Objectives: A simple and reliable biomarker for Crohn disease (CD) would be a valuable clinical tool. We hypothesized that anti-Saccharomyces cerevisiae antibody (ASCA) may be present in the stool of patients with CD. Accordingly, we measured ASCA in the stool and serum of children and adolescents with known or suspected inflammatory bowel disease (IBD).
Methods: We included 114 patients 19 years or younger (73 boys) with IBD, including 83 patients with CD and 31 subjects without CD (28 with ulcerative colitis, and 3 patients with suspected IBD but without evidence of chronic inflammation at the time of their endoscopy and colonoscopy). Fecal and serum samples were analyzed using semiquantitative ASCA enzyme-linked immunoassays.
Results: Median ASCA levels were significantly elevated in the stool (P = 0.04) and serum (P = 0.0008) of patients with CD, when compared to levels observed in patients without CD. Fecal ASCA levels were similarly more elevated in patients with active CD, relative to levels observed in patients with active ulcerative colitis and acute colitis (P = 0.004). Among patients with CD, fecal and serum ASCA levels were higher (P = 0.01 and 0.01, respectively) in patients with more recently diagnosed disease.
Conclusions: Fecal ASCA levels are higher in patients with active and newly diagnosed disease. Data from the present study suggest that measurement of fecal ASCA levels could represent a novel noninvasive biomarker for use in evaluating patients with suspected or known IBD. Further studies are necessary to better define the value of fecal ASCA measurements in identifying CD and response to therapy in children and young adults.