PDCD1 and Sepsis: Individually, only raised neutrophil PD-1 (OR 1.78 (95% CI 1.23–2.57); p = 0.002), raised monocyte PD-1 (1.32 (1.03–1.70); p = 0.03) or reduced monocyte HLA-DR (0.73 (0.55–0.97); p = 0.03) expression were associated with subsequent sepsis.