Clinical and Immunological Responses to Dermatophagoides farinae Allergen Immunotherapy in Dogs With Atopic Dermatitis
Jakaphan Wannawong, Maturawan Tunhikorn, Pannathee Prangtaworn, Nawannaporn Saelim, Thapani Srisai, Nitaya Indrawattana, Sivapong Sungpradit, Anchalee Tungtrongchitr, Witthawat WiriyaratABSTRACT
Background
Atopic dermatitis (AD) in dogs is a prevalent allergic disorder associated with environmental allergens, including the house dust mite Dermatophagoides farinae (Df).
Hypothesis/Objectives
To describe clinical and immunological changes over time in dogs with canine (c)AD sensitised to Df undergoing Df allergen‐specific immunotherapy (ASIT) and to test the hypothesis that ASIT is associated with changes in Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI‐04), pruritus and medication scores and selected immunological markers.
Materials and Methods
Fifteen dogs with cAD sensitised to Df received ASIT for 12 months. Clinical evaluations included CADESI‐04 and pruritus Visual Analog Scale (PVAS). Gene expression of interleukin (IL)‐31, interferon‐gamma (IFN‐γ) and glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) in peripheral blood mononuclear cells (PBMCs) was analysed using real‐time PCR. Serum levels of Df‐specific immunoglobulin (Ig)E, total IgG and IgG subclass 1 were measured using immunoassays. Evaluations were performed at 0, 6 and 12 months.
Results
Significant reductions in pruritus scores and IL‐31 expression were observed, while IFN‐γ expression increased. CADESI‐04 scores decreased, although the change was not statistically significant. A reduction in medication scores was observed over time. Serum analysis showed increased concentrations of IgG and IgG1, while Df‐specific IgE remained elevated.
Conclusions and Clinical Relevance
Dermatophagoides farinae ASIT resulted in a reduction in pruritus and medication use over a 12 month period. Associated with this, PBMCs IL‐31 was reduced and IFN‐γ elevated. An increased serum IgG and IgG1 were measured, and Df‐specific IgE remained elevated. These findings support an immunological effect of ASIT, yet further studies with a larger cohort are required to validate the findings.