title: Detection of anti-neutrophil cytoplasmic antibodies under actual clinical testing conditions.
abstract: Anti-neutrophil cytoplasmic antibodies (ANCA) are a useful diagnostic tool for Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA). To maximize diagnostic utility, current guidelines recommend dual testing by standard indirect immunofluorescence (IIF) and target antigen-specific assays. Most published data come from specialized research laboratories, not reflecting the performance of assays under routine clinical conditions. Therefore, we compared the performance of standard IIF, PR3-, and MPO-ANCA-specific direct ELISA, and a PR3-ANCA-specific capture ELISA used alone and in combination under routine clinical conditions. Consecutive serum samples (615) submitted for routine ANCA testing over a 10-month period were assayed. Diagnoses were WG/MPA (n = 86), other autoimmune disease (n = 118), and various others (n = 411). The combination of PR3-ANCA and MPO-ANCA ELISA had the highest sensitivity (72.1%), and C-ANCA determination using IIF, the highest specificity (99.6%). While maintaining maximal diagnostic accuracy, significant labor savings are achieved by screening for WG/MPA by ELISA followed by confirmatory IIF.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Russell
authors.forename: Elaine
authors.initials: E
authors.lastname: Wiegert
authors.forename: Darrell R
authors.initials: DR
authors.lastname: Schroeder
authors.forename: Henry A
authors.initials: HA
authors.lastname: Homburger
authors.forename: Ulrich
authors.initials: U
authors.lastname: Specks
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015267:Churg-Strauss Syndrome / Q000175:diagnosis / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods / Q000706:statistics & numerical data; D014890:Granulomatosis with Polyangiitis / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic