Crohn's disease and ulcerative colitis are complex disorders with some shared and many unique predisposing genes. Accurate phenotype classification is essential in determining the utility of genotype-phenotype correlation. The Montreal Classification of IBD has several weaknesses with respect to classification of children. The dynamic features of pediatric disease phenotype (change in disease location and behavior over time, growth failure) are not sufficiently captured by the current Montreal Classification.
Focusing on facilitating research in pediatric inflammatory bowel disease (IBD), and creating uniform standards for defining IBD phenotypes, an international group of pediatric IBD experts met in Paris, France to develop evidence-based consensus recommendations for a pediatric modification of the Montreal criteria.
Important modifications developed include classifying age at diagnosis as A1a (0 to <10 years), A1b (10 to <17 years), A2 (17 to 40 years), and A3 (>40 years), distinguishing disease above the distal ileum as L4a (proximal to ligament of Treitz) and L4b (ligament of Treitz to above distal ileum), allowing both stenosing and penetrating disease to be classified in the same patient (B2B3), denoting the presence of growth failure in the patient at any time as G1 versus G0 (never growth failure), adding E4 to denote extent of ulcerative colitis that is proximal to the hepatic flexure, and denoting ever severe ulcerative colitis during disease course by S1.
These modifications are termed the Paris Classification. By adhering to the Montreal framework, we have not jeopardized or altered the ability to use this classification for adult onset disease or by adult gastroenterologists. (Inflamm Bowel Dis 2011)
1 Wolfson Medical Center, Tel Aviv University, Israel
2 Hospital for Sick Children, Toronto, Ontario, Canada
3 Cohen Children Medical Center of New York, New Hyde Park, New York
4 Child Life and Health, University of Edinburgh and Department of Paediatric Gastroenterology and Nutrition, Royal Hospital for Sick Children, Edinburgh, Scotland, UK
5 Shaare Zedek Medical Center, Jerusalem, Israel
6 Department of Paediatric Gastroenterology and Nutrition, Royal Hospital for Sick Children, Glasgow, Scotland, UK
7 Imperial College, London, UK
8 Université Paris-Descartes, INSERM U989, Assistance Publique-Hopitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
9 Department of Pediatrics, Maxime Dunitz Children Hospital, Pediatric IBD Center, Cedars-Sinai Medical Center, Los Angeles, California
10 Connecticut Children Medical Center, Hartford, Connecticut
*Reprints: Connecticut Children Medical Center, 282 Washington St., Hartford, CT 06106
Received 10 July 2010; Accepted 19 August 2010
Published online 8 November 2010 in Wiley Online Library (wileyonlinelibrary.com).
All authors contributed equally to this article.
This article was published online on November 8th, 2010. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected.