Endoscopic activity in asymptomatic patients with an ileal pouch is associated with an increased risk of pouchitis

Background The significance of endoscopic activity in asymptomatic ulcerative colitis (UC) patients with an ileal pouch is unknown. Aim To investigate understand the association of endoscopic pouch activity in asymptomatic patients with the subsequent development of pouchitis. Methods We analyzed a retrospective cohort of patients with UC or IBD-unspecified who underwent a total proctocolectomy with ileal pouch anal anastomosis (IPAA). Asymptomatic patients with a Pouchitis Disease Activity Index (PDAI) symptom sub-score of zero who underwent an index surveillance pouchoscopy were included. Endoscopic pouch body activity was graded as 0: normal, 1: mucosal inflammation, or 2: mucosal breaks (ulcers and/or erosions). The primary outcome was primary acute idiopathic pouchitis defined as PDAI score >= 7 with symptoms lasting less than four weeks and responsive to standard antibiotics, not otherwise meeting criteria for secondary pouchitis. The secondary outcome was chronic idiopathic pouchitis defined as PDAI score >= 7 with symptoms lasting greater than four weeks despite standard antibiotics. Predictors of pouchitis were analyzed using Kaplan-Meier and Cox regression methods with hazard ratios (HR) and 95% confidence intervals (CI) reported. Results 143 asymptomatic pouch patients were included. Index endoscopic pouch body activity was 0 in 86 (60.1%) patients, 1 in 26 (18.2%) and 2 in 31 (21.7%). The median length of follow-up after index surveillance pouchoscopy was 3.03 [IQR 1.24-4.60] years. Primary acute idiopathic pouchitis occurred in 44 (31%) patients and chronic idiopathic pouchitis in 12 (8.4%). Grade 2 endoscopic pouch activity was associated with the development of acute pouchitis (HR 2.39, 95% CI 1.23-4.67), although not chronic pouchitis (HR 1.76, 95% CI 0.53-5.87). Histologic inflammation in endoscopically normal pouch mucosa was not associated with acute or chronic pouchitis. Conclusions Mucosal breaks are present in nearly a quarter of asymptomatic patients with IPAA and are associated with an increased risk of acute pouchitis.