Ina Herrmann

Allergen-specific immunotherapy (AIT) is the only current intervention that has the ability to modify the immune response toward a tolerogenic state. This study aimed to assess the efficacy and safety of AIT in horses with allergic diseases in a systematic manner. Three databases were searched to identify articles reporting clinical outcomes and adverse events associated with AIT. The articles were evaluated for beneficial responses to AIT, defined as a ≥50% reduction in clinical signs, and clinical remission. Horses with respiratory diseases, urticaria, and pruritic dermatitis receiving insect monotherapy or multi-allergen AIT were included. All adverse events were graded, and analytical and confounding biases were assessed. The results showed that multi-allergen AIT had a beneficial response in 75% of horses with respiratory diseases, 88% with urticaria, and 56% with pruritic dermatitis. However, horses treated solely with insect AIT for pruritic dermatitis had a lower response rate (36%). Self-limiting local reactions were the most common adverse events, with systemic reactions grade II accounting for 11% of reported events. Analytical and confounding biases were identified as major limitations in the available studies. Further research is needed to address these biases and provide stronger evidence on the efficacy and safety of AIT in horses with allergic diseases.

Background Atopic dogs often are managed with allergen‐specific immunotherapy (AIT) and concurrent dosages of ciclosporin (CSA) or oclacitinib to alleviate their clinical signs. Both drugs might affect proper tolerance induction by inhibiting regulatory T‐cell (Treg) induction. Hypothesis/Objectives We evaluated Treg cell numbers and serum interleukin (IL)‐10 and transforming growth factor‐beta (TGF‐β)1 levels in dogs diagnosed with atopic dermatitis (AD) and successfully treated with either CSA or oclacitinib for nine or more months. Animals We included 15 dogs receiving oclacitinib, 14 dogs treated with CSA, 15 healthy dogs, 13 dogs with untreated moderate‐to‐severe AD and 15 atopic dogs controlled with AIT. Materials and Methods Peripheral blood CD4+CD25+FOXP3+ T‐cell percentages were determined using flow cytometry. Serum concentrations of IL‐10 and TGF‐β1 were measured by enzyme‐linked immunosorbent assay. Results The percentage of Treg cells in the CSA group was significantly lower in comparison with the healthy group ( p = 0.0003), the nontreated AD group ( p = 0.0056) or the AIT group ( p = 0.0186). There was no significant difference in Treg cell percentages between the CSA and oclacitinib groups, nor between the oclacitinib and the healthy, nontreated AD or AIT‐treated dogs. No significant differences were detected in IL‐10 and TGF‐β1 serum concentrations between the five groups. Conclusions and Clinical Relevance Lower Treg cell percentages in the CSA‐treated dogs suggest an impact of this drug on this cell population; however, it does not necessarily mean that it diminishes tolerance. Functionality and cytokine production may be more important than the number of Treg cells. Further studies evaluating the treatment outcome of dogs receiving AIT and concurrent drugs are needed to show clinical relevance.