Abstract

Background: CD30 is a protein that belongs to the tumor necrosis factor receptor superfamily. Its expression was observed in increasing numbers of cutaneous inflammatory conditions. Natural killer cells (CD57 positive cells) have an important role in several inflammatory conditions of the skin. CD99 is a long-known leukocyte antigen expressed at the endothelial cell contacts. It participates in the transendothelial migration of monocytes into the inflamed skin tissue in mice. Objectives: To examine the presence of lymphocyte-surface antigens including CD30, CD99, and CD57 in skin lesions of eczematous dermatitis and to compare the presence of the same molecules in the normal skin. Materials and methods: The presence of these molecules was immunohistologically evaluated in biopsies of normal and lesional skin (50 specimens). Biopsies were obtained from 50 patients suffering from chronic dermatitis. Ten more skin biopsies (normal skin) were included as a control group. Results: In eczematous dermatitis skin, CD30+, CD57+ NK and CD99+ cells were seen in the dermis. Compared to normal skin, there was a statistically significant higher average numbers of these molecules (on the histiocytes and lymphocytes) in the dermis of eczematous skin [CD30: 0.0 (SEM, 0.0) versus 0.23 (SEM, 0.0); CD57: 0.16 (SEM, 0.07) versus 1.52 (SEM, 0.10) and CD99: 4.5 (SEM, 0.11) versus 17.3 (SEM, 0.5) for normal and eczematous skin, respectively; p< 0.05]. A strong membranous CD99 immunoreactivity was observed in the epithelial cells (epidermis and adnexa) of both normal and eczematous skin. No CD30+ cells were observed in normal skin. Conclusions: This study demonstrates for the first time that cells expressing leukocyte CD30, CD57 and CD99 antigens are present in eczematous dermatitis. The high cell counts in eczematous dermatitis suggest a possible link between the capabilities of these cells and development of these lesions.