Effluent Molecular Analysis Guides Liver Graft Allocation to Clinical Hypothermic Oxygenated Machine Perfusion

Abstract

Hypothermic-oxygenated-machine-perfusion (HOPE) allows assessment/reconditioning of livers procured from high-risk donors before transplantation. Graft referral to HOPE mostly depends on surgeons’ subjective judgment, as objective criteria are still insufficient. We investigated whether analysis of effluent fluids collected upon organ flush during static-cold-storage can improve selection criteria for HOPE utilization. Effluents were analyzed to determine cytolysis enzymes, metabolites, inflammation-related mediators, and damage-associated-molecular-patterns. Molecular profiles were assessed by unsupervised cluster analysis. Differences between “machine perfusion (MP)-yes” vs. “MP-no”; “brain-death (DBD) vs. donation-after-circulatory-death (DCD)”; “early-allograft-dysfunction (EAD)-yes” vs. “EAD-no” groups, as well as correlation between effluent variables and transplantation outcome, were investigated. Livers assigned to HOPE (n = 18) showed a different molecular profile relative to grafts transplanted without this procedure (n = 21, p = 0.021). Increases in the inflammatory mediators PTX3 (p = 0.048), CXCL8/IL-8 (p = 0.017), TNF-α (p = 0.038), and ANGPTL4 (p = 0.010) were observed, whereas the anti-inflammatory cytokine IL-10 was reduced (p = 0.007). Peculiar inflammation, cell death, and coagulation signatures were observed in fluids collected from DCD livers compared to those from DBD grafts. AST (p = 0.034), ALT (p = 0.047), and LDH (p = 0.047) were higher in the “EAD-yes” compared to the “EAD-no” group. Cytolysis markers and hyaluronan correlated with recipient creatinine, AST, and ICU stay. The study demonstrates that effluent molecular analysis can provide directions about the use of HOPE.

Hypothermic Oxygenated Machine Perfusion Attenuates Peri-Perfusional Inflammatory Mediator Release and Preserves Cholangiocyte Structure and Function Early After Liver Transplant

“…We propose that liver preservation uid e uent analysis could provide a reliable and quantitative method for multiplex assessment of in ammatory markers released during preservation, and it could provide a mechanism by which to detect concentration differences in injury markers between SCS-and HMP-O 2 -preserved liver grafts. Ultimately, detecting these damage-associated factors prior to organ transplantation, may identify biomarkers for irreversible injury and de ne therapeutic targets for early intervention in the peri-transplant period 21 .…”

“…While the utility of ex vivo biomarker assessment in HMP-O 2 is questioned as decreased metabolic rate in hypothermic conditions may prevent functional assessment, recent data suggest markers of injury are released in the preservation e uent, can be measured in real-time, and are predictive of post-operative outcomes. 20,21 To date, however, only one e uent biomarker has shown predictive potential in post-operative graft failure, and is currently undergoing multicenter validation. 20 Furthermore, to our knowledge, no large scale studies exist comparing e uent from HMP-O 2 to SCS-preserved grafts.…”

“…provide therapeutic targets early in the peri-transplant period. 21 HMP-O 2 technology is especially versatile in this arena. This dynamic mode of liver graft preservation provides continuous oxygenated vascular ush, resulting in e uent amenable to real-time, non-invasive sampling.…”

Hypothermic Machine Perfusion of the Liver. The Reasons for Success

“…In the last decades, there was a call for new assessment tools, which can make the organ evaluation more objective. Although different parameters could already be explored in the donor and measured in flush solutions, an active oxygenation is usually required for the release of certain molecules from organs presenting features of IRI 60 . Since MP has regained wider interest within the liver preservation field, many efforts were made to identify better viability criteria 61,62 .…”

Mitochondria and ischemia reperfusion injury

“…With an increasing number of listed candidates and prolonged waiting times, novel technologies are increasingly tested to safely utilize livers from extended-criteria donors (ECD) for transplantation. Such grafts are known to convey a higher risk for posttransplant complications due to a more pronounced ischemia-reperfusion-injury (IRI) [1 ▪ ,2]. To successfully limit the various consequences of the IRI-cascade, the field should aim for a wider understanding of specific underlying subcellular mechanisms, which are essential to develop strategies to mitigate this critical cascade.…”