Langerhans cells are immunocompetent, dendritic cells of bone marrow derivation that reside within the epidermis. Langerhans cells have been implicated as playing a key role in the processing and presentation of antigens to lymphocyte in contact allergic cell-mediated immune reactions.
The present study was undertaken in order to clarify the effect of topical glucocorticosteroids on the number and the morphological alterations of epidermal Langerhans cells. Three kinds of topical glucocorticosteroids with different potency were applied to the back of guinea pig twice. a day for 14 days. Skin specimens were taken 2nd, 7th, 14th day of the application and 7th day after cessation of application. The ATPase stain and electron microscopic observations were performed to assess the numbers and morphological alterations of epidermal Langerhans cells.
The following results were obtained:
1) The number of epidermal Langerhans cells significantly decreased after 7 days applications of glucocorticosteroids in all experimental groups compared with control(p<0.05).
2) In each experimental group, the decrease of the number of epidermal Langerhans cells was more significant in 0.5% concentration than those in 0.1% concentrations(p<0.05).
3) The difference of effects on Langerhans cell density between corticosteroids was significant(p<0.05).
4) The morphological changes of epidermal Langerhans cells were prominent from 7th day of the application of glucocorticosteroids. Many Langerhans cells showed shortness of dendritic processes, decreased staining properties, enlargement of nuclear chromatin, swelling of mitochondria, dilatation of perinuclear cisternae and endoplasmic reticulum.
In summary, decrements in Langerhans cell density were correlated with the concentration and potency of the topical glucocorticosteroids.
