Cytokine gene expression in the skin and peripheral blood of atopic dermatitis patients and healthy individuals.

OBJECTIVES: Atopic dermatitis (AD) is an increasingly common, chronic, relapsing, inflammatory skin disease characterized by impaired epidermal barrier function and cutaneous inflammation. The prevalence of AD has steadily increased during the past few decades. The aim of this study was to comparatively investigate cytokine gene expression in the skin and peripheral blood of atopic dermatitis patients and healthy individuals. RESULTS: In the skin of patients with AD, a significant increase of the level of gene expression was observed for interleukin (IL)-2r (p < 0.0023), IL-5 (p = 0.002), IL-6 (p < 0.0023), IL-8 (p = 0.01), IL-12B (p < 0.0023), IL-10 (p < 0.0023), IL-23 (p = 0.002), IL-29 (p < 0.0023), and transforming growth factor beta (tGFbeta) (p < 0.0023) as compared to healthy individuals. In contrast, no difference between AD patients and healthy donors was detected with respect to cytokine gene expression in the peripheral blood. METHODS: Samples of skin and peripheral blood from 48 severe AD patients (SCORAD = 78.5 [57;89], IGA = 4.2 [3,9;4,7]) at the age of 17 to 45 years and 20 healthy donors aged from 19 to 32 years were analyzed for gene expression of cytokines using real-time reverse transcription polymerase chain reaction (RT-PCR). CONCLUSIONS: Activity of markers of chronic inflammation and Th1 immune response in severe AD, namely IL-2r, IL-8, IL-12B, IL-23, IL-29 and TGFbeta, as well as activity of anti-inflammatory IL-5 were predominant in the skin but not in the blood of AD patients.