Perfusate Enzymes and Platelets Indicate Early Allograft Dysfunction after Transplantation of Normothermically Preserved Livers.

BACKGROUND: Normothermic machine perfusion (NMP) has become a clinically established tool to preserve livers in a near-physiological environment. However, little is known about the predictive value of perfusate parameters towards the outcomes after transplantation. METHODS: Fifty-five consecutive NMP-livers between 2018-2019 were included. All of the livers were perfused on the OrganOx metra® device according to an institutional protocol. Transplant and perfusion data were collected prospectively. RESULTS: Forty-five livers were transplanted after NMP. Five livers stem from donors after circulatory death and 31 (68.9%) from extended criteria donors (ECD). Mean (SD) cold ischemia time (CIT) was 6.4 (2.3) hours; mean (SD) total preservation time 21.4 (7.1) hours. Early allograft dysfunction (EAD) occurred in 13/45 (28.9%) patients. Perfusate aspartate-aminotransferase (p=0.008), alanine-aminotransferase (p=0.006), lactate-dehydrogenase (p=0.007) and their development over time, alkaline phosphatase (p=0.013) and sodium (p=0.016) correlated with EAD. Number of perfusate platelets correlated with CIT-duration and were indicative for the occurrence of EAD. Moreover, vWF antigen was significantly higher in perfusates of EAD-livers (p<0.001) and ΔvWF antigen correlated with EAD. While perfusate lactate and glucose had no predictive value, EAD was more likely to occur in livers with lower perfusate pH (p=0.008). ΔPerfusate AP, Δperfusate AST, Δperfusate ALT and Δperfusate LDH correlated closely with MEAF but not L-GrAFT. Bile parameters correlated with ECD and donor risk index. CONCLUSION: Biomarker assessment during NMP may help to predict EAD after liver transplantation. The increase of transaminases and LDH over time as well as platelets and vWF antigen are important factors indicative for EAD.