摘要Objective To evaluate the efficacy of using procalcitonin (PCT) and interleukin-6 (IL-6) to differentiate sepsis from non-infectious systemic inflammatory response syndrome (SIRS). Methods We made a prospective study in a general intensive care unit at Peking Union Medical College Hospital. Twenty patients with sepsis and 31 patients with non-infectious SIRS were enrolled in this study. Serum concentrations of PCT, IL-6 and C-reactive protein (CRP) were determined within 24 h after clinical onset of sepsis or non-infectious SIRS. Leukocyte count, percentage of neutrophils, and absolute neutrophil count, as well as maximal body temperature were also recorded.Results Serum concentrations of PCT, IL-6, and CRP, as well as maximal body temperature, were significantly higher in septic patients [3.6 (1.8, 27.5) μg/L, 810±516 ng/L, 180±108 g/L, 38.6±1.2℃] than non-infectious SIRS patients [0.5 (0.2, 1.8) μg/L, 235±177 ng/L, 109±70 g/L, 37.9±0.9℃]. IL-6 and PCT exhibited the best discriminative power between sepsis and non-infectious SIRS, with sensitivity above 80% and specificity above 70%. A sepsis score with combination of IL-6 and PCT showed the best discriminative power with the area under the receiver operating characteristic curve of 0.923.Conclusions Assessing IL-6 and PCT levels are more reliable ways to differentiate sepsis from non-infectious SIRS, compared with conventional inflammatory parameters.