P329 Utility of faecal calprotectin to assess Crohn’s disease activity in patients with an ileostomy

Abstract

Faecal calprotectin (FCP) is increasingly used as a non-invasive tool to monitor ulcerative colitis. However, to date the use of FCP to monitor patients with an ileostomy due to Crohn’s disease (CD) has not been established. The aim of this study was to assess the performance characteristics of FCP in patients with Crohn’s disease and an ileostomy. Patients with an ileostomy due to CD, attending a single academic centre were identified. Patient demographics were recorded using a prospectively maintained database of >3800 IBD patients. Endoscopy activity was graded using modified Rutgeert’s score. Radiological investigations included MRE/CT, and classified as active or inactive CD. Seventeen patients were identified. Patient demographics, disease characteristics, and baseline biochemistry are given in Table 1. Patient demographics and disease characteristics Patient demographics and disease characteristics A total of 19 contemporaneous endoscopic and FCP results from 15 patients were analysed. 63.2% had i0/1 disease, 15.7% i2, and 21.1% i3/i4. Furthermore, no significant correlation was identified between endoscopic scores and FCP results (R = 0.312; p = 0.19). The median FCP result for those patients with i0/i1 disease was 139.5 μg/g (IQR 41.25–232), while those with i2–i4 disease activity had a median FCP of 426 μg/g (IQR 44.75–2284.5). There was no significant difference between these two groups (p = 1.00). Five patients underwent radiological and FCP assessment simultaneously. There was no significant correlation identified (R = 0.866; p = 0.33). The utility of FCP to detect endoscopic activity was assessed. An FCP of 117.5 μg/g had a sensitivity of 67% and specificity of 63%; AUROC = 0.75 (Figure 1). Sensitivity and specificity of FCP to detect disease activity (AUROC) In this study, there was poor correlation between FCP and established tools in assessing disease activity. FCP measurement alone has only moderate sensitivity/specificity for the detection of disease activity in patients with CD and an ileostomy. FCP is best utilised in conjunction with other objective tools in this particular patient cohort as it is not a reliable independent non-invasive marker of disease activity.