Background We aimed at appraising real-life efficacy of Crohn’s Disease Exclusion Diet (CDED) coupled with partial enteral nutrition (PEN) in inducing clinical and biochemical remission at disease onset and in patients with loss of response to biologics in a tertiary-level center. We also aimed at identifying early responders to this dietary regimen. Methods We gathered clinical, anthropometric and laboratory data of patients aged less then 18 years of age with a diagnosis of CD, who were consecutively treated with CDED coupled with PEN as main treatment for the induction of remission or in the setting of loss of response to other therapies. We collected data of patients who received CDED plus PEN from April 2019 to June 2022 at diagnosis, at the beginning of the dietary treatment, and at the phase 1. Patients who interrupted diet during follow-up were considered as treatment failures on an intent to treat basis. We compared groups using chi-square, Fisher’s exact test, Mann-Whitney U or related-samples Wilcoxon signed rank tests or McNemar’s test as appropriate. Results 47 patients were retrospectively identified. Table 1. summarizes clinical and biochemical characteristics at diagnosis and at CDED with PEN initiation. 24 (51.1%) patients started CDED as induction therapy at disease onset, whereas 23 (48.9%) of them received CDED with PEN as add-on therapy. 32/47 (68%) patients achieved clinical remission (wPCDAI < 12.5) at the end of phase 1, 16/24 patients (66.7%) who started CDED as induction therapy and 16/23 (69.5%) of those who started CDED as add-on, with no statistically significant difference among the two groups (p=1.00). Laboratory parameters significantly improved in both groups (Figure 1.). There were no statistically significant differences in clinical remission rates between patients with mild-to-moderate and severe disease at the end of phase 1 (25/35 vs 7/12, p=0.481). At disease onset, 14 patients added a concomitant treatment (11 patients added anti-TNF alpha, 3 patients added IMM and one patient added anti-TNF alpha + IMM) after a median time of 4 weeks (IQR: 3-5 weeks). 28 patients had clinical data gathered at week 3. Patients who achieved clinical response at week 3 (a change in wPCDAI > 12.5) were more likely to be in clinical remission at the end of phase 1 (17/20 vs 1/8, p<0.01), both in patients who started CDED at disease onset and in the add-on setting. Conclusion CDED with PEN confirmed its efficacy in a real-life setting, both as induction regimen and as add-on therapy, also in patients with clinically severe disease. Early clinical response predicts clinical remission at the end of phase 1, possibly allowing identification of dietary responsive disease. Table 1. Figure 1.

Background Ulcerative colitis tend to present with a more extensive phenotype and a more aggressive behavior in pediatric populations when compared to adult ones. Treatment targets are shifting from symptom alleviation to more objective outcomes, such as the healing of the mucosa and the complete resolution of microscopic inflammation. However, data regarding real-life attainment of such outcomes and their prognostic implications are lacking. Methods We performed a retrospective analysis on pediatric patients affected by UC who were followed up for at least, 12 month at a tertiary referral center. We included only patients who underwent endoscopic reassessment during clinical remission. Results Eighty-four patients were included. At diagnosis, patients were divided with regard to the extent of disease as assessed by the Paris classification as follows:, 45 (53.6%) showed pancolitis E4, 2 (2.4%) left colitis E3, 22 (26.2%) proctosigmoiditis E2, and, 15 (17.8%) proctitis E1. Globally, 14 (16.7%) patients presented with an acute severe colitis (ASC) attack at diagnosis. The median age at diagnosis was, 13 years and, 7 months (IQR=94 months). Patients were followed for a median time of, 18 months (IQR:, 22 months). The second endoscopy was performed after a median time of, 27 months (IQR=32). At the second endoscopic re-evaluation, 64 (76.2%) patients out of the total had regression of disease; whereas, 20 (23.8%) patients out of the total had progression of disease. Twenty (23.8%) patients had a Mayo score of, 1, whereas, 36 (42.8%) patients had a Mayo score of, 0. Complete histological healing was achieved by, 17 (20.2%) patients. When observing recurrence-free survival, patients who achieved partial and complete MH showed a significantly higher recurrence-free survival (p<0.001 and p<0.001, respectively). Lastly, when considering only patients who achieved at least partial MH, the subgroup with complete HH showed lower recurrence rates compared to those with persistent microscopic inflammation (p=0.049) Conclusion We reported the long-term outcomes of a selected group of pediatric patients with ulcerative colitis. Achievement of mucosal and histological healing appeared to protect against disease recurrence, with patients who resolved completely microscopic inflammation showing longer relapse-free survival rates.