Interleukin-18 and High-Mobility-Group-Protein B1 are Early and Sensitive Indicators for Cell Damage During Normothermic Machine Perfusion after Prolonged Cold Ischemic Storage of Porcine Liver Grafts

Abstract

In the era of organ machine perfusion, experimental models to optimize reconditioning of (marginal) liver grafts are needed. Although the relevance of cytokine signatures in liver transplantation has been analyzed previously, the significance of molecular monitoring during normothermic machine perfusion (NMP) remains elusive. Therefore, we developed a porcine model of cold ischemic liver graft injury after prolonged static cold storage (SCS) and subsequent NMP: Livers obtained from ten minipigs underwent NMP for 6 h directly after procurement (control group) or after 20 h of SCS. Grafts after prolonged SCS showed significantly elevated AST, ALT, GLDH and GGT perfusate concentrations, and reduced lactate clearance. Bile analyses revealed reduced bile production, reduced bicarbonate and elevated glucose concentrations after prolonged SCS. Cytokine analyses of graft perfusate simultaneously demonstrated an increase of pro-inflammatory cytokines such as Interleukin-1α, Interleukin-2, and particularly Interleukin-18. The latter was the only significantly elevated cytokine compared to controls, peaking as early as 2 h after reperfusion (11,012 ng/ml vs. 1,493 ng/ml; p = 0.029). Also, concentrations of High-Mobility-Group-Protein B1 were significantly elevated after 2 h of reperfusion (706.00 ng/ml vs. 148.20 ng/ml; p < 0.001) and showed positive correlations with AST (r2 = 0.846) and GLDH (r2 = 0.918) levels. Molecular analyses during reconditioning of liver grafts provide insights into the degree of inflammation and cell damage and could thereby facilitate future interventions during NMP reducing acute and chronic graft injury.

Composition of ex vivo perfusion solutions and kinetics define differential cytokine/chemokine secretion in a porcine cardiac arrest model of lung preservation

“…Of the analyzed proteins, only IL-18 showed a trend toward higher concentrations in perfusates of the D-EVLP samples, although not reaching significance. Similar observations were made in a porcine liver transplant model with elevated IL-18 concentrations in perfusate after a prolonged CSP ( 17 ), and IL-18 enhances the secretion of pro-inflammatory IFN-γ ( 18 , 19 ). Remarkably, we did not detect increased IFN-γ concentrations in the delayed perfusion samples, suggesting that longer period of CSP in the D-EVLP lungs did not translate into an enhanced secretion of inflammatory mediators (i.e., IFN-γ).…”

Association between serum HMGB1 elevation and early pediatric acute respiratory distress syndrome: a retrospective study of pediatric living donor liver transplant recipients with biliary atresia in China

“…Likewise, the peak concentration of serum HMGB1 is correlated with the length of ICU stay and duration of mechanical ventilation [ 25 ]. In one study, a porcine model of cold ischemic liver graft injury was developed; in this model, IL-18 and HMGB1 were found to be early and sensitive indicators of cell damage after prolonged cold ischemic storage [ 26 ]. Intraoperative RBC transfusion enhances susceptibility to lung inflammation through the release of HMGB1 and induces necroptosis of lung endothelial cells [ 27 , 28 ].…”