The Correlation between Clinico-Endoscopic Activity and Fecal Calprotectin in IBD

Introduction: Endoscopy is the gold standard examination for evaluating the activity of inflammatory bowel diseases (IBD). However, it remains an invasive procedure with a significantly high cost. Many studies have focused on the study of non-invasive markers, particularly fecal calprotectin (FC), in monitoring inflammatory activity in IBD. Objective: The aim of this study is to comparatively evaluate the correlation between biological markers, including FC, and clinical scores with endoscopic findings in assessing inflammatory activity in IBD. Materials and Methods: This is a retrospective, analytical study conducted in the Hepato-Gastroenterology Department of Hassan II University Medical Center, Fez, over a period of two years. It includes all patients with IBD who were followed in the department and who underwent clinical, biological (measuring FC and CRP), and endoscopic evaluation through ileocolonoscopy. The latter is based on the SES-CD for Crohn’s disease and the Mayo endoscopic subscore for ulcerative colitis. Results: We collected data on 111 patients in our study, with 49 followed for ulcerative colitis (UC) and 62 for Crohn’s disease. The female/male sex ratio is 1.36. The average age of our patients was 40.6 years. Based on endoscopic activity, patients are divided into two groups: Group I (n = 46), consisting of patients in endoscopic remission, and Group II (n = 65), consisting of patients with active disease endoscopically. Patients in Group I were predominantly in clinical remission (89%) compared to those in Group II (70%), without a significant difference (P = 0.274). The average CRP level was higher in Group II (21 mg/l [57 - 800]) compared to Group I (11 mg/l [57 - 800]), without a significant difference in this case (p = 0.098). The average fecal calprotectin level was significantly higher (p = 0.001) in patients in Group II (253 μg/g [57 - 800]) compared to those in Group I (135.7 μg/g [19.5 - 192]). In our study, we determined a threshold of 157 µg/g to detect endoscopically active IBD with a sensitivity of 86.2% and specificity of 63%. Conclusion: In our series, FC shows a good correlation with endoscopic activity. Therefore, it constitutes an alternative method that allows for extending intervals between control endoscopies, thus reducing the cost of managing IBD.