Diagnostic Role and Clinical Association of ASCA and ANCA in Brazilian Patients with Inflammatory Bowel Disease

Abstract

Anti-Saccharomyces cerevisae antibody (ASCA) and perinuclear anti-neutrophil cytoplasmatic antibody (pANCA) remain the most well-established markers in inflammatory bowel disease (IBD), and both may be associated with disease phenotype. To determine the utility of ASCA and pANCA as markers in a Brazilian cohort of IBD patients. A total of 90 patients with ulcerative colitis (UC), 77 patients with Crohn's disease (CD), and 57 healthy individuals were included in the study. ASCA was determined by enzyme-linked immunosorbent assay (ELISA) and pANCA by immunofluorescence assay. In support of diagnosis of UC, the sensitivity and specificity of pANCA were 51% and 100%, respectively. ASCA (IgA or IgG isotypes) presented sensitivity of 62% and specificity of 93% for CD. The combination of ASCA negativity and pANCA positivity (ASCA-/pANCA+) displayed sensitivity of 43% and specificity of 100% for diagnosis to UC. In CD patients, ASCA+/pANCA- presented sensitivity and specificity of 57% and 93%, respectively. Additionally, ASCA positivity correlated with early age at disease onset and ileal location in CD patients. In UC patients, pANCA positivity was correlated with pancolitis or left colitis. The results evidenced that low sensitivity of ASCA and pANCA markers limits their use in IBD screening in the general population; however, their specificity may contribute to differentiation between CD and UC in IBD patients. Our study lends further support to the suggestion that serologic assessment identifies different subtypes of IBD.