Small-Bowel Crohn Disease Treated With Anti-Tumor Necrosis Factor-α Therapy: MR Enterography Score Changes After 1 Year Predict Long-Term Outcomes

Abstract

OBJECTIVE. The purpose of this article is to assess the ability of MR enterography (MRE) to predict the evolution of Crohn disease (CD) under anti-tumor necrosis factor-alpha (anti-TNF) therapy. In particular, we analyzed the effect of achieving a radiologic response (RR) on long-term patient outcomes. MATERIALS AND METHODS. We included patients with small-bowel CD who successfully started receiving anti-TNF (infliximab or adalimumab) therapy and achieved clinical remission between 2008 and 2015. MRE was performed at baseline and close to 1 year after treatment initiation. The degree of CD activity was evaluated on the basis of a per-patient MRE score used at our hospital. Individual scores were calculated and recorded on the day of analysis. The median duration of follow-up after induction therapy was 5 years (interquartile range, 2.5-9.0 years). Cumulative probabilities of not having a loss of response (LOR) were assessed using the Kaplan-Meier method and compared using the log-rank test. RESULTS. Thirty-four patients fulfilled the prerequisites for inclusion in the study. Complete RR was achieved in nine patients (26.5%), partial RR in 13 (38.2%), and either no RR or worsening in 12 (35.3%). For the three aforementioned response groups, the estimated probability of absence of LOR at 5 years was 0.88, 0.69, and 0.25, respectively, and the log-rank test suggested that the risk rates for LOR were different (p = 0.023). Based on Cox regression, an MRE score reduction of less than 50% at close to 1 year after treatment initiation was an independent risk factor for LOR (hazard ratio, 0.257; 95% CI, 0.070-0.953; p = 0.027). CONCLUSION. The MRE response after 1 year is a predictor of the efficacy of anti-TNF treatment.