Abstract: Abstract: Objective To investigate the protein markers that specifically expressed in patients with acute rejection (ACR) after liver transplantation, and to explore preliminarily the mechanisms. Methods Serum samples from three pa⁃ tients with pathologically confirmed ACR after liver transplantation in Tianjin First Central Hospital were collected as ACR group. Three serum samples from patients with normal liver function indicators after liver transplantation were collected as No-ACR group. And six serum samples from healthy examination were mixed with equal amount as healthy control group. Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) was employed to separate, screen and identify the differential⁃ ly expressed proteins between three groups. KEGG and STRING software were applied to deeply analyze the data of three groups. Results A total of 88 differentially expressed proteins were found between ACR group and healthy control group. There were 39 differentially expressed proteins between No- ACR group and healthy control group. Ten differentially ex⁃ pressed proteins were acquired between ACR group and No-ACR group. Comparing 88 and 10 differentially expressed pro⁃ teins, 9 proteins were the same. Among 88 differentially expressed proteins, 30 of them showed a direct interaction, and can be positioned in 13 signaling pathways based on KEGG and STRING software. Fourteen (46.67%) of the 30 proteins were lo⁃ cated in the complement and coagulation cascade pathway. Among 39 differentially expressed proteins, which were detected between No-ACR group and control group, 10 proteins showed a direct interaction including 9 proteins concentrated in the complement and coagulation cascade pathway. Conclusion By proteomic analysis, nine differentially expressed proteins are obtained, which may be regarded as the candidate bio-markers for ACR early diagnosis after liver transplantation. The complement and coagulation cascades system is significantly adjusted after liver transplantation, indicating this pathway plays an important role in the occurrence of ACR.

Key words: liver transplantation, serum,  , biological markers,  , acute cellular rejection, protein biomarkers,  , isobaric tags
for relative andabsolute quantitation