Interleukin 6 at reperfusion: A potent predictor of hepatic and extrahepatic early complications after liver transplantation

Background and aims Ischemia‐reperfusion injury impacts early liver graft function. Interleukin 6 (IL‐6) as early as at reperfusion has shown to predict in‐hospital complications, but its impact on vascular complications and long‐term outcomes is not ascertained. Methods A retrospective study was conducted on all consecutive patients transplanted during a 6‐year period to define significant early systemic inflammatory response (ESIR). The main end‐point was 3‐year graft survival. Significant ESIR was defined according to IL‐6 level at reperfusion on an exploratory set of 121 patients and validated on an independent cohort (n = 153). Results Significant ESIR was defined as IL‐6 at reperfusion >1000 ng/mL in the exploratory cohort. Three‐year graft and overall survival were lower in patients with ESIR in the determination set (P = 0.001 and 0.045, respectively). This was confirmed in the validation set (P = 0.045 and 0.027). In patients with high cytolysis, IL‐6 identified patients at risk for arterial thrombosis. The main determinants for IL‐6 level were intragraft lactate level, cold ischemia time, and anhepatic phase duration (P = 0.005). IL‐6 level independently predicted graft survival (P = 0.0003). Conclusions IL‐6 at reperfusion is a valid biomarker to predict long‐term survival. Furthermore, it helps the interpretation of cytolysis in the prediction of early vascular complications.