| Neonatal sepsis is a systemic infection that occurss within 28 days of the birth of a newborn,in which early-onset sepsis(EOS)is neonatal sepsis occurring within 7 days of birth,while foreign scholars tend to the neonatal early-onset sepsis is defined as 72 hours after birth onset.The morbidity and mortality of EOS in preterm infants were higher than those of full-term infants and EOS was one of main factors leading to premature death.The early clinical symptoms and signs of EOS are not typical,and laboratory infection indicators less sensitive leading to the guiding significance of early clinical diagnosis is not ideal.Therefore,early diagnosis of EOS is still a major challenge for neonatal physicians.Cord blood can be obtained as the earliest blood samples available in the neonatal period,the detection of its infection index theoretically has reference value for early prediction and diagnosis of EOS.Furthermore,the studys of cord blood infection indicators,such as procalcitonin(PCT)and interleukin-6(IL–6),on the early prediction,diagnosis of EOS have been some results.This study was to investigate the value of cord blood vitamin D binding protein(VDBP),25-hydroxyvitamin D(25-(OH)D)and procalcitonin(PCT)in predicting EOS in preterm infants.Vitamin D is a fat-soluble vitamin whose main biological function is involved in the metabolism of bone and minerals in the body.However,the important function of vitamin D in immune regulation has attracted much attention in recent years.VDBP is a major protein for the metabolism of vitamin D,its main function is combine and transport of vitamin D and its derivatives.In recent years,VDBP has been found to play a role in inflammation and injury process.A study of adult sepsis showed that serum 25-(OH)D and VDBP levels in patients with sepsis were significantly lower than those in the healthy group,and were associated with poor prognosis.Another study of VDBP in critically ill patients found that VDBP levels in critically ill patients with sepsis were significantly lower than those without sepsis,and serum low VDBP levels affected survival.The above results showed that the serum 25-(OH)D and VDBP levels were both decreased in adult patients with sepsis,and were associated with poor prognosis.In 2005,Mehmet N C designed a study on EOS neonatal cord blood 25-(OH)D levels,pointed out that EOS neonatal cord blood 25-(OH)D levels were significantly lower than the neonatal of normal control group,and low 25-(OH)D levels can increase the risk of neonatal early-onset sepsis.However,changes in serum VDBP levels in EOS neonates have not been reported.Objective:1 By detecting the levels of cord blood VDBP,25-(OH)D and PCT in preterm infants with EOS and control group,try to investigate the predictive value of cord blood VDBP,25-(OH)D and PCT levels in preterm infants with EOS and whether VDBP,25-(OH)D can be used as new indicator for predicting EOS.2 By measuring the leves of cord blood VDBP,25-(OH)D and PCT of preterm infants in EOS group and control group by contrast,to explore whether there is any advantage of cord blood VDBP,25-(OH)D in early diagnosis of preterm infants with EOS with the traditional index PCT.3 To explore the relationship between VDBP and 25-(OH)D levels in preterm infants of EOS group and control group,and to find out whether there was a synergistic relationship between the two in the course of EOS.Method:1 Research objects and groups:This study was performed in preterm infants who were <37 weeks of gestational age and wrere born in Department of Obstetrics and Gynecology and admitted to Neonatal Intensive Care Unit(NICU)of the fourth hospital of Hebei Medical University between 2015-10 to 2016-12.In addition to the existence of other systems serious deformity,genetic metabolic diseases,birth trauma or birth asphyxia anoxia;death within 72 hours after birth and automatic abandonment of treatment;hospital disease classification is unknown,discharged at the time of diagnosis of late-onset sepsis;Insufficient specimen collection and hemolysis of blood samples.A total of 85 preterm infants were included,the basic clinical characteristics of gender,birth weight and gestational age were recorded.According to the disease outcome and gestational age were divided into four groups,EOS group 1(27weeks≤GA<34weeks),EOS group 2(34weeks≤GA<37weeks)and control group 1(27weeks≤GA<34weeks),Control group 2(34weeks ≤GA< 37weeks).All the changes in preterm infants were enrolled(including childbirth,premature transfer,access to NICU until discharge)were observed by the experienced neonatal paediatrician of the fourth hospital of Hebei Medical University.EOS diagnostic criteria in accordance with the fourth edition of 2011 Practical Neonatal Science EOS diagnostic criteria.2 Specimen retention and preparation: Collect navel artry blood 2-3ml immediately after delivery,peripheral venous blood 1.5ml-2ml within 72 hours after birth,EOS infants were collected from peripheral venous blood 1.5ml-2ml after 10-14 days effective antibiotic treatment.All blood samples were collected and centrifuged(3000r/5min)to collect serum,and keep in-80℃ for testing VDBP,25-(OH)D