Predictive Value of Pre-Transplant Monocyte-to-Lymphocyte Ratio for Delayed Graft Function in Kidney Transplant Recipients

Background: Delayed graft function (DGF) after kidney transplantation (KT) negatively impacts long-term allograft survival. Inflammatory and immune response markers in transplant recipients have been linked to allograft outcomes. However, the association between the pre-transplant monocyte-to-lymphocyte ratio (MLR) and DGF following KT has not been previously investigated.Methods: This study included 162 patients who underwent KT between January 1989 and December 2023. The optimal pre-transplant MLR cutoff for predicting DGF was identified using receiver operating characteristic (ROC) curve analysis. Univariate and multivariate logistic regression analyses were performed to identify factors associated with DGF.Results: DGF occurred in 58 patients (35.8%). The optimal MLR cut-off for predicting DGF was 0.255 (Area under the curve (95% confidence interval) = 0.686 (0.603–0.769), P < 0.001), with a sensitivity of 81.0% and specificity of 55.8%. In multivariate analysis, MLR ≥ 0.255 was independently associated with DGF (Odds ratio (95% confidence interval) = 3.74 (1.55–9.02), P = 0.003). Higher MLR values were also correlated with longer hospital stays.Conclusions: An elevated pre-transplant MLR was a significant predictor of DGF following KT. MLR may serve as a useful, non-invasive biomarker for risk stratification and prediction of post-transplant outcomes.