PANCA REPRESENTS A CROSS-REACTIVITY TO ENTERIC BACTERIAL-ANTIGENS

pANCA (perinuclear antineutrophil cytoplasmic antibodies) occur at a h igh frequency in patients with ulcerative colitis. The purpose of this study was to investigate the frequency of pANCA in different mouse mo dels of colitis and to determine whether there is any cross-react of p ANCA with bacterial antigens. Sera from 146 colitic mice and controls and from 30 patients with ulcerative colitis were tested for the prese nce of pANCA by indirect immunofluorescence with or without prior abso rption with homogenized murine cecal bacteria. pANCA was found in 24 o f 36 IL10-/- mice. In contrast to the human pANCA, both nuclear and pe rinuclear staining was found. Absorption of either human or mouse pANC A-positive sera with enteric bacterial antigens greatly reduced or abo lished the specific perinuclear staining of PANCA. We conclude that pA NCA occurs not only in humans but also in IL10-/- mice with colitis an d likely represents a cross-reactivity with enteric bacterial antigens .