The future of immunotherapy for canine atopic dermatitis: a review

Abstract

Allergen specific immunotherapy (ASIT) is a foundation treatment for canine atopic dermatitis (CAD), though few critical studies have documented its effectiveness as a disease-modifying treatment in dogs. The mechanisms by which ASIT works in dogs have not been elucidated, although they are likely to parallel those known for humans. Current ASIT approaches in CAD focus on either subcutaneous or sublingual administration. Greater knowledge of major allergens in dogs, ideal dosage regimes and details of allergen admixture are likely to lead to better efficacy in CAD. Evaluation of biomarkers for successful therapy may also be of benefit. Potentially important advances in human medicine, that have yet to be explored in dogs, include use of modified allergen preparations such as allergoids, recombinant major allergens or allergen peptides; modification with adjuvants; or packaging of the above in virus-like particles. Co-administration of immunomodulators such as CpG oligodeoxynucleotides or specific monoclonal antibodies might direct the immune response in the desired direction while calming the "cytokine storm" of active disease. Initial trials of alternative routes of administration such as intralymphatic immunotherapy have yielded exciting results in humans, and continuing study in dogs is underway. Progress in ASIT of human food allergy may provide clues that will assist with improved diagnosis and patient management of CAD. Importantly, further study must be undertaken to clarify the conditions under which ASIT is a valuable treatment modality for dogs.

Atopic dermatitis in cats and dogs: a difficult disease for animals and owners

“…Using recombinant allergens such as Dermatophagoides farinae allergen (Der f 2) [ 149 , 150 ] may result in more reproducible results and a higher success rate compared to standard AIT and ILIT [ 151 ]. Modified allergen preparations such as allergoids, allergen peptides as well as alteration with adjuvants may decrease the risk of adverse effects and increase efficacy [ 152 ]. First studies evaluated bacterial oligodeoxynucleotides in canine AD [ 79 , 107 ] with promising results.…”

A pilot study to identify perceived barrier and motivating factors of primary veterinarians in the USA for specialty referral and management of atopic dermatitis with allergen‐specific immunotherapy

“…This is in discordance with many specialists' beliefs and previously published data. 5 Reasons for the discordance in perception of ASIT efficacy may be due to differences in the definition of "successful" therapy, the expectation that ASIT will ameliorate the need for all concomitant therapy, or a lack of understanding about the expected timeline for improvement following initiation of ASIT. Specialist outreach to the referring community through continuing education and training events provides an excellent opportunity for dermatologists to reach the referring population, build their referral network, and increase awareness of the benefits of ASIT and options for dermatological immunotherapy.…”

“…Allergen-specific immunotherapy (ASIT) is the only therapeutic option with the ability to reduce clinical signs of atopic dermatitis (AD) and potentially prevent progression of disease by modifying or reversing its pathogenesis. [5][6][7] Various studies have demonstrated ≥50% amelioration in severity of clinical signs, with decreased incidence of secondary yeast and bacterial infections in 60-72% of dogs with cAD. [5][6][7][8][9][10] Compared to a lifetime of systemic medications with potential for unintended adverse effects, ASIT protocols can be tailored to induce tolerance in most animals with minimal long-term risks.…”

“…[5][6][7] Various studies have demonstrated ≥50% amelioration in severity of clinical signs, with decreased incidence of secondary yeast and bacterial infections in 60-72% of dogs with cAD. [5][6][7][8][9][10] Compared to a lifetime of systemic medications with potential for unintended adverse effects, ASIT protocols can be tailored to induce tolerance in most animals with minimal long-term risks. Adverse events associated with ASIT are uncommon, with pruritus noted in 5-50% of individuals, and <1% of the population reported to experience systemic adverse events.…”

Atopic Dermatitis in Animals and People: An Update and Comparative Review

“…Allergen specific immunotherapy (ASIT) is still considered the best long-term approach for young animals with symptoms present for many months/years [ 44 ]. Although allergen-specific immunotherapy is typically presented as “expensive”, when compared to the cumulative cost of other forms of management (e.g., cyclosporine in a large-breed dog) it is actually cost effective, as it can decrease the frequency of infections and, therefore, reduce the use of antibiotics and the risk of resistance, as well as the need for other medications.…”