Kidney Perfusion as an Organ Quality Assessment Tool—Are We Counting Our Chickens Before They Have Hatched?

Abstract

The final decision to accept an organ for transplantation remains a subjective one. With “poor organ quality” commonly cited as a major reason for kidney discard, accurate, objective, and reliable quality assessment is essential. In an era of increasingly higher-risk deceased donor kidneys, the catch is to accept those where the risk–benefit scale will tip in the right direction. Currently available assessment tools, such as risk-scores predicting outcome and zero-time biopsy, perform unsatisfactory, and assessment options during static cold storage are limited. Kidney perfusion technologies are finding their way into clinical practice, and they bring a new opportunity to assess kidney graft viability and quality, both in hypothermic and normothermic conditions. We give an overview of the current understanding of kidney viability assessment during ex situ kidney perfusion. A pragmatic framework to approach viability assessment is proposed as an interplay of three different compartments: the nephron, the vascular compartment, and the immune compartment. Although many interesting ways to assess kidney injury and function during perfusion have been proposed, none have reached the stage where they can reliably predict posttransplant outcome. Larger well-designed studies and validation cohorts are needed to provide better guidance.

Assessing Kidney Graft Viability and Its Cells Metabolism during Machine Perfusion

“…In addition to the capability of monitoring perfusion dynamics, the circulating perfusate can be sampled for levels of damage and injury biomarkers. In both instances, perfusion dynamics and biochemical perfusate analysis have been described in the assessment of organ viability and suitability for organ transplantation [ 34 ].…”

Role of novel biomarkers in kidney transplantation

“…In their review from 2020, De Beule et al[ 51 ] nicely summarize the current status of the allograft viability assessment. They illustrate potential roles for different biomarkers in different perfusion contexts e.g ., hypothermic, normothermic machine perfusion[ 51 ].…”

“…In their review from 2020, De Beule et al[ 51 ] nicely summarize the current status of the allograft viability assessment. They illustrate potential roles for different biomarkers in different perfusion contexts e.g ., hypothermic, normothermic machine perfusion[ 51 ]. In the context of hypothermic machine perfusion, they, in conjunction with a recent meta-analysis performed by Guzzi et al[ 52 ] report that glutathione S-transferase and its isoforms alpha- and pi-, a family of detoxification enzymes associated with acute kidney injury and renal injury, have moderate predictive ability for delayed graft function (DGF)[ 52 ].…”

“…In their review, De Beule et al[ 51 ] postulated a potential biomarker role for flavin mononucleotide (FMN), a subunit of mitochondrial complex I. This molecule has been demonstrated in porcine kidney transplant models and human liver graft perfusion, as markers of mitochondrial, early allograft dysfunction and loss.…”

“…This molecule has been demonstrated in porcine kidney transplant models and human liver graft perfusion, as markers of mitochondrial, early allograft dysfunction and loss. This has not been studied in the context of human kidney transplantation[ 51 ].…”