Serologic testing for inflammatory bowel disease

Objectives: To determine the accuracy of anti-neutrophil cytoplasmic antibo dies (ANCAs) and anti-Saccharomyces cerevisiae antibodies (ASCA) in disting uish;ng patients with inflammatory bowel disease from patients with other d isorders, seen in a pediatric gastroenterology clinic setting, and in disti nguishing ulcerative colitis (UC) from Crohn's disease (CD). Study design: Serum samples from 120 children with new or established diagn oses of UC (n = 25) or CD (n = 20) and control children (n = 74) were analy zed in blinded fashion for the presence of IgG ANCAs and IgA and IgG ASCA. Results: The highest sensitivity for detecting inflammatory bowel disease, 71%, was achieved by using ANCAs and ASCA together. The best test for uc wa s ANCAs, which had a sensitivity of 80%. However, the ANCA pattern characte ristic of UC, perinuclear ANCAs eliminated by DNAse, had a sensitivity of 6 0%. High-titer ANCAs were specific for UC, whereas ASCA were specific for C D. Conclusions: Testing for ANCAs and ASCA together did not achieve sensitivit y necessary for population screening. However, ANCAs and ASCA may be helpfu l in evaluating children suspected of having inflammatory bowel disease and in distinguishing UC from CD.