Objectives: The combined measurement of perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) and anti-Saccharomyces cerevisiae mannan antibodies (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 with CD, and four with indeterminate colitis) and 150 healthy controls. Determination of pANCA was performed by a standard indirect immunofluorescence technique 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 combination of positive pANCA and negative ASCA was used. ASCA test in diagnosing CD yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 39%, 89%, 54%, and 81%. The combination of pANCA 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 has a rather limited value in the differential diagnosis between UC and CD but may be of help in studying disease heterogeneity.