Differential analysis of serum proteomics in Crohn's disease treated with infliximab

AIM: To identify the serum proteins that might serve as biomarkers for predicting mucosal healing (MH) in the patients with Crohn's disease (CD) treated with infliximab (IFX). METHODS: We collected serum samples before treatment (0 week, group A) and 14 weeks after treatment (group B) from 7 CD patients with IFX treatment who had achieved MH, as well as the serum samples from 7 CD patients who had not achieved MH (0 week, group C; 14 weeks, group D). Two-dimensional fluorescence difference gel electrophoresis was applied to analyze and compare the results of serum profiles between groups A and B, C and D, A and C, B and D. Matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry and bioinformatics tools were utilized to preliminarily identify and figure out the differentially expressed proteins. RESULTS: (1) In total, there were 44 differentially expressed spots, 36, 3, 10 and 31 differentially expressed spots were detected while comparing A with B, C with D, A with C and B with D, respectively. (2) Among those spots, 17, 2, 2 and 15 proteins were identified, respectively. In total, there were 19 differentially expressed proteins, including apolipoprotein E, apolipoprotein A-I, complement factor H, and so on. (3) Protein functional association networks were carried out based on STRING database. CONCLUSION: The serum protein profiles obviously change after IFX treatment in MH CD patients, and the serum protein profiles of MH patients are different from that of non-MH patients after IFX treatment. The 19 proteins we identified may serve as potential biomarkers for predicting MH in CD patients with IFX treatment.