Upregulated PD-1 Expression Is Associated with the Development of Systemic Lupus Erythematosus, but Not the PD-1.1 Allele of the PDCD1 Gene

Figure 1

Increased basal programmed death 1 (PD-1) expression in PBMCs from SLE patients. (a) Representative flow cytometry analysis of PD-1 expression on CD4⁺, CD8⁺, and CD56⁺ T cells in SLE patients and normal healthy controls (NC); (b) upregulated expression of PD-1 on CD4⁺, CD8⁺, and CD56⁺ T cells from SLE patients, as compared with those from NC; (c) mRNA expression of PD-1 in PBMCs from SLE patients. Horizontal bars indicate the mean±SD.