Fecal level of calprotectin identifies histologic inflammation in patients with ulcerative colitis in clinical and endoscopic remission.

BACKGROUND & AIMS: Histologic recovery of patients with ulcerative colitis (UC) often is incomplete, even among those in clinical and endoscopic remission. Persistent active microscopic inflammation is associated with an increased risk of relapse and colorectal neoplasia. A high level of fecal calprotectin (FC) is a reliable marker of endoscopic lesions in patients with UC. We evaluated the accuracy of FC in identifying patients with UC in clinical and endoscopic remission who still have histologic features of inflammation. METHODS: We performed a prospective observational study of 59 patients with UC in clinical and endoscopic remission undergoing colonoscopy. Several biopsy specimens were collected from each colonic segment. Endoscopic remission was defined as a Mayo endoscopic subscore with a grade of 0 or 1. Active histologic inflammation was defined by the presence of neutrophils infiltrating crypt epithelial cells. FC was determined by enzyme-linked immunosorbent assay analysis. RESULTS: Eighteen patients (30.5%) showed evidence of active histologic inflammation. Patients with active histologic inflammation had a significantly higher median level of FC (278 µg/g; interquartile range, 136-696 µg/g) than those without active histologic inflammation (68 µg/g; interquartile range, 30-172 µg/g) (P = .002). In multivariate analysis, the FC and Mayo endoscopic subscore (0 or 1) were each independent predictors of histologic inflammation. The level of FC identified active histologic inflammation in patients in clinical and endoscopic remission, with an area under the receiver operator characteristic curve value of 0.754. CONCLUSIONS: Histologic inflammation is common among patients with UC in clinical and endoscopic remission. Patients with histologic features of inflammation can be identified reliably based on their fecal level of calprotectin.

Relationship between methylation and colonic inflammation in inflammatory bowel disease.

AIM: To investigate the relationship between the methylation status in the SLIT2 and TGFB2 promoters and colonic inflammation in inflammatory bowel disease patients. METHODS: We evaluated the methylation status of 2 genes (SLIT2 and TGFB2) in 226 biopsies taken from 62 colonoscopies of 38 patients (29 ulcerative colitis and 9 Crohn's colitis) using methylation-specific melting curve analysis. The relationships between methylation status and clinical, biological, endoscopic and histological activities were evaluated. Twenty-three of the 38 patients had a second colonoscopy and were included in a longitudinal analysis. Numerical results were given as the means ± SD of the sample and range, except when specified. Student t analysis, U Mann Whitney and ANOVA factor were used to compare the means. Qualitative results were based on the χ(2) test. RESULTS: SLIT2 methylation was more frequent in samples with endoscopic activity than with endoscopic remission (55% vs 18%, P < 0.001). SLIT2 methylation was also higher in samples with acute inflammation (56.5%) than in samples with chronic (24%) or absent inflammation (15%) (P < 0.001). For TGFB2 methylation, the correlation was only significant with endoscopic activity. Methylation was higher in the distal colon for both genes (P < 0.001 for SLIT2 and P = 0.022 for TGFB2). In the multivariate analysis, only inflammation status (and not disease duration or extension) was independently associated with SLIT2 methylation [OR = 6.6 (95%CI: 1.65-27.36), P = 0.009]. In the longitudinal analysis, the maintenance of endoscopic remission was protective for methylation. CONCLUSION: Endoscopic and histological inflammation are predictive for SLIT2 methylation.