The relationship between the expression of serum IL-18 mRNA, CC16, and sTREM-1 and the severity and prognosis of ventilator-associated pneumonia in elderly patients

Abstract

Background: This study aimed to explore the relationship between the severity and prognosis of elderly patients with ventilator-associated pneumonia (VAP) and the expression of serum interleukin-18 mRNA (IL-18 mRNA), Clara cell secretory protein 16 (CC16) and the soluble triggering receptor expressed on myeloid cells 1 (sTREM-1). Methods: The patients were divided into a VAP group (n=75) and a non-VAP group (n=110). According to the Acute Physiology and Chronic Health Evaluation II (APACHEII) score, the patients with VAP were divided into a low-risk group, an intermediate-risk group and a high-risk group. According to the 28-day outcome, the patients were divided into a survival group and a death group. Serum levels of IL-18, CC16 and sTREM-1 were detected, and their value in the prediction and prognosis of VAP was analyzed using a receiver operating characteristic (ROC) curve. Results: Serum levels of IL-18 and sTREM-1 in the VAP group were higher than those in the non-VAP group, while CC16 levels were lower in the VAP group than those in the non-VAP group (P<0.05). Serum levels of IL-18 and sTREM-1 decreased in order from the high-risk group to the intermediate-risk group to the low-risk group, while CC16 levels increased in order (P<0.05). ROC curve analysis showed that the Youden index and AUC of combined diagnosis of VAP with serum IL-18 mRNA, CC16 and sTREM-1 were 0.710 and 0.930, which were higher than those of single diagnosis (P<0.05). Serum levels of IL-18 mRNA and sTREM-1 in the survival group were lower than those in the death group, and the CC16 level was higher than that in the death group (P<0.05). ROC curve analysis showed that the Youden index and AUC of combined diagnosis with serum IL-18 mRNA, CC16 and sTREM-1 were 0.506 and 0.731, which were higher than those of single diagnosis (P<0.05). Conclusions: The combination of these 3 factors is of high value in predicting the severity and prognosis of VAP and can provide reference for clinical treatment.