ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES (ANCA) IN INFLAMMATORY BOWEL-DISEASE - CHARACTERIZATION AND CLINICAL CORRELATES

ANCA were detected by indirect immunofluorescence in 34 out of 67 pati ents with ulcerative colitis (UC, 51%) and in 14 out of 35 patients wi th Crohn's disease (CD, 40%). All but one ANCA-positive sera produced a perinuclear pattern of fluorescence (P-ANCA) on ethanol-fixed neutro phils. On paraformaldehyde-fixed neutrophils 76% of P-ANCA-positive se ra in UC and 50% of P-ANCA-positive sera in CD produced cytoplasmic fl uorescence, indicating that, indeed, cytoplasmic antigens are recogniz ed by a considerable number of these sera. By Western blot analysis us ing whole neutrophil extract as a substrate 46% of sera from patients with UC and 32% of sera from patients with CD showed reactivity with e ither lactoferrin, polypeptides occurring as a doublet of 66/67 kD mol . wt, or polypeptides occurring as a doublet of 63/54 kD mel. wt, resp ectively. Identical patterns of reactivity have been observed among P- ANCA-positive sera from patients with autoimmune liver disease and rhe umatoid arthritis. These data suggest that ANCA of restricted specific ities are not specific for inflammatory bowel disease (IBD), but are p resent in diverse conditions characterized by chronic idiopathic infla mmation.