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An International Consensus to Standardize Integration of Histopathology in Ulcerative Colitis Clinical Trials
  • Christopher Ma, Cumming School of Medicine
  • Rocio Sedano, Western University
  • Ahmed Almradi, Western University
  • Niels Vande Casteele, Robarts Research Institute
  • Claire E. Parker, Robarts Research Institute
  • Leonardo Guizzetti, Robarts Research Institute
  • David F. Schaeffer, University of British Columbia, Faculty of Medicine
  • Robert H. Riddell, University of Toronto
  • Reetesh K. Pai, University of Pittsburgh School of Medicine
  • Robert Battat, Weill Cornell Medicine
  • Bruce E. Sands, Icahn School of Medicine at Mount Sinai
  • Christophe Rosty, Faculty of Medicine
  • Marla C. Dubinsky, Icahn School of Medicine at Mount Sinai
  • Florian Rieder, Cleveland Clinic Foundation
  • Noam Harpaz, Icahn School of Medicine at Mount Sinai
  • Maria T. Abreu, University of Miami Leonard M. Miller School of Medicine
  • Robert V. Bryant, The Queen Elizabeth Hospital, North Western Adelaide Health Service
  • Gregory Y. Lauwers, Moffitt Cancer Center
  • Richard Kirsch, University of Toronto
  • Mark A. Valasek, Department of Pathology
  • Eileen Crowley, Western University
  • William J. Sandborn, Robarts Research Institute
  • Brian G. Feagan, Robarts Research Institute
  • Rish K. Pai, Mayo Clinic Scottsdale-Phoenix, Arizona
  • Vipul Jairath, Robarts Research Institute
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Background & Aims: Histopathology is an emerging treatment target in ulcerative colitis (UC) clinical trials. Our aim was to provide guidance on standardizing biopsy collection protocols, identifying optimal evaluative indices, and defining thresholds for histologic response and remission after treatment. Methods: An international, interdisciplinary expert panel of 19 gastroenterologists and gastrointestinal pathologists was assembled. A modified RAND/University of California, Los Angeles appropriateness methodology was used to address relevant issues. A total of 138 statements were derived from a systematic review of the literature and expert opinion. Each statement was anonymously rated as appropriate, uncertain, or inappropriate using a 9-point scale. Survey results were reviewed and discussed before a second round of voting. Results: Histologic measurements collected using a uniform biopsy strategy are important for assessing disease activity and determining therapeutic efficacy in UC clinical trials. Multiple biopsy strategies were deemed acceptable, including segmental biopsies collected according to the endoscopic appearance. Biopsies should be scored for architectural change, lamina propria chronic inflammation, basal plasmacytosis, lamina propria and epithelial neutrophils, epithelial damage, and erosions/ulcerations. The Geboes score, Robarts Histopathology Index, and Nancy Index were considered appropriate for assessing histologic activity; use of the modified Riley score and Harpaz Index were uncertain. Histologic activity at baseline should be required for enrollment, recognizing this carries operational implications. Achievement of histologic improvement or remission was considered an appropriate and realistic therapeutic target. Current histologic indices require validation for pediatric populations. Conclusions: These recommendations provide a framework for standardized implementation of histopathology in UC trials. Additional work is required to address operational considerations and areas of uncertainty.

Citation Information
Christopher Ma, Rocio Sedano, Ahmed Almradi, Niels Vande Casteele, et al.. "An International Consensus to Standardize Integration of Histopathology in Ulcerative Colitis Clinical Trials" Gastroenterology Vol. 160 Iss. 7 (2021) p. 2291 - 2302
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