Anti-Saccharomyces cerevisiae mannan antibodies and antineutrophil cytoplasmic autoantibodies in Greek patients with inflammatory bowel disease

OBJECTIVES: The combined measurement of perinuclear antineutrophil cytoplas mic autoantibodies (pANCA) and anti-Saccharomyces cerevisiae mannan antibod ies (ASCA) has recently been suggested as a valuable diagnostic approach in inflammatory bowel disease (IBD). The aim of this study was to assess the value of detecting pANCA and ASCA in the differentiation between ulcerative colitis (UC) and Crohn's disease (CD) in a Greek population with IBD. METHODS: Sera were collected from 157 patients with IBD (97 with UC, 56 wit h CD, and four with indeterminate colitis) and 150 healthy controls. Determ ination of pANCA was performed by a standard indirect immunofluorescence te chnique on ethanol-fixed granulocytes and ASCA by an ELISA assay. RESULTS: In patients with UC, sensitivity, specificity, positive predictive value, and negative predictive value of the pANCA test was 67%, 84%, 93%, and 46% respectively. These values did not change significantly when the co mbination of positive pANCA and negative ASCA was used. ASCA test in diagno sing CD yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 39%, 89%, 54%, and 81%. The combination of pAN CA negative and ASCA positive increased the positive predictive value to 77 % and it was associated with small bowel disease. CONCLUSIONS: A positive pANCA test in Greek patients has a diagnostic value in confirming a diagnosis of UC. Measurement of pANCA and ASCA together ha s a rather limited value in the differential diagnosis between UC and CD bu t may be of help in studying disease heterogeneity. (C) 2001 by Am. Cell. o f Gastroenterology.