Diagnostic Value Of C-reactive Protein,Procalcitonin And Mean Platelet Volume In Late Preterm Infants With Early-onset Sepsis

Objective:This study explores the effects of laboratory indicators such as C-reactive protein(CRP),procalcitonin(PCT)and mean platelet volume(MPV)in late preterm infants with early onset sepsis(EOS).It provides a clinical basis for the early diagnosis of EOS in late preterm infants.Methods:162 late premature infants within 3 days after birth who were diagnosed with early-onset sepsis were selected as the case group.These newborns were admitted to the Neonatal Intensive Care Unit(NICU)of the Affiliated Hospital of North Sichuan Medical College between January 2017 and December 2020.Meanwhile,158 late preterm infants hospitalized in the NICU for non-infectious diseases were selected as the control group.A retrospective case-control study method was used to record clinical data.Blood samples 0-12 hours after birth were collected for the case and control group,including late preterm infants and high-risk factors(gender,gestational age,birth weight,mode of delivery,mode of conception,single or multiple births,premature rupture of membranes,fetal distress,Cholestasis of pregnancy,amniotic fluid contamination,history of mechanical ventilation,etc.)as well as laboratory results[white blood cell(WBC),C-reactive protein(CRP),calcitonin(PCT)and average platelet volume(MPV),etc.SPSS 25.0 statistical software was used for statistical analysis of clinical data.Categorical variables were presented as frequency and percentage.Pearson’s chi-square test was used for the difference between groups of categorical variables.Continuous variables satisfying normal distribution were presented as mean±standard deviation((?)±s),the independent sample t-test was used to compare serum C-reactive protein(CRP),procalcitonin(PCT)and mean platelet volume(MPV)level.Receiver operating characteristic curve(receiver operating characteristic curve,ROC curve)analysis was used to calculate the best cut-off prediction results of CRP,PCT,MPV and the area under the curve(AUC)of different laboratory indicators,including their positive predictions value(PPV)and negative predictive value(NPV),as well as the diagnostic accuracy of three parameters to detect EOS in late preterm infants.If the P value of all tests was less than 0.05,the difference is statistically significant.Results:1.This study includes 162 late preterm infants in the case group and 158 late preterm infants in the control group.No significant statistical differences between the two groups of late preterm infants in terms of maternal pregnancy before delivery,general conditions of children during delivery and treatment of children after delivery.2.The serum levels of CRP,PCT and MPV in late preterm infants in the case group were(6.14±5.60)mg/L,(7.66±7.09)ng/ml,and(10.31±1.21)fL,which were significantly higher than those in the control group in late preterm delivery,respectively.The differences of(1.63±0.96)mg/L,(1.69±1.47)ng/ml,(9.31±0.68)fL of children were statistically significant(P<0.05).However,WBC,Hb,RDW,PDW,PLT,EOS and hsCRP indicators showed no significant difference in numerical changes(P>0.05).3.When the best diagnostic cut-off value of CRP was 1.95 mg/L,the area under the curve(AUC)was 0.841,the sensitivity was 73.5%,the specificity was 83.5%,the positive predictive value was 82.01%,the negative predictive value was 75.43%and 95%CI was 0.798-0.883;when the best diagnostic cut-off value of PCT was 2.25 ng/L,AUC was 0.891,sensitivity was 78.4%,specificity was 84.2%,positive predictive value was 83.55%,negative predictive value was 79.17%and 95%CI was 0.857～0.925;when the best diagnostic cut-off value of MPV was 10.35 fL,AUC was 0.747,sensitivity was 43.8%,specificity was 96.8%,positive predictive value was 93.42%,negativepredictive value was 62.70%and 95%CI was 0.693～0.800.The sensitivity and specificity of the combined detection of CRP,PCT and MPV were higher than the combination of CRP and PCT,CRP and MPV,PCT and MPV,and the difference was statistically significant(P<0.05).Conclusion:1.MPV may be a predictor of EOS in late preterm infants.2.The combined detection of CRP,PCT and MPV has high clinical value in the diagnosis of EOS in late premature infants.