IgE Sensitization to the Food Allergen Galactose-α-1,3-Galactose is Associated with Coronary Atherosclerosis

RATIONALE: The oligosaccharide galactose-α-1,3-galactose (α-Gal) is the target of IgE in cases of delayed anaphylaxis to red meat. Sensitization to α-Gal is more prevalent in the community than cases of delayed anaphylaxis and is particularly common in the southeastern United States, a region with high incidence of cardiovascular disease. Additionally, recent reports have linked mast cells and elevated total IgE with coronary artery disease. We sought to test the hypothesis that sensitization to α-Gal represents an independent risk factor for coronary atherosclerosis.

METHODS: Total IgE and specific IgE to α-Gal (cut-off ≥0.1kU/L) were assayed on sera from 118 subjects who had symptoms suggestive of possible coronary heart disease and underwent coronary imaging with intravascular ultrasound (IVUS).

RESULTS: Of the cohort 26% had detectable titers of IgE to α-Gal. There were no significant differences in traditional risk factors such as obesity, hypertension, diabetes or cholesterol levels in sensitized and non-sensitized subjects. Atheroma burden was higher in the sensitized group. Focusing on subjects less than 65 years old (n=70) the association was stronger, and lesions in the sensitized group were more calcified and necrotic but less fibrous. Regression analysis accounting for age, diabetes, HTN and statin use supported a significant association between between α-Gal sensitization and atheroma burden (p=0.009).

CONCLUSIONS: α-Gal is an oligosaccharide that is present in mammalian foods, i.e – red meat and dairy, which are common in a Western diet and have been associated with coronary artery disease. IgE sensitization to α-Gal represents a novel, and potentially modifiable, risk factor for coronary atherosclerosis.