⁻ Treg cells (C), the number of HLADR⁻CD45RA⁻ Treg cells (D), and the number of HLADR⁻CD45RA⁺ Treg cells (E). Data are shown by group as estimated marginal means (A and left side, bar graphs B-D) calculated by linear mixed model analysis (Model 1, all participants). Individual data points are also shown for each woman at each cycle phase in the N and OC groups (right side, bar graphs B-D), with mean ± SE of the mean indicated. In (A), the effects of group were analyzed by Chi-square analysis. In (B) to (D), the effects of participant group, female sex, OC use, and cycle phase were assessed by linear mixed model analysis and pairwise comparisons (n = 10-17 participants/group). ^a,b,cDifferent superscripts indicate differences between participant group (Model 1). ǂSignificant effect of sex (Model 1). ^ϕSignificant effect of cycle phase (Model 2). *Significant effect of OC at specific cycle phases (Model 2). All Ps < 0.05.