Hepatocyte- and Cholangiocyte-derived MicroRNAs in Perfusate and Bile during Ex-Situ Normothermic Machine Perfusion of Human Donor Livers

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A.P.M. Matton, H.P. Roest, C.J. Verhoeven, N. Karimian, S. op den Dries, M.E. Sutton, J. de Jonge, L.J.W. van der Laan, R.J. Porte

Chair(s): dr. Robert A. Pol, vaat-en transplantatiechirurg, UMC Groningen & dr. Wojaiech G. Polak, chirurg, Erasmus MC

Thursday 10 march 2016

9:50 - 10:00h at Zaal 5 & 6

Categories: Parallelsessie (klinisch)

Parallel session: Parallelsessie VIII - Klinisch chirurgisch en acuut

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Introduction:
MicroRNAs are gaining increasing attention for their use as biomarkers for tissue injury and biological factors. Normothermic machine perfusion (NMP) enables viability assessment of donor livers prior to transplantation, and we investigated whether the release of hepatocyte- and cholangiocyte-derived microRNAs (HDmiRs and CDmiRs, respectively) during NMP of human donor livers is predictive for hepatocytic and cholangiocytic function and viability.

Methods:
After a median cold preservation time of 8.4 hrs, 18 donor livers that were declined for transplantation were subjected to 6 hrs of NMP. Perfusion solution contained red blood cells, fresh frozen plasma and nutrients. Perfusate and bile samples were taken at 2 and 6 hrs of NMP for quantification of miRNA by qRT-PCR assays for HDmiRs 122 and 148a, and for CDmiRs 30e and 222. Ct values were used to calculate relative expression levels (2-(Ct)). Pearson correlations were performed between the microRNAs and biliary bilirubin (marker for hepatocytic function), AST in perfusate (hepatocytic injury), biliary bicarbonate (biliary function) and biliary LDH (biliary injury).

Results:
Biliary bilirubin levels correlated moderately negatively with both HDmiRs in perfusate (r<-0.58, p<0.05) and with HDmiR148a and CDmiR222 in bile (r<0.53, p<0.05) at 6 hrs NMP. All miRs measured in perfusate correlated very strongly with AST in perfusate (r>0.89, p<0.005) at 2 hrs of NMP and only HDmiRs correlated very strongly (r>0.82, p<0.005) at 6 hrs NMP. At 2 hrs NMP, only CDmiRs correlated very strongly with AST in perfusate (r>0.84, p<0.005), at 6 hrs all miRs correlated very strongly (r>0.80, p<0.005). Biliary bicarbonate did not correlate with HD or CDmiRs in bile or perfusate. Biliary LDH correlated very strongly with CDmiRs in bile (r>0.80, p>0.05) at 2 hrs and strongly with all miRs at 6 hrs (r>0.75, p<0.005). Biliary LDH correlated strongly with HDmiRs in perfusate at 2 and 6 hrs NMP (r>0.68, p<0.05).

Conclusion:
This study suggests hepatocyte- and cholangiocyte-derived miRs in perfusate and bile are reflective of hepatic and cholangiocytic injury rather than function. CDmiRs tend to be released into bile rather than into perfusate, and HDmiRs are released in bile at a later stage. Furthermore, HDmiRs in perfusate could potentially be used for assessment of biliary injury.