Immune Regulatory Signatures Associated with Different Recovery Durations of Delayed Graft Function after Kidney Transplantation

Abstract

Delayed graft function (DGF) is a common early complication of kidney transplantation characterized by immune activation. The duration of DGF may significantly affect long-term graft survival, yet the immune mechanisms underlying the different DGF durations remain unclear. Using a functional definition of delayed graft function (fDGF), defined as a failure of serum creatinine to decrease by at least 10% per day for three consecutive days within the first postoperative week, patients were stratified into short-term DGF (SDGF) and long-term DGF (LDGF) groups according to recovery periods. In this exploratory study, targeted proteomic analysis indicated that proteins enriched in SDGF were primarily involved in innate immune responses and acute inflammatory processes, including neutrophil chemotaxis and migration, whereas LDGF exhibited features related to adaptive immune responses and chronic inflammation, such as T-cell differentiation and activation. IL-7 and CCL20 were identified as candidate molecules potentially associated with different DGF durations. Targeted metabolomics revealed disturbances in amino acid metabolism, particularly alanine, aspartate, and glutamate metabolism, as well as in energy metabolism, including the tricarboxylic acid (TCA) cycle, which may be involved in LDGF. These findings provide preliminary insights into immune metabolic features associated with different DGF recovery durations.