IgE antibody response to vertebrate meat proteins including tropomyosin

Background: Although meat is a main source of proteins in western diets, li ttle information is available regarding allergy to vertebrate meats or the allergens implicated in these reactions. Objective: To evaluate the in vitro IgE antibody response to different vert ebrate meats in suspected meat-allergic subjects, as well as the possible r ole of tropomyosin in meat allergy and to analyze the cross-reactivity betw een vertebrate meats and the effect of heating on the IgE-binding to meat p roteins. Methods: Fifty-seven sera from suspected meat-allergic subjects were tested by grid blot to extracts of beef, lamb, pork, venison, chicken, and turkey and to four mammalian tropomyosins of different origins. Results: Meat-allergic subjects have IgE antibodies to proteins in differen t mammalian meats (43/57 subjects); cross-reactivity with avian meat was li mited: less than 50% (19/43) of meat positive sera reacted to chicken. In c ontrast, most of the poultry-positive sera also reacted to different mammal ian meats; In general, there was stronger IgE reactivity to raw meats in co mparison to cooked meats; an exception was six cases in which IgE reactivit y to cooked poultry was stronger. Weak IgE reactivity to tropomyosin was de tected in only 2/57 sera tested. Conclusions: Suspected meat-allergic subjects have serum IgE directed to me at proteins. In vitro cross-reactivity among mammalian meats appears to be important, while cross-reactivity to poultry is limited indicating mammalia n-specific proteins. Although cooking in general denatures meat proteins re ndering them less allergenic, in some cases the process of cooking may resu lt in the formation of new allergenic moieties. The muscle protein tropomyo sin is not an important vertebrate meat allergen.