Atopic dermatitis: immunophenotyping of inflammatory cells in skin lesions

Abstract

Background  The ever increasing incidence of atopic dermatitis (AD) has stimulated many researchers to use various diagnostic procedures to obtain new data to help elucidate the pathogenesis of the disease.Aims  To perform cell immunophenotyping and to analyze the presence of inflammatory cell‐surface markers in the biopsies of skin lesions from 15 AD patients and five healthy subjects.Methods  Immunohistochemical analysis was performed in a group of AD patients and compared with that in a control group of healthy subjects. Avidin–biotin immunoperoxidase staining of paraffin‐embedded, 4 μm skin sections, with semiquantitative counting of cells labeled with anti‐CD3, anti‐CD8, anti‐CD20, anti‐HLA‐DR (HLA, human leukocyte antigen), and anti‐immunoglobulin E (anti‐IgE) primary antibodies, was used.Results  The results of AD skin analysis showed a greater infiltration of CD3+ lymphocytes, especially of CD4+ subtype, compared with CD8+ lymphocytes. AD skin biopsy specimens also showed a higher intraepidermal HLA‐DR+ Langerhans' cell count, the presence of HLA‐DR on lymphocytes in the dermis, and higher intraepidermal expression of IgE+ cells compared with healthy controls.Conclusions  A statistically significant difference (P < 0.05) was found between the two groups for intradermal and intraepidermal CD3, CD4, and HLA‐DR, intradermal CD8, and intraepidermal IgE+ cells. Immunophenotyping was found to be a useful diagnostic method in AD patients.