94 Looking Beyond Deep Remission: Effect of Biologic Therapy on Transmural Healing Evaluated by Ultrasound in Pediatric Ileal Crohn's Disease

Abstract

BACKGROUND AND AIM: Therapeutic goals for Crohn's disease (CD) have evolved from a mere control of symptoms to the concept of deep remission (DR), including clinical and biomarker remission and mucosal healing (MH). Biologic therapy with anti-TNFα is effective in achieving MH. Yet, CD is a transmural disease, characterized by a progressive bowel damage leading to complications. This is the first pediatric study prospectively evaluating the efficacy of anti-TNFα therapy in inducing clinical remission, MH and transmural healing (TH) in ileal CD. METHODS: Pediatric patients (pts) with ileal CD starting biological therapy with Infliximab or Adalimumab were prospectively enrolled. All pts were Naive to biologics. Clinical activity (Pediatric Crohn's Disease Activity Index, PCDAI), laboratory tests (CRP, ESR), endoscopic activity (simple endoscopic score, SES-CD) and transmural disease assessed by small intestine contrast ultrasonography (SICUS) were evaluated before starting (T0) and after 9-12 months of therapy (T1). Complete MH was defined as a SES-CD of 0-1, partial MH as 50% decrease vs T0. At US the evaluated parameters were: extension of disease (cm), bowel wall thickness >3 mm (BWT), bowel wall vascularity, stratification of the BW (BWS), presence of stricture, fistulae and abscess. Wilcoxon signed rank test was used for pair comparison (T1-T0). RESULTS: 26 pts (mean age 13.3 ± 4, 16 males) were included. The mean PCDAI, ileal SES-CD, CRP, ESR, BWT and disease extension values significantly decreased at T1 (table). Increased bowel wall vascularity was present in 80% of pts at T0 and in 24% at T1 (p<0.0001). In pts with complete and partial MH the extension of disease and themean BWT at US were significantly reduced at T1 (p<0.02); in pts without endoscopic response the US parameters didn't change significantly, despite clinical response. Presence of strictures and BWS didn't modify during therapy in any group. CONCLUSIONS: Biologics are effective in inducing clinical and laboratory remission and in achieving MH in pediatric CD. Transmural inflammation significantly improves during therapy, however when a substantial bowel damage (stricture) is present, the effect on TH might be poorer. Further studies are needed to evaluate the impact of TH on the long term outcome of CD. CLINICAL, ENDOSCOPIC AND US DATA AT T0 AND T1