Selected cytokine expression in dogs with alergic conjunctivitis: Correlation with disease activity

• Published in: Research in veterinary science Vol. 130; pp. 33 - 40
• Main Authors: Varandas, Cláudia, Cartaxeiro, Clara, Lourenço, Ana Mafalda, Delgado, Esmeralda, Gil, Solange
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-06-2020; Elsevier Limited
• Subjects: Allergens; Allergies; Animal models; Antigens; Atopic dermatitis; Canine allergic conjunctivitis; Canine atopic dermatitis; Conjunctivitis; Cytokines; Dermatitis; Disease; Dogs; Drug dosages; Eczema; Gene expression; Hay fever; Histamine; IL-12; IL-6; Immunology; Immunotherapy; Interleukin 1; Interleukin 12; Interleukin 6; Neutrophils; Nonsteroidal anti-inflammatory drugs; Population studies; Pruritus; Statistical analysis; T cell receptors; Translational medicine; Tumor necrosis factor-α; Veterinary medicine; Germany; Canine atopic dermatitis; Animal models; IL-12; Canine allergic conjunctivitis; Translational medicine; IL-6
• ISSN: 0034-5288; 1532-2661
• DOI: 10.1016/j.rvsc.2020.02.009

Canine allergic conjunctivitis (cAC) is described as the most frequent ocular manifestation associated with canine atopic dermatitis (cAD).
Clinical and immunological characterization of cAD through IL-6, TNF-α and IL-12 mRNA expression quantification in canine conjunctivae.
Twenty client-owned dogs with both cAC and cAD and twenty-one healthy controls were enrolled and clinician assessed CADESI-04 and grade of ocular signs were calculated. Conjunctival biopsies were performed on all animals and relative quantification of the interleukins mRNA expression performed by qRT-PCR. The correlation between cytokine gene expression and cAC score was evaluated, as well as CADESI-04 values.
The qRT-PCR showed a significant gene upregulation of respectively 291.48 (p = 1.306e-09) and 4.85 (p = .00033) folds on IL-6 and IL-12 in dogs with allergic conjunctivitis compared to the control group. Regarding the average expression of TNF-α there were no statistical significant differences between both groups (p = .18). Higher cAC scores were associated with enhanced gene expression of TNF-α and IL-12. No correlation was found between the cytokine gene expression levels and the CADESI-04 values.
An increase of IL6 and IL12 in cAC was found in the studied population. These two cytokines may be potential immunotherapy targets cAC classification.
•cAD clinical and immunological characterization were conducted through IL-6, TNF-α and IL-12 expression in conjunctive.•A significant gene overexpression of IL-6 and IL-12 was found in dogs with allergic conjunctivitis.•A negative correlation between the cAC score and the gene expression of TNF-α was detected.•No correlation was found between the cytokine gene expression levels and the CADESI-04 values.•There is an increase of the pro-inflammatory cytokines and a Th1 subset activation in cAC.