The systemic immune-inflammation index at kasai portoenterostomy: related to clinical outcomes

Background Systemic Immune-Inflammation Index (SII), known as an easy, economical and useful marker, correlates with the balance of inflammation and immune response. However, the usefulness of SII in biliary atresia (BA) remains unclear. Therefore, we evaluated the relationship of SII level and postoperative clinical outcomes of BA. Methods Retrospective review of 168 patients with BA was conducted with assessments of demographic information, histological findings, laboratory parameters, and clinical outcomes. The LASSO logistic regression analysis was established using the "glmnet" software package to explore the influencing factors related to native liver survival time. Numerical variables were dichotomized based on the receiver operating characteristic (ROC) curve and Youden index yielding the best performance of prediction. R software was used for statistical analysis. Results Overall, the 24 month native liver survival rate was 43.5% (73 cases) after Kasai portoenterostomy. LASSO logistic regression analysis show that preoperative malnutrition (OR = 0.032, 95%CI 0.001-0.424), gamma-glutamyltransferase (GGT, OR = 0.994, 95%CI 0.987-0.998), lymphocyte count (LY, OR = 2.426, 95%CI 1.467-4.604), SII (OR = 0.977, 95%CI 0.960-0.989), and liver fibrosis grading (LFG, reference: Grade 1, Grade 3, OR = 0.076, 95%CI 0.007-0.614) were the independent influencing factors for 24 month native liver survival. ROC curve analysis showed that the area under the curve of SII level (0.919) was larger than that of preoperative malnutrition (0.690), LFG (0.759), GGT (0.747), and Ly (0.773). A SII < 140.09 was found to be a significant marker in the prediction of 24-month native liver survival, with 90.41% sensitivity and 93.68% specificity. Furthermore, the rates of 24-month native liver survival (33.1% vs. 72.7%), jaundice clearance (46.8% vs. 75.0%), and good liver function recovery (46.8% vs. 65.9%) were lower in the SII >= 140.09 group than that in the SII < 140.09 group (all P < 0.05), but there was no difference in the occurrence of cholangitis (P > 0.05). Conclusion Preoperative malnutrition, GGT, Ly, SII, and LFG were independent influencing factors for postoperative 24-month native liver survival of BA. The SII level, as a routine haematological marker, has better universality and simplicity and is related to clinical outcomes after Kasai portoenterostomy.