Antineutrophil cytoplasmic antibodies in inflammatory bowel disease

PURPOSE: Perinuclear antineutrophil cytoplasmic antibodies have been found consistently in patients with ulcerative colitis; however, their pathogenetic and clinical role is still uncertain. In this study we tested the prevalence of perinuclear antineutrophil cytoplasmic antibodies in a large population of patients with ulcerative colitis and Crohn's disease, with particular attention to the possible correlation with clinical features. METHODS: Perinuclear antineutrophil cytoplasmic antibody reactivity was investigated with indirect immunofluorescence in 279 patients with ulcerative colitis, 110 patients with Crohn's disease, and 252 unrelated healthy subjects. RESULTS: Perinuclear antineutrophil cytoplasmic antibodies were found in 84 of 279 patients with ulcerative colitis (30 percent), 10 of 110 patients with Crohn's disease (9 percent), and 2 of 252 healthy subjects (<1 percent;P<0.001), respectively. Perinuclear antineutrophil cytoplasmic antibodies were significantly more frequent in patients with ulcerative colitis with higher relapse rate (43vs. 27 percent;P<0.002), and patients with Crohn's disease with colitis (27vs. 2.5 percent;P<0.0003). Perinuclear antineutrophil cytoplasmic antibodies were also significantly less frequent in patients with ulcerative colitis in remission (18vs. 34 percent;P<0.0025). CONCLUSIONS: In this study we confirm the relative specific of perinuclear antineutrophil cytoplasmic antibodies, either for ulcerative colitis or for Crohn's disease involving the colon. Perinuclear antineutrophil cytoplasmic antibodies were more frequently found in patients with ulcerative colitis with a more aggressive clinical behavior; however, their presence had a limited value in identifying homogeneous subgroups of patients in our population.