Comparative proteomics analysis identifies L-FABP as a putative biomarker of graft injury during liver transplantation

BackgroundTo a large extent the success of liver transplantation depends on quality of allografts. The molecular basis of the susceptibility of different liver allografts to transplant injury remains undefined. MethodsTransplanted liver samples were collected and divided into three groups: the optimal graft (OG) group, early allograft dysfunction (EAD) group, and primary nonfunction (PNF) group. iTRAQ comparative quantitative proteomic analysis and multiple reaction monitoring (MRM) verification was performed. ResultsMore than 160 differentially expressed proteins were detected in the PNF group, compared to 54 and 36 proteins in the EAD and OG groups respectively. Liver-type fatty acid-binding protein (L-FABP) was found as differentially expressed in both cold preserved and reperfused liver. Serum L-FABP level in donors was higher in the PNF and EAD groups than in the OG group. A lower tissue expression of L-FABP was observed in the PNF groups than other groups after reperfusion, indicating incompetent liver donor quality. In mouse ischemia reperfusion injury (IRI) model, the serum levels and tissue expression of L-FABP corresponded to the ALT variation curve. ConclusionsSuboptimal donor livers are more sensitive to ischemia reperfusion injury. L-FABP might be an effective biomarker for evaluating donor quality in liver transplantation.