Altered plasma cytokines in dogs with atopic dermatitis

BACKGROUND: Canine (Canis lupus familiaris) atopic dermatitis (AD) shares similar clinical signs to human AD. The abnormal immune response of AD is orchestrated by T lymphocytes, and may include variable involvement of cytokines, regulatory T (Treg) cells, eosinophils, mast cells and other immune components. Helper T (Th)2 cytokines often predominate initially, followed by Th1 cytokines in more chronic phases. HYPOTHESIS/OBJECTIVES: Pro‐inflammatory and Treg cytokines have been shown to play a role in human AD, yet their importance is not clear in canine AD. Hence, this study aimed to measure the concentrations of cytokines/chemokines not traditionally associated with Th1/Th2 response. ANIMALS: Canine AD patients (n = 27), compared to control dogs (n = 11). METHODS AND MATERIALS: A total of 19 plasma cytokines were assayed using canine specific multiplex immuno‐assays. RESULTS: The plasma concentrations of CXC Motif Chemokine Ligand 8 (CXCL8), interleukin (IL)‐7 and IL‐15 cytokines were elevated in canine AD patients, compared to control dogs. In addition, stem‐cell factor (SCF) concentrations were reduced in the plasma of canine AD patients compared to control dogs. Distinct cytokine profiles were found in dogs belonging to the Staffordshire breeds, a group with increased risk of AD. In particular, granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) had significantly elevated concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Some of the plasma cytokine alterations in canine AD described here, particularly of IL‐7, have not been reported previously. Monitoring these distinctive cytokine alterations could be useful for diagnosis and monitoring of canine AD in dogs.