Clinical significance of antibodies against neutrophils in patients with inflammatory bowel disease and primary sclerosing cholangitis.

The presence of perinuclear antibodies against neutrophils (pANCA) has been detected recently in sera of patients with inflammatory bowel disease and primary sclerosing cholangitis. In order to evaluate their clinical significance, sera from 126 patients with inflammatory bowel disease (80 Crohn's disease and 46 ulcerative colitis and 22 patients with primary sclerosing cholangitis were examined for pANCA by indirect immunofluorescence on liver sections and cytocentrifuge slides of neutrophils and by immunoblot. Perinuclear antibodies against neutrophils were found in 83% of patients with ulcerative colitis in 88% of patients with primary sclerosing cholangitis and inflammatory bowel disease, in 40% of patients with primary sclerosing cholangitis but without inflammatory bowel disease, and in 25% of patients with Crohn's disease using the immunofluorescence test. Titres of pANCA ranged from 1:10 to 1:1000 in ulcerative colitis and primary sclerosing cholangitis (median 1:100), whereas in Crohn's disease only four patients had titres of more than 1:10. The occurrence of pANCA did not correlate with clinical activity of Crohn's disease and primary sclerosing cholangitis whereas in ulcerative colitis high titres of pANCA were found mainly in active disease. Using an immunoblot system with sonified neutrophils as antigen, 82% of sera from patients with primary sclerosing cholangitis reacted with up to five different determinants, whereas only 12% of sera from patients with Crohn's disease and 11% of sera with ulcerative colitis detected one of the determinants, suggesting different antigens involved in pANCA reaction.