title: Serum antibodies associated with complex inflammatory bowel disease.
abstract: BACKGROUND
  Antibodies to microbial antigens have been associated with specific diagnoses and phenotypes of inflammatory bowel disease. We evaluated the prevalence of pANCA, IgA and IgG anti-Saccharomyces cerevisiae antibodies, anti-OmpC, and anti-flagellin in a large well-defined population of patients with Crohn's disease (CD) and ulcerative colitis (UC) and analyzed for various clinical outcomes.
  
  
  METHODS
  Samples were collected from 391 patients with CD, 207 patients with UC, and 62 healthy controls. Patients were phenotyped using the Montreal classification. Blinded serological analyses were performed for pANCA, IgA and IgG anti-Saccharomyces cerevisiae antibodies, anti-OmpC, and anti-flagellin.
  
  
  RESULTS
  In CD, increasing quantitative levels for antibodies were associated with a younger age of diagnosis, longer disease duration, increased surgeries, ileocolonic and perianal disease, and internal perforating behavior. In UC, they were associated with colectomy. An increasing number of seropositive antibodies in CD was associated with a younger age at diagnosis, increased disease duration, ileocolonic and perianal disease, internal penetrating and stricturing behavior, and increased surgeries. Multivariate analysis confirmed the association of antimicrobial antibodies with features of complicated CD and UC.
  
  
  CONCLUSIONS
  Increased serological markers are associated with a more aggressive CD phenotype and an increased need for colectomy in UC. This raises the possibility for use of these markers in patients at risk of complex disease.
authors.affiliation: The Zane Cohen Centre for Digestive Diseases, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Abdul A
authors.initials: AA
authors.lastname: Elkadri
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Stempak
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Walters
authors.forename: Simon
authors.initials: S
authors.lastname: Lal
authors.forename: Anne M
authors.initials: AM
authors.lastname: Griffiths
authors.forename: A Hillary
authors.initials: AH
authors.lastname: Steinhart
authors.forename: Mark S
authors.initials: MS
authors.lastname: Silverberg
mesh_terms: D000293:Adolescent; D000328:Adult; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood* / Q000276:immunology; D002170:Canada / Q000453:epidemiology; D003093:Colitis, Ulcerative / Q000453:epidemiology / Q000276:immunology / Q000473:pathology*; D003424:Crohn Disease / Q000453:epidemiology / Q000276:immunology / Q000473:pathology*; D005260:Female; D005408:Flagellin / Q000097:blood* / Q000276:immunology; D005500:Follow-Up Studies; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood* / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D008297:Male; D015995:Prevalence; D011379:Prognosis; D012441:Saccharomyces cerevisiae / Q000276:immunology*; D055815:Young Adult
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D005408:Flagellin