title: The Link between the Appendix and Ulcerative Colitis: Clinical Relevance and Potential Immunological Mechanisms.
abstract: The human appendix has long been considered as a vestigial organ, an organ that has lost its function during evolution. In recent years, however, reports have emerged that link the appendix to numerous immunological functions in humans. Evidence has been presented for an important role of the appendix in maintaining intestinal health. This theory suggests that the appendix may be a reservoir or 'safe house' from which the commensal gut flora can rapidly be reestablished if it is eradicated from the colon. However, the appendix may also have a role in the development of inflammatory bowel disease (IBD). Several large epidemiological cohort studies have demonstrated the preventive effect of appendectomy on the development of ulcerative colitis, a finding that has been confirmed in murine colitis models. In addition, current studies are examining the possible therapeutic effect of an appendectomy to modulate disease course in patients with ulcerative colitis. This literature review assesses the current knowledge about the clinical and immunological aspects of the vermiform appendix in IBD and suggests that the idea of the appendix as a vestigial remnant should be discarded.
authors.affiliation: Department of Surgery, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Sahami
authors.affiliation: Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: I A
authors.initials: IA
authors.lastname: Kooij
authors.affiliation: Department of Pathology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: S L
authors.initials: SL
authors.lastname: Meijer
authors.affiliation: Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Amsterdam, The Netherlands.|Department of Gastroenterology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: G R
authors.initials: GR
authors.lastname: Van den Brink
authors.affiliation: Department of Surgery, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: C J
authors.initials: CJ
authors.lastname: Buskens
authors.affiliation: Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: A A
authors.initials: AA
authors.lastname: Te Velde
mesh_terms: D001062:Appendectomy; D001065:Appendix / Q000276:immunology* / Q000382:microbiology; D001402:B-Lymphocytes / Q000276:immunology; D003093:Colitis, Ulcerative / Q000453:epidemiology / Q000276:immunology*; D003424:Crohn Disease / Q000453:epidemiology / Q000276:immunology; D018450:Disease Progression; D064806:Dysbiosis / Q000453:epidemiology / Q000276:immunology*; D000069196:Gastrointestinal Microbiome / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology; D055611:Natural Killer T-Cells / Q000276:immunology; D065840:Protective Factors; D012720:Severity of Illness Index
chemical_list: D007070:Immunoglobulin A