Fig. 2

Elevated PD-L1 was observed in AD CD8⁺ T cells and other T-cell subsets. A, B The median fluorescence intensity of PD-1 and PD-L1 expressed on T-cell subsets in healthy volunteers and AD patients. C, D The percentage of the PD-L1⁺ population in its subset and PBMCs, respectively, in healthy volunteers and AD patients. E The median fluorescence intensity of PD-L2 expressed on T-cell subsets in healthy volunteers and AD patients. A Mann‒Whitney U test was used to compare the healthy volunteers (n = 16) and AD patients (n = 16); median values are indicated by thick black lines in the scatter plots. *p < 0.05, **p < 0.01