IL-17-producing CD4+ T helper cells (Th17 cells) are known to participate in the pathogenesis of specific skin disorders and exhibit proinflammatory properties. To address the possibility of involvement in atopic dermatitis (AD), studies were carried out to investigate Th17 cells in the peripheral blood of patients, the effect of IL-17 on the production of cytokines/chemokines and vascular endothelial growth factor (VEGF) by keratinocytes and the possible association with AD skin lesions. A group of 23 AD patients, 9 non-AD controls and 16 psoriasis patients (disease controls) were studied. AD patients were divided into 3 severity groups (mild, moderate and severe). The analysis of peripheral blood lymphocytes showed a significant increase (p ...