Abstract
BACKGROUND: Interleukin-6 (IL-6) is used as a marker for infection and inflammation. After liver surgery, IL-6 is also crucial for hepatic regeneration. The value of IL-6 serum-levels to differentiate infection from imminent post-hepatectomy liver failure (PHLF) remains unclear. This review focuses on IL-6 and complications after liver resections, specifically PHLF and infections. METHODS: A systematic review was performed in the PubMed, Embase, and Cochrane libraries from January 2000 to June 2025 according to PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). All English language human data publications were assessed. RESULTS: Overall, 12 studies (n = 589 patients) evaluating perioperative serum IL-6 levels were included. Six publications reported PHLF rates, and two specifically addressed IL-6, PHLF, and infection. Several patient and surgical parameters influence IL-6 dynamics. Despite five randomized trials being published, the overall study quality was low, with a high risk of bias. In particular, IL-6 on the first postoperative day was associated with PHLF and infections, but multivariable analyses of confounding factors are lacking. A meta-analysis of studies with a specific cut-off calculation was precluded by heterogeneous cohorts and endpoints. CONCLUSIONS: IL-6 levels may have early diagnostic value regarding imminent infectious complications or PHLF early after liver resection, but the evidence is exploratory and limited by methodological weaknesses. At present, IL-6 as a single marker does not seem to show sufficient clinical discriminatory potential to differentiate between infection and impaired hepatic regeneration. Future studies should address confounding factors, ideal timepoints of assessment, different methods of serum IL-6 assays, specific cut-offs, and multi-marker combinations.