title: Short article: Absence of serological rheumatoid arthritis biomarkers in inflammatory bowel disease patients with arthropathies.
abstract: OBJECTIVE
  Biomarkers that are associated with future progression to rheumatoid arthritis (RA) and joint destruction have been discovered previously in patients with arthralgia. The present study examined these RA biomarkers in inflammatory bowel disease (IBD) patients with arthropathies.
  
  
  METHODS
  Sera from 155 IBD patients with and 99 IBD patients without arthropathies were analyzed for immunoglobulin (Ig) M rheumatoid factor (RF), IgA-RF, anti-cyclic citrullinated peptide 2, anti-cyclic citrullinated peptide 3.1, and anti-carbamylated protein antibody positivity using enzyme-linked immunosorbent assays. The prevalence of the autoantibodies in the IBD patients was compared with the prevalence in RA patients.
  
  
  RESULTS
  No differences were found in biomarker positivity between IBD patients with and without arthropathies. Significantly more biomarker positivity (P<0.001) was observed in RA patients compared with IBD patients with arthropathies. Also, smoking turned out to be significantly associated with positivity for IgM-RF or IgA-RF.
  
  
  CONCLUSIONS
  Our findings suggest that there is no apparent clinical value in the detection of RA biomarkers in serum of IBD patients to help identify arthropathies.
authors.affiliation: Departments of aGastroenterology and Hepatology bRheumatology, Leiden University Medical Center, Leiden, The Netherlands cCenter for Inflammatory Bowel Diseases, University of California Los Angeles, Los Angeles dInova Diagnostics, San Diego, California, USA.
authors.forename: Sanne J H
authors.initials: SJ
authors.lastname: Van Erp
authors.forename: Marije K
authors.initials: MK
authors.lastname: Verheul
authors.forename: E W Nivine
authors.initials: EW
authors.lastname: Levarht
authors.forename: Johan J
authors.initials: JJ
authors.lastname: van der Reijden
authors.forename: Désirée
authors.initials: D
authors.lastname: van der Heijde
authors.forename: Floris A
authors.initials: FA
authors.lastname: van Gaalen
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Hommes
authors.forename: Gary L
authors.initials: GL
authors.lastname: Norman
authors.forename: Zakera
authors.initials: Z
authors.lastname: Shums
authors.forename: Michael
authors.initials: M
authors.lastname: Mahler
authors.forename: Hein W
authors.initials: HW
authors.lastname: Verspaget
authors.forename: Leendert A
authors.initials: LA
authors.lastname: Trouw
authors.forename: Andrea E
authors.initials: AE
authors.lastname: van der Meulen-de Jong
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D003424:Crohn Disease / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D007592:Joint Diseases / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D010456:Peptides, Cyclic / Q000276:immunology; D011237:Predictive Value of Tests; D012217:Rheumatoid Factor / Q000097:blood; D016036:Seroepidemiologic Studies; D012698:Serologic Tests; D012907:Smoking / Q000009:adverse effects / Q000097:blood / Q000276:immunology
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D007075:Immunoglobulin M; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor