Perfusate Proteomes Provide Biological Insight Into Oxygenated Versus Standard Hypothermic Machine Perfusion in Kidney Transplantation

Ann Surg. 2023 Nov 1;278(5):676-682 doi: 10.1097/SLA.0000000000006046.
Abstract
OBJECTIVE:

To provide mechanistic insight into key biological alterations in donation after circulatory death kidneys during continuous pefusion we performed mass spectrometry profiling of perfusate samples collected during a phase 3 randomized double-blind paired clinical trial of hypothermic machine perfusion with and without oxygen (COMPARE).

BACKGROUND:

Despite the clinical benefits of novel perfusion technologies aiming to better preserve donor organs, biological processes that may be altered during perfusion have remained largely unexplored. The collection of serial perfusate samples during the COMPARE clinical trial provided a unique resource to study perfusate proteomic profiles, with the hypothesis that in-depth profiling may reveal biologically meaningful information on how donor kidneys benefit from this intervention.

METHODS:

Multiplexed liquid chromatography-tandem mass spectrometry was used to obtain a proteome profile of 210 perfusate samples. Partial least squares discriminant analysis and multivariate analysis involving clinical and perfusion parameters were used to identify associations between profiles and clinical outcomes.

RESULTS:

Identification and quantitation of 1716 proteins indicated that proteins released during perfusion originate from the kidney tissue and blood, with blood-based proteins being the majority. Data show that the overall hypothermic machine perfusion duration is associated with increasing levels of a subgroup of proteins. Notably, high-density lipoprotein and complement cascade proteins are associated with 12-month outcomes, and blood-derived proteins are enriched in the perfusate of kidneys that developed acute rejection.

CONCLUSIONS:

Perfusate profiling by mass spectrometry was informative and revealed proteomic changes that are biologically meaningful and, in part, explain the clinical observations of the COMPARE trial.

CET Conclusion
Reviewer: Mr John O'Callaghan, Centre for Evidence in Transplantation, Nuffield Department of Surgical Sciences University of Oxford
Conclusion: This well-written report details an analysis of perfusate samples collected during the COMPARE study, an RCT comparing oxygenated with non-oxygenated machine perfusion. Mass spectrometry was used to analyse the proteomic make up of the perfusate fluid. During hypothermic machine perfusion, proteins enter the perfusate system, increasing over time. The authors explored the relation between perfusate proteins and clinical outcomes, with some indication that outcomes such as acute rejection and kidney function at 12 months.
Study Details
Aims: The aim of this study was to provide mechanistic insight into biological alterations that occur in deceased donor kidneys during standard nonoxygenated versus oxygenated hypothermic machine perfusion (HMP), using perfusate samples collected in the COMPARE study.
Interventions: In the COMPARE trial, pairs of kidneys donated following circulatory death were randomly assigned to receive either oxygenated HMP or nonoxygenated HMP.
Participants: 210 perfusate samples.
Outcomes: The main outcome of this paper was to identify protein changes across durations of perfusion and in relation to 12-month estimated glomerular filtration rate (eGFR).
Follow Up: 12 months
Metadata
Funding: Non-industry funding
Publication type: Randomized Controlled Trial, Randomised Controlled Trial
Trial registration: ISRCTN32967929
Organ: Kidney
Language: English
Author email: maria.kaisar@nds.ox.ac.uk
MeSH terms: Humans; Kidney Transplantation; Proteome; Proteomics; Organ Preservation; Kidney; Perfusion; Tissue Donors; 0 (Proteome)