Response of aged versus young skin to intradermal administration of interferon gamma.

Abstract

Interferon gamma (IFN-gamma) induces the interaction of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen type 1 expression, and of HLA-DR antigens by keratinocytes. The aim of the present study was to determine the potential ability of aged versus young skin to respond to intradermal administration of IFN-gamma, as an in vivo immunologic stimulus. For 3 consecutive days elderly and young volunteers were injected with 10 micrograms of recombinant IFN-gamma diluted in 0.1 ml of sterile water. On day 5, punch biopsy specimens were obtained from the injected sites. Histologic and immunohistochemical stainings were performed on all sections. ICAM-1 was expressed by keratinocytes in both aged and young skin. An impairment was manifested mainly by the reduced accumulation of mononuclear cells throughout the dermis, the absence of HLA-DR expression by keratinocytes in 7 of 10 elderly volunteers, and the absence of an effect on the Langerhans cell population. This observation shows a diminished immune response in aged skin.