Intestinal ultrasound: a non-invasive alternative to monitor and predict biologic treatment persistence in patients with inflammatory bowel disease.

BACKGROUND AND AIMS: Patients with Inflammatory bowel disease (IBD) are at risk of disease progression. We examined the ability of transabdominal intestinal ultrasound (IUS) to predict treatment persistence to biologics in patients with IBD. METHODS: One-year prospective observational cohort study. Clinical disease activity indices, CRP, fecal-calprotectin (FC), IUS and ileocolonoscopy were performed at baseline and pre-defined timepoints. IUS transmural remission (TR) was defined by bowel wall thickness ≤3mm and zero color Doppler activity in all bowel segments; endoscopic remission (ER) as simple endoscopic score (SES)-CD ≤ 2 or Mayo endoscopic score 0. The primary outcome was association between baseline evaluations and treatment persistence, defined as no need for dose escalation or switching to another biologic or small molecule, corticosteroids or surgery. RESULTS: Seventy-seven patients (Crohn's disease n = 43, ulcerative colitis n = 34) were included (n = 30 receiving induction, n = 47 maintenance therapy). Most patients received infliximab (n = 48). More patients with baseline ER (84% vs. 45%; p = 0.001) and TR (78% vs. 38%; p < 0.001) achieved 1-year treatment persistence. There was no difference between TR and ER, p = 0.3. Mean treatment persistence of patients in TR was 318 days vs. 221 days without TR (p < 0.001); and 332 days vs. 235 days for ER (both p < 0.002). There was no difference between TR and ER (318 vs. 332 days; p = 0.36). Combined TR and ER showed treatment persistence in 95% (19/20) of patients. CONCLUSION: IUS is comparable to endoscopy in identifying patients who maintain biologic treatment persistence for 1 year. Achieving both TR and ER showed increased likelihood of treatment persistence.