Meat allergy and allergens

Abstract

IgE-mediated hypersensitivity to ingested animal products, including both mammalian and avian sources, is increasingly appreciated as an important form of food allergy. Traditionally described largely in children, it is now clear that allergy to meat (and animal viscera) impacts both children and adults and represents a heterogeneous group of allergic disorders with multiple distinct syndromes. The recognition of entities such as pork-cat syndrome and delayed anaphylaxis to red meat, i.e- the α-Gal syndrome, have shed light on fundamental, and in some cases newly appreciated, features of allergic disease. These include insights into routes of exposure and mechanisms of sensitization, as well as the realization that IgE-mediated reactions can be delayed by several hours. Here we review mammalian and avian meat allergy with an emphasis on the molecular allergens and pathways that contribute to disease, as well as the role of in vitro IgE testing in diagnosis and management.

Keywords: Albumin; Alpha-Gal; Meat allergy; Pork-Cat.

Figure 1.

Comparison of structure of α-Gal and blood Group B antigen

Figure 2.

Correlation of sIgE to cetuximab (IU/mL) and beef thyroglobulin (IU/mL) in 34 subjects with α-Gal syndrome and 11 control subjects. Modeled with linear regression (p<0.001).

Figure 3.

Cetuximab is a chimeric IgG1 monoclonal antibody produced in a mouse cell line (SP2/0). Demonstrated here are representative bi- and tri-antennary glycans with terminal α-Gal epitopes that are often present on the variable region of the heavy chain (V_H). Other glycans with α-Gal are also possible. Glycans are very common on the constant heavy chain domain 2 (C_H2) but only rarely do these have terminal α-Gal epitopes. When present on the Fc α-Gal epitopes are most frequently mono-antennary. Anti-Gal IgE can bind to α-Gal epitopes on Fab, but not Fc because the tertiary structure of the antibody precludes exposure of these epitopes[, 56].