Fig. 1.

Programmed cell death 1 (PD-1) expression in CD4⁺ lymphocytes and programmed cell death ligand 1 (PD-L1) expression in CD14⁺ monocytes in patients with acute pancreatitis (AP). a PD-1 expression in circulating CD4⁺ lymphocytes and b PD-L1 and c human leukocyte antigen (HLA)-DR expression in CD14⁺ monocytes were measured in whole blood from healthy control subjects (HC, n = 32) and patients with AP (n = 63) on day 1 (D1) and day 3 (D3) after disease onset. Results are presented as percentages of positive cells among the total population of CD14⁺ monocytes or CD4⁺ lymphocytes. d Representative PD-1 expression levels in CD4⁺ lymphocytes and e PD-L1 and f HLA-DR expression in CD14⁺ monocytes. Values in the upper right quadrant indicate the percentage of cells that express PD-1, PD-L1, or HLA-DR. *P < 0.05 compared with healthy controls. **P < 0.01 compared with healthy controls