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.
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.
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.
aInflammation Research Network and Smooth Muscle Research Group, Snyder Institute of Infection, Immunity and Inflammation, Department of Physiology & Pharmacology, Canada
bDepartment of Medicine, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
Correspondence to Pierre-Yves von der Weid, Department of Physiology & Pharmacology, Faculty of Medicine, University of Calgary, 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada Tel: +1 403 220 7967; fax: +1 403 270 2211; e-mail: email@example.com