Role Of IL-6, IL-8 And Procalcitonin In The Diagnosis Of Secondary Infection In Severe Acute Pancreatitis

Objective: To study the clinicopathological significance of the expression of IL-6,IL-8 and PCT in severe acute pancreatitis. To investigate the Role of IL-6,IL-8 and Procalcitonin in the diagnosis of secondary infection in severe acute pancreatitis.To compare the power of IL-6,IL-8 and PCT respectively and combined both of or all of them.Methods:Enzyme-Linked Immunosorbent Assay (ELISA) was used to examine the expression of IL-6,IL-8 and PCT during the initial 24h after onset of severe acute pancreatitis.The study was performed in 27 patients with sepsis and 30 patients with non-infectious SIRS. The levels of the expression were analyzed combined with clinicopathological features of the patients including age, gender, basic disease,body temperature, heart beating rate,breathing rate,white blood cell count,blood platelet count, serum bilirubin,concentration of inosine, PaCO2, PaO2,chest radiograph and the result of enhanced CT. Make use of SPSS15.0 for Windows software to carry out statistical treatment. All measurement data were firstly treated with normality test (Kolmogorov-Smirnov test) and the homogeneity of variance test (Levene's test). Data were expressed as x_±s values, if accorded with the normal distribution , and t test was adopted for the comparison of difference in measurement data. Enumeration count data were expressed as percentage of patients,andχ2 test was applied in the comparion between two groups. To investigate the Role of IL-6,IL-8 and Procalcitonin in the diagnosis of secondary infection in severe acute pancreatitis , two methods were used in this study:(1)receiver operating characteristic curve was performed and the area under the curve (AUC) was calculated(2)the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated and intercompared.Results:The serum levels of IL-6,IL-8 and PCT were significantly higher in patients with sepsis than in thoses with non-infectious SIRS(IL-6: 134.664±99.194ng/L vs 58.998±41.144 ng/L, p=0.001; IL-8: 106.211±35.862ng/L vs 58.998±87.443±18.497, p=0.019 and PCT: 2.577±1.384μg/L vs 1.485±0.649,p=0.001). The level of IL-8 was higher in patients with sepsis (106.211±35.862ng/L) than those with non-infectious SIRS (87.443±18.497 ng/L) (p<0.05). Receiver operating characteristic cure showed that compared with IL-6 (AUC=0.743,p=0.002) and IL-8 (AUC=0.677, p=0.022) the power of PCT (AUC=0.754, p=0.001) was the best of all above.The specificity of IL-6, IL-8 and PCT was 93.0%, but the sensitivity and accuracy of PCT (55.6%, 75.4%) were higher than IL-6(51.9%, 73.7%) and IL-8 (48.1%, 71.9%). The sensitivity, specificity and accuracy of IL-6 in combination with IL-8(AUC=0.773, p=0.000) was 63.0%, 90.0% and 75.4% respectively. The sensitivity, specificity and accuracy of IL-6 in combination with PCT (AUC=0.758, p=0.001) was 55.6%, 96.7% and 77.2% respectively. The sensitivity, specificity and accuracy of IL-8 in combination with PCT (AUC=0.793, p=0.000) was 74.1%, 80.0% and 78.9% respectively.The sensitivity, specificity and accuracy of IL-6 in combination with IL-8 and PCT (AUC=0.800, p=0.000) was 63.0%, 96.7% and 80.7% respectively.Conclusion: IL-6, IL-8 and PCT can be used as valuable indexes to predict the secondary infection of severe acute pancreatitis at the early stage.The power of PCT was the best in all above, and when combined with IL-6, the specificity and the accuracy inceased. When IL-8 was conbined with PCT, the sensitivity and the accuracy inceased but the specificity decreased. When IL-8 was conbined with IL-6, the sensitivity was better than PCT although the spcecificity and the accuracy decreased. When all of them were combined, the sensitivity and the accuracy increased further.