Diagnostic Value of Perinuclear Antineutrophil Cytoplasmic Antibody and Anti-Saccharomyces Cerevisiae Antibody and their Relationship with inflammatory Bowel disease Characteristics in Iranian Patients

Introduction: inflammatory bowel disease (ibd) has two major groups: ulcerative colitis (uc) and crohn's disease (cd), diagnosed by routine invasive methods. in recent years, diagnostic value of immunologic tests including perinuclear antineutrophil cytoplasmic antibody (panca) and anti-saccharomyces cerevisiae antibody (asca) has been mentioned. these tests are supposed to be used as a diagnostic tool and also have some relationship with clinical characteristics of ibd.in this study; we investigated the diagnostic value of above tests and their relationship with ibd manifestations. methods: sera from 144 patients with ibd (113 with uc and 31 with cd) as cases and 176 patients with non-ibd rectorrhagia, flatulence, dyspepsia, gi cancers, ibs as controls were analyzed. patients' serum was assayed for asca by enzyme-linked immunosorbent assay (elisa) & for panca by indirect immunofluorescence assay (ifa). results: sensitivity, specificity, positive and negative predictive value of panca in uc were: 39%, 82%, 70%, and 56%. in patients with cd the above parameters were: 58%, 70%, 31%, and 87%, respectively. using both tests increased the specificity and positive predictive value in uc patients to 89% and 84% and in patients with cd to 80% and 46%. there was a significant difference between cd and uc groups in asca results (p= 0.002).uc patients with sclerosing cholangitis (p=0.003) and severe bleeding (p=0.004) were significantly positive for panca more than other uc patients, respectively. conclusion: we recommend panca & asca for differentiation of cd & uc, although it is not useful for screening. using both tests together improves the specificity and positive predictive value. positive panca results might be seen together with some complications like: sclerosing cholangitis & severe bleeding.