Fig. 3

Upregulation of the T-cell PD-L1 immune checkpoint status was detected in the moderate stage of AD. A Comparison of T-cell subset proportions among healthy volunteers, mild AD patients, and moderate AD patients. B Comparison of CD8⁺CD25⁺ T-cell population among healthy volunteers, mild AD patients, and moderate AD patients. C The median fluorescence intensity of PD-L1 expressed on T-cell subsets in healthy volunteers, mild AD patients, and moderate AD patients. D, E The percentage of the PD-L1⁺ population in its subset and PBMCs in healthy volunteers, mild AD patients, and moderate AD patients. A Mann‒Whitney U test was used to compare healthy volunteers (n = 16), mild AD patients (n = 10), and moderate AD patients (n = 6); median values are indicated by thick black lines in the scatter plots. *p < 0.05, **p < 0.01