FAECAL CALPROTECTIN - AN OBJECTIVE MEASURE OF DISEASE ACTIVITY IN CHILDHOOD INFLAMMATORY BOWEL DISEASE

Abstract

20 A non-invasive, objective test of disease activity is much needed in the management of Inflammatory Bowel Disease (IBD). Calprotectin is an abundant neutrophil protein, extremely stable in faeces, whose faecal concentration can be measured by a simple ELISA. The aim of this study was to assess the usefulness of faecal calprotectin as a measure of disease activity. Spot faecal samples from 40 children with IBD and 31 control children were sent by ordinary mail to the laboratory, where faecal calprotectin concentration was measured by an in-house ELISA. A modified Lloyd-Still & Green score (mLSS) was calculated for each IBD child at an outpatient visit within 10 days of the faecal sample collection. Compared with control values (median 2.1, range 0.5 - 6.3mg/L), faecal calprotectin (median, range) was significantly increased in 16 children with ulcerative colitis, (11.5, 0.6 - 272.5mg/L, p<0.001) and in 21 children with Crohn's disease, (14.0, 0.7 - 59.7mg/L, p<0.001). Faecal calprotectin did not differ from controls in 3 children with indeterminate colitis. The children with IBD had mLSS's of 54-85 (median 72). 12 "moderately affected" children (mLSS 35-65), had significantly higher faecal calprotectin (22.2, 2.7-141.7mg/L) than 28 "mildly affected" children (mLSS >65), (10.0, 0.6-27.2mg/L), p<0.001. For the total IBD group, faecal calprotectin bore a highly significant negative correlation to the mLSS (r2 = 0.38, p<0.001). Faecal calprotectin also correlated negatively with serum albumin (r2= 0.27, p = 0.001) and positively with erythrocyte sedimentation rate, (r2= 0.14, p<0.05). Thus, faecal calprotectin is increased in children with IBD, and appears to reflect disease activity. As a simple, non-invasive test, it has the potential to reduce the number of invasive investigations performed on children with IBD. Further study, validating faecal calprotectin against colonoscopy and histology as "gold standard" measures of bowel inflammation are well advanced.