Diagnostic Value Of Procalcitonin In Discriminating Between Gram-negative And Gram-positive Bacterial Infection Sepsis

Background and Objective As a new found of useful sepsis marker in recent years,procalcitonin has recently emerged as a powerful biomarker for an early and accuratediagnosis of bacterial infection, in addition, blood PCT concentrations have beenproven to correlate with the severity of the disease and the prognosis of patients.However, the research about the diagnostic value of procalcitonin in discriminatingbetween Gram-negative and Gram-positive bacterial infection sepsis was less. Weretrospectively investigated the levels of PCT in patients with positive blood culturessepsis, aiming to examine the diagnostic value of procalcitonin in discriminatingbetween Gram-negative and Gram-positive bacterial infection sepsis.MethodsPatients with sepsis which was in line with the standard developed by theInternational septic defined Meeting2001whose blood culture were positiveadmitted to be in ZhongShan Hospital XiaMen University between April2010andMarch2013were involved, a total of103patients.59patients,blood culture wereGram-negative bacteria, while44patients，blood culture were Gram-negative bacteria.The two groups were determined Serum PCT, hsCRP levels prior administeredantimicrobial drug according to standard procedures. Then we analyzed the differenceof PCT and the difference of hsCRP between the two groups.Results (1) The mainbacterial distribution of cases. E. coli was identified as the most frequent causalpathogens in our cohort(20.4%), followed by pneumonia Klebsiella(13.6%),Staphylococcus aureus(12.6%), Staphylococcus epider-midis(11.7%), Pseudomonasaeruginosa(7.8%) and Enterococcus faecalis(3.9%).(2) Comparison of two groupsPCT levels and two groups hsCRP levels.Procalcitonin levels were found to bemarkedly higher in patients with GN bacterium [17(2.03；60.11)ng/ml]than in thosewith GP bacterium[0.46(0.14；2.27)ng/ml], which was a statistically significant difference(P<0.0001). HsCRP levels were not found any statistically significantdifference (P>0.05) between GN bacterium[101(48.2；157.8)mg／L] and GPbacterium[76.95(35.6；113.4)mg／L].(3) The ROC curve analysis of two groups PCTlevels and two groups hsCRP levels. When using PCT levels as a biomarker todiscriminate between the GN bacterium and GP bacterium, we found the area underthe curve(AUC) was0.821(95％CI:0.735－0.907)，which was found a statisticallysignificant difference (P<O.0001) compared to area been0.5. When taken1.67ng/mLas a cutoff value of PCT, we found the largest Youden index(0.535).the sensitivitywas83.05and the specificity was70.45. When using hsCRP levels as a biomarker todiscriminate between the GN bacterium and GP bacterium, we found the area underthe curve(AUC) was0.608(95％CI:0.498－0.718)， which was not found anystatistically significant difference (P>0.05) compared to area been0.5.Conclusion(1) Higher PCT levels are found in GN bacterium and it can pay a role indiscriminating between the GN bacterium and GP bacterium.(2) HsCRP levels areunrelated with blood culture results，and cannot discriminate between the GNbacterium and GP bacterium.(3) E. col、Pneumonia Klebsiella、Pseudomonasaeruginosa are the most common GN bacteria causative agents of blood infection,while Staphylococcus aureus is the most common GP bacterium causative agent ofblood infection, we should pay more attention to the above bacteria in clinicalpractice.