Background: Thera are no data on long-term mucosal healing (MH) and deep remission (DR) in children with Crohn's disease (CD). Previously, we reported prospectively assessed MH and DR rates on the entire GI tract by performing two CCE over 24 weeks in children with CD, in comparison with biomarkers, magnetic resonance enterography (MRE) and SB contrast ultrasonography (SICUS). This extension evaluates MH and DR in the same cohort of patients at 52-week follow-up. The long-term efficacy of a “treat-to-target” strategy was also evaluated at the end of the study.
Methods: Children with known CD were prospectively recruited and underwent imaging studies followed by CCE, at 0, 24 and 52 weeks. The Lewis score (LS) and Simple endoscopic score for Crohn's disease (SES-CD) were calculated for SB and colon, respectively. C-reactive protein (CRP) and fecal calprotectin (FC) were also evaluated for their association with clinical activity, imaging and CCE findings. Clinical remission was defined as PCDAI<10. SB and colonic MH were defined as LS<135 and SES-CD ≤1, respectively; moderate-to-severe inflammation was defined as LS >790 or SES-CD >7. Biomarker remission (BR) was defined as a combination of clinical remission (PCDAI<10) and normal biomarkers. Deep remission (DR) was defined as a combination of BR and MH. Therapy was calibrated according to CCE results at baseline and week 24.
Results: Of 48 patients (pts) recruited, 46 completed the 52-week evaluation (2 developed an ileo-cecal valve stricture). At baseline, 22 were clinically active and 26 were in remission. After a “treat to target strategy”, at week 24, only 8 were in clinical activity, while 40 were in remission. CCE identified DR in 26/40 (54%) of the remission group; while in 8 with mild clinical activity (100%) showed a partial MH (according to baseline evaluation). At 52 weeks, CCE showed DR in 28 (58%): with the detection of new lesions in 4 and a complete MH in 6 (with previous partial MH at 24 weeks). MRE and SICUS had good concordance in evaluating DR (24/28, 86%), but did not identify mucosal lesions in 4 as well as mucosal improvements after therapy (p<0.05). FC and CRP were not able to accurately evaluate DR at 24 and 52 weeks (BR in 65% and 69%, respectively). The DR and MH rates increased over the time (23% to 58%) by using CCE and a treat to target strategy.
Conclusions: This study evaluates long-term MH and DR rate in children with CD and indicates that CCE is effective for monitoring long as well as short term DR and MH of the entire GI tract and in directing therapy for pediatric patients with CD. Additional studies are needed to explore these issues further.