Infections in Liver Retransplantation: A Prospective Study of Microbial Patterns, Immune Biomarkers, and Survival

Liver retransplantation (Re-Tx) recipients are at elevated risk for infectious complications due to increased immunologic and clinical vulnerability. However, prospective data on infection incidence, microbial etiology, immune biomarkers, and survival outcomes in this population remain limited.

We conducted a prospective cohort study of 26 adult Re-Tx recipients treated between 2021 and 2023 at the Inonu University Liver Transplantation Institute (Malatya, Türkiye). Demographic, clinical, and laboratory data-including preoperative immune biomarkers (TNF-α, TGF-β, IL-1β, IL-4, IL-6, IL-22, β-galactosidase, GDH, IFN-γ, GM-CSF)-were collected. Infections were classified as early (0-30 days) or early-intermediate (1-6 months) post-transplant. Multivariate logistic regression was used to assess infection risk factors. Kaplan-Meier analysis was performed to evaluate survival.

Female sex (OR = 7.377) and elevated procalcitonin levels on postoperative day 3 (OR = 1.054) were independently associated with early infections. Early infections were predominantly caused by gram-negative bacteria and fungi, including E. coli, Klebsiella spp., and Acinetobacter baumannii. These infections significantly reduced 1-, 3-, and 5-year survival rates (log-rank P < .05). No significant differences were found in preoperative immune biomarker levels between infected and non-infected patients (P > .05).

Re-Tx recipients face high early infection risk, especially from multidrug-resistant organisms such as Candida spp. and A. baumannii. Female sex and postoperative PCT elevation may serve as early warning indicators. Although biologically relevant, preoperative immune biomarkers showed limited prognostic value. Tailored prophylactic and monitoring strategies are needed in this high-risk group.