Anti-neutrophil cytoplasmic antibodies (ANCA) directed against bactericidal/permeability increasing protein (BPI): a new seromarker for inflammatory bowel disease and associated disorders.

It was our purpose to determine the immunodiagnostic value of ANCA directed against BPI in diseases known to he associated with ANCA. such as ANCA-associated vasculitides, inflammatory bowel disease (IBD) and the associated condition primary selerosing cholangitis. The immunoreactivity of recombinant BP1 (rBP1) was established in order to an ELISA specific for rBPI. By means of this assay. BPI-ANCA were assessed in sent of 178 patients with IBD or the associated disorder primary selerosing cholangitis. 112 patients with ANCA-associated vasculitides, arid in sera ol 182 disease and 140 healthy controls. BPI-ANCA were found to he closely associated with IBD and primary selerosing cholangitis (34% and 44% of ANCA-positive sera respectively). By contrast, BPI-ANCA positivity was low t<10%) in the double-negative sera of patients with ANCA-associated vasculitides and in disease and healthy controls. BP1-ANCA appear to constitute an important marker for IBD and primary selerosing cholangitis, but not for the ANCA-associated vasculitides. [ABSTRACT FROM AUTHOR]