Abstract

The detection of a nuclear anti-neutrophil antibody in patients with primary sclerosing cholangitis (PSC), using an immunoperoxidase technique, was recently reported by us. Subsequently, detection of a cytoplasmic anti-neutrophil antibody was reported by others, using a two stage procedure of enzyme linked immunosorbent assay followed by an immunofluorescent method. Detection of cytoplasmic anti-neutrophil antibody in PSC, which, in contrast to that two stage procedure, uses a simple one step immuno-alkaline phosphatase method is now reported. Normal human neutrophils were cytocentrifuged, ethanol fixed, and then incubated with coded patients' sera. Rabbit anti-human immunoglobulin conjugated with alkaline phosphatase was used to detect the bound antibody. Fast red was used to visualise the reaction. Twenty three of 30 (77%) PSC patients showed positive granular cytoplasmic staining (with some perinuclear accentuation) with a network of cytoplasmic filaments. Fifteen of 45 (33%) ulcerative colitis patients and 1 of 3 chronic active hepatitis patients showed similar staining. Thirty five of 152 patients with ulcerative colitis, chronic active hepatitis, and a variety of other liver diseases showed a different pattern of cytoplasmic labelling, with no surrounding filaments. Seventy nine patients, including seven PSC patients and 33 normal subjects, were negative. In comparison, 86% of PSC patients, 57% of patients with primary biliary cirrhosis, 50% of normal subjects, and well over 60% of patients with ulcerative colitis, Crohn's disease, alcoholic liver disease, and chronic active hepatitis were positive using the one step immunofluorescent method. This method is more specific for PSC than those described in recent reports and may be of diagnostic importance.