title: Role of the lymphatic system in the pathogenesis of Crohn's disease.
abstract: OBJECTIVE
  Intestinal lymph containing interstitial fluid, proteins, immune cells, and digested lipids is actively transported back to the blood stream thanks to rhythmical contractions of the mesenteric lymphatic vessels. During this process, lymph flows through several lymph nodes, allowing antigens to be sampled by the immune system. Abnormalities in lymphatic drainage have been noted in the original descriptions of Crohn's disease, but essentially ignored since. The lymphatic system is re-emerging as a critical player in inflammatory and immune processes and the purpose of this review is to present and discuss new concepts related to the involvement of the lymphatic system in the development of inflammatory bowel diseases (IBDs) and more specifically Crohn's disease.
  
  
  RESULTS
  Recent studies reporting lymphangitis, lymphangiogenesis, bacterial infiltration and lymph node infection, immune cell trafficking, and fat-wrapping in Crohn's disease suggest altered lymph drainage and lymphatic pumping, implicating the lymphatic system as a likely player in inflammatory disorders and IBDs.
  
  
  CONCLUSIONS
  Improved knowledge and appreciation of the roles that the lymphatic system plays in immune cell trafficking, infection, fat transport, distribution and metabolism and, of course, edema resolution is necessary to better understand the pathogenesis of chronic inflammatory conditions such as Crohn's disease and may provide the basis for new therapeutic strategies.
authors.affiliation: Inflammation Research Network and Smooth Muscle Research Group, Snyder Institute of Infection, Immunity and Inflammation, Department of Physiology & Pharmacology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada. vonderwe@ucalgary.ca
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: von der Weid
authors.forename: Sonia
authors.initials: S
authors.lastname: Rehal
authors.forename: José Gp
authors.initials: JG
authors.lastname: Ferraz
mesh_terms: D003424:Crohn Disease / Q000276:immunology*; D006801:Humans; D042583:Lymphangiogenesis / Q000502:physiology; D008205:Lymphangitis / Q000150:complications*; D008208:Lymphatic System / Q000276:immunology / Q000382:microbiology / Q000503:physiopathology*