Diagnostic value of perinuclear antineutrophil cytoplasmic antibodies and anti-Saccharomyces cerevisiae antibodies in inflammatory bowel disease

Objective To determine the prevalence of perinuelear antineutrophil cytoplasmic antibodies(pANCA)and anti-Saccharomyces eerevisiae antibodies(ASCA)in Chinese patients with inflammatory bowel disease(IBD),and to evaluate their diagnostic value in ulcerative colitis(UC)and Crohn's disease(CD).Methods One hundred and fifty-six well-characterized,unrelated,consecutive Chinese patients with IBD(126 with UC,30 with CD),and 60 healthy controls were included.Sera were assayed for pANCA and ASCA by the standardized indirect immunofluoreseenee technique.Results The prevalence of pANCA was 42.9% in UC patients and 46.7% in CD patients respectively,which was significantly higher than in healthy controls(5.0%).Sensitivity,specificity,positive and negative predictive value of the pANCA test were 43%,87%,93%,and 27%,respectively for UC.The combination of positive pANCA and negative ASCA was more accurate than the pANCA alone.Positive pANCA was associated with phenotype of severe UC and surgical procedures.ASCA test yielded sensitivity,specificity,positive and negative predictive value of 47%,95%,82%,and 78%,respectively for CD.The combination of negative pANCA and positive ASCA did not change these values significantly.Conclusion pANCA and ASCA were beneficial to the diagnosis of UC or CD diagnosis,and could be used to evaluate the clinical features of the diseases. Key words: Inflammatory bowel disease; Ulcerative colitis; Serology; Antibody