A pilot study of the effect of pullulan-conjugated Der f 2 allergen-specific immunotherapy on canine atopic dermatitis.

BACKGROUND: Dermatophagoides farinae is a major and common environmental house dust mite involved in canine atopic dermatitis (CAD). A formulation of recombinant protein Der f 2 is available in Japan for immunotherapy in dogs.

HYPOTHESIS/OBJECTIVES: To evaluate the efficacy of a recombinant allergen based on Der f 2-pullulan for the treatment of cAD.

METHODS: Dogs (n = 15) with atopic dermatitis were administered Der f 2 conjugated with pullulan (-P). Two dogs were eliminated because of death unrelated to the treatment during the study. The remaining 13 cases were included in the analysis. Clinical signs were evaluated with the Canine Atopic Dermatitis Lesion Index (CADLI) and pruritus levels were evaluated from 0 to 10 with a pruritus Visual Analog Scale (PVAS).

RESULTS: The mean ± standard deviation (SD) of CADLI [before allergen-specific immunotherapy (pre-ASIT) 21.9 ± 9.7; 60 days post-ASIT 9.8 ± 8.4 and 120 days post-ASIT 9.7 ± 8.2] and the mean ± SD of PVAS [pre-ASIT 7.2 ± 1.2; post-ASIT (60 days) 2.6 ± 2.2 and post-ASIT (120 days) 3.1 ± 2.5] significantly decreased after treatment (Dunnett's test, P < 0.05). Furthermore, the total doses of oral glucocorticoids in the two months pre-ASIT significantly decreased in comparison with two months post-ASIT (123 ± 72.6 mg vs. 70.0 ± 84.3 mg; Dunnett's test, P < 0.05).

CONCLUSIONS AND CLINICAL IMPORTANCE: The results indicate the effectiveness of Der f 2-P recombinant protein in the treatment of dogs with CAD and testing positive to D. farinae.