The Clinical Significance And Change Of STERM-1,IL-6, PCT,CRP Level In Neonates With Ventilator-associated Pneumonia

Objective: To investigate theclinical significance and dynamic change of the soluble myeloid cell trigger receptor-1(s TREM-1),procalcitonin(PCT),interleukin 6(IL-6)and C-reactive protein(CRP)in peripheral blood of newborn babiesunderinvasive mechanical ventilation and to explore the value of these biomarkers as potential predictors for neonatal ventilator-associated pneumonia(VAP).Methods: 1.A total of 30 newborns in the experimental group and 30 in the control group were enrolled in the neonatal intensive care unit(NICU)between January 2017 and January 2018 in the Children's Hospital of Soochow University.2.Each neonate was collected blood samples at 0h,24 h,72h,120 h after given with mechanical ventilation(MV).The serum level of s TREM-1 and IL-6 were detected by double antibody sandwich enzyme-linked immunosorbent assay(ELISA),meanwhile CRP and PCT were determined by latex turbidimetry and immunofluorescence dry quantitative method respectively.3.SPSS22.0 was used for statistical processing and Graph Pad Prism5 for drawing analysis.Results: 1.0h and 24 h points after MV,s TREM-1,IL-6 and CRP showed no significant difference between VAP group and N-VAP group(P> 0.05).There was no statistical difference of PCT level between the two groups at MV 0h(P>0.05).Compared with N-VAP group,the content of PCT in VAP group was significantly higher at 24 h point(P = 0.001).The levels of s TREM-1,PCT and CRP in VAP group were higher than that of N-VAP group at 72 hours after MV(P <0.05).IL-6 also increased in 72 h compared with N-VAP group,but the difference was not significant(P = 0.119);The content of all biomarkers was lowerat 120 h point than 72 h point,while PCT and IL-6 showed no significant difference between VAP and N-VAP(P> 0.05),The difference of s TREM-1 and CRP between VAP group and N-VAP group was significant(P = 0.042,P = 0.04).2.Serum s TREM-1,PCT and CRP were all higher at 72 h than 0h in neonates with VAP(P <0.05).All the biomarkers in the N-VAP group were lower at 120 h point than 72 h point with a significantly difference(P < 0.05).The trends of thesebiomarkers in the VAP and the N-VAP groups were generally consistent over time.The s TREM-1,IL-6 and CRP levels were the lowest at the beginning of MV in both groups,peaking on the third day and then decreasing gradually.3.There were highest correlation between s TREM-1 and VAP at 72h(r=0.697.P<0.001),while lower correlations at 0h,24 h,120h(r=0.079,P > 0.05;r=0.208,P >0.05;r=0.266,P=0.04).The correlation coefficients between PCT and VAP at 24h?72h were 0.429 and 0.601 respectively and there were significant differences between the two groups(P<0.05),and the correlation between 0h and 120 h was not higher.The correlation between CRP &IL-6 and VAP were all lower at four points.4.The Logistic regression analysis showed that none of the four parameters was statistically significant at 0h?120h(P>0.05),while there was statistical difference of PCT at 24 h point(P=0.045).Boths TREM-1 and PCT have statistical significance at 72 h after MV(P=0.007)5.The receiver operating characteristic(ROC)curve showed that the area under the ROC curve(AUC)of the four biomarkers at 0h and 120 h was less than 0.67,and the Youden index was less than 0.35.The AUC of s TREM-1,IL-6 and CRP was under 0.65,and the PCT was 0.748.The optimal cut-off value ofs TREM-1 was 165.05 pg / ml at 72 h,and the AUC was 0.902.The sensitivity ofthe predicted VAP was 90%,the specificity was 77%,and the Youden index was 0.67.The best cut-off value of PCT was 1.55ng/ml,the AUC was 0.847,the sensitivity and specificity were 67% and 87% respectively.The CRP was higher than 8.425mg/l and the AUC was 0.65.The AUC of IL-6 was less than 0.65.6.The ROC curve combined with logistic regression analysis showed that the AUC of PCT &s TREM-1 were larger than that of the single index on diagnostic sensitivity and specificity of the VAP.Conclusion: 1.The biomarkers of s TREM-1,PCT,CRP at 72 h point could be potential predictors for VAP.The sensitivity and specificity of s TREM-1 at 72 h were better than those of PCT,CRP and IL-6 in the early prognosis of VAP.2.s TREM-1,PCT,IL-6 and CRP are of little significance in predicting VAP at 0h?24h and 120 h after MV.3.The value of combination of thoseindexes is better than single index on prognostic efficiency.