Diagnostic value of antineutrophil cytoplasmic antibodies and anti-Saccharomyces cerevisiae antibody in Iranian patients with inflammatory bowel disease.

BACKGROUND AND STUDY AIMS: Perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) and anti-Saccharomyces Cerevisiae antibody (ASCA) are potential markers for diagnosis of inflammatory bowel disease (IBD). The aim of the present study was to evaluate the diagnostic value of pANCA and ASCA in Iranian patients with IBD.

PATIENTS AND METHODS: Serum samples were collected from 144 patients with IBD (113 ulcerative colitis and 31 Crohn's disease) and patients with non-IBD problems were assayed for ASCA by Enzyme-Linked Immunosorbent Assay (ELISA) and for pANCA by indirect immunofluorescence assay.

RESULTS: Sensitivity and specificity of pANCA in UC were 39.8% and 82.1%, respectively. For CD, pASCA test provided the sensitivity of 58% and specificity of 70%. A combination of pANCA+/ASCA- for diagnosis of UC showed a sensitivity of 31.9% and specificity of 89.1%. In addition the combination of pANCA-/ASCA+ showed a sensitivity of 35.5% and specificity of 79.8% for diagnosis of CD.

CONCLUSION: Due to low sensitivity of pANCA and ASCA alone or in combination, they are not valuable serological markers for diagnosis of UC or CD.