Cytokine expression in feline allergic dermatitis and feline asthma

Abstract

Background The pathogenesis of feline allergic dermatitis (FAD) is unclear, with several differences from allergic dermatitis in dogs and humans. Hypothesis/objectives To survey cytokine expression levels in healthy cats and cats affected with allergic dermatitis or asthma. Animals Formalin‐fixed, paraffin‐embedded skin biopsies from 22 cats with allergic dermatitis and 21 cats without allergic dermatitis were used for cutaneous assays. Serum was obtained from 17 healthy cats, 18 cats with allergic dermatitis, and 18 cats with a presumptive diagnosis of asthma. Methods and materials Cutaneous mRNA expression was evaluated with quantitative PCR [interleukin (IL)‐31 and IL‐31 Receptor A] and RNA in situ hybridisation (ISH) [IL‐5, IL‐31, IL‐31RA, IL‐33 and Oncostatin M receptor (OSMR)‐β]. IL‐31 protein concentrations were evaluated in serum with an enzyme‐linked immunosorbent assay. Serum levels of 19 additional cytokines were evaluated using a Luminex panel. Results IL‐31, IL‐31RA, IL‐5 and IL‐33 mRNA expression were either expressed in low quantities or undetectable in most samples. By contrast, OSMR‐β expression was significantly higher in the skin of allergic versus healthy cats (P < 0.0001). Although serum IL‐31 was detected in a larger number of cats with allergic dermatitis than healthy cats, and concentrations appeared to be higher in cats with allergies, this difference was not statistically significant. Cats affected by asthma also exhibited insignificantly higher concentrations of IL‐31 in the serum. Conclusions and clinical relevance Our results suggest that feline allergic diseases may exhibit different pathomechanisms from allergic diseases affecting other species. These findings are useful in guiding further therapeutic development toward targets that may have a role in the pathogenesis of feline allergic skin disease.

Transcriptome analysis of selected cytokine and chemokines in the eosinophilic plaques of cats with atopic skin syndrome

“…The results of our study show that eosinophilic plaques in cats with FASS exhibit a predominantly Th2 inflammatory response in the skin. Our study findings expand from the conclusions of two previous large transcriptome studies where a Th2 skewing of cytokines in lesional skin of allergic cats was absent or minimally observed 5,6 . These contrasting results could reflect the different protocols in inclusion criteria (e.g.…”

“…Our study findings expand from the conclusions of two previous large transcriptome studies where a Th2 skewing of cytokines in lesional skin of allergic cats was absent or minimally observed. 5,6 These contrasting results could reflect the different protocols in inclusion criteria (e.g. diagnostic criteria, withdrawal times for medication effects, the severity of disease, including both feline atopic syndrome and cats with FASS, FASS clinical phenotypes) and the processing of the skin biopsies for RNA isolation.…”

“…18 In addition, elimination diet trials were not performed in the majority of allergic cats in one study 5 and the other investigation enrolled samples from allergic cats based on histological descriptions without detailed clinical phenotypes. 6 Compared to the two previous studies, 5,6 we evaluated a larger number of cytokines in the lesional skin of cats with FASS, the results of which build upon the limited body of knowledge regarding the immunological pathways in skin lesions of cats with FASS. Furthermore, to the best of the authors' knowledge, our study provides the most comprehensive assessment to date of cytokine and chemokine expression of a single clinical phenotype of FASS.…”

“…4 Two large gene expression studies involving 38 allergic cats showed no apparent difference in several proinflammatory and pro-allergic cytokine messenger RNA (mRNA) transcript expressions in lesional skin compared to healthy controls. 5,6 Based on these results, 5,6 the authors proposed that cats with allergic dermatitis lack the common allergy-associated T-helper 2 (Th2) immunopathogenesis observed in other species (e.g. human, canine and equine).…”

Leishmaniose Ocular Canina: Uma Revisão Das Manifestações Clínicas, Diagnóstico E Tratamento

“…Estudos realizados com o intuito de esclarecer o papel das citocinas inflamatórias presentes na síndrome atópica felina demonstram uma concentração de IL-13, e outras citocinas inflamatórias ligadas à resposta Th2, no soro e pele de gatos afetados por SATF e no soro de gatos afetados por asma. O envolvimento de IL-13 na asma felina e sua contribuição no prurido precisa de estudos mais elucidativos (OLDER et al, 2021).…”