The novel high molecular weight Dermatophagoides farinae protein Zen-1 is a major allergen in North American and European mite allergic dogs with atopic dermatitis.

BACKGROUND

Atopic dogs with hypersensitivity to Dermatophagoides farinae (Df) have IgE recognizing high molecular weight (MW) allergens more often than the low MW Der f 1 and 2. A new high MW Df allergen, Zen-1, has been identified recently.

OBJECTIVES

To determine the IgE reactivity of American and European Df-hypersensitive dogs to Zen-1, Der f 1 and Der f 2.

METHODS

We tested sera from 33 Df-reactive dogs from the USA, 29 from Europe and 15 experimentally sensitized to Df, by ELISA against crude Df, Der f 1, Der f 2 and Zen-1. ELISA inhibition was performed with sera reactive to Zen-1. Intradermal testing (IDT) was also done with the same allergens in 25 other American atopic dogs.

RESULTS

Altogether, IgE seropositivity to Zen-1 was more prevalent (86%) than that to Der f 1 (17%) or Der f 2 (19%). The IgE reactivity to Zen-1 was correlated to that against crude Df; this allergen alone inhibited a high percentage (median: 50%; range: 22-84%) of the binding to the crude mite extract. The seropositivity to low MW allergens was highest in experimentally sensitized dogs. Serum IgE recognition of Der f 1 was low in dogs with AD; that to Der f 2 was significantly lower in American dogs (6%) than in European ones (28%). A high prevalence of positive immediate IDT reactions to Zen-1 confirmed the likely relevance of serological results.

CONCLUSIONS AND CLINICAL

IMPORTANCE

This study establishes Zen-1 as a major allergen in atopic dogs sensitized to Df.