title: Anti-neutrophil cytoplasmic antibodies in inflammatory bowel disease with special attention for IgA-class antibodies.
abstract: Perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA) of the IgG class have been reported in inflammatory bowel disease, mainly in ulcerative colitis. Since this disease affects the gastrointestinal tract, we determined whether IgA class ANCA were present in inflammatory bowel disease. We used an indirect immunofluorescence assay for IgG and IgA ANCA testing. Sera from 34 patients with Crohn's disease and 29 patients with ulcerative colitis were collected together with clinical and laboratory data. We found IgA class ANCA of a perinuclear type in 52% of patients with ulcerative colitis and in 9% of Crohn's disease patients. There was a significant association between the presence of IgA ANCA and the occurrence of blood in the feces in the ulcerative colitis group (P = 0.03). IgG ANCA was found in 56% of patients with ulcerative colitis and in 7% of patients with Crohn's disease. Because of partial overlap between IgG and IgA ANCA positivity, the sensitivity of ANCA testing in ulcerative colitis increased from 56% up to 78% by combining IgG and IgA assays. In conclusion, IgA ANCA occurs with a high prevalence in ulcerative colitis. Moreover there is a possible relationship between IgA ANCA and disease activity in ulcerative colitis.
authors.affiliation: University of Antwerp, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Gigase
authors.forename: L S
authors.initials: LS
authors.lastname: De Clerck
authors.forename: K A
authors.initials: KA
authors.lastname: Van Cotthem
authors.forename: C H
authors.initials: CH
authors.lastname: Bridts
authors.forename: W J
authors.initials: WJ
authors.lastname: Stevens
authors.forename: M
authors.initials: M
authors.lastname: Van Outryve
authors.forename: P A
authors.initials: PA
authors.lastname: Pelckmans
mesh_terms: D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D015212:Inflammatory Bowel Diseases / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D007070:Immunoglobulin A; D002097:C-Reactive Protein