P878 Assessment of Ulcerative Colitis Relapse Risk Using RDI (Red Dichromatic Imaging)

Abstract

Abstract Background In the management of patients with UC, mucosal healing has been proven to be a therapeutic goal and a factor influencing prognosis. It has been reported that MES 1 has a higher rate of recurrence than MES 0. However, it has been reported that MES 0 also has a relapse rate of approximately 10%. Red dichromatic imaging (RDI) is a new imaging technology that has been closely correlated with the activity index of UC. (Naganuma et al. Endosc Int Open 2017). It also correlates with histological findings and holds promise as a modality that could further stratify MES 0 (Hashimoto et al. Surgical Endosc 2023). However, it is unclear whether RDI findings is associated with UC relapse. The aim of this study was to investigate the predictive ability of RDI for UC relapse. Methods This was a single-center retrospective study. A total of 93 clinically remitted UC patients who underwent colonoscopy at our department from May 2019 to October 2021 were enrolled, and at least one RDI and WLI image was taken at each of six sites from the cecum to the rectum. Patient information and still images of RDI and WLI were blinded, and two physicians independently evaluated both images taken using the RDI score of Naganuma et al. Clinical remission was defined as partial Mayo Score (pMayo) 0-1, and relapse was defined as pMayo ≥ 2 and additional treatment. Results The median after observation was 1022 days (5-1427 days), and the overall cumulative relapse rate was 24 % (21 patients), The mean of RDI score was 2.02, with 37 patients in RDI score 1, 28 patients in RDI score 2, 17 patients in RDI score 3, and 11 patients in RDI score 4. The relapse rate for RDI score 1 was 0%, 18% (5 patients) for RDI score 2, 47% (8 patients) for RDI score 3, and 73% (8 patients) for RDI score 4.73 % (8 patients).None of the patients with RDI score 1 had a relapse, In contrast, 11% (6 of 54) of MES 0 patients relapsed, and 33% (8 of 24) of MES 1 patients relapsed. 31 patients had RDI score 1 and 17 patients had score 2 in MES 0, which could be stratified within MES 0 by using the RDI. Conclusion This study suggested that the RDI score can further stratify MES 0, which is defined as mucosal healing, and may be a more accurate predictor of relapse.