Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 0 0 2026 03 12 1 12 Nini Zhou Department of Infectious Diseases, the Second Affiliated Hospital of Naval Medical University, Shanghai, China Junyan Zhang Department of Infectious Diseases, the Second Affiliated Hospital of Naval Medical University, Shanghai, China Liping Tian Department of Infectious Diseases, the Second Affiliated Hospital of Naval Medical University, Shanghai, China Ling Yin Department of Infectious Diseases, the Second Affiliated Hospital of Naval Medical University, Shanghai, China 2025 06 11 2025 11 09 Postoperative infections (POIs) significantly contribute to morbidity and mortality following partial hepatectomy for hepatocellular carcinoma (HCC). While the Systemic Immune-Inflammation Index (SII) and Prognostic Nutritional Index (PNI) are recognized biomarkers for immune-inflammatory and nutritional status, their combined predictive value for POIs in liver surgery requires further investigation. This study evaluates SII and PNI as preoperative predictors for infections in this patient population. A retrospective observational study was conducted on 300 patients undergoing partial hepatectomy between 2022 and 2024. Preoperative laboratory data were used to calculate SII and PNI, with POIs identified within 30 days based on CDC guidelines. Statistical analyses, including multivariate logistic regression, were performed to compare infected and non-infected cohorts and identify independent predictors of infection. Of the 300 patients, 96 (32%) developed POIs. The infected group exhibited significantly higher SII (1142 ± 618 vs 792 ± 450) and lower PNI (40.1 ± 5.8 vs 46.4 ± 5.9) than the non-infected group. Multivariate analysis confirmed high SII (OR 2.85) and low PNI (OR 3.26; 95% CI, 2.01–5.12) as independent predictors. Furthermore, infections were associated with prolonged hospitalization, increased ICU admissions, and higher 30-day mortality. Preoperative SII and PNI are effective, independent predictors of POIs in patients undergoing hepatectomy for liver cancer. Integrating these biomarkers into routine evaluation enhances risk stratification and guides perioperative optimization. Early identification through these indices allows for targeted interventions, such as nursing-led nutritional support and intensified surveillance, to reduce complications and improve surgical outcomes. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/4489 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/4489/2316