Oral (15W135)

Faecal Calprotectin in the Diagnosis and Monitoring of Inflammatory Bowel Disease

Author(s)

S Boyle, J McGoran, C Loughrey, G Rafferty, Dr Graham Turner

Department(s)/Institutions

Department of Gastroenterology, Belfast City Hospital

Introduction

Faecal calprotectin (FC) is a novel method for measuring gut inflammation which was conceived originally to distinguish between inflammatory bowel disease (IBD) and irritable bowel syndrome.(1)

Aims/Background

FC use has expanded as a surveillance tool in established IBD. Manufacturers commonly determine that values under 50μg/g should be regarded as normal, application of which level leads to a very high test sensitivity.(2) Sampling is estimated in our healthcare trust to cost around £30/€40 each so prudent requesting for this novel test is vital to ensure its sustainability.

Method

We collected data on the first 150 FC results of 2014. Paediatric cases and those from the independent sector were excluded from the analysis. Each patient’s clinical notes were then examined.

Results

108 patients were identified after exclusions were applied, 55 of which had known IBD. Three cut-off points were used in analysing the FC- <50?g/g, 50-199?g/g and >200?g/g. Of those not known to have IBD, 6/12 of patients who had calprotectin >200?g/g and none of the 15 who had levels 50-199?g/g had evidence of inflammation on colonoscopy.(See Table) Among those with known IBD reviewed in clinic, 51.4%(18/35) of patients in the FC >200?g/g underwent a step-up in therapy compared to 23%(3/13) in the 50-199?g/g group. Twenty-five out of the 54 patients without known IBD had FC <50?g/g, with all such patients declared as not having IBD, only two of which actually undergoing colonoscopy to support this.

Conclusions

Our data corresponds with the literature in that that a FC level below 50μg/g can adequately exclude IBD. Applying exact cut-off figures may be hazardous and should not substitute clinical and endoscopic assessment but if applied as part of the entire approach to the care of those with a suspected or established diagnosis of IBD, faecal calprotectin can be a useful and costeffective tool. FC levels exceeding 200μg/g when used appropriately can carry high positive predictive value for IBD and steer treatment in established disease.