Using a Chemical Biopsy for Graft Quality Assessment

Abstract

Kidney transplantation is a life-saving treatment for a large number of people with end-stage renal dysfunction worldwide. The procedure is associated with an increased survival rate and greater quality of patient's life when compared to conventional dialysis. Regrettably, transplantology suffers from a lack of reliable methods for organ quality assessment. Standard diagnostic techniques are limited to macroscopic appearance inspection or invasive tissue biopsy, which do not provide comprehensive information about the graft. The proposed protocol aims to introduce solid phase microextraction (SPME) as an ideal analytical method for comprehensive metabolomics and lipidomic analysis of all low molecular compounds present in kidneys allocated for transplantation. The small size of the SPME probe enables performance of a chemical biopsy, which enables extraction of metabolites directly from the organ without any tissue collection. The minimum invasiveness of the method permits execution of multiple analyses over time: directly after organ harvesting, during its preservation, and immediately after revascularization at the recipient's body. It is hypothesized that the combination of this novel sampling method with a highresolution mass spectrometer will allow for discrimination of a set of characteristic compounds that could serve as biological markers of graft quality and indicators of possible development of organ dysfunction.

Metabolomic Phenotyping of Gliomas: What Can We Get with Simplified Protocol for Intact Tissue Analysis?

“…This strategy is intended to be used eventually for the analysis of brain tumors and healthy brain tissue in the given patient at the same time. Moreover, an approach using regular SPME probe without implementing any modification to the device itself was used for the assessment of kidney graft quality during transplantation with only 10 min extraction time [ 59 ] and for the determination of the concentration of doxorubicin in pig and human lungs in vivo along with untargeted metabolomic profiling of the lung tissue with a 20 min extraction time [ 60 ]. The examples above show that modifications to the protocol related to the time of extraction are possible and have already been tested on different applications.…”

A Review of Current and Emerging Trends in Donor Graft-Quality Assessment Techniques

“…A novel and minimally invasive metabolomic and lipidomic diagnostic protocol based on solid-phase microextraction (SPME) has been proposed to address the lack of representative methods of assessing graft quality [93,94]. The small size of the SPME probe allows the performance of chemical biopsy, which enables metabolites to be extracted directly from the kidney without any tissue collection.…”

SPME Probes: A Novel Chemical Biopsy Tool for Spatially Resolved Profiling of Human Brain Tissue in vivo

“…The metabolomic analyses utilized reversed-phase liquid chromatography (RPLC) and hydrophilicinteraction liquid chromatography (HILIC) in positive and negative ion mode. The protocol used in these analyses has been detailed in 17,18 .…”

“…Reversed-phase liquid chromatography (RPLC) and hydrophilic interaction chromatography (HILIC) in positive ion mode were conducted for the lipidomic analyses. The protocol used for these analyses is detailed in 17 and with some modi cation in 18 .…”