title: Histologic evaluation of ulcerative colitis: a systematic review of disease activity indices.
abstract: BACKGROUND
  Ulcerative colitis (UC) is an idiopathic inflammatory disorder. Currently, the main goals of treatment are to induce and maintain clinical and/or endoscopic remission. However, evidence indicates that persistent disease activity on colonic biopsies in the setting of clinical or endoscopic remission is an independent predictor of poor outcomes. A number of previous studies have proposed histologic indices for use in specific trials of UC. The aim of this study was to systematically review the existing histological indices for UC and assess their potential use in both patient management and clinical trials.
  
  
  METHODS
  We performed a systematic review of histological indices evaluating disease activity in UC. MEDLINE (Ovid), EMBASE (Ovid), PubMed, the Cochrane Library (CENTRAL), and Digestive Diseases Week (DDW) abstracts of randomized and/or controlled trials clinical trials were searched from inception to February 2013 for applicable studies. Data from these studies were reviewed and analyzed.
  
  
  RESULTS
  After systematically applying inclusion criteria, we identified 108 scientific articles including 88 clinical studies and 21 related clinical reviews. Eighteen indices of histological activity in UC were identified and reviewed.
  
  
  CONCLUSIONS
  Although multiple histological scoring indices for assessment of UC disease activity currently exist, none of these instruments were developed using a formal validation process and their operating properties remain poorly understood. Future studies are needed to address this deficiency.
authors.affiliation: *Department of Medicine, Western University, London, Ontario, Canada; †Department of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia; ‡Department of Epidemiology and Biostatistics, McGill University, Montreal, Canada; §Robarts Clinical Trials, Inc., Robarts Research Institute, Western University, London, Ontario, Canada; ‖Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada; ¶Division of Gastroenterology, University of California San Diego, La Jolla, California; **Department of Gastroenterology, Academic Medical Center, Amsterdam, The Netherlands; ††Pacific Rim Pathology Medical Corporation, San Diego, California; ‡‡Carolinas Medical Center, Charlotte, North Carolina; §§Department of Pathology, Western University, London, Ontario, Canada; and ‖‖Department of Pathology, University Hospital of KU Leuven, Leuven, Belgium.
authors.forename: Mahmoud H
authors.initials: MH
authors.lastname: Mosli
authors.forename: Brian G
authors.initials: BG
authors.lastname: Feagan
authors.forename: William J
authors.initials: WJ
authors.lastname: Sandborn
authors.forename: Geert
authors.initials: G
authors.lastname: Dʼhaens
authors.forename: Cynthia
authors.initials: C
authors.lastname: Behling
authors.forename: Keith
authors.initials: K
authors.lastname: Kaplan
authors.forename: David K
authors.initials: DK
authors.lastname: Driman
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Shackelton
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Baker
authors.forename: John K
authors.initials: JK
authors.lastname: Macdonald
authors.forename: Margaret K
authors.initials: MK
authors.lastname: Vandervoort
authors.forename: Karel
authors.initials: K
authors.lastname: Geboes
authors.forename: Barrett G
authors.initials: BG
authors.lastname: Levesque
mesh_terms: D003093:Colitis, Ulcerative / Q000473:pathology*; D005069:Evaluation Studies as Topic; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D011379:Prognosis; D012720:Severity of Illness Index