Transmural healing evaluated by magnetic resonance enterography in paediatric patients with Crohn's disease receiving maintenance treatment with biologics

Abstract

Background The optimal treatment goal in Crohn's disease (CD) is endoscopic healing (EH). However, transmural healing (TH) facilitated by the development and increasing performance of magnetic resonance enterography (MRE) is emerging as a potential treatment goal. Aims To assess TH rates after 1 year of treatment by MRE and its relationship with EH in paediatric patients with CD receiving anti-tumour necrosis factor (TNF) agents, and to investigate factors associated with TH after 1 year of treatment. Methods This multi-centre, prospective, observational study included Korean paediatric patients with luminal CD diagnosed at age < 19 years who were naive to anti-TNF treatment. They simultaneously underwent ileocolonoscopy and MRE at baseline and after 1 year of treatment with biologics. Results We included 116 patients. At 1 year, EH and TH were achieved in 59.5% (69/116) and 38.8% (45/116) of the patients, respectively. Both EH and TH was observed in 35.3% (41/116), EH without TH in 24.1% (28/116), TH without EH in 3.4% (4/116), and neither EH nor TH in 37.1% (43/116). Moreover, 59.4% (41/69) of patients who achieved EH at 1 year exhibited TH, and 91.1% (41/45) of patients who achieved TH exhibited EH. Baseline MaRIA score was associated with TH according to a multivariate analysis (OR 0.97, 95% CI 0.95-0.99, p = 0.023). Conclusion TH is a more stringent goal than EH. Regular follow-up evaluation of transmural status, and efforts to achieve TH, may alter the natural course of CD in the era of treat-to-target.