MAJOR CAT AND DOG ALLERGENS SHARE IGE EPITOPES

Background: Patients allergic to cats and dogs frequently display IgE reactivity against allergens from different animals, suggesting a cros s-sensitization to common allergenic determinants. Although albumins h ave been recognized as relevant cross-reactive allergens, little is kn own regarding cross-reactive epitopes of the major cat and dog allerge ns. Objective: In this study, sera from patients allergic to cats and/ or dogs were used to investigate the presence of common IgE epitopes a mong the major cat and dog allergens. Methods: The IgE reactivity prof ile of 109 patients who were allergic to allergens from several specie s of animals was determined with nitrocellulose-blotted cat and dog al lergens. Sera from patients who were strongly allergic to the major ca t and dog allergens were tested for the presence of cross-reactive IgE antibodies by one-dimensional and two-dimensional immunoblot inhibiti on experiments and by quantitative measurements obtained with the CAP- FEIA system (Pharmacia). Results: Sixty-eight of 109 patients with ani mal allergy showed IgE reactivity to cat allergens and dog allergens. Sera from patients with both cat and dog allergy detected allergens of similar molecular weight in nitrocellulose-blotted cat and dog hair/d ander extracts. Common, as well as species-restricted, IgE epitopes of the major cat and dog allergens could be demonstrated by IgE inhibiti on studies. Conclusion: shared IgE epitopes of the major cat and dog a llergens may provide an explanation for the clinical observation that allergies to cats and dogs are frequently associated.