Comparison Of Value Of Presepsin,Procalcitonin And C-reactive Protein In Differentiating Different Types Of Pathogenic Bacteria In Septic Patients

Objective At present,pathogen culture is still an important method to identify the etiology of sepsis,but the time required for pathogen culture is longer,and the positive rate is not high,therefore,the early diagnosis of sepsis caused by different pathogens and targeted anti-infective treatment become extremely difficult.Procalcitonin and C-reactive protein are commonly used biomarkers for the diagnosis of sepsis and have been widely used in clinical practice.The soluble CD14 subtype(sCD14-ST,Presepsin)is a novel biomarker for the diagnosis of sepsis and has high sensitivity and specificity in the early diagnosis of sepsis.Therefore,this study aimed to compare the value of Presepsin,Procalcitonin(PCT)and C-reactive protein(CRP)in differentiating different types of pathogenic bacteria in septic patients.Methods This was a prospective clinical study.Three hundred twenty-two septic patients who met the"sepsis-3"diagnostic criteria were collected in the emergency intensive unit of the First Affiliated Hospital of Dalian Medical University from July 2016to January 2018.On the first day of admission,10 ml of peripheral venous blood was collected and injected into a blood culture flask(8ml)and a vacuum blood collection tube(2ml)for blood culture,bacterial identification and detection of Presepsin,PCT and CRP.Blood culture was measured by Bactec FX200 automatic blood culture instrument from American BD Company.The bacteria identification was carried out by the German Siemens MicroScan96 automatic bacteria identification instrument.Presepsin is determined by the Japanese Mitsubishi Chemical and Pharmaceutical Company PATHFAST Chemiluminescence Immunoassay Analyzer.PCT is determined by Roche Cobas e411 electrochemical luminometer.CRP is determined by German BN-II special protein analyzer.The reagents used are all selected from the original manufacturer's instrument supporting reagents.According to the results of blood culture,114 cases(n=114)and 208 cases(n=208)were included in the blood culture positive group.The blood culture positive group was further divided into four subgroups:Gram-positive(G~+)cocci,Gram-negative(G~-)bacilli,mixed bacteria and fungal infection groups.45 healthy volunteers were selected as the control group(n=45).Compare differences in Presepsin,PCT,and CRP levels,and plot the receiver operating characteristic curve(ROC)curve,determine the area under the ROC curve.Data were analyzed using SPSS 20.0 software,P<0.05 was considered statistically significant.Results Presepsin,PCT and CRP were significantly increased in the positive blood culture and negative blood culture groups compared with healthy volunteers(all P<0.05);Presepsin and PCT were significantly higher in the positive blood culture group than those in the negative blood culture group(both P<0.05).There was no significant difference between the blood culture positive group and the blood culture negative group(P>0.05).Presepsin had no significantly difference among 4 subgroups(all P>0.05);CRP had no significantly difference among 4 subgroups(all P>0.05);but PCT was significantly higher in the G~-and mixed bacteria groups than that in the G~+and fungi groups(all P<0.05).There was no significant difference in PCT between G~-bacteria infection group and mixed bacteria infection group(P>0.05).There was no significant difference in PCT between G~+cocci infection group and fungal infection group(P>0.05).Presepsin's area under the curve(AUC)is higher than PCT(0.680 vs0.599,P<0.05)or CRP(0.680 vs 0.479,P<0.05).When the Presepsin cutoff value is451 pg/mL,Presepsin predicts that the sensitivity of blood culture positive in patients with sepsis is 91.2%,and the specificity is 42.3%.When the PCT cutoff value was 2.75ng/mL,the AUC of PCT for G~-bacteria and G~+cocci infection was 0.749(95%confidence interval 0.654-0.845)with a sensitivity of 65.4%and a specificity of 78.7%.When the PCT cutoff value was 2.18 ng/mL,the AUC of the PCT for G-bacteria and fungal infection was 0.739(95%confidence interval 0.619-0.859)with a sensitivity of 67.3%and a specificity of 91.7%.Conclusions Presepsin is more valuable than PCT in early predicting positive blood culture in septic patients,but only PCT has an ability to differentiate pathogenic bacteria in septic patients with positive blood culture.It indicated that a combination of Presepsin and PCT should be considered in the clinical practice.