Aiad, Monika

Background and Aims: Hypothermic oxygenated machine perfusion (HOPE) improves outcomes in orthotopic liver transplantation (OLT), but reliance on University of Wisconsin machine perfusion solution (UW-MPS) increases costs and logistical burden. Histidine-tryptophan-ketoglutarate (HTK) has potential as a single-solution alternative for HOPE. This study evaluated the safety and efficacy of HTK versus UW-MPS during HOPE. Methods: A retrospective, propensity score-matched cohort study including 46 patients who received donation after brain death (DBD) grafts that were preserved with HOPE at the Medical University of Vienna between May 2018 and October 2024 was conducted. A total of 23 patients received grafts perfused with HTK; another 23 patients transplanted with organs perfused with UW-MPS were matched based on recipient age and sodium model of end-stage liver disease score, donor age and sex, cold ischemia time, and perfusion time. Postoperative outcomes, perfusion parameters, and cost differences were assessed. Results: The HTK and UW-MPS cohorts demonstrated comparable perfusion dynamics and vascular resistance. While arterial pressure and flow were higher in the UW-MPS group, clinical outcomes—including early allograft dysfunction (47.8% each), ICU stay, and comprehensive complication index—were statistically similar. A trend toward fewer biliary complications (13.0% vs. 30.4%) and reduced hemodialysis requirement (17.4% vs. 30.4%) was observed in the HTK group. Use of HTK reduced perfusion-related costs by approximately EUR 560 per procedure. Conclusion: HTK is a viable alternative to UW-MPS during HOPE in OLT of DBD grafts, offering comparable short-term outcomes and relevant cost savings. Prospective studies are warranted to validate these findings and explore broader applications of single-solution perfusion strategies.

Post-hepatectomy liver failure (PHLF) remains a significant risk for patients undergoing partial hepatectomy (PHx). Reliable prognostic markers and treatments to enhance liver regeneration are lacking. Plasma nanoparticles, including lipoproteins, exosomes, and extracellular vesicles (EVs), can reflect systemic and tissue-wide proteostasis and stress, potentially aiding liver regeneration. However, their role in PHLF is still unknown. Methods: Our study included nine patients with hepatocellular carcinoma (HCC) undergoing PHx: three patients with PHLF, three patients undergoing the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure, and three matched controls without complications after PHx. Patient plasma was collected before PHx as well as 1 and 5 days after. EVs were isolated by ultracentrifugation, and extracted proteins were subjected to quantitative mass spectrometry using a super-SILAC mix prepared from primary and cancer cell lines. Results: We identified 2625 and quantified 2570 proteins in the EVs of PHx patients. Among these, 53 proteins were significantly upregulated and 32 were downregulated in patients with PHLF compared to those without PHLF. Furthermore, 110 proteins were upregulated and 78 were downregulated in PHLF patients compared to those undergoing ALPPS. The EV proteomic signature in PHLF indicates significant disruptions in protein translation, proteostasis, and intracellular vesicle biogenesis, as well as alterations in proteins involved in extracellular matrix (ECM) remodelling and the metabolic and cell cycle pathways, already present before PHx. Conclusions: Longitudinal proteomic analysis of the EVs circulating in the plasma of human patients undergoing PHx uncovers proteomic signatures associated with PHLF, which reflect dying hepatocytes and endothelial cells and were already present before PHx.

Liver resection (LR) is the primary treatment for hepatic tumors, yet posthepatectomy liver failure (PHLF) remains a significant concern. While the precise etiology of PHLF remains elusive, dysregulated inflammatory processes are pivotal. Therefore, we explored the theragnostic potential of extracellular high-mobility-group-box protein 1 (HMGB1), a key damage-associated molecular pattern (DAMP) released by hepatocytes, in liver recovery post LR in patients and animal models. Plasma from 96 LR patients and liver tissues from a subset of 24 LR patients were analyzed for HMGB1 levels, and associations with PHLF and liver injury markers were assessed. In a murine LR model, the HMGB1 inhibitor glycyrrhizin, was administered to assess its impact on liver regeneration. Furthermore, plasma levels of keratin-18 (K18) and cleaved cytokeratin-18 (ccK18) were quantified to assess suitability as predictive biomarkers for PHLF. Patients experiencing PHLF exhibited elevated levels of intrahepatic and circulating HMGB1, correlating with markers of liver injury. In a murine LR model, inhibition of HMGB1 improved liver function, reduced steatosis, enhanced regeneration and decreased hepatic cell death. Elevated levels of hepatic cell death markers K18 and ccK18 were detected in patients with PHLF and correlations with levels of circulating HMGB1 was observed. Our study underscores the therapeutic and predictive potential of HMGB1 in PHLF mitigation. Elevated HMGB1, K18, and ccK18 levels correlate with patient outcomes, highlighting their predictive significance. Targeting HMGB1 enhances liver regeneration in murine LR models, emphasizing its role in potential intervention and prediction strategies for liver surgery.