P058 ISOLATED TERMINAL ILEITIS AT COLONOSCOPY – WHAT FACTORS PREDICT A NEW DIAGNOSIS OF CROHN’S DISEASE?

Abstract

Abstract Background Faecal calprotectin (FC) is a biomarker elevated in active inflammatory bowel disease (IBD). FC is more sensitive in colonic than small bowel IBD. Ileo-colonoscopy is usually performed to confirm a diagnosis of IBD. Isolated non-specific terminal ileitis is often inconclusive despite biopsy. We aimed to assess the factors that predict terminal ileal Crohn’s disease after ileitis is seen at colonoscopy. Methods A single centre retrospective study of all endoscopic cases of isolated terminal ileitis diagnosed at colonoscopy over a 4 year period (January 2015 – December 2018) was performed. Data was obtained from the Unisoft Endoscopy reporting software. Statistical analyses included chi-square, student t-test and binary logistic regression. Faecal calprotectin, CRP and histology were noted. >150μg/mg was used as a cut off for elevated FC. Results 139 cases were identified and exclusion criteria were applied (known Crohn’s disease, colonic disease). 74 cases were included for analysis. The mean age was 43.9. 44 (59.5%) of the cases were women. 38 (51.4%) had FC performed of which 27 (71.1%) had a FC >150μg/mg. 60 (81.1%) cases had macroscopic terminal ileum ulcers, 9 (15%) of these had histological evidence of ulceration. Subsequent diagnoses of Crohn’s disease were made in 15 (20.3%) patients. Odds ratio of 1.28 (p = 0.016, Cl 0.45-0.047) in the TI ulcers + FC >150μg/mg vs. no TI ulcers + FC <150μg/mg. Conclusion 1 in 5 patients with isolated terminal ileitis were subsequently diagnosed with Crohn’s disease. Almost 90% of these new cases had a faecal calprotectin >150μg/mg. There is poor correlation between endoscopic and histological terminal ileum ulceration. We conclude that terminal ileal ulceration in combination with faecal calprotectin >150μg/mg increases the likelihood of a new diagnosis of Crohn’s disease.