Objectives: Studies have suggested that antineutrophil cytoplasmic antibodies (ANCA), known as a useful diagnostic marker in patients with ulcerative colitis (UC), may have a genetic basis, particularly in association with HLA class II genes. Because most studies examining the role of ANCA in UC have been performed in ethnically undefined populations, we have analyzed ANCA status in an ethnically distinct group of patients with UC.
Methods: Serum samples from 24 Korean patients with a known diagnosis of UC and 58 healthy Koreans were examined for the presence of ANCA, using a fixed neutrophil enzyme-linked immunosorbent assay. ANCA-binding patterns were examined by indirect immunofluorescence.
Results: The incidence of ANCA in 83.3% of Korean patients with UC was significantly higher than in controls (p < 0.0001). The mean binding level at a 1:100 dilution and the titer of ANCA were significantly higher in patients with UC than in controls. Among UC patients with ANCA, there was also a high incidence of perinuclear binding pattern. In contrast, there was no relationship between ANCA and age of patients, duration, activity, or extent of disease.
Conclusions: High sensitivity and specificity of ANCA in an ethnically distinct group of patients with UC show that ANCA expression may not be ethnically determined, and they confirm the utility of ANCA as a useful diagnostic indicator of UC in an ethnically diverse groups of patients.