Early predictors of infected pancreatic necrosis in acute severe pancreatitis – Implications of neutrophil to lymphocyte ratio, blood procalcitonin concentration and modified CT severity index

Background: Infected pancreatic necrosis (IPN) accounts for 30% mortality in severe acute pancreatitis (SAP). Early prediction of IPN occurrence is critical for prophylactic measures to be taken. This study aimed to evaluate the predicting value for IPN of combined markers at early stages of SAP. Methods: The clincial records of 324 SAP patients admitted within 48 hours after disease onset were retrospectively analyzed. As potential predictors, the neutrophil to lymphocyte ratio (NLR), blood procalcitonin concentration (PCT) on the 1st, 4th and 7th day post admission, as well as modified computerized tomography severity index (MCTSI) on the 5 – 7th day post admission, were extracted. Correlations between these features with IPN were analyzed using logistic regression, and predictive values were estimated using the Receiver operating characteristic (ROC) curve analyses. Results: NLR, PCT, body mass index (BMI) and MCTSI were significantly higher in IPN group (p < 0.001) compared to the control, among which NLR, PCT and MCTSI were identified as independent predictors for IPN in logistic regression model. Combination of these parameters yielded signficant predicting valuse with an area under curve (AUC) of 0.92, sensitivity of 97.2% and specificity of 77.2% in ROC curve analysis. Conclusion: Combination of NLR, PCT, MCTSI might facilitate the prediction of IPN occurrence in SAP patients.