Fig. 2

CD4⁺ and CD8⁺ T cells are decreased in PD. A CD3⁺CD4⁺ T cells are significantly decreased in PD patients (as % of all leucocytes, two-way ANOVA: case *p < 0.05, sex p > 0.36, age p > 0.41, no statistically significant interactions). B Correlation of CD3⁺CD4⁺ cell numbers with PD clinical traits (Spearman’s ρ). C, D CD3⁺CD4⁺ cell numbers in PD patients stratified by disease duration (C) and disease progression (D). E CD3⁺CD8⁺ T cells are significantly decreased in PD patients (as % of all leucocytes, two-way ANOVA: case **p < 0.01, sex p > 0.41 age p > 0.62, no statistically significant interactions). F Correlation of CD3⁺CD8⁺ cell numbers with PD clinical traits (Spearman’s ρ). G, H CD3⁺CD8⁺ cell numbers in PD patients stratified by disease duration (G) and disease progression (H). Boxplots: median ± interquartile range; *p < 0.05, ****p < 0.0001, Mann–Whitney U test, two-way ANOVA