iTRAQ- and MRM-Based Proteomics Identify Early Injury Biomarkers for Primary Dysfunction After Liver Transplantation

BACKGROUND Primary nonfunction (PNF) is a severe complication following liver transplantation (LT), yet precise molecular biomarkers for early identification of patients at risk remain lacking, which can delay timely therapeutic intervention. MATERIAL AND METHODS Liver biopsies were collected from patients and classified into 4 groups: control, optimal graft (OG), early allograft dysfunction (EAD), and PNF. Samples were obtained at 3 time points: T0 (pre-cold perfusion), T1 (pre-reperfusion), and T2 (post-reperfusion). Isobaric tags for relative and absolute quantitation (iTRAQ) and multiple reaction monitoring (MRM) were used for proteomic analysis and biomarker verification. RESULTS Baseline characteristics of the patients showed no significant differences between groups. A total of 6505 proteins were identified in human liver samples. There were 160 differentially expressed proteins (67 upregulated and 93 downregulated) found in the PNF group compared to the control, while 54 and 36 proteins were identified in the EAD and OG groups, respectively. Ten proteins were selected for MRM verification, confirming the significant upregulation of VWF and downregulation of PRDX1, HGD, THIO, 6PGD, and HPPD, consistent with the iTRAQ results. CONCLUSIONS PRDX1, HGD, THIO, 6PGD, HPPD, and VWF were identified as candidate proteins associated with PNF and ischemia-reperfusion injury (IRI) after LT. These findings are hypothesis-generating and require validation in larger, independent cohorts to determine their potential clinical value.