Atopic dermatitis: immunophenotyping of inflammatory cells in skin lesions

Background The ever increasing incidence of atopic dermatitis (AD) has stim ulated 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 infla mmatory cell-surface markers in the biopsies of skin lesions from 15 AD pat ients and five healthy subjects. Methods Immunohistochemical analysis was performed in a group of AD patient s and compared with that in a control group of healthy subjects. Avidin-bio tin immunoperoxidase staining of paraffin-em bedded, 4 mum skin sections, w ith semiquantitative counting of cells labeled with anti-CD3, anti-CD8, ant i-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 CD 3+ lymphocytes, especially of CD4+ subtype, compared with CD8+ lymphocytes. AD skin biopsy specimens also showed a higher intraepidermal HLA-DR+ Lange rhans' cell count, the presence of HLA-DR on lymphocytes in the dermis, and higher intraepidermal expression of IgE+ cells compared with healthy contr ols. Conclusions A statistically significant difference (P<0.05) was found betwe en 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.