P919 Crohn’s Disease Exclusion Diet as add-on therapy in refractory pediatric patients

Despite the accumulating body of evidence of the efficacy and tolerability of Crohn’s disease exclusion diet (CDED) combined with partial enteral nutrition (PEN), there is still a paucity data regarding its use in combination with other medical treatments. We aimed at assessing its efficacy in re-inducing remission in pediatric CD patients experiencing disease relapse while on other maintenance therapies. This was a single-center, retrospective, observational study conducted at an Italian national referral pediatric IBD center. Incident patients who received CDED coupled with PEN in the setting of the loss of response to other maintenance therapies from January 1st, 2020 to June 30th 2023 were included. Clinical remission at the end of each phase was defined by a weighted Pediatric Crohn’s Disease Activity Index (wPCDAI) below 12.5. Biochemical remission was defined by a c-reactive protein (CRP) lower than 0.5 mg/dL. A FC lower than 150 mg/kg was used as a surrogate of mucosal improvement (MI). 25 patients (52% males) met inclusion criteria and were included in the analysis. Median disease duration at CDED+PEN initiation was 31 months (Q1-Q3: 8.4-13.8). The most frequent disease location was ileocolonic (64%), 3 (12%) patients had isolated colonic involvement. 9 (36%) patients had stricturing/penetrating phenotype. 16 patients (68%) were being treated with an anti-TNF-alpha agent, whereas 5 (20%) patients were receiving ustekinumab (Table 1). wPCDAI, CRP and FC significantly decreased after the firs 8 weeks of treatment (22.5 vs 2.5, 1 vs 0.2, 640 vs 360, p<0.001, p=0.019 and p=0.007, respectively). At the end of phase I, 19/25 (76%) of the patients achieved clinical remission, 15 (60%) patients had CRP levels within normal range and 7 (28%) of them had normalized FC. 18/25 patients (72%) had received Exclusive Enteral Nutrition (EEN) for the induction of remission at diagnosis. Patients who achieved clinical remission with the EEN course (i.e.: a wPCDAI of < 12.5 after a complete course of EEN) were more likely to achieve clinical remission when receiving CDED + PEN (11/13 vs 1/5, p=0.022). CDED coupled with PEN is a valid treatment strategy in the setting of secondary loss of response to maintenance treatments in children with CD. A previous successful course of EEN was associated with higher rates of clinical remission at the end of phase I, thereby possibly identifying a subset of “nutritional responder” patients.