Antineutrophil and Pancreatic Autoantibodies in First-Degree Relatives of Patients with Inflammatory Bowel Disease

BACKGROUND: Perinuclear antineutrophil antibodies (P-ANCA) are found in ulcerative colitis, and autoantibodies against exocrine pancreas (PAB) in Crohn's disease. Their potential role as genetic or pathophysiologic factors is unclear. METHODS: In 61 patients with ulcerative colitis, 76 patients with Crohn's disease, 101 first-degree relatives of patients with ulcerative colitis, 105 first-degree relatives of Crohn's disease patients, and 56 healthy unrelated controls autoantibodies were detected by indirect immunofluorescence. RESULTS: Forty-six per cent of patients with ulcerative colitis (28 of 61) and 38% of patients with Crohn's disease (29 of 76) were P-ANCA- and PAB-positive, respectively. In relatives of patients with ulcerative colitis P-ANCA were found in 3% (3 of 101), and in relatives of Crohn's disease patients PAB were detected in 4% (4 of 105), which is not significantly different from the occurrence in the healthy controls. CONCLUSIONS: The frequency of P-ANCA and PAB does not suggest a role as genetic markers for inflammatory bowel disease.