Metabolomic and lipidomic landscape of porcine kidney associated with kidney perfusion in heart beating donors and donors after cardiac death

Abstract With the ever-increasing shortage of kidney donors, transplant centers are faced with the challenge of finding ways to maximize their use of all available organ resources and extend the donor pool, including the use of expanded criteria donors. To address the need for a new analytical solution for graft quality assessments, we present a novel biochemical analysis method based on solid-phase microextraction (SPME) – a chemical biopsy. In this study, renal autotransplantation was performed in porcine models to simulate two types of donor scenarios: heart beating donors (HBD) and donors after cardiac death (DCD). All renal grafts were perfused using continuous normothermic ex vivo kidney perfusion. The small diameter of SPME probes enables minimally invasive and repeated sampling of the same tissue, thus allowing changes occurring in the organ to be tracked throughout the entire transplantation procedure. Samples were subjected to metabolomic and lipidomic profiling using high-performance liquid chromatography coupled with a mass spectrometer. As a result, we observed differences in the profiles of HBD and DCD kidneys. The most pronounced alterations were reflected in the levels of essential amino acids, purine nucleosides, lysophosphocholines, phosphoethanolamines, and triacylglycerols. Our findings demonstrate the potential of chemical biopsy in donor graft quality assessment and monitoring kidney function during perfusion.