A New Type of Perinuclear Anti-Neutrophil Cytoplasmic Antibody (p-ANCA) in Active Ulcerative Colitis but not in Crohn's Disease

Sera of 64 patients with chronic inflammatory bowel disease (IBD) were screened for antibodies against neutrophil cytoplasmic antigens (ANCA) using an indirect immunofluorescence technique on ethanol-fixed human neutrophil granulocytes.20 of 34 sera (59 %) from patients with ulcerative colitis (UC) produced a fine-granular and perinuclear ANCA staining pattern (p-ANCA) clearly different from the typical diffuse and granular cytoplasmic ANCA fluorescence (c-ANCA, synonym ACPA) seen in active Wegener's granulomatosis (WG).The majority of the 20 p-ANCA positive UC patients had a high inflammatory disease activity.Among the 14 p-ANCA negative UC patients nine were without steroids; five of them had active disease, two were inactive and two had previously undergone colectomy.The remaining five patients still had active disease but received steroids for more than 4 weeks.Only 3 of the 30 sera from patients with Crohn's disease (CD) showed positive p-ANCA reactions. To narrow the specificity of the p-ANCA reaction all 64 sera were tested by ELISA for antibodies against anti-proteinase-3 (WG specific) and on HEp-2 cells for antinuclear (ANA) and anticytoplasmic antibodies.Ten p-ANCA positive UC sera were also tested in a myeloperoxidase ELISA.Only one UC serum reacted positively in the proteinase-3-ELISA and another one produced a weakly positive anti-nucleolar ANA fluorescence on HEp-2 cells.None of the tested sera reacted with myeloperoxidase suggesting that the p-ANCA staining pattern of granulocytes is not restricted to anti- myeloperoxidase antibodies as reported in the literature. These preliminary results suggest that sera from patients with active UC contain a new type of perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA) and that ANCA screening may be of value in differentiating active UC from CD.