Zhen LI, Yanping HAO, Jin CHEN, Xuan LIU, Weilin XU, Yuexin CHENG
Turkish Journal of Gastroenterology - 2026;37(11):1184-1195
Background/Aims: Monitoring endoscopic inflammation in Crohn's disease (CD) is difficult. This study examined whether X-C motif chemokine ligand 1 (XCL1) is associated with endoscopic activity, as defined by the Simple Endoscopic Score for Crohn's Disease (SES-CD). Materials and Methods: This was a single-center observational biomarker study. Peripheral blood mononuclear cell (PBMC) transcriptome sequencing was performed in 6 patients with newly diagnosed CD and 6 controls without inflammatory bowel disease. XCL1 protein expression was evaluated using immunohistochemistry and western blotting in 12 intestinal biopsy samples. Serum XCL1 levels were measured using enzyme-linked immunosorbent assay in 125 patients with CD and 40 controls. Patients with CD were classified according to the SES-CD. Correlation, logistic regression, receiver operating characteristic, bootstrap validation, and treatment-adjusted analyses were performed. Results: XCL1 was upregulated in PBMCs and increased in the intestinal mucosa of patients with active disease. Serum XCL1 levels differed among controls and SES-CD groups (P < .001). In patients with CD, serum XCL1 correlated with SES-CD (r = 0.692), fecal calprotectin (FC) (r = 0.573), Crohn's Disease Activity Index (r = 0.420), and C-reactive protein (CRP) (r = 0.433; all P < .001). XCL1 remained associated with endoscopic activity after adjustment (odds ratio = 1.005, 95% CI= 1.001-1.008, P = .012). The areas under the curve were 0.76 for XCL1, 0.81 for FC, and 0.85 for the XCL1+FC+CRP model. Conclusion: Although serum XCL1 was associated with SES-CD-defined endoscopic activity, its performance was lower than that of FC. XCL1 may serve as an exploratory adjunctive serum marker but requires further validation.
