Soluble Syndecan-1 Levels Are Elevated in Patients with Inflammatory Bowel Disease

Background: Syndecan-1 plays a central role in maintaining normal intestinal barrier function. Shedding of syndecan-1, reflected by soluble syndecan-1 serum concentrations, is highly regulated by inflammation. Aim: To determine soluble syndecan-1 levels in inflammatory bowel disease patients and its relationship with other inflammatory markers, disease activity, and medical treatment. Methods: Cross-sectional, pilot study in which serum concentrations of soluble syndecan-1 were analyzed by ELISA in a cohort of 41 inflammatory bowel disease patients (22 Crohn’s disease, 19 ulcerative colitis) and 16 healthy controls. Disease activity was estimated by the Crohn’s disease activity index, partial Mayo score, and C-reactive protein. Results: Soluble syndecan-1 levels were significantly higher in inflammatory bowel disease patients compared to healthy controls (29.5 ± 13.4 vs. 21.1 ± 10.4 ng/ml, respectively, P = 0.03). Soluble syndecan-1 displayed a reliable ability to discriminate inflammatory bowel disease patients from healthy controls with a sensitivity of 95 %, specificity of 50 %, and positive predictive value of 83 %. Patients treated with anti-inflammatory medications demonstrated significantly lower soluble syndecan-1 levels compared to untreated patients (26.45 ± 9.75 vs. 38 ± 18.43 ng/ml, respectively, P = 0.008). Conclusions: Our results suggest that soluble syndecan-1 is potentially a novel diagnostic marker in the management of inflammatory bowel disease patients. Its applicability as a surrogate, prognostic biomarker remains to be determined.