Delayed anaphylaxis, angioedema, or urticaria after consumption of red meat in patients with IgE antibodies specific for galactose-alpha-1,3-galactose.
BACKGROUND
Carbohydrate moieties are frequently encountered in food and can elicit IgE responses, the clinical significance of which has been unclear. Recent work, however, has shown that IgE antibodies to galactose-alpha-1,3-galactose (alpha-gal), a carbohydrate commonly expressed on nonprimate mammalian proteins, are capable of eliciting serious, even fatal, reactions.


OBJECTIVE
We sought to determine whether IgE antibodies to alpha-gal are present in sera from patients who report anaphylaxis or urticaria after eating beef, pork, or lamb.


METHODS
Detailed histories were taken from patients presenting to the University of Virginia Allergy Clinic. Skin prick tests (SPTs), intradermal skin tests, and serum IgE antibody analysis were performed for common indoor, outdoor, and food allergens.


RESULTS
Twenty-four patients with IgE antibodies to alpha-gal were identified. These patients described a similar history of anaphylaxis or urticaria 3 to 6 hours after the ingestion of meat and reported fewer or no episodes when following an avoidance diet. SPTs to mammalian meat produced wheals of usually less than 4 mm, whereas intradermal or fresh-food SPTs provided larger and more consistent wheal responses. CAP-RAST testing revealed specific IgE antibodies to beef, pork, lamb, cow's milk, cat, and dog but not turkey, chicken, or fish. Absorption experiments indicated that this pattern of sensitivity was explained by an IgE antibody specific for alpha-gal.


CONCLUSIONS
We report a novel and severe food allergy related to IgE antibodies to the carbohydrate epitope alpha-gal. These patients experience delayed symptoms of anaphylaxis, angioedema, or urticaria associated with eating beef, pork, or lamb.
Commins
Scott P
SP
Asthma and Allergic Diseases Center, University of Virginia Health System, Charlottesville, VA, USA.
Satinover
Shama M
SM
Hosen
Jacob
J
Mozena
Jonathan
J
Borish
Larry
L
Lewis
Barrett D
BD
Woodfolk
Judith A
JA
Platts-Mills
Thomas A E
TA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens / Q000276:immunology; D000707:Anaphylaxis / Q000209:etiology / Q000276:immunology; D000799:Angioedema / Q000209:etiology / Q000276:immunology; D000818:Animals; D002417:Cattle; D004187:Disaccharides / Q000276:immunology*; D005260:Female; D005512:Food Hypersensitivity / Q000209:etiology / Q000276:immunology*; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000209:etiology / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008460:Meat / Q000009:adverse effects*; D008875:Middle Aged; D012756:Sheep; D012882:Skin Tests; D013552:Swine; D014581:Urticaria / Q000209:etiology / Q000276:immunology; D055815:Young Adult
D000485:Allergens; D004187:Disaccharides; C055075:galactosyl-(1-3)galactose; D007073:Immunoglobulin E