P236. Fecal calprotectin as a surrogate marker of acute microscopic inflammation in ulcerative colitis patients with endoscopic remission
T. Lobaton Ortega1, E. Dueñas1, A. Lopez-Garcia1, F. Rodriguez-Moranta1, L. Carolina2, X. San Juan2, L. Rodriguez1, A. Ruiz1, J. Guardiola1, 1Hospital Universitari Bellvitage, Gastroenterology, Barcelona, Spain, 2Hospital Universitari Bellvitage, Pathology, Barcelona, Spain
The presence of acute microscopic inflammation (AMI) in ulcerative colitis (UC) patients with endoscopic remission has demonstrated a prognostic value (increased risk of relapse). Fecal calprotectin (FC) has shown a good accuracy to predict endoscopic activity but data on FC ability to predict histological activity in UC patients in endoscopic remission is scarce.
Our aim was to evaluate the ability of FC as a surrogate marker to predict histological activity in UC patients with endoscopic remission.
59 UC patients with endoscopic remission (defined as Mayo endoscopic subscore 0–1) were prospectively included between January 2011 and January 2012.
55 complete colonoscopies with biopsies from rectum, left colon, transverse colon and right colon and 4 rectosigmoidoscopies with rectal biopsies were performed.
Histological activity was scored as acute microscopic inflammation (AMI), chronic inflammation or absence of inflammation. For each patient, the biopsy with most severe histological activity was considered.
FC was determined both by an enzyme-linked immunoassay (ELISA, Bühlmann®) test and a rapid quantitative test (Quantum Blue, Bühlmann®).
Correlation between both techniques was very good: interclass correlation index (ICI) of 0.904 (CI 95%: 0.864–0.932; P < 0.001). Results are presented with the ELISA test.
FC levels were significantly higher in patients with Mayo endoscopic subscore grade 1 (n = 31), than in patients with Mayo endoscopic subscore grade 0 (n = 28): median FC levels of 351.60±452.95 vs. 172.86±322.46 (P = 0.002).
AMI was more frequently present in patients with Mayo endoscopic subscore grade 1 than in those with Mayo endoscopic subscore grade 0 (48.3% (16/31) vs. 8% (2/28), P < 0.001).
FC levels were significantly higher in patients with AMI (n = 18) than in patients with chronic or absence of inflammation (n = 41): mean FC levels of 486.02±533.27 vs. 158.59±301.10, P = 0.023).
In the multivariate analysis, after adjusting for the endoscopic activity, FC was an independent predictor of histological activity (P = 0.028).
Clinical activity and the rest of biomarkers (leucocytes, platelets and CRP) didn't predict histological activity.
Fecal calprotectin predicts acute microscopic inflammation in UC patients with endoscopic remission.