Identification of major and minor chicken allergens in dogs.

BACKGROUND

Allergens targeted by serum-specific immunoglobulin E (sIgE) in dogs clinically allergic to chicken have not been reported.

OBJECTIVES

To characterise the allergens targeted by sIgE in dogs sensitised and allergic to chicken.

ANIMALS

Sera from three dogs not sensitised to chicken, from 10 chicken sensitised dogs and from 12 chicken allergic dogs.

METHODS AND MATERIALS

Enzyme-linked immunosorbent assay (ELISA) and immunoblotting with a commercial chicken extract were utilized. The bands identified on immunoblotting were sequenced by mass spectrometry for allergen characterization.

RESULTS

Using ELISA, we detected chicken-sIgE above the positive threshold in zero of three (0%) nonsensitised dogs, five of five (100%) chicken-sensitised dogs (a selection criterion), and in seven of 12 (58%) chicken-allergic dogs. Immunoblotting performed with the same extract revealed IgE-bound protein bands in 100% of all chicken-sensitised and -allergic dogs, respectively. To identify the allergens, we excised the corresponding bands on the electrophoretic gel, and submitted them for sequencing by mass spectrometry. We conclusively identified seven major allergens (serum albumin, pyruvate kinase M, enolase 3, creatine kinase M, lactate dehydrogenase A, glyceraldehyde-3-phosphate dehydrogenase and triose-phosphate isomerase) and one minor allergen (troponin C), which are relevant to dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

We identified herein seven major chicken allergens for dogs, several of which are known to be cross-reactive allergens for humans. Based on their degree of sequence identity, these allergens exhibit the theoretical potential to be cross-reactive between poultry and mammalian meats; six of these allergens already are known to be cross-reactive between chicken and fish species. Future studies should address the clinical relevance and cross-reactivity potential of these chicken allergens in dogs.