Objectives: Perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA) and anti-Saccharomyces cerevisiae antibody (ASCA) have been proposed as markers for diagnosis and for subtyping of inflammatory bowel disease (IBD). The aim of this study was to investigate the association of p-ANCA and ASCA with a 10-year disease outcome in terms of cumulative rate of colectomy and relapse in a population-based European inception cohort of ulcerative colitis (UC) patients.
Methods: Serum samples from 432 consenting patients were analysed for p-ANCA and ASCA. The results were compared with the cumulative colectomy rate, relapsing disease and total number of relapses. We used multiple regression analyses adjusted for age, sex, residence, disease extent at diagnosis, smoking, familial IBD and drug treatment to study the relationship between serological values and disease course.
Results: The relapse rate was higher in the p-ANCA-positive patients: 82% (95% confidence interval [CI] 75-89%) compared with 67% (CI 62-72%, p=0.011) in the p-ANCA-negative patients. The risk of relapsing disease course was higher by a factor of 1.4 (CI 1.1-1.8, p=0.009) for p-ANCA-positive patients than for p-ANCA-negative patients, and the corresponding relative risk (RR) for the total number of relapses was 1.9 (CI 1.7-2.1, p<0.001). In ASCA-positive patients RR for the total number of relapses was 1.8 (CI 1.5-2.1, p<0.001). No significant association with colectomy rate was found for the presence of either p-ANCA or ASCA.
Conclusion: UC patients positive for p-ANCA and possibly for ASCA may have a more unfavourable long-term disease outcome in terms of relapse than UC patients without these markers.