and PCT.3 Determination of experimental indicators:The serum levels of VDBP,25-(OH)D and PCT were measured by enzyme-linked immunosomal assay(ELISA).4 Statistical analyses: In this experiment,all the data are used SPSS13.0 statistical software for statistical analysis and processing.Data with normal distribution measurement said by the mean and standard deviation(X ±S),the skewness distribution measurement data using the median(four percentile interval)(M(Q)),count data using rate(%)said.Measurement data: Two independent samples with normal distribution and homogeneity compared use t test(t-test),two non normal samples were compared with Mann-Whitney U test;correlation analysis using Spearman s linear correlation.Enumeration data: Chi square test or Fisher exact probability method.ROC curve was used to test the diagnostic value of different indexes.Statistical analysis using the two-sided test,P<0.05 as the difference was statistically significant.Result:1 The analysis of the basic clinical characteristics of preterm infants in EOS group and control group: there was no tatistical difference in gender,birth weight and gestational age between two groups,P>0.05.2 Comparison the levels of cord blood VDBP,25-(OH)D and PCT in preterm infants of two groups :The levels of cord blood VDBP and 25-(OH)D in preterm infants of EOS group and control group were 69.37±13.42,91.30±17.07ng/ml and 22.09±7.13,31.01±12.63ng/ml respectively,the differences were significant by t test(P<0.05);the levels of PCT were 131.79,95.89 pmol/L respectively,the difference was significant by Mann-Whitney U test(P < 0.05).3 Comparison the levels of cord blood VDBP,25-(OH)D and PCT in preterm infants with different gestational ages:EOS group: The levels of cord blood VDBP and 25-(OH)D in preterm infants of EOS group 1 and EOS group 2 were 65.22 ± 12.22,76.00 ± 12.93ng/mL and 19.99 ± 8.83,25.45 ± 7.90ng/mL respectively,the differences were significant by t test(P<0.05);the levels of PCT were 138.71,110.83pmol/L,respectively,the difference was significant by Mann-Whitney U test(P < 0.05).Control group: The levels of cord blood VDBP and 25-(OH)D in preterm infants of control group 1 and control group 2 were 87.50±15.52,94.49± 17.95ng/mL and 27.52±12.86,33.94±11.91ng/mL respectively,there were no significant differences by t test,(P>0.05);the levels of PCT were 95.64,89.51pmol/L respectively,there was no significant difference by Mann-Whitney U test,(P> 0.05).4 Correlation analysis of 25-(OH)D and VDBP levels in preterm infants :Using Spearman’s correlation analysis: There was no significant correlation between 25-(OH)D and VDBP levels in cord blood and postnatal 72 h blood of preterm infants in EOS group(r=0.272,P=0.086 and r=0.170,P=0.299).25-(OH)D levels were positively correlated with VDBP levels in cord blood and postnatal 72 h blood of preterm infants in control group(r= 0.315,P=0.033 and r=0.303,P=0.041).5 Changes of the postnatal 72 h blood VDBP,25-(OH)D and PCT levels in preterm infants of EOS group and control group:The postnatal 72 h blood VDBP,25-(OH)D levels in preterm infants of EOS group and control group were 64.60±11.32,93.96±14.25ng/mL and 23.52 ±6.03,34.23 ±10.71ng/mL respectively,the differences were significant by t test,(P<0.05);PCT levels were 186.48,125.29 pmol/L respectively,the difference was significant by Mann-Whitney U test(P<0.05).6 Changes of VDBP,25-(OH)D and PCT levels in postnatal 72 h blood and after application of antibiotics blood in EOS group preterm infants:The VDBP,25-(OH)D levels in postnatal 72 h blood and after application of antibiotics blood were 64.60±11.32,91.09±12.99ng/ml and 23.52±6.03,28.52±8.46ng/ml respectively,the differences were significant by t test,(P<0.05);PCT levels were 186.48,89.83 pmol/L respectively,the difference was significant by Mann-Whitney U test(P<0.05).7 The clinical value of cord blood VDBP,25-(OH)D and PCT in the prediction of EOS:The ROC curves were plotted on the cord blood VDBP,25-(OH)D,PCT,the AUC were 0.777(95%CI 0.678~0.876),0.807(95%CI 0.710~0.904),0.840(95%CI 0.754~ 0.926)respectively.Suggesting that cord blood VDBP,25-(OH)D,PCT have the value on early prediction of preterm infant EOS.Conclusion:1 The cord blood VDBP,25-(OH)D and PCT levels have the value of early prediction of EOS.2 The VDBP and 25-(OH)D levels in cord blood and postnatal 72 h blood of preterm infants with EOS were significantly reduced and the levels in after application of antibiotics blood were increased,suggesting that they are expected to be new indicators of early prediction,diagnosis of EOS in preterm infants and assessment of efficacy.3 There was a positive correlation between VDBP and 25-(OH)D levels in cord blood and postnatal 72 h blood of the premature infants in the control group,and there was no significant correlation between VDBP and 25-(OH)D in cord blood and postnatal 72 h blood of the premature infants with EOS group,suggesting that VDBP interacts with 25-(OH)D levels in normal physiological conditions,while there was no correlation between VDBP and 25-(OH)D levels in the pathophysiological process of EOS. |
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