P273. Colonic confocal laser endomicroscopy findings in patients with primary sclerosing cholangitis
M. Iacucci1, X. Gui2, S. Ghosh1, R. Panaccione1, G. Kaplan1, J. Love1, M. Swain1, B. Eksteen1, 1University of Calgary, Gastroenterology, Calgary, Canada, 2University of Calgary, Pathology, Calgary, Canada
85% of patients with primary sclerosing cholangitis (PSC) suffer from coexisting IBD. Controversy exists as to whether IBD seen in PSC patients represents a different entity to those with isolated IBD and whether the remaining fifteen percent of PSC patients without IBD detectable with standard diagnostic tests truly have normal colonic mucosa. Confocal laser endomicroscopy (CLE) enables real time endoscopic assessment of crypt histology and mucosal vasculature. We report the colonic features seen at CLE of 15 patients with PSC with or without known IBD.
15 patients (10 male, median age 43y, range 20–71y) with PSC underwent colonoscopy with CLE (Pentax). Mayo endoscopy subscore were used to grade known UC patients and the SES-CD score were used to describe the white light findings in known CD patients. CLE findings were classified using a 4 grade classification of inflammation describing crypt architecture, vascular alteration and leakage of fluorescein. CLE images were collected for each segment of the colon and targeted biopsies were taken for matched histologic analysis.
Of the 15 PSC patients 13 had coexistent clinically quiescent IBD (6 UC, 7 CD). Absence of rectal inflammation based on CLE findings was seen in all 13 known IBD patients. Nine of the 13 IBD patients had moderate to severe inflammation in the right colon with irregular, decreased or necrotic crypts as detected by CLE. Two patterns of fluorescein leakage were observed. In 5 patients we observed leakage of fluorescein into spaces among epithelial cells or non-uniform abundant leakage of fluorescein in the lumen of the crypts associated with moderate to severe histological inflammation; In 5 patients we observed uniform leakage of the fluorescein in the lumen of crypts in the left side of the colon with normal crypts architecture and micro-vasculature in the absence of histological inflammation. Two patients, not known to suffer from IBD and had normal light microscopy findings were shown to have active inflammation by CLE with fluorescein leakage.
CLE is a powerful tool to capture sub-clinical inflammation in patients with PSC with or without co-existing IBD which is not detectable by standard light microscopy. CLE in PSC-IBD reaffirms the concept of rectal sparing in PSC with IBD. CLE performed with fluorescein is able to detect subtle alterations in colonic permeability in quiescent IBD and in PSC without IBD suggesting colonic barrier defects in these patients.