Limited Role of Allergy Testing in Patients With Eosinophilic Gastrointestinal Disorders

Norihisa Ishimura; Kenji Furuta; Shuichi Sato; Shunji Ishihara; Yoshikazu Kinoshita

Disclosures

J Gastroenterol Hepatol. 2013;28(8):1306-1313. 

In This Article

Abstract and Introduction

Abstract

Background and Aim Allergies have been implicated in the pathogenesis of eosinophilic gastrointestinal disorders, although it remains unknown what type of allergen is closely associated with their development. The aim of this study is to investigate the possible involvement of food and/or aeroallergen factors in eosinophilic gastrointestinal disorders.

Methods Eighteen patients with eosinophilic esophagitis (EoE), 23 with eosinophilic gastroenteritis (EGE), and 28 healthy volunteers were enrolled. The levels of total serum immunoglobulin E (IgE) and 33 different allergen-specific IgE antibodies, including those for six foods used in a standard EoE elimination diet, were determined in each subject. Serum antigen-specific IgE levels were measured using a chemiluminescence enzyme immunoassay with a multiple antigen simultaneous test 33 (MAST33). The expression patterns of specific antigens were compared among the groups.

Results The mean level of total IgE antibodies was significantly higher in patients with EGE (553.6 ± 115.3 IU/mL) than the healthy volunteers (230.6 ± 87.1 IU/mL). Two thirds of all subjects had sensitivity to at least one inhaled antigen. In positive cases, allergies against multiple antigens were more frequently seen in the EoE and EGE patients. Japanese cedar and dust mite aeroallergens were more prevalent than food antigens.

Conclusions Consistent with higher levels of serum total IgE antibodies, patients with EoE and EGE were frequently sensitized to several different allergens. Reactions to aeroallergens were more prevalent in these groups, although no particular antigen causing EoE and/or EGE was detected by measuring serum antigen-specific IgE antibodies.

Introduction

Eosinophilic gastrointestinal disorders (EGID) are characterized by eosinophilic infiltration and inflammation of the gastrointestinal tract with various gastrointestinal manifestations, and subdivided into eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE).[1–3] The incidence and prevalence of EoE are rapidly increasing, especially in Western countries,[4] whereas those of EGE remain obscure.[5] The clinical characteristics of EoE patients in Western countries have been extensively investigated,[6,7] while those of EGE patients remain to be fully clarified. EoE cases are frequently associated with atopic disorders, as affected individuals often have coexistent asthma, allergic rhinitis, atopic dermatitis, and various food or drug allergies.[8,9] Of note, recent studies showed that a six-food elimination diet significantly improved symptoms, and reduced endoscopic and histopathologic features of EoE not only in pediatric patients[10] but also in adults,[11] suggesting the importance of food allergies in the pathogenesis of EoE in both pediatric and adult patients.

There are two different types of reactions regarding food allergies: immunoglobulin E (IgE)-mediated immediate and non-IgE-mediated chronic reactions. Mast cells and IgE antibodies play important roles in immediate reactions. Allergic proteins are bound by two molecules of specific IgE antibodies on the surfaces of mast cells, and high affinity IgE receptors activate signal transduction pathways, leading to the release of histamine, leukotrienes, and prostaglandins. Since EGID are non-immediate chronic-type reactions, they appear to be mainly caused by non-IgE-mediated allergic reactions. However, Vicario et al. recently demonstrated that local immunoglobulin class switching to IgE antibodies and their production in the esophageal mucosa of EoE patients comprise a significant mechanism contributing to disease pathogenesis.[12] Therefore, the relationships of antigen-specific IgE with pathogenic mechanisms of EGID remain unclear.

Two general types of allergy testing are commonly used for identifying specific allergens in patients with atopic disorders. The first, which includes skin prick and patch testing, relies upon a skin reaction to a specific allergen.[13] The second type, in which blood is used, utilizes tests for the presence of IgE antibodies directed against allergens.[14,15] In the latter, a patient serum sample is incubated with a large number of allergens, and the results can easily demonstrate a type 1 immediate allergic reaction. Information regarding food or aeroallergen reactions identified by allergy testing is helpful for diagnosis and treatment of EoE, especially in pediatric patients.[13,16] However, those reactions in adult patients with EoE are not as well understood as in those with EGE. Moreover, it remains unknown which type of allergen is closely associated with the pathogenesis of EGID.

In the present study, we performed allergy testing using serum antigen-specific IgE antibodies, including six foods used in a standard elimination diet for EoE, mainly in adult patients with EoE and EGE, as well as healthy individuals, for examining the possible roles of food and aeroallergen reactions in the pathogenesis of EGID.

processing....