• atopic dermatitis;
  • CD4+ cells;
  • CD8+ cells;
  • flow cytometry;
  • interleukin-4;
  • interleukin-13

Summary Background  A number of studies exist demonstrating the increased expression of type 2 cytokines and decreased capacity to produce interferon-γ (IFN-γ) in peripheral blood mononuclear cells (PBMCs) of patients with atopic dermatitis (AD).

Objectives  To clarify the results of recent studies concerning the role of interleukin (IL)-4 and IL-13 in PBMCs of AD patients, we analysed the activation status of lymphocyte subpopulations.

Methods  We measured the intracellular expression and serum levels of certain type 1 and type 2 cytokines, using cell surface and intracellular cytokine staining, flow cytometry and enzyme-linked immunosorbent assay techniques.

Results  The frequency of IL-10 and IL-13 producing CD4+ and CD8+ T cells was significantly higher in patients with AD, while the frequency of IFN-γ secreting helper and cytotoxic T cells was significantly lower in patients with AD than in control subjects. The serum levels of IL-10 and IL-13 were also significantly increased. There were no significant differences observed between the experimental groups in the frequency of IL-4 producing CD4+ and CD8+ cells.

Conclusions  This study demonstrates a type 2 cytokine production in the CD4+ and CD8+ T cells of AD patients, which is characterized by an elevated IL-13, but not by IL-4 secretion, and by an increased level of the immunoregulatory IL-10, which can contribute to a decrease in IFN-γ expression.