Multi-compartment profiling of donor-derived microRNAs during liver graft procurement: a prospective feasibility study.

Liver grafts from donors after brain death (DBD) and donors after circulatory death (DCD) are exposed to distinct mechanisms of injury. We evaluated the feasibility of multi-compartment profiling of liver injury-associated microRNAs (miRNAs) across serum, liver tissue, and preservation fluid in deceased donor liver grafts and explored compartment-specific expression patterns according to donor type. In this prospective single-centre exploratory study, miR-122, miR-148a, miR-22, miR-222, and miR-155 were quantified by RT-qPCR in serum, liver tissue, and preservation fluid from 10 DBD and 10 DCD donors, including paired serum sampling before and during abdominal normothermic regional perfusion (aNRP). Three declined steatotic DBD grafts were analysed descriptively. A total of 79 samples were analysed. Baseline serum miRNA profiles and post-transplant outcomes were comparable between DBD and DCD grafts. Distinct compartment-specific expression patterns were observed, particularly in preservation fluid, where DCD grafts recovered following aNRP showed lower expression of miR-148a, miR-222, and miR-22 than DBD grafts. In DCD donors, serum during aNRP showed lower miR-148a expression. Exploratory descriptive analyses of declined steatotic grafts identified miRNA patterns consistent with hepatocellular injury. These findings demonstrate the feasibility of multi-compartment donor-derived miRNA profiling and provide a framework for future studies evaluating compartment-specific molecular markers for graft assessment.