title: Predicting a change in diagnosis from ulcerative colitis to Crohn's disease: a nested, case-control study.
abstract: OBJECTIVE
  Some patients diagnosed with UC undergo a change in diagnosis to CD. Identification of predictors of a diagnostic change could potentially impact the management of patients with colonic inflammation. Our aim was to characterize clinical and serologic predictors of a change in diagnosis from UC to CD.
  
  
  METHODS
  A nested, case-controlled study was performed to compare individuals with a change in diagnosis from UC to CD (cases) with age-matched UC and CD controls; primary analysis compared cases with UC controls. Subjects underwent chart review for clinical "red flags" identified by gastroenterologists with expertise in IBD. Serum collected at the time of database enrollment was tested for antibodies to oligomannan (anti-Saccharomyces cerevisiae), Pseudomonas fluorescens-related protein, Escherichia coli outer membrane porin C, CBir1 flagellin, and perinuclear antineutrophil cytoplasmic antibodies.
  
  
  RESULTS
  Twenty-one cases, 52 UC controls, and 56 CD controls were assessed. Three red flags, but no serologic markers, differed between cases and UC controls. At initial colonoscopy, cases were more likely to have extensive colonic involvement than UC controls (P = .008). Multivariate regression identified non-bloody diarrhea at initial presentation (P = .01) and weight loss >10% at presentation (P = .007) as independent predictors of diagnostic change. Serologic markers did not add to the contribution of these 2 clinical factors in predicting a change in diagnosis from UC to CD. Diagnostic change was evident in 6 of 6 (100%) patients with both predictors, compared with 8 of 50 (16%) with neither of these factors (P < .0001).
  
  
  CONCLUSIONS
  Patients with a diagnosis of UC with initial non-bloody diarrhea or weight loss have an increased likelihood of subsequent change in diagnosis to CD and might thus warrant further diagnostic work-up.
authors.affiliation: Inflammatory Bowel Disease Center, Division of Gastroenterology, Department of Medicine, Cedars-Sinai Medical Center, David Geffen School of Medicine, University of California Los Angeles, California, USA.
authors.forename: Gil Y
authors.initials: GY
authors.lastname: Melmed
authors.forename: Robert
authors.initials: R
authors.lastname: Elashoff
authors.forename: Gary C
authors.initials: GC
authors.lastname: Chen
authors.forename: Igor
authors.initials: I
authors.lastname: Nastaskin
authors.forename: Konstantinos A
authors.initials: KA
authors.lastname: Papadakis
authors.forename: Eric A
authors.initials: EA
authors.lastname: Vasiliauskas
authors.forename: Weiqing
authors.initials: W
authors.lastname: Liu
authors.forename: Carol
authors.initials: C
authors.lastname: Landers
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Ippoliti
authors.forename: Stephan R
authors.initials: SR
authors.lastname: Targan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D003093:Colitis, Ulcerative / Q000097:blood* / Q000175:diagnosis / Q000473:pathology*; D003424:Crohn Disease / Q000097:blood* / Q000175:diagnosis / Q000473:pathology*; D003967:Diarrhea / Q000209:etiology; D005260:Female; D005408:Flagellin / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015431:Weight Loss
chemical_list: D000906:Antibodies; D015415:Biomarkers; C502160:CBir1 flagellin; D005408:Flagellin