Changes in leukocyte counts, lymphocyte subpopulations and the mRNA expression of selected cytokines in the peripheral blood of dogs with atopic dermatitis

Abstract

Canine atopic dermatitis (CAD) is a chronic allergic disease characterised by genetic predisposition. The exact pathogenesis of the disease is still not fully understood. Blood parameters, lymphocyte subpopulations, cytokines and other molecules involved in pro-and anti-inflammatory activities, and Th1/Th2 polarisation in peripheral blood were assessed in clinically healthy dogs and dogs with AD by haematological examination, flow cytometry and qRT-PCR. The group of diseased dogs was further divided into subgroups according to the severity of clinical signs expressed as CADESI-03 (canine atopic dermatitis extent and severity index) values. The group of dogs with CAD showed mild neutrophilia without general leucocytosis, reduced numbers of B-lymphocytes (P < 0.05), increased relative numbers of T-lymphocytes (P < 0.01) decreased absolute numbers of double-positive lymphocytes (P < 0.001) and NK cells (P < 0.05) as compared with healthy controls. The expression levels of IL-10 mRNA were significantly higher (P < 0.05) in the group with CAD. Correlation with CADESI-03 was observed in expression levels of CCL3 (P < 0.05), CCL5 (P < 0.05) and SOCS-3 mRNAs (P < 0.05). In conclusion, the disease stage investigated in the present study is characterised by a chronic inflammatory response.

Update on the role of cytokines and chemokines in canine atopic dermatitis

“…By contrast, a more recent study could not detect any difference in plasma IL‐10 and TFG‐β concentration between atopic and healthy dogs 41 . Some studies in canine experimental AD or client‐owned dogs even showed an upregulation of IL‐10 or TGF‐β mRNA in the PBMCs or lesional skin samples 12,21,90 . One could infer that this upregulation of immunosuppressive cytokines is merely a normal compensatory response to control skin inflammation and is not specific to AD.…”

“…37 Of the remaining studies, four showed no difference, and one showed reduced, although not significantly, protein and mRNA levels of IFNγ in the blood (sera, plasma and PBMCs). [38][39][40][41]90 The mRNA expression of IFNγ also was unchanged after HDM challenge in the acute skin lesions or primary keratinocytes collected from the cAD model, 21,91 whereas its mRNA expression was significantly increased in PBMCs collected from dogs of a similar AD model. 12 A study of dogs treated with oclacitinib showed that IFNγ production by peripheral blood CD4 + and CD8 + T cells was significantly reduced on Day (D)240 and D300 after the initiation of treatment yet returned to baseline levels on D360 without an associated clinical relapse.…”

“…Among six studies with client‐owned dogs, only one showed an increased IFN‐γ mRNA expression in PBMCs compared to healthy controls 37 . Of the remaining studies, four showed no difference, and one showed reduced, although not significantly, protein and mRNA levels of IFN‐γ in the blood (sera, plasma and PBMCs) 38–41,90 . The mRNA expression of IFN‐γ also was unchanged after HDM challenge in the acute skin lesions or primary keratinocytes collected from the cAD model, 21,91 whereas its mRNA expression was significantly increased in PBMCs collected from dogs of a similar AD model 12 .…”

“…41 Some studies in canine experimental AD or client-owned dogs even showed an upregulation of IL-10 or TGFβ mRNA in the PBMCs or lesional skin samples. 12,21,90 One could infer that this upregulation of immunosuppressive cytokines is merely a normal compensatory response to control skin inflammation and is not specific to AD. Either way, these results highlight the difficulty of evaluating isolated cytokines in AD that are characterised by remarkably complicated and dynamic cytokine networks.…”

Gambaran Histologi Kulit Bagian Abdomen dan Profil Total Leukosit Anjing yang Menderita Dermatitis

“…Lebih lanjut diungkapkan bahwa jumlah eosinofil absolut yang ditemukan berkorelasi positif dengan rasio neutrofil terhadap limfosit (NLR) pada anjing dermatitis. Sedangkan, Hoskova et al (2015) melaporkan, anjing yang menderita Canine atopic dermatitis (CAD) menunjukkan neutrofilia ringan tanpa leukositosis umum, dengan penurunan jumlah limfosit absolut. Profil ini dapat digunakan untuk diagnostik dalam mengukur respons inflamasi yang dapat dipakai dalam membantu pengobatan (Ambily et al, 2022).…”