Cross-Reactivity and Molecular Mass of the ε Chains of the IgE Antibodies in Dogs, Humans, Rats, and Mice

Abstract

We report the cross-reactivities and comparative molecular masses of the IgE ε chains in humans, rats, mice, and dogs. Monoclonal human, rat, and mouse IgE, and our purified polyclonal dog IgE were used in the study. IgE of the 4 species, separated by SDS-PAGE, were analyzed by immunoblotting with polyclonal and monoclonal antihuman IgE, polyclonal and monoclonal antimouse IgE, monoclonal antirat IgE, and polyclonal antidog IgE antibodies. The polyclonal anti-human and polyclonal antimouse IgE cross-reacted with the IgE of the other 3 species, while their monoclonal forms cross-reacted with dog IgE only. Polyclonal antidog IgE cross-reacted with human and mouse IgE, while the monoclonal antirat IgE did not cross-react with any other species. ‘Reverse’ passive cutaneous anaphylaxis in ragweed-sensitized dogs revealed that polyclonal anti-human and polyclonal antimouse IgE were able to elicit positive skin responses, and monoclonal antihuman, antirat, and antimouse IgE antibodies were not. The molecular masses of the ε chains were 77 kDa for mice, 75 kDa for rats and dogs, and 70 kDa for humans.

Comparison of two diagnostic tests for canine atopy using monoclonal anti‐IgE antibodies

“…Similarly, the results obtained with the ELISA D9 correspond to those published previously 17 . In contrast to human IgE diagnosis where multicentric quality control studies are often performed and diagnostic products used by service reference laboratories freely available on the market for independent evaluation, comparison between skin tests and various serological assays have up to now been relatively rare in veterinary medicine 12 . 13 Concordant results from various independent studies should now become a prerequisite for establishing the diagnostic value of any new diagnostic test proposed to veterinary surgeons, and in the field of allergy.…”

“…However, diagnostic tests based on polyclonal antibodies are not satisfactory because such antisera invariably also recognize, in part, allergen‐specific IgG antibodies, which are present against ubiquitous allergens, such as house dust mites, and in normal nonallergic dogs 9 . 10 This is probably the reason why commercial tests using such antibodies have often been shown to lack specificity 11 , 12 and to correlate poorly with the results of skin tests 13 . 14…”