Diagnostic Value Of Serum Levels Of Procalcitonin, C-reactive Protein And White Blood Cell Count In Children With Infectious Diseases

Objective:To evaluate the diagnostic value of serum procalcitonin(PCT)、C-reactive protein (CRP)and white blood cell count(WBC) in children with bacterial infectious diseases.Methods:A retrospective analysis was performed on132hospitalized children between May2012and May2013with confirmed diagnosis of infectious diseases, consisting of56caseswith bacterial infection、40cases with mycoplasma pneumoniae infection and36caseswith virus infection.Clinical data were collected before using antibiotics.Using RocheCobas automatic immunity analyzer(immune fluorescence quantitative method) todetermine PCT, and using Roche Modular automatic biochemical analyzer to determineCRP,and using Beckman XE5000to determine blood routine examination. According tothe results of PCT, CRP and WBC values, compared them by statistical methods forfollowing analysis.1.According to the results, compared the average values of PCT, CRP and WBC,byuesing Mean±Standard deviation (x±s). Using single factor analysis of variancebetween groups when comparing the values of PCT, CRP and WBC whether they hadstatistical significance (P <0.05).2.With the positive standard (PCT≥0.5ng/mL, CRP≥10mg/L and WBC≥10×109/L),calculated the sensitivity, specificity, posititive predictive value, negative predictivevalue and Youdens,index of PCT, CRP and WBC in diagnosis of becterial infectious, and compared which groups had higher sensitivity and specificity.3.Drawing the ROC curve with the datas of PCT, CRP and WBC, and comparing theAUC of each index in diagnosis of bacterial infection disease, and analyzing the ROCcurve for studying.Results:1.Comparaed with the viral infection group, the serum PCT, CRP and WBC levels inbacterial infection group were higher (P<0.05), the CRP levels in mycoplasmapneumoniae infection group were higher than the virus infection group (P<0.05), whilethe serum PCT levels is higher in bacterial infection group (P<0.05), when comparaedwith Mycoplasma pneumoniae infection group, but there was no significant differencein serum CRP levels(P>0.05).2.When PCT≥0.5ng/ml, the sensitivity of PCT is91.07%, specificity is90.79%，posititive predictive value is87.94%, negative predictive value is90.79%and Youdens,index is0.82. The sensitivity, specificity, posititive predictive value, negative predictivevalue and Youdens,index of PCT is higher than that of CRP and WBC in diagnosis ofbacterial infection disease.3.The area of PCT under the ROC curve was0.737(P=0.00,95%CI:0.664-0.810) whichis the biggest of all. the AUC of CRP is second, with0.693(P=0.00,95%CI:0.612-0.774) while the AUC of WBC is0.689(P=0.00,95%CI:0.603-0.775) is thesmallest in diagnosis of bacterial infection disease.Conclusion:It will be helpful to diagnose the bacterial infection at early stage and it can also direct the therapy according to the serum PCT,CRP and WBC count. The levels of PCT issuperior to CRP and WBC in distinguishing children with bacterial infection.