# Metabolomic Insight into Donation After Circulatory-Death Kidney Grafts in Porcine Autotransplant Model: Normothermic Ex Vivo Kidney Perfusion Compared with Hypothermic Machine Perfusion and Static Cold Storage

## TL;DR

This study compares kidney preservation methods in pigs, finding that normothermic ex vivo perfusion activates protective mechanisms and could improve organ transplant outcomes.

## Contribution

The study introduces chemical biopsy as a novel method to assess kidney graft quality and reveals metabolomic differences between preservation techniques.

## Key findings

- NEVKP activates anti-oxidative and anti-inflammatory mechanisms in donor kidneys.
- HMP and SCS reduce cellular energy demand but limit physiological repair processes.
- Chemical biopsy identifies metabolite changes linked to ischemia and preservation methods.

## Abstract

Organ shortage is a major challenge in transplantation, prompting the use of extended criteria donor grafts. These require improved preservation techniques and reliable methods to assess graft function. This study aimed to evaluate changes in the kidney metabolome following three preservation methods: normothermic ex vivo kidney perfusion (NEVKP), hypothermic machine perfusion (HMP) and static cold storage (SCS) in porcine autotransplant models. A chemical biopsy allowed minimally invasive sampling of metabolites, which were analyzed using liquid chromatography coupled with high-resolution mass spectrometry. The results highlighted metabolites affected by ischemia and oxidative stress in donor kidneys, as well as changes specific to each preservation method. Differences were observed immediately after transplantation and reperfusion and several days post-surgery. NEVKP was associated with the activation of physiological anti-oxidative and anti-inflammatory mechanisms, suggesting potential protective effects. However, some metabolites had dual roles, which may influence future graft treatment designs. HMP and SCS, while reducing energy demand in cells, also limit physiological repair mechanisms. These findings provide a basis for improving graft assessment and organ preservation, with chemical biopsy serving as both a tool for discovery and a potential diagnostic method for monitoring graft quality.