The influence of anti-TNF therapy on the magnetic resonance enterographic parameters of Crohn's disease activity

Magnetic resonance enterography (MRE) is a useful tool in assessing the transmural and extraintestinal lesions in Crohn's disease (CD). However, the influence of anti-tumor necrosis factor (anti-TNF) therapy on MRE features of CD severity remains unknown. The purpose of the study was to assess the short- and long-term changes in MRE features of CD activity in relation to CD clinical course in patients treated with anti-TNF antibodies. The influence on the most important parameters of CD activity seen in MRE was assessed retrospectively using a validated score. Patients were treated with anti-TNF agents and the clinical, laboratory, and MRE CD activity was estimated at baseline, after the induction therapy and after 1 year of treatment. 71 patients were enrolled in a study. The change in CD clinical activity correlated significantly with fluctuations in MRE activity score (P < 0.0001, r = 0.5 for induction; P = 0.004, r = 0.7 for maintenance anti-TNF therapy, respectively). Bowel wall thickening, mesenteric lymphadenopathy, and fat wrapping with vascular proliferation were MRE parameters which changed significantly both after the induction and maintenance treatment in patients responding to the therapy. The change in MRE activity score was mostly pronounced during the first 3 months of treatment, when compared to the continuation of the therapy till week 52-54 (-6 points vs. -2 points, respectively; P = 0.0008). Transmural and extraintestinal healing seen in MRE correlates with changes in CD clinical activity during anti-TNF therapy, thus MRE seems to be a useful tool in monitoring the efficacy of biological agents.