P0646 PRESENCE OF ANTIBODIES TO SACCHAROMYCES CEREVISIAE (ASCA) CORRELATES WITH RISK OF ILEOCECAL RESECTION IN CHILDREN AND YOUNG ADULTS WITH CROHN???S DISEASE

Abstract

Introduction: Studies have demonstrated that ASCA antibodies will identify 40–80% of cases of Crohn’s disease (CD) in children and adults. However, it is less well established whether these antibodies identify a particular phenotype of disease, and if ASCA positive patients have a different clinical outcome. Methods: Clinical data and serum were obtained and banked between 1993 and 2000 from 83 children with Crohn’s disease (mean age 14.8 y, M:F 58:25), 54 with ulcerative colitis, and 63 controls. The serum was assayed for ASCA IgG and IgA, in a blinded fashion, with the laboratory being unaware of clinical diagnosis or history. In November 2003, charts of the 83 CD patients were reviewed for disease location data and surgical history. Significant differences in the frequencies of surgical procedures in ASCA positive and ASCA negative patients was established by the chi-square test. Results: Of the 83 CD patients, 36 (43%) were positive for ASCA IgA, ASCA IgG, or both markers. In contrast, 0 of 54 UC patients and 1 of 63 controls were positive for ASCA. Fourteen of 36 (39%) patients with positive ASCA underwent resection of the terminal ileum, TI and cecum, or TI and ascending colon. In contrast, only 11% of ASCA negative patients underwent such a resection (P<0.01). Nine of 17 patients with both ASCA IgA and IgG antibodies underwent resection. In thirteen of the 83 CD patients, serum was obtained after surgery (range 15–720 days after ileocecal resection). Of these thirteen, eleven patients had positive ASCA titers; two of these patients underwent a second ileal resection for restenosis. Conclusion: The presence of ASCA antibodies in pediatric Crohn’s disease correlates with increased risk of ilececal resection. Detection of this subset of children at initial presentation could potentially identify a group of patients at high risk for surgery, and who may warrant more intensive immunosuppressive therapy at disease onset. A prospective study by obtaining serum at initial diagnosis and monitoring the natural history of the disease is necessary to validate this observation.