Repeated exclusive enteral nutrition in the treatment of paediatric Crohn's disease: predictors of efficacy and outcome

Background Exclusive enteral nutrition (EEN) induces remission and mucosal healing in children with active Crohn's disease (CD). Aim To compare short- and long-term outcomes of the first vs. second courses of EEN, and to identify predictors of sustained remission. Methods Retrospective single centre analysis of all patients with CD (6-18years) treated with EEN over 7.5years. Patients were excluded if exposed to anti-TNF or corticosteroids 3months prior to EEN. Data included disease phenotype, activity, NOD2 genotype, laboratory indices and anthropometrics. Remission and relapse were defined by mathematically weighted Paediatric Crohn's Disease Activity Index (wPCDAI) with 1-year follow-up. Results Of 94 patients treated with EEN, 52 fulfilled inclusion criteria (31 male, mean age 13.2years). Azathioprine was started within the first month in 33/52 patients; 26/52 received a second EEN course. First compared to second EEN revealed higher wPCDAI at start (59 vs. 40, P<0.0001), tended to higher remission rates after 3months (92% vs. 77%, n.s.), but showed comparable 1-year relapse rates (67% vs. 70%, median time 231 vs. 145days, n.s.). Disease activity, weight gain and inflammatory markers showed better improvement with first EEN. Faecal calprotectin >200g/g during EEN was associated with shorter remission (median time 157 vs. 287days, n.s.). Certain NOD2 genotypes were related to higher relapse rates (92% R702W or G908R vs. 50% 1007fs vs. 60% wild-type, P<0.01). Conclusions Exclusive enteral nutrition induces remission in active Crohn's disease, but efficacy tends to decrease with the second course. Despite early azathioprine use, 1-year relapse rates are high, but may be related to NOD2 genotype.