The influence of vitamin D on allergic diseases, including atopic dermatitis, is linked to the presence of vitamin D nuclear receptors in immune cells. The present study seeks to determine the possible relationship between serum vitamin D content and immune indices in children with atopic dermatitis. The study was conducted in 19 children with atopic dermatitis. The control consisted of 17 age-matched healthy children. A single significant finding was a distinctly lower number of serum regulatory T cells in atopic dermatitis compared with controls (p < 0.00001). There were no appreciable differences between the two groups concerning the immunological indices such as the phenotypes: CD3, CD4, CD8, CD4/CD8, CD19, CD16/56, natural killer T cells, and anti-CD3 human leukocyte antigen - antigen D related cell surface receptor (HLA-DR3), or the percentage of lymphocytes, eosinophils, and the IgE level. We also revealed an inverse association between the serum vitamin D and the percentage of CD8+ cells (p < 0.05; r = 0.62) in atopic dermatitis. In conclusion, the results point to a regulatory role of T cells in the pathogenesis of atopic dermatitis, but fail to substantiate the influence of vitamin D on the course of the disease.
Keywords: Allergy; Atopic dermatitis; Children; Regulatory T cells; Vitamin D.