P012 - Atypical perinuclear anti-neutrophil cytoplasmic antibodies (x-ANCA) are associated with disease extent and arthralgia in patients with ulcerative colitis

Abstract

Introduction: Anti-neutrophil cytoplasmic antibodies (ANCA) recognize proteins from the primary granules and from other constituents of the neutrophil cytoplasm. There are 3 main staining patterns of ANCA: cytoplasmic (c-ANCA), perinuclear (p-ANCA) and atypical (x-ANCA). The prevalence of x-ANCA is from 59% to 84%. Aims and Methods: In order to determine the prevalence of c-ANCA, p-ANCA, x-ANCA patterns, and its association with disease extent, activity, medical treatment and extraintestinal manifestations (EIM) we studied 113 consecutive patients with ulcerative colitis (UC) evaluated from September 2006 to June 2008. The detection of ANCA was performed with indirect immunofluorescence using healthy human neutrophils fixed with ethanol and formalin. Slides were viewed using an epifluorescence microscope equipped with a 40× objective. Sera were examined independently for their immunofluorescence patterns by 3 diagnosis-blinded investigators. Serum endpoint titres 1:40 were considered positive. Colonoscopy was performed in a 30 day-period and C-reactive protein in a 7 day-period prior the clinical evaluation. The Mayo score activity index was used. Numerical variables were analyzed with t-test, and the categorical with chi2 or Fisher’s exact test. P value 0.05 was considered as statistically significant. Results: The mean age of the 113 patients (M = 58, F = 55) was 39.4±13.3 years, with 7.3±6.4 years disease evolution. Treatment for UC was based on aminosalicylates (96%), azathioprine (30%), and corticosteroids (29%). The prevalence of EIM was 47% (arthralgia 34%, arthritis 8%, primary sclerosing cholangitis 8%, uveitis 5%, pyoderma gangrenosum 4%, sacroiliitis 2%, ankylosing spondylitis 2% and others in 3%). The prevalence of x-ANCA+ was higher in those patients with arthralgia (52% vs 17%, P< 0.0001, OR 5.3, 95%CI 2.2 12.5). c-ANCA and p-ANCA patterns were not associated with EIM. The prevalence of pancolitis, distal colitis, left-sided colitis and extensive colitis were 64%, 28%, 4% and 4%, respectively. The prevalence of x-ANCA+ was higher in those patients with pancolitis (74% vs 56%, P= 0.034, OR 2.3, 95%CI 1 5). c-ANCA and p-ANCA patterns were not associated with disease extent. No association was observed with any of the ANCA patterns with disease activity, CRP, and medical treatment. Conclusion: The prevalence of c-ANCA, p-ANCA and x-ANCA in Mexican UC patients is 67%, 28%, and 48%, respectively. x-ANCA pattern was associated with pancolitis and the presence of arthralgia. P013 Different segmental transit times through the small bowel may affect diagnostic efficacy of wireless capsule endoscopy