Skin prick testing does not reflect the presence of IgE against food allergens in adult eosinophilic esophagitis patients: a case study

Eosinophilic esophagitis (EoE) is a gastrointestinal disorder that is associated with allergic disease. Studies have described personal or family histories of asthma or allergic rhinitis in adult EoE patients [1,2] and a murine model has shown that aeroallergen sensitization may be responsible for the eosinophilic response in the esophagus [3]. Adult EoE patients display a broad range of reactivity to multiple allergens that spans both aero and food allergens. In one study, 81% of EoE patients had poly-reactivity to environmental allergens on skin prick testing (SPT) [4]. In light of such broad reactivity, we queried the reliability of SPT for determining actual IgE-mediated reactions in this patient population.Here, we compared the presence of specific IgE (determined by Western blots) to SPT in patients with biopsy-proven EoE. Blood was drawn from 12 EoE patients (demographics, EoE diagnostic criteria, allergic status and therapeutic treatments shown in Table 1) who were SPT positive (wheal size greater than 3 mm with surrounding erythema) to a minimum of one aero and one food allergen. None of the patients has a history of IgE-mediated food allergy and, instead had been determined as EoE patients due to a history of dysphagia, presence of endoscopic characteristics (e.g. rings, furrows, strictures) and pathological assessment of eosinophils in esophageal biopsy tissue that were greater than 25 per high powered field (hpf). Western blot-based screening for IgE-specific recognition of proteins in 5 aero and 5 food allergen extracts was undertaken and compared to the SPT outcomes towards the same extracts. In determining the positive or negative responses by Western blot, each extract was resolved, transferred and probed with patient specific serum. The presence of IgE specific to bands within the extracts was determined using HRP-labeled anti-human IgE. While several bands were observed, the results reflect the presence or absence of any recognition.The overall mat