The Diagnostic Threshold Value Of High-sensitivity C-reactive Protein Test In Neonatal Septicemia

Objective: To evaluate the significance and find the optimal thresholdvalue of high sensitive C-reactive protein test for the diagnosis of neonatalsepticemia.Methods:81cases of confirmed septicemia,152cases of the clinicaldiagnosis of septicemia and103cases of non-septicemia who were admittedto our neonatal department during October2010to October2011wereenrolled for study. The high sensitive C-reactive protein concentration ofthose three groups was analyzed. Taking blood culture as the gold standard,receiver operating characteristic（ROC）curve was drew, and the diagnosticthreshold value of hs-CRP was determined. The high sensitive C-reactiveprotein (hs-CRP), tradition C-reactive protein (CRP), white cell count(WBC), ratio of immature neutrophils to total neutrophils (I/T) and plateletcount (PLT) of all the cases were conducted and analyzed with their clinicalcharacteristics.Results:(1)The hs-CRP concentration of confirmed septicemia group, clinical diagnosis of septicemia group and non-septicemia group were15.0mg/L,11.0mg/L and1.0mg/L, respectively.(2)The area under the ROC curve of hs-CRP is0.851, and the optimalthreshold value is3.0mg/L.(3)There is a significant difference (p＜0.05) between confirmedsepticemia group and non-septicemia group in hs-CRP, CRP, WBC, I/T andPLT. The sensitivity of each test were90.1%,42.0%,34.6%,16.0%,22.2%,respectively; specificity were66.0%,95.1%,87.4%,95.1%,97.1%,respectively.（4）The positive rate of high sensitivity C reactive protein (hs-CRP)was high in preterm infants septicemia group or full term infants septicemiagroup (>74%)，and no significant difference between each group (P>0.05).The positive rates of septicemia nonspecific investigations in preterm infantswere obviously lower than full term infants (P<0.05), like white cell count(30.3%vs51.6%), ratio of immature neutrophils to total neutrophils (I/T)(9.2%vs24.2%) and CRP (27.6%vs46.5%).Conclusions:（1）hs-CRP test is an ideal screening project for the diagnosis ofneonatal septicemia.（2）the optimal threshold value is3.0mg/L for the diagnosis ofneonatal septicemia.（3）hs-CRPisbetterthanothernon-specificdiagnosismethodsrelated to routine blood in the diagnosis of preterm infants septicemia.