Value of interleukin-27 as a diagnostic biomarker of sepsis in critically ill adults

Abstract

To evaluate interleukin-27 (IL-27) as a sepsis diagnostic biomarker in critically ill adults with sepsis. A retrospetive study was conducted. A total of 176 systemic inflammatory response syndrome (SIRS) patients in Department of Critical Care Medicine of Xinxiang Medical College First Affiliated Hospital from March to November in 2014 were enrolled. The patients were divided into no sepsis group (n=66), pulmonary originated sepsis group (n=65), and non-pulmonary originated sepsis group (n=45). Plasma IL-27 and procalcitonin (PCT) were determined with enzyme linked immunosorbent assay (ELISA). Receiver operating characteristic curve (ROC) and classification and regression tree methodology was used to evaluate diagnostic biomarker performance. The proportion of patients in pulmonary original sepsis group whose body temperature in line with SIRS criteria was significantly higher than no sepsis group (66.2% vs. 44.5%, P<0.05), and they were easy to suffer from tumor (44.6% vs. 22.7%, P<0.05). The proportion of patients in non-pulmonary originated sepsis group whose white blood cell count in line with SIRS criteria was significantly higher than no sepsis group (68.9% vs. 42.7%, P<0.05). It indicated that patients in pulmonary originated sepsis group and non-pulmonary originated sepsis group were more in line with SIRS criteria compared with no sepsis group. It was shown by ROC curve that IL-27 and PCT was not effective in discriminating sepsis among unselected patients showing symptoms and signs of SIRS. The area under the curve (AUC) was 0.59 [95% confidence interval (95%CI)=0.49-0.65] and 0.61 (95%CI=0.55-0.71). According to the further analysis from different infection sources, the highest AUC was 0.71 (95%CI=0.59-0.79) for IL-27 in patients with a non-pulmonary originated sepsis. A decision tree incorporating IL-27, PCT, and age had an AUC of 0.78 (95%CI=0.71-0.87) in patients with a non-pulmonary originated sepsis, which was higher than IL-27 [0.71(95%CI=0.59-0.79)] or PCT [0.65 (95%CI=0.57-0.78)]. Compared to that of pediatric cohort with sepsis, lower expression of IL-27 was found in adult patients. IL-27 performed overall poorly as a sepsis diagnostic biomarker in adults. IL-27 may be a more reliable diagnostic biomarker for sepsis in children than in adults. The combination of IL-27 and PCT can reasonably estimate the risk of sepsis in subjects with a non-pulmonary originated sepsis.