Food-specific serum IgE and IgG reactivity in dogs with and without skin disease: lack of correlation between laboratories

• Published in: Veterinary dermatology 2014-10, Vol.25 (5), p.447-e70
• Main Authors: Hardy, Jonathan I., Hendricks, Anke, Loeffler, Anette, Chang, Yu-Mei, Verheyen, Kristien L., Garden, Oliver A., Bond, Ross
• Format: Article
• Language: English
• Subjects: Animals; Clinical Laboratory Techniques - standards; Clinical Laboratory Techniques - veterinary; Dog Diseases - blood; Dog Diseases - diagnosis; Dog Diseases - immunology; Dogs; Female; Food Hypersensitivity - blood; Food Hypersensitivity - immunology; Food Hypersensitivity - veterinary; Immunoglobulin E - blood; Immunoglobulin E - immunology; Immunoglobulin G - blood; Male; Reproducibility of Results; Skin Diseases - blood; Skin Diseases - diagnosis; Skin Diseases - immunology; Skin Diseases - veterinary
• ISSN: 0959-4493; 1365-3164
• DOI: 10.1111/vde.12137

Background Despite conflicting data on their utility and no reports on interlaboratory reproducibility, serum food‐specific antibodies are commonly assayed in first‐opinion canine practice. Hypothesis/Objectives To determine both the variability of test results between two laboratories and the frequencies and magnitudes of food reactivity in dogs of different disease status. Animals Sera were obtained from eight dogs with cutaneous adverse food reaction (Group A), 22 with nonfood‐induced atopic dermatitis (Group B), 30 with an allergic/inflammatory phenotype (Group C), 12 with miscellaneous skin diseases (Group D) and nine healthy dogs (Group E). Methods Paired sera were submitted to two laboratories (A and B) for assays of food‐specific IgE and IgG antibodies. Results Numbers of positive IgE and IgG tests determined by each laboratory in Groups A, B, D and E were comparable (Group C not included). Significant differences in the magnitude of IgE reactivity between groups for each allergen were seen only for lamb (Laboratory A, P = 0.003); lamb reactivity in Group D exceeded Group E (P = 0.004) but was comparable between all other groups. Agreement (kappa statistic) between the two laboratories’ tests was ‘moderate’ for one antigen (potato IgE), ‘fair’ for four (corn IgE, rice IgE and IgG and soya bean IgG), ‘slight’ for eight (six IgE and two IgG) and ‘less than chance’ for the remaining six antigens (three IgE and three IgG). Conclusions and clinical importance These laboratories’ tests appear to have dubious predictive clinical utility because they neither correlate nor distinguish between dogs of different disease status. Résumé Contexte Malgré des données conflictuelles sur leur utilité et aucun élément sur leur reproductibilité interlaboratoire, les anticorps sériques spécifiques alimentaires sont fréquemment dosés en première intention en pratique canine. Hypothèses/Objectifs Déterminer à la fois la variabilité des résultats des tests entre deux laboratoires et les fréquences et magnitudes de la réactivité alimentaire chez les chiens de différents statuts. Sujets Les sera ont été obtenus sur huit chiens présentant des lésions cutanées liées à une hypersensibilité alimentaire (Groupe A), 22 avec une dermatite atopique non liée à l'alimentation (Groupe B), 30 avec un phénotype allergique/inflammatoire (Groupe C), 12 avec diverses dermatoses (Groupe D) et neuf chiens sains (Groupe E). Méthodes Les sera par pair, ont été soumis à deux laboratoires (A et