Fig. 3

Receiver operating characteristic (ROC) curve for predicting 28-day mortality in patients with sepsis. Areas under the curve (AUCs) for predicting 28-day mortality: procalcitonin (PCT) (blue line) 0.726 (95 % CI: 0.647 to 0.785), mortality in emergency department sepsis (MEDS) score (green line) 0.743 (95 % CI: 0.672 to 0.814), percentage of B and T lymphocyte attenuator (BTLA)+/CD4+ T cells (black line) 0.693 (95 % CI: 0.613 to 0.773), mean of fluorescence intensities (MFI) of BTLA on CD4+ T cells (purple line) 0.653 (95 % CI: 0.569 to 0.736)