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

Summary 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 U niversity of N orth C arolina EoE P atient R egistry and B iobank. 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 kU A /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 kU A /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.