Abstract Background Crohn’s disease (CD) is a chronic inflammatory bowel disease (IBD) characterized by immune cell infiltration and increased proteolytic activity, driving pathological changes in the structure and function of the intestines. Ileocolonoscopy (IC) is the gold standard for diagnosing and monitoring patients with CD but the invasive nature of IC renders it least acceptable from a patient perspective. Pan-enteric capsule endoscopy (PCE) is an attractive and less invasive alternative. In this study, we investigated whether biomarkers of immune cell activity could identify patients with suspected CD, and if they associated with endoscopic disease activity at IC and PCE. Methods 127 patients were included from the Advanced Non-Invasive Diagnostics in Inflammatory Bowel Disease (ANDI) cohort, a study evaluating the diagnostic efficacy of PCE in subjects with clinically suspected CD. Serum was drawn at time of inclusion. Patients were examined with IC and PCE within a 2-week period from blood sampling, with CD diagnosed by IC. Biomarkers of neutrophil activity (CPa9-HNE: neutrophil-derived fragment of calprotectin) and macrophage activity (VICM: macrophage-derived fragment of citrullinated vimentin) were measured in serum. Endoscopic disease activity was assessed with SES-CD both for IC and PCE. For SES-CD analysis, non-CD patients without malignancies from the cohort were used as reference. Mann-Whitney tests and ROC statistics were applied. Results CPa9-HNE and VICM were significantly elevated in patients with a confirmed CD diagnosis compared to non-IBD patients (fig. 1A&D) (AUC 95% CI: 0.71 0.62–0.79 & 0.68 0.59–0.76. For SES-CD obtained from both IC and PCE, CPa9-HNE and VICM were significantly elevated in patients with moderate and severe disease compared to non-IBD (fig. 1B-C&E-F). Both CPa9-HNE and VICM had superior discriminative abilities between non-IBD and patients with severe disease based on PCE (AUC 95% CI: 0.87 0.77–0.94 & 0.92 0.83–0.97). CPa9-HNE was significantly elevated in patients with severe disease compared to moderate, based on PCE (fig. 1C). VICM was significantly elevated in patients with moderate and severe disease compared to mild, based on PCE (fig. 1F), with superior discriminative capabilities between mild and severe disease (AUC 95% CI: 0.91 0.66–0.99). Conclusion CPa9-HNE and VICM could identify patients with confirmed CD and were associated with endoscopic disease activity. Both biomarkers provided stronger discriminative performance when assessing disease activity by PCE, consistent with ileal involvement in CD. These findings suggest that markers of neutrophil and macrophage activity may provide additional information to endoscopic assessment in the diagnosis and monitoring of CD. Conflict of interest: Dr. Sorokina Alexdóttir, Marta: Employee of Nordic Bioscience Brodersen, Jacob: No conflict of interest Jensen, Michael Dam: No conflict of interest Tsapanou Katranara, Thomai: Industrial PhD at Nordic Bioscience Satriano, Letizia: Full time employee at Nordic Bioscience Bay-Jensen, Anne-Christine: Employee and stakeholder at NB Karsdal, Morten: Employee and stakeholder at NB Kjeldsen, Jens: No conflict of interest Mortensen, Joachim: Fulltime employee and shareholder at Nordic Bioscience
Alexdóttir et al. (Thu,) studied this question.