702 Development of a New Classification for Confocal LASER Endomicroscopy in IBD

Abstract

Development of a New Classification for Confocal LASER Endomicroscopy in IBD Helmut Neumann*, Emmanuel Coron, Klaus MoNkemuLler, Markus F. Neurath, Michael Vieth Department of Medicine 1, University of Erlangen-Nuremberg, Erlangen, Germany; Centre Hospitalier Universitaire, Nantes, France; Basil Hirschowitz Endoscopic Center of Excellence, University of Alabama at Birmingham, Birmingham, AL; Institute of Pathology, Klinikum Bayreuth, Bayreuth, Germany Introduction: Probe-based confocal laser endomicroscopy (pCLE) allows in vivo on demand histology during ongoing colonoscopy and has the potential to analyze mucosal and submucosal alterations in real time. Here, an international collaboration of five experts proposed a new and unique pCLE classification for the use in patients with inflammatory bowel disease (IBD). Aims: Main study objective was to establish a pCLE classification for IBD. Second study objective was to assess accuracy, interobserver and intraobserver agreement of the new classification. Material & Methods: Consecutive patients with known IBD underwent screening or surveillance colonoscopy and were evaluated using pCLE. First, a post hoc review of 25 pCLE video sequences was performed in order to accomplish a new classification system based on different vessel and crypt categories. Accordingly, all observers scored an additional set of 100 pCLE video sequences, using the new classification. In all cases, histopathological analysis served as the reference standard. Results: Based on different vessel and crypt categories a new pCLE classification for IBD was developed. The interobserver agreements for vessel and crypt architecture were substantial with kappa values of 0.7737 (95% confidence interval: 0.6475-0.8999) and 0.6311 (95% confidence interval: 0.4776-0.7846), respectively. Intraobserver agreements for vessel and crypt architecture were substantial with kappa values of 0.7541 (95% confidence interval: 0.4931-1) and 0.6753 (95% confidence interval: 0.3837-0.9669), respectively. Overall, sensitivity, specificity and accuracy for predicting histological inflammation in macroscopically uninflamed mucosa were 94%, 81%, and 87%, respectively. Positive and negative predictive values were 82% and 94%, respectively. Conclusion: A new and unique classification for pCLE in IBD was developed and validated by a panel of international experts. The classification allows prediction of microscopic inflammation in macroscopically non-inflamed mucosa. Final results will be reported at DDW.