Clinical usefulness of linked color imaging for evaluation of endoscopic activity and prediction of relapse in ulcerative colitis

Purpose In the treatment of ulcerative colitis (UC), accurate evaluation of UC activity is important to achieve mucosal healing. We sought to investigate the clinical utility of linked color imaging (LCI) for the evaluation of endoscopic activity and prediction of relapse in UC patients. Methods We enrolled 72 consecutive UC patients in remission who underwent colonoscopy at our institution between September 2016 and October 2018. The relationship between the presence of redness in white light imaging (WLI) and LCI and histopathological inflammation (Geboes score: GS) at 238 biopsy sites was examined. We also assessed the presence or absence of planar redness in the entire rectum as ± and classified the patients into three groups according to the combination of WLI/LCI: A: WLI-/LCI-, B: WLI-/LCI+, and C: WLI+/LCI+. The relationship between WLI/LCI classification and relapse in 64 patients followed up for more than 12 months from initial colonoscopy was assessed and compared to the Mayo endoscopic subscore (MES). Results A GS of 0 or 1 accounted for 89% of WLI/LCI non-redness sites, while a GS of 2 or 3 accounted for 42% of WLI non-redness/LCI redness sites. LCI findings were significantly correlated with GS. During follow-up, 10 patients in group C and four patients in group B relapsed, but none in group A. Non-relapse rates were significantly correlated with WLI/LCI classification, but not with MES. Conclusion LCI is a useful modality for accurate assessment of endoscopic activity and prediction of relapse in UC by detecting mild inflammation unrecognizable by WLI.