title: The impact of co-existing immune-mediated diseases on phenotype and outcomes in inflammatory bowel diseases.
abstract: BACKGROUND
  Inflammatory bowel diseases lead to progressive bowel damage and need for surgery. While the increase in prevalence of other immune-mediated diseases in IBD is well recognised, the impact of this on the natural history of IBD is unknown.
  
  
  OBJECTIVE
  To determine the impact of concomitant immune-mediated diseases on phenotypes and outcomes in IBD.
  
  
  METHODS
  Patients with IBD enrolled in a prospective registry were queried about the presence of other immune-mediated diseases, defined as those where immune dysregulation plays a role in pathogenesis. Demographics and disease-related information were obtained. Subjects also completed measures of quality of life. Multivariable regression models compared disease phenotype and outcomes of IBD patients with and without other immune-mediated diseases.
  
  
  RESULTS
  The cohort included 2145 IBD patients among whom 458 (21%) had another immune-mediated disease. There was no difference in CD phenotype between the two groups. UC patients were more likely to have pancolitis in the presence of another immune-mediated disease (62%) compared to those without (52%, P = 0.02). IBD patients with another immune-mediated disease had higher rates of needing anti-TNF biologics [Odds ratio (OR) 1.31, 95% CI 1.05-1.63] and surgery (OR 1.26, 95% CI 0.99-1.61). The presence of another immune-mediated disease was also associated with lower disease-specific and general physical quality of life.
  
  
  CONCLUSIONS
  The presence of another immune-mediated disease in IBD patients was associated with higher likelihood of pancolonic involvement in UC, and a modest increase in need for IBD-related surgery and anti-TNF biological therapy. Such patients also experienced worse quality of life.
authors.affiliation: Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: G
authors.initials: G
authors.lastname: Conway
authors.affiliation: Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: G
authors.initials: G
authors.lastname: Velonias
authors.affiliation: Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: E
authors.initials: E
authors.lastname: Andrews
authors.affiliation: Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Garber
authors.affiliation: Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: V
authors.initials: V
authors.lastname: Yajnik
authors.affiliation: Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: A N
authors.identifier: http://orcid.org/0000-0002-9436-1821
authors.initials: AN
authors.lastname: Ananthakrishnan
mesh_terms: D000328:Adult; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology; D015897:Comorbidity; D003424:Crohn Disease / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D006801:Humans; D007154:Immune System Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D007155:Immunologic Factors / Q000494:pharmacology / Q000627:therapeutic use; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011446:Prospective Studies; D011788:Quality of Life; D012042:Registries; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D007155:Immunologic Factors; D014409:Tumor Necrosis Factor-alpha