Reproducibility of the electronic chromoendoscopy PICaSSO score (Paddington International Virtual ChromoendoScopy ScOre) in ulcerative colitis using multiple endoscopic platforms: a prospective multicenter international study (with video).

BACKGROUND AND AIMS: Endoscopic and histologic remission (HR) are key therapeutic targets in the management of ulcerative colitis (UC). The aim of this study was to evaluate the reproducibility of the Paddington International virtual ChromoendoScopy ScOre (PICaSSO), a virtual chromoendoscopy score originally validated by use of the iSCAN platform, with the narrow-band imaging (NBI), linked-color imaging (LCI), and blue-laser imaging (BLI) platforms. METHODS: We evaluated endoscopic activity using the Mayo Endoscopic Score (MES), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and PICaSSO in 159 UC patients (78 NBI and 81 BLI/LCI) who underwent colonoscopy in 2 tertiary referral centers. HR was defined by the Robarts Histopathology Index (RHI) and the Nancy Histologic Index (NHI). Receiver operating characteristic curves were plotted to evaluate endoscopic scores for the prediction of HR. Intraclass correlation coefficients (ICC) between endoscopists were evaluated. RESULTS: PICaSSO had an ICC of 0.825 when the NBI and BLI/LCI cohorts were combined, higher than MES and UCEIS. The correlation between PICaSSO and RHI and NHI was 0.83 and 0.79 in the NBI cohort and between 0.63 and 0.65 in LCI/BLI. In the NBI cohort, the accuracy of MES, UCEIS, and PICaSSO was 0.936, 0.897, and 0.808 for HR measured by RHI and 0.897, 0.885, and 0.821 by NHI, respectively. In the BLI/LCI cohort, the accuracy of MES, UCEIS, LCI PICaSSO and BLI PICaSSO was 0.765, 0.778, 0.827, and 0.79 to predict HR with RHI and NHI, respectively. CONCLUSIONS: The PICaSSO score can be consistently and accurately reproduced with NBI and LCI/BLI and therefore can be applied to all virtual electronic chromoendoscopy platforms.

Fecal Calprotectin Thresholds to Predict Endoscopic Remission Using Advanced Optical Enhancement Techniques and Histological Remission in IBD Patients.

BACKGROUND: Fecal calprotectin (FC) is a common surrogate marker of mucosal healing (MH) in patients with ulcerative colitis (UC) and Crohn's disease (CD). We investigated the optimum FC thresholds for defining endoscopic remission (ER) and histological remission (HR) using advanced endoscopic techniques. PATIENTS AND METHODS: In this cross-sectional study, we collected clinical, endoscopic, histological data, and FC from 76 UC and 41 CD patients. Receiver operating characteristic curves were created to evaluate the optimum cut-off of FC to predict ER evaluated by Mayo Endoscopic Score (MES), Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and modified PICaSSO (Paddington International Virtual Chromoendoscopy Score) for UC patients and Simple Endoscopic Score (SES-CD) in CD patients; and HR was scored by the Robarts Histology Index (RHI) and Nancy Index for UC and modified Riley for CD. RESULTS: In UC patients, the best thresholds of FC to identify ER calculated with MES, UCEIS, and modified PICaSSO were 112, 148, and 161 mcg/g with accuracy of 86.9% 86.8%, and 81.6%, respectively. The best value of FC to predict HR was 112 mcg/g and 172 mcg/g with accuracy of 84.2% and 81.6% for RHI and Nancy Index, respectively.In CD patients, the best cut-off of FC to predict ER was 96 mcg/g with accuracy of 82.9%. The HR was best predicted by an FC value of 225 mcg/g with accuracy of 75.6%. CONCLUSIONS: The FC value threshold between 112 and 172 mcg/g could identify ER and HR in UC patients, whereas a value under 225 mcg/g should be considered for CD patients.