Fecal antibody subtypes predict disease activity in pediatric patients with Crohn disease

Thesis (M.A.)--Boston UniversityBackground: Pediatric patients with Inflammatory Bowel Disease (IBD) often receive a delayed diagnosis due to the presence of a variety of nonspecific gastrointestinal and extra-intestinal symptoms. As a result, patients are at an increased risk for growth and pubertal delays, as well as other developmental problems. Therefore, there is great need for the development of a noninvasive, inexpensive, reliable, and objective method of diagnosing and monitoring this disease. Fecal biomarkers have the potential for meeting all of these requirements, and are thought to have increased value because they may better reflect the interaction between luminal bacteria and the mucosal immune system than serum biomarkers. Antibodies in the serum that are directed against Saccharomyces cerevisiae (ASCA) have been identified in patients diagnosed with Crohn disease (CD). It has been suggested that the presence and levels of ASCA, as well as other serum antibodies, may be able to predict the severity, duration, complications, and response to treatments and therapies in patients with IBD. Data from an unpublished study carried out at the Center for Inflammatory Bowel Disease at Boston Children’s Hospital shows that fecal ASCA is detectable in the stool of patients with CD, and that ASCA levels change over time and in response to disease activity. Therefore, the goal of the present study is to further explore the relationship between fecal ASCA and disease activity in patients with CD and to discern if differences in ASCA immunoglobulin subtypes reflect disease activity in pediatric patients with CD. Methods: Stool from 21 patients with Crohn disease, which were tested to be positive for ASCA, were analyzed in this study. Of the 21 patients, 13 were categorized as having active disease, while 8 were categorized as having inactive disease. ASCA immunoglobulin (Ig) testing and fecal lactoferrin (FLA) testing were performed on these samples. Marker values were compared between the active and inactive disease groups. [TRUNCATED