Determining the usefulness of Capsule Scoring of Ulcerative Colitis in predicting relapse of inactive ulcerative colitis.

Matsubayashi, Mao; Kobayashi, Taku; Okabayashi, Shinji; Nakano, Masaru; Sagami, Shintaro; Ozaki, Ryo; Kiyohara, Hiroki; Morikubo, Hiromu; Asonuma, Kunio; Miyatani, Yusuke; Maeda, Shin; Hibi, Toshifumi

BACKGROUND The usefulness of second-generation colon capsule endoscopy (CCE2) in ulcerative colitis (UC), especially in clinically inactive patients, has been reported. Capsule Scoring of Ulcerative Colitis (CSUC) was developed as a severity index for UC. We aimed to determine whether CSUC is useful for predicting relapse during clinical remission. METHODS Forty-one UC patients in clinical remission were prospectively registered from April 2016 to August 2019. Patients' CSUC score was obtained; those with subsequent relapse were followed up retrospectively. The correlation of CSUC with white blood cell (WBC) count, Platelet count, albumin (Alb), C-reactive protein (CRP), fecal calprotectin (FC) and fecal lactoferrin (FL) levels, and fecal immunochemical test (FIT) results was evaluated; their predictive values for future relapse were compared. RESULTS The correlations of CSUC with WBC, Platelet, Alb, CRP, FC, FIT, and FL values were rs =0.13, 0.27, -0.25, 0.15, 0.50, 0.43 and 0.50 respectively. CSUC was higher in 12 patients who relapsed within 1 year than in 29 patients who remained in clinical remission (2.83±1.95 vs. 0.72±1.00, p<0.01). Receiver operator characteristic curve analysis showed that CSUC >1 was a predictor of relapse (area under the curve 0.82, sensitivity 83.3%, specificity 58.6%) and maybe superior to fecal biomarkers. In the univariate analysis, patients with CSUC of 0 had a lower relapse rate than those with CSUC of ≧1 (p=0.03, logrank test). After analyzing patients who underwent CCE2 6 within 6 months after the successful induction treatment, results showed that those with CSUC of ≤1 remained in clinical remission for a year. CONCLUSION CSUC predicts relapse within 1 year in UC patients in clinical remission, especially when used 6 months after induction treatment.