A preliminary study of serum IgE against cross‐reactive carbohydrate determinants (CCD) in client‐owned atopic dogs

• Published in: Veterinary dermatology 2018-06, Vol.29 (3), p.243-e90
• Main Authors: Levy, Britt J., DeBoer, Douglas J.
• Format: Article
• Language: English
• Subjects: Allergens; Animals; Antigens; Assaying; Atopic dermatitis; Carbohydrates; Cell surface; Dermatitis; Diagnosis; Enzymes; Grasses; Immune response (humoral); Immunoglobulin E; Immunoglobulins; Molecular chains; Pollen; Venom
• ISSN: 0959-4493; 1365-3164
• DOI: 10.1111/vde.12529

Background Cross‐reactive carbohydrate determinants (CCD) are defined carbohydrate portions of glycoprotein cell surface molecules common to many plant and insect species. Mammalian species recognize CCD as foreign antigens and can mount humoral immune responses against them. Approximately 20–37% of grass and venom allergic people possess circulating IgE against CCD; these antibodies are generally considered clinically irrelevant. Anti‐CCD IgE is, however, recognized as a cause of false positive, clinically incongruent serum allergen test results in people; this phenomenon has not been investigated in animals. Objective To determine if anti‐CCD IgE could be detected in sera of client‐owned atopic dogs and how frequently it is found. Animals Sera from 38 dogs with a clinical diagnosis of atopic dermatitis and prior serological evidence of IgE antibodies, defined as a positive result to at least one mite and pollen (of any type). Methods Sera were analysed for IgE against CCD and environmental allergens with a commercially available multiplex enzyme‐labelled allergen‐specific IgE assay. Results Anti‐CCD IgE was detected in nine of 38 (24%) of atopic dog sera. As with their human counterparts, all dogs with anti‐CCD IgE had strong serological reactivity to grass pollens. Conclusions and Clinical Importance Anti‐CCD IgE can confound serological allergen testing in people; the same might be true in dogs. Further studies are warranted to investigate the clinical implications of anti‐CCD IgE in dogs, including the potential for these antibodies to affect serum allergen‐specific IgE assays used for clinical diagnosis, and whether they are relevant to clinical disease. Résumé Contexte Les CCD (Cross‐reactive carbohydrate determinants) sont définis comme des portions de carbohydrates des glycoprotéines des molécules fréquentes de la surface cellulaire de nombreuses plantes et espèces d'insectes. Les espèces de mammifères reconnaissent les CDD comme antigènes étrangers et peuvent développer une réponse immune humorale. Approximativement 20‐37% des gens allergiques aux graminées et au venin possèdent des IgE circulant anti‐CDD ; ces anticorps sont généralement considérés cliniquement non pertinents. L’ IgE anti‐CDD est cependant reconnue comme une cause de faux positifs, cliniquement non correspondant aux tests allergiques sériques chez l'homme ; ce phénomène n'a pas été étudié chez l'animal. Objectif Déterminer si les IgE anti‐CDD peuvent être détectés dans les sera