Low prevalence of antibodies to cyclic citrullinated peptide in patients with inflammatory bowel disease regardless of the presence of arthritis

Abstract

Crohn's disease (CD) and ulcerative colitis are chronic idiopathic inflammatory bowel diseases (IBD) often associated with axial and/or peripheral arthritis. Antibodies against cyclic citrullinated peptide (anti-CCP) are highly specific for rheumatoid arthritis, whereas their role in IBD remains unclear. Antitumour necrosis factor-alpha agents such as infliximab (IFX) may achieve and maintain remission of both IBD and rheumatoid arthritis; however, they may also trigger the development of various autoantibodies and autoimmune manifestations. This study aims at assessing the prevalence and clinical associations of anti-CCP antibodies in IBD patients with and without arthritis under either conventional treatment or IFX. Eighty four consecutive patients with CD [36 (42.8%) patients on IFX scheduled maintenance therapy (5 mg/kg intravenously every 8 weeks) and 48 (57.2%) on nonbiological treatment] and 50 patients with ulcerative colitis [20 (40%) patients on IFX (as described earlier) and 30 (60%) on nonbiological treatment] were evaluated. Among these 134 patients, 48 (35.8%) patients presented with concurrent arthritis. Ninety healthy individuals matched for sex and age with the IBD patients served as controls. Anti-CCP antibodies were detected using a commercially available enzyme-linked immunosorbent assay. Anti-CCP antibodies were detected in one CD patient on IFX maintenance therapy without evidence of arthritis. Neither the presence of arthritis nor treatment with IFX was associated with the presence of anti-CCP antibodies in IBD patients. Our data suggest that the prevalence of anti-CCP antibodies is very low in IBD patients regardless of the presence of arthritis and/or of IFX treatment.