Histological healing as a predictor of sustained clinical remission in paediatric ulcerative colitis

The study aimed to assess the longitudinal impact of endoscopic healing (EH) and histological healing (HH) in a cohort of paediatric patients affected by ulcerative colitis (UC). Methods: This was a retrospective single-centre longitudinal study. 86 children with UC who underwent endoscopic re-assessment while in clinical and biochemical remission were included. Partial EH was defined as a Mayo Endoscopic Subscore (MES) of 1 and complete EH was defined as a MES of 0. HH was defined as the absence of active inflammation in all biopsies. The cumulative incidence of clinical relapse was evaluated during follow-up. Results: At the second endoscopic re-evaluation, 59 (68.6%) patients achieved EH (MES ≤1). Of these patients, 39 (66%) achieved complete EH. 20 of the 39 patients who achieved complete EH attained complete HH. Patients who achieved partial and complete EH showed higher recurrence-free survival rates compared to those who did not (p < 0.01 and p < 0.01, respectively). Amongst patients with complete EH, those who achieved complete HH had lower recurrence rates when compared to patients who still showed microscopic inflammation (p = 0.049). Conclusion: Achievement of EH and HH is associated with fewer disease relapses, with patients achieving HH showing longer relapse-free survival rates.