High rate of galactose-alpha-1,3-galactose sensitization in both eosinophilic esophagitis and patients undergoing upper endoscopy.

Eosinophilic esophagitis (EoE) is an antigen/allergy-mediated chronic inflammatory condition. The rapid rise in the number of cases of EoE suggests an as-yet undiscovered environmental trigger. This study tested the hypothesis that immunoglobulin E (IgE) to galactose-alpha-1,3-galactose (alpha-gal), a newly recognized sensitization induced by a tick bite that causes mammalian meat allergy, is a risk factor for EoE. We conducted a case-control study using prospectively collected and stored samples in the University of North Carolina EoE Patient Registry and Biobank. Serum from 50 subjects with a new diagnosis of EoE and 50 non-EoE subjects (either with gastroesophageal reflux disease or dysphagia from non-EoE etiologies) was tested for alpha-gal-specific IgE using an ImmunoCAP-based method. Specific IgE > 0.35 kUA /L was considered a positive result. Subjects with EoE were a mean of 35 years old, 68% were male, and 94% were white. Non-EoE controls were a mean of 42 years, 50% were male, and 78% were white. A total of 22 (22%) subjects overall had alpha-gal-specific IgE > 0.35 kUA /L. Of the EoE cases, 12 (24%) were positive, and of the non-EoE controls, 10 (20%) were positive (p=0.63). Neither the proportion sensitized nor the absolute values differed between EoE and non-EoE subjects. We found a similar but high rate of alpha-gal sensitization in patients with EoE as found in non-EoE controls who were undergoing endoscopy. While our data do not support alpha-gal sensitization as a risk factor for EoE, the high rates of sensitization observed in patients undergoing upper endoscopy for symptoms of esophageal dysfunction is a new finding.