P108 Validation of a new score for paediatric Crohn's disease on a paediatric tertiary hospital: the MINI-Index (Mucosal Inflammation Non-Invasive Index)

The incidence of paediatric Crohn’s disease has increased in the last years. New non-invasive tools for the prediction of endoscopic activity have been proposed to improve the selection of patients who require an ileocolonoscopy. In 2017, Turner et al., developed the MINI-INDEX (Mucosal Inflammation Non-Invasive Index) as a new clinical–analytical index in paediatric patients with high correlation with the endoscopic activity assessed by SES-CD (Simplified Endoscopic Activity Score for Crohn's Disease). Our study aims to validate the Mini-Index in our paediatric Crohn’s disease patients. Retrospective cohort study of patients with Crohn's disease who underwent ileocolonoscopy between 2015 and 2017 in a paediatric tertiary hospital. We performed the endoscopic index SES-CD and the MINI INDEX, which evaluates in each patient the stool pattern, faecal calprotectin (mg/kg), C-reactive protein (mg/l) and erythrocyte sedimentation rate (mm/h), obtaining a total score index between −3 and 25. A total of 96 ileocolonoscopies performed on Crohn's disease patients were included in the study (69.8% males and 30.2% females), with an average age of 13.65 ± 2.78 years. Overall, the mean SES-CD score was 13.26 ± 9.25 and the median (IQR) of the Mini-Index was 16.5 (10). 15.6% had an SES-CD score < 3 (remission), 21.9% between 3 and 10 (mild activity) and 62.5% > 10 (moderate–severe activity). The median of the Mini-Index for each group of SES-CD was: − (7) in patients with SES-CD < 3, 14 (8) in SES-CD 3–10 and 18.5 (5) in the group of SES-CD > 10, obtaining statistically significant differences (p < 0.001). Furthermore, Pearson correlation was performed between the Mini-Index and SES-CD values, which was statistically significant (p < 0.001, r = 0.701). Selecting mucosal healing as an SES-CD value of <3 we performed a ROC curve for the Mini-Index obtaining an AUC of 0.985 (p < 0.001). In our cohort, the best cut-off point was a Mini-Index value <6 (p < 0.001), with a sensitivity of 100%, specificity 96%, positive predictive value 83% and negative predictive value 100%. Our results confirm the Mini-Index as a useful non-invasive tool in paediatric Crohn's disease to predict the inflammatory status of the mucosa with high precision. The Mini-Index could be incorporated into the clinical practice of paediatric Crohn's disease to help us to select those patients that require an ileocolonoscopy. However, further prospective studies are needed to confirm these results.