P120 Faecal calprotectin and S100A12 detect the early response to treatment by quantifying colonic inflammation in patients with ulcerative colitis
T. Kobayashi*, T. Toyonaga, S. Kuronuma, O. Takeuchi, M. Nakano, E. Saito, S. Umeda, N. Watanabe, T. Hibi
Kitasato University Kitasato Institute Hospital, Centre for Advanced IBD Research and Treatment, Tokyo, Japan
Endoscopic severity scores such as Mayo endoscopic sub-score (MES) are frequently used to evaluate the severity of mucosal inflammation in ulcerative colitis (UC). However, MES only grades the most severely affected area without taking the extent of disease into account, and it is not feasible to repeat colonoscopy when assessing the response to the therapy in a short period. Faecal biomarkers including S100 proteins (calprotectin and S100A12) are considered a non-invasive alternative to endoscopy. To further optimise the utility of these biomarkers in clinical practice, we assessed if faecal S100 proteins can reflect the sum of inflammation in the colon and detect the early response to treatment in a short period.
Stool samples were collected from 59 active and inactive UC patients planning to have a colonoscopy, and faecal S100 proteins were measured using ELISA. Endoscopic disease activity was evaluated by MES and modified score (MS), which is the sum of individual MES of 5 colonic sections from ascending colon to rectum . Faecal levels of S100 proteins were evaluated for the correlation with MES and MS. 2) Thirteen patients who responded to the remission induction treatment were followed-up for their faecal S100 proteins before, and at 1, 2, 4, and 12 weeks after starting treatment.
Faecal calprotectin and S100A12 showed a significantly positive correlation with MES and MS (AUC, 0.8631 and 0.7826 for MES, respectively; 0.9343 and 0.8659 for MS, respectively). The correlation with MS was stronger than that with MES. Faecal levels of S100 proteins were significantly lower at 2–4 weeks after remission induction treatment compared with those before starting treatment. Four patients showed transiently increased levels of either or both of faecal S100 proteins at 1 week after starting treatment.
Both faecal S100 proteins can quantify colonic inflammation in UC patients. Faecal S100 proteins seemed useful in detecting response to treatment; however, it should be noted that they frequently show transient increase early in their response.
 Triana Lobatón T, Bessissow T, De Hertogh G, et al. The Modified Mayo Endoscopic Score (MMES): A New Index for the Assessment of Extension and Severity of Endoscopic Activity in Ulcerative Colitis Patients. J Crohns Colitis 2015; 9(10): 846–852.