Intestinal Ultrasound, Fecal Calprotectin, and Their Combination to Predict Endoscopic Mucosal Healing in Ulcerative Colitis: A Real-Life Cross-Sectional Study

Abstract Background The development of noninvasive markers to assess mucosal healing in ulcerative colitis (UC) is essential in the treat-to-target era. The aim of this study was to evaluate the performance of intestinal ultrasound (IUS), fecal calprotectin (FC), and their combination to assess mucosal healing in UC patients. Methods All consecutive patients between January 2021 and September 2022 with UC who underwent a complete colonoscopy and IUS and/or an FC test within 4 weeks were included in a prospective cohort. Bowel wall thickness (BWT) and the color Doppler signal (CDS) were assessed for each segment. Endoscopic mucosal healing was defined by a Mayo score of 0 to 1. Results A total of 61 patients were included, of whom 79% showed endoscopic healing (26 Mayo 0 and 11 Mayo 1). Among the patients, 16 (27.6%) of 58 had a BWT <3 mm, and 41 (70.7%) of 58 had no CDS. The sensitivity, specificity, positive predictive value, and negative predictive value of a BWT <3 mm to predict endoscopic mucosal healing were 37%, 77%, 72%, and 44%, respectively. The association of FC <150 µg/g, a BWT <3 mm, and a CDS = 0 increased the specificity and positive predictive value (sensitivity 33%, specificity 94%, positive predictive value 89%, negative predictive value 48%). The combination of a normal IUS, no rectal bleeding, and an FC <172 µg/g identified all patients with mucosal healing. Conclusion The combination of IUS and FC is effective in identifying mucosal healing in UC. Noninvasive evaluation of mucosal healing is possible for most UC patients.