Cytokines Adsorption During Ex Situ Machine Perfusion of Liver Grafts from Elderly Donors: A Pilot, Prospective, Randomized Study

Ischemia-reperfusion injury (IRI) is a mechanism based on inflammatory mediators' release and activation of effectors of damage. Studies showed a correlation between cytokine, severity of damage, and post-operative outcomes. Ex situ perfusion may work as a platform for the treatment of IRI mechanisms, such as the removal of cytokines using cytokine adsorption (CA). We assessed the safety and benefits of an integrated CA during ex situ dual-oxygenated hypothermic (D-HOPE) and normothermic perfusion (NMP). During the period of July 2021-December 2023, 84 octogenarian liver grafts, suitable for transplantation, were considered: 12 were randomized to D-HOPE or NMP with or without CA (D-HOPE + CA, D-HOPE, NMP + CA, NMP groups, n = 3 each) and compared to 72 performed using grafts preserved in static cold storage (SCS). IL-1, IL-6, IL-10, and TNF-a perfusate concentrations were evaluated together with perfusion parameters and post-operative outcomes. Perfusion procedures were unaffected by CA integration. In NMP, cytokine levels were 10-40 times higher than in healthy subjects and 20-50 times higher than D-HOPE. Cytokines were removed both in D-HOPE and NMP, but the concentration-dependent mechanisms of action of CA led to more remarkable removal in NMP. IL-10 and TNF-a concentrations were significantly lower in NMP + CA than in NMP. The application of CA was associated with significantly higher arterial flows both in D-HOPE and NMP, and reduced neutrophil infiltration in NMP. No differences in post-operative outcomes were found among groups. In conclusion, cytokine adsorption during ex situ machine perfusion of liver grafts from elderly donors is safe and feasible and is associated with modulation of inflammatory mediators and perfusion dynamics. These findings are hypothesis-generating, and larger studies are required to determine the clinical impact of this strategy.