Assessment of Endoscopic Mucosal Healing of Ulcerative Colitis Using Linked Colour Imaging, a Novel Endoscopic...

Mucosal healing and control of intestinal mucosal inflammation are important treatment goals for maintaining clinical remission in ulcerative colitis [UC] patients. Here, we investigated the efficacy of linked colour imaging [LCI], a novel endoscopic enhancement system, for diagnosing mucosal inflammation in UC patients.

All examinations were carried out with a LASEREO endoscopic system [FUJIFILM Co., Tokyo, Japan]. Fifty-two patients with UC were enrolled, and 193 areas assessed by LCI were examined. LCI patterns were classified as; A, no redness; B, redness with visible vessels; and C, redness without visible vessels. Regions of interest [ROIs] were set at biopsy sites, and the red colour in the ROI was calculated from the Commission internationale de l'éclairage [CIE] color space and digitized [LCI-index]. Biopsy specimens were taken at each ROI and evaluated with Matts histopathological grade. Thirty months was defined as the time interval between endoscopic diagnosis and relapse of UC.

Interobserver agreement for LCI classification was excellent between an expert and non-experts. Among areas with a Mayo endoscopic subscore of 0, 41.8% and 4.6% were classified as LCI-B and LCI-C, respectively. Among areas with a Mayo endoscopic subscore of 1, 60.5% and 34.6% were classified as LCI-C and LCI-B, respectively. The LCI index strongly correlated with the histopathological Matts score. Non-relapse rates significantly correlated with LCI classification [p = 0.0055], but not with Mayo endoscopic subscore [p = 0.0632].

Endoscopic LCI classification and LCI index can subdivide samples with the same Mayo endoscopic subscore. LCI may be a novel approach for evaluating colonic mucosal inflammation and for predicting outcome in UC patients.