ABSTRACTS: Satellite Symposia Abstracts
NON-IgE MEDIATED FOOD ALLERGY
Satellite Symposium organized by SHS
Non-IgE mediated gastrointestinal food allergies are generally thought to fall in the category of delayed, T-cell mediated disease. While the pathophysiology, diagnosis and treatment of disorders like celiac disease are well known, in contrast, the etiology, diagnosis and treatment of the eosinophilic disorders of the gastrointestinal tract has yet to be fully defined.
Celiac disease, or gluten sensitive enteropathy, is caused by an immune response triggered by wheat gluten (and its related products) resulting in a T-cell mediated inflammatory response of the small intestinal mucosa. The diagnosis is made endoscopically (via biopsy specimens) and the treatment consists of strict dietary avoidance of wheat gluten and all of its by products.
Eosinophilic disorders of the gastrointestinal tract are becoming increasingly recognized. The eosinophilic gastroenteropathies are an interesting, yet somewhat poorly defined set of disorders that range from isolated esophageal involvement to disease that encompasses the entire GI tract. First reported over 50 years ago, the clinical spectrum of these disorders was defined solely by various case reports. As these reports became more frequent, various aspects of the disease have been enhanced. Additional insight into the role of the eosinophil in health and disease has been identified regarding the defect that drives the inflammatory response in those afflicted.
Within the broad definition of the eosinophilic disorders lie at least three clinical entities that are defined in large part by the presence of abnormal numbers of eosinophils in various GI sites: eosinophilic proctocolitis (EoP), eosinophilic gastroenteritis (EoG), and eosinophilic esophagitis (EoE). EoG is difficult to diagnose not only because of the inability to obtain mucosal specimens of the small bowel but also because of the difficulty in differentiating normal from abnormal GI mucosa. Moreover, EOG is extremely difficult to treat. In contrast, EoP and EoE are much more common and are more easily diagnosed by endoscopic biopsy and respond to the removal of specific food antigens. While EoP is a well accepted entity, the diagnosis of EoE has recently been receiving a great deal of attention. Argument still exists regarding the etiology and treatment of EoE. Further studies are needed to effectively differentiate patients with eosinophilic esophagitis from those with reflux esophagitis. It would appear that significant esophageal eosinophilia (>20 per HPF) suggests a diagnosis of eosinophilic esophagitis, while <5 per HPF and an improvement with acid blockade suggests GERD.
This lecture will not only attempt to define these disorders, highlighting their similarities as well as their differences, but also will concentrate on the diagnosis and treatment of these disorders.