Evaluation of Langerhans' cells in normal and eczematous dermatitis skin by CD1a protein immunohistochemistry: preliminary findings

Background:  Langerhans' cells (CD1a positive, bone marrow–derived cells), are the antigen presenting cells of the skin. Our knowledge about the status of these cells in eczematous dermatitis is incomplete.
Aim:  This study tests the hypothesis that 'the development of eczematous dermatitis is associated with alterations of Langerhans' cells'.
Materials and methods:  Biopsy specimens from patients with eczematous dermatitis and normal skin (20 cases, each) were studied. Langerhans' cells were stained for CD1a using imunoperoxidase-staining methods and mouse monoclonal antibodies.
Results:  In normal skin, CD1a+ Langerhans' cells were seen in suprabasal position. In eczematous dermatitis skin, CD1a positive cells were seen scattered in the acanthotic epidermis. Compared with normal skin, the mean values of the Langerhans' cells were statistically significantly higher in eczematous dermatitis epidermal Langerhans' cells: 1.20 (standard error of mean, SEM, 0.13) vs. 2.50 (SEM, 0.16); and dermal Langerhans' cells: 1.30 (SEM, 0.15) vs. 2.7 (SEM, 0.15); for normal and eczematous skin, respectively; p < 0.05].
Conclusions:  The higher Langerhans' cell counts in eczematous dermatitis suggest a possible link between antigen presenting capabilities of these cells, and development of these lesions.