Evaluation of the Combination of Fecal Lactoferrin and Fecal Anti-Saccharomyces Cerevesiae Antibodies To Detect Active Crohnʼs Disease

Abstract

Purpose: Prior studies of a quantitative assay for fecal lactoferrin showed high sensitivity and specificity in detecting intestinal inflammation in inflammatory bowel disease (IBD). Prior studies have indicated that an assay to detect fecal antibodies to Saccharomyces cerevesiae (ASCA) may be able to identify patients (pts) with Crohn's disease (CD). We sought to determine the diagnostic utility of a combined analysis to detect both fecal lactoferrin and fecal ASCA in pts evaluated at an IBD clinic. Methods: Between 3/04 and 10/06, pts with known or suspected CD who were undergoing evaluation with colonoscopy +/− small bowel x-ray were offered enrollment. Study subjects provided stool and serum samples within 72 hrs of colonoscopy and these were sent for analysis (quantitative enzyme-linked immunoassay [EIA] for fecal lactoferrin, qualitative EIA for both fecal and serum ASCA, and INOVA serum ASCA IgG). The reference standard was physician global assessment based on colonoscopy, biopsy, and (if available) small bowel x-ray (CT enterography or small bowel follow-through). Results: A total of 69 pts were enrolled (39 active CD, 12 inactive CD, 5 active ulcerative [UC] or indeterminate colitis[IC], and 13 non-IBD conditions). In the active CD group, 6 did not submit stool samples and 3 did not submit serum. Three non-IBD pts and 1 UC/IC pt did not submit serum. See table for comparisons of fecal lactoferrin and fecal/serum ASCA. Fecal lactoferrin was elevated in 33 of 38 pts with active IBD (87%) vs. 17% of inactive CD and 38% non-IBD miscellaneous. Fecal ASCA was detected in both active and inactive CD. Conclusion: Fecal lactoferrin distinguishes active IBD from inactive IBD and miscellaneous GI disorders. Fecal ASCA is present in the majority of CD pts and may aid in distinguishing CD from non-IBD; however, additional studies using a larger number of active UC pts are needed to evaluate the role of fecal ASCA to differentiate UC from CD.Table