Ia + Keratinocyte / 대한피부과학회지

ABSTRACT

Ia antigen (HLA-DR in rnan) is confined to the Langerhans cells and indeterminate cells in the normal epidermis in man. However the keratinocyte express la antigen in a variety of dermatoses. IFN-r (irnmune interfcron), known as macrophage activating factor, has been shown to induce Ia antigen expression in a wide variety of cell types. However the Ia antigen induced by 1FN-r is inhibited PGE2, a product of cyclooxygenase pathway of arachidonic acid metabolism. LTB4, a product of lipoxygenase pathway, can replace the IL-2 requirement for IFN-r production in the lymphocytes. There are three main morphalogical patterns of Ia antigen staining in the epidennis. Staining of the basal cells, staining in the mid epidermis in Malphigian layer and staining throughout the epidermis. The staining of Ia' keratinocyte was found to be confined to the lesional area of contact hypersensitivity reaction, graft vs host disease, and lichen planus. la+staining to extend beyond the lesional area was also seen in the study on turberculosis and leporsy.