Delayed Anaphylaxis Involving IgE to Galactose-alpha-1,3-galactose

Abstract

Hypersensitivity in the allergic setting refers to immune reactions, stimulated by soluble antigens that can be rapidly progressing and, in the case of anaphylaxis, are occasionally fatal. As the number of known exposures associated with anaphylaxis is limited, identification of novel causative agents is important in facilitating both education and other allergen-specific approaches that are crucial to long-term risk management. Within the last 10 years, several seemingly separate observations were recognized to be related, all of which resulted from the development of antibodies to a carbohydrate moiety on proteins where exposure differed from airborne allergens but which were nevertheless capable of producing anaphylactic and hypersensitivity reactions. Our recent work has identified these responses as being due to a novel IgE antibody directed against a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal). This review will present the history and biology of alpha-gal and discuss our current approach to management of the mammalian meat allergy and delayed anaphylaxis.

Figure 1

Percent of subjects (n=311) identified with delayed reactions to red meat and positive IgE Ab to alpha-gal with urticaria or angioedema (red bars) or anaphylaxis (blue bars) analyzed for time of presentation (A) and age of onset of first reaction attributable to mammalian meat allergy (B).

Figure 1

Percent of subjects (n=311) identified with delayed reactions to red meat and positive IgE Ab to alpha-gal with urticaria or angioedema (red bars) or anaphylaxis (blue bars) analyzed for time of presentation (A) and age of onset of first reaction attributable to mammalian meat allergy (B).