title: Anti-Integrins in Ulcerative Colitis and Crohn's Disease: What Is Their Place?
abstract: BACKGROUND
  Inflammatory bowel diseases (IBD) are a group of heterogeneous conditions, characterized by immune-mediated inflammation of the gastrointestinal tract. Traditionally, medical management of these disorders has been based on use of systemic immunosuppressives. The development of new drugs that selectively inhibit leukocyte trafficking to the gut has the potential to reduce inflammation and minimize systemic toxicities.
  
  
  CONCLUSIONS
  In this article, we review the immunology of the gut and the mechanism of action these emerging therapies for IBD. Natalizumab, a monoclonal antibody to the α4 integrin, was approved for the treatment of multiple sclerosis and showed promise in Crohn's disease (CD), however it is encumbered by the risk of progressive multifocal leukoencephalopathy. Vedolizumab inhibits the α4β7 integrin to induce clinical remission in patients with both ulcerative colitis and CD. Long-term safety data on this agent is not yet available. We also review agents in the pipeline. Finally, we discuss the positioning of therapies and potential alterations to therapeutic algorithms as new medications emerge.
  
  
  CONCLUSIONS
  New therapies are emerging for IBD; however, long-term data are pending. The positioning of these agents in algorithms will evolve.
authors.affiliation: Department of Medicine, University of Western Ontario, London, Ont., Canada.
authors.forename: Reena
authors.initials: R
authors.lastname: Khanna
authors.forename: Mahmoud H
authors.initials: MH
authors.lastname: Mosli
authors.forename: Brian G
authors.initials: BG
authors.lastname: Feagan
mesh_terms: D018925:Chemokines / Q000378:metabolism; D003093:Colitis, Ulcerative / Q000188:drug therapy*; D003424:Crohn Disease / Q000188:drug therapy*; D006801:Humans; D016023:Integrins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007962:Leukocytes / Q000473:pathology; D019707:Receptors, Chemokine / Q000378:metabolism
chemical_list: D018925:Chemokines; D016023:Integrins; D019707:Receptors, Chemokine