Aimed at Subtype Discrimination but Yielding a Shared Marker: Integrative Analysis of Blood Transcriptomes Reveals Upregulated TLR5 as a Potential Biomarker for IBD

Background: Despite the similarities, Crohn's disease (CD) and ulcerative colitis (UC), the two major subtypes of inflammatory bowel disease (IBD), exhibit distinctions. The increasing burden of IBD necessitates discovering novel diagnostic markers. Considering the importance of distinguishing between CD and UC in selecting therapeutic strategies in clinical settings, this investigation focused on identifying subtype-specific blood biomarkers. Methods: The discovery set was formed by integrating five blood transcriptomic datasets, including GSE119600, GSE126124, GSE94648, GSE86434, and GSE71730, which incorporated samples from CD, UC, and controls. After determining DEGs in CD and UC, they were separately filtered according to WGCNA and then analyzed by LASSO and RF algorithms. Eventually, ROC analysis of the diagnostic performances was conducted independently in the datasets used for discovery. Moreover, ROC analysis was implemented in independent cohorts to assess the generalizability of findings. Results: was identified as a shared biomarker for both subtypes. Conclusion: exhibits reproducible diagnostic efficacy for IBD.