The Role of Serum Procalcitonin and Interleukin-6 in the Differentiation and Surveillance of Sepsis and Non-Infectious Systemic Inflammatory Response Syndrome.

To evaluate the discrimination of serum procalcitonin (PCT) and interleukin-6 (IL-6) between patients with sepsis and non-infectious inflammatory response syndrome (SIRS) and the pridicton power of clinical outcome, a perspective study was performed in 27 patients with sepsis and 30 patients with non-infectious SIRS. The serum concentrations of PCT, IL-6, and C-reactive protein (CRP), white blood cell count, percentage of neutrophil, and maximal body temperature were obtained less than 24 hours after clinical onset of SIRS. The serum levels of PCT and IL-6, and percentage of neutrophil were significantly higher in patients of sepsis than in those of SIRS (PCT 5.54 [1.20, 32.74] μg/L vs 0.77 [0.22, 3.90] μg/L, P=0.001; IL-6 163.66 [33.60, 505.26] ng/L vs 37.72 [22.52,110.78] ng/L, P=0.004; CRP 15.28±8.41 g/L vs 9.51±7.65 g/L, P=0.010; and percentage of neutrophil 91%±4% vs 88%±4%, P=0.010). Receiver operating characteristic curves showed that the power of PCT and IL-6 were the best of all above. There was significant correlation between serum concentrations of PCT or IL-6 and the APACHE II or SOFA score, so was between serum PCT concentration and the ICU length of stay. Serum concentrations of PCT and IL-6 are more reliable indicators to differentiate sepsis and non-infectious SIRS than the conventional inflammatory markers, and correlate with the disease severity. And PCT levels were significantly correlated with ICU length of stay. (Supported by research grants from PUMCH, China)