Fig. 2
Expression of PD-1/PD-L1 and T-cell proliferative capacity according to physical activity levels in COPD patients. Patients were stratified by physical activity level (PAL) into three groups: moderate activity (MA; PAL > 1.65, yellow), moderate sedentary (MS; PAL 1.35–1.65, orange), and severe sedentary (SS; PAL < 1.35, red). (A) Frequency of PD-1–expressing CD4⁺ T cells (left) and CD8⁺ T cells (right) in MA (n = 20), MS (n = 40), and SS (n = 25) groups. (B) Frequency of PD-L1–expressing CD14⁺ monocytes in the same patient groups. (C) Proliferation of CD4⁺ (left) and CD8⁺ (right) T cells from peripheral blood mononuclear cells (PBMCs) after 96 h stimulation with 2 µg/mL pokeweed mitogen in MA (n = 19), MS (n = 36), and SS (n = 20) patients. (D) Correlation matrix between CD4⁺ and CD8⁺ T-cell proliferation and clinical, physical activity, and immune parameters (n = 75). Only significant Spearman’s correlations (P < 0.05) are shown. (E) T-cell proliferation (CD4⁺, left; CD8⁺, right) following 96 h culture under basal conditions or with PD-1 blockade (Nivolumab) in MA (n = 9), MS (n = 12), and SS (n = 10) groups. Paired data are shown. Data are presented as medians with 95% confidence intervals. Differences are analyzed using Kruskal–Wallis tests with Dunn’s post hoc correction or Wilcoxon matched-pairs signed-rank test, as appropriate. Adjusted P values are shown; n.s., not significant.
