Systemic Immune-Inflammation Index (SII) Can Be an Early Indicator for Predicting the Severity of Acute Pancreatitis: A Retrospective Study

OBJECTIVE: Systemic immune-inflammation index (SII) is a new systemic inflammatory prognostic indicator associated with outcomes in patients with different tumors. Studies have shown an association between SII and many chronic/acute inflammatory diseases. This study aimed at exploring whether SII can be used as an effective parameter for predicting the severity of acute pancreatitis (AP). METHODS: A total of 101 acute pancreatitis patients were enrolled in this study (mild acute pancreatitis (MAP): n = 73 and severe acute pancreatitis (SAP): n = 28). Patient demographics and SII were analyzed using the chi-square test, Student’s t-test, and Mann–Whitney U-test. A receiver operating characteristic curve was generated to test the potential of using neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and SII to predict AP’s severity. Logistic regression analysis was performed to determine major risk factors. RESULTS: Patients with SII value ≥2207.53 had a higher probability of having SAP (sensitivity = 92.9%, specificity = 87.7%, and AUC = 0.920), and SII was a significantly better predictive value than PLR and NLR. Logistic regression analysis results showed SII could differentiate MAP from SAP as a major risk factor. CONCLUSION: This study has shown that SII is a potential indicator for predicting the severity of acute pancreatitis. The findings suggested that SII is more sensitive and specific than NLR and PLR in predicting the severity of acute pancreatitis.