P0566Calprotectin in Acute Severe Colitis As a Discriminator of Early Response in Glasgow Study (CASCADE)

Background Acute severe colitis (ASC) is a life-threatening manifestation of Inflammatory Bowel Disease. Current approaches to ASC management involve first-line intravenous steroid treatment before escalation to second line therapies in non-responders. Despite these agents, up to 20% of patients will require an emergency colectomy. Several scores exist to predict probability of corticosteroid failure however they involve subjective markers and may be less relevant in the advanced therapy era. Faecal calprotectin is a well-established biomarker of disease activity in the outpatient setting but has not been widely investigated in the acute setting due to lack of exact values at high endo the spectrum and concern regarding laboratory turnaround times. In this study we investigate the utility of high sensitivity faecal calprotectin (hsFCP) as a marker of early corticosteroid response in ASC. Methods A prospective observational study was performed across two large tertiary referral hospitals. Patients >16 years presenting with ASC (defined by Truelove & Witts classification) requiring IV corticosteroid were recruited. Standard clinician led care was followed (standardised protocol across centres). Daily hsFCP were collected for three days when provided in addition to routine biochemical investigations and flexible sigmoidoscopy. Results 69 patients were recruited over two years.11 patients were subsequently excluded- 7 did not provide stool samples, 2 had a subsequent diagnosis of Crohn’s Colitis and 2 an alternative cause of symptoms identified (infection & immune mediated colitis). 39/58 (66%) improved with steroid therapy, 12/58 (21%) required infliximab therapy, 3/58 (5%) had an emergency subtotal colectomy, 2/58% (3%) a semi elective subtotal colectomy and 2/58 (3%) received a small molecule. Median age in response was 37 vs 44 in non-response (p = 0.570). 13/39 responders were on no IBD related therapy at time of presentation vs 5/19 in non responders (p = 0.764). 13/39 responders met the Day 3 Oxford Criteria [1] vs 10/19 non responders (p = 0.301). Median hsFCP in responders at day 1 was 3684 mg/g (Interquartile Range 2037- 7141mg/g) vs 5921mg/g (IQR 3001-13198mg/g) in non-responders (p = 0.032) while at day 3 median hsFCP in responders was 2437 mg/g (IQR 986- 3264mg/g) vs 3482mg/g (IQR 2235-10790) in non-responders (p = 0.025). Responders remained on IV corticosteroid for 3 days vs 5.5 days in non-responder with median length of stay 5 and 8 days respectively. Conclusion In the era of advanced therapy, traditional scores may be less effective at predicting steroid response in ASC. Lower day 1 and 3 hsFCP were associated with response to IV corticosteroid, suggesting hsFCP may offer an early objective guide in treatment decisions in ASC. Reference: 1. Travis SPL, Farrant JM, Ricketts C, Nolan DJ, Mortensen NM, Kettlewell MGW, et al. Predicting outcome in severe ulcerative colitis. Gut [Internet]. BMJ Publishing Group; 1996;38:905–10. https://doi.org/10.1136/GUT.38.6.905 Conflict of interest: Dr. Palmer, Josh: No conflict of interest Macdonald, Jonathan: None to declare Seenan, John Paul: No conflict of interest Gerasimidis, Konstantinos: Grant: Nestle Health Science, Nutricia-Danone, Mylan Personal Fees: Abbott, Baxter, Nestle Health Science, Nutricia-Danone, Servier, Janssen Gaya, Daniel: No conflict of interest