Serum procalcitonin and interleukin-6 help differentiate between severe sepsis and systemic inflammatory response syndrome of non-infectious origin

Objective: To evaluate the efficacy of serun procalcitonin (PCT) and interleukin (IL)-6 in differentiating between severe sepsis and systemic inflammatory response (SIRS) of non-infectious origin.

Methods: The serum PCT, IL-6, C-reactive protein (CRP), white blod cell count, percentage of neutrophils, and absolute neutrophil count were determined, and maximal body temperature was recorded among 21 patients was 3.6 (1.8, 27.5) micro g/L, significantly higher than that in SIRS patients (1.3 micro g/L +/- 1.6 micro g/L, P < 0.05). The IL-6 in sepsis patients was 810 ng/L +/- 516 ng/L, significantly higher than that in SIRS patients (235 ng/L +/- 177 ng/L, P < 0.01). However, the differences of CRP, WBC count, percentage of neutrophil, and absolute neutrophil count between the severe sepsis patients and SIRS patients were not statistically significant. PCT and IL-6 showed sensitivity equal or over 80% and specificity equal to or over 70%. The infection score based on PCT and IL-6 showed the best discriminative power to differentiate between severe sepsis and SIRS with the artea under the receiver operating characteristic curve of 0.923.

Conclusions: In comparison with the conventional inflammatory markers, PCT and IL-6 are more reliable indicators to differentiate between sepsis and SIRS.