P248 Non-invasive Methods for monitoring mucosal healing in paediatric ulcerative colitis with usage of faecal calprotectin.
M. Meglicka, M. Szczepanski, M. Dadalski, J. Kierkus*
The Children's Memorial Health Institute, Department of Gastroenterology, Hepatology, Feeding Disorders and Paediatrics, Warsaw, Poland
Faecal calprotectin (FC) is a good marker in monitoring mucosal healing in adults with ulcerative colitis. Its concentrations in faeces is closely related to state of mucosa observed in endoscopy. There are a few studies concerning FC in mucosa status assessment in paediatrics population with UC. The aim of the study was to assess the usefulness of FC as a biomarker of endoscopy proven mucosal healing in monitoring of children with UC.
66 patients with UC (F 36, M 30, ±14,16 years) were involved to the study and had elective colonoscopy performed, FC level and erythrocyte sedimentation rate (ESR) within a week before endoscopy measured. Each patient had also body mass index (BMI) and paediatric ulcerative colitis activity index (PUCAI) calculated. Mucosa status during endoscopy was assessed with Baron score. Full mucosal healing was defined as Baron score=0. We have identified two subgroups: those with full mucosal healing, and patients with inflamed gut mucosa. The receiver operating characteristic curve (ROC ) was used as a statistical method to establish cut-off points. The cut-off points are calprotectin threshold for simple model and posterior probability threshold for the linear discriminant analysis (LDA). The area under the curve (AUC) assesses the differentiation quality of the study group based on the model score. To increase sensitivity at high specificity the LDA with FC, ESR, BMI and PUCAI was taken.
AUC for the simple model was 0,90. The selected cut-off level of discrimination between subgroup with full mucosal healing vs. subgroup with mucosal inflammation present was 189 μg/g with sensitivity 0,96 and specificity 0,75. When specificity was outweighed over sensitivity the cut-off point was 62 μg/g with sensitivity 0,50 and specificity 0,95. Due to the low sensitivity accompanying high specificity we used LDA with other parameters to increase sensitivity rate. With LDA used on FC, ESR, BMI and PUCAI the AUC was 0,90, and we could discriminate our patient with sensitivity 0,61 and specificity 0,97.
FC is a good marker of mucosal healing in monitoring of children with UC. FC above 189 μg/g enable to select 75% of patients with active inflammation in gut mucosa. LDA with FC, ESR, BMI and PUCAI let us select 61% of patients with full mucosal healing. Using these two Methods, step by step, we could discriminate patients with unknown mucosa status, that requires endoscopy.