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

Abstract

Abstract Background Hypothermic Oxygenated Machine Perfusion (HMP-O2) is a dynamic preservation technique which improves ischemia/reperfusion injury (IRI) of liver grafts vs. static cold storage (SCS). The exact molecular pathways affected, particularly in the setting of biliary injury, remain undefined. Here we investigate the peri-perfusional and tissue mediators of liver preservation injury and cholangiocyte dysfunction early after liver transplant. Methods Patients were transplanted at a single center as part of the multi-center randomized controlled PILOT trial (NCT03484455). Livers were randomized to perfusion via the LifePort Liver Transporter (HMP-O2, Organ Recover Systems, Itasca, IL) or to SCS. Clinical complications were assessed utilizing the Comprehensive Complication Index (CCI). Corresponding biospecimen analysis of preservation fluid (effluent, prior to liver implantation), bile, and bile duct tissue (both 1hr post-reperfusion) was performed. Effluent biochemistry was assessed via Luminex, and bile biochemistry was assessed via iSTAT-1/CG8+. Tissue injury was identified via histology and immunohistochemistry (IHC). p < 0.05 was considered significant. Results Liver transplant was performed in 20 patients (7 HMP-O2; 13 SCS). Early allograft dysfunction (EAD) occurred in three cases, all SCS. HMP-O2 resulted in fewer immediate post-operative complications (CCI 42 vs 56, p < 0.05) and fewer biliary complications (14% vs 23%). Following HMP-O2, multiplex analysis of effluent showed decreased release of MIP-1ß (p < 0.05), IL-8, IL-6, and TNFα; bile fluid biochemistry revealed significantly preserved cholangiocyte resorptive function; and IHC analysis of bile ducts demonstrated attenuated activation of inflammatory signaling (decreased total and activated NF-κB, p < 0.0001). Conclusions HMP-O2 provides excellent preservation for liver allografts. Pre-implant machine perfusion appears to decrease inflammatory signaling, preserve cholangiocyte function, and protect cellular function, and may therefore confer protection from transplant related IRI